Necrotizing enterocolitis: long-term follow up of height and weight

A cross-sectional study was made of height and weight growth in children having survived neonatal nectrotizing enterocolitis. Values were compared to standardized growth norms. Retardation in height was noted in 23 fo the 30NEC survivors. Retardation in weight was noted in 21 o f30 NEC survivors. Retardation in height and weight was of great frequency and severity in girls than in boys. A normal relative body weight. Revealing proportionate weight for height, was demonstrated in all NEC survivors. The findings were interpreted in relation to an number of grouping including: gestational age. Birth weight, disease management, part of intestine affected by NEC, complicating persisting disease, duration of initial hospitalization with NEC, and family socioecomic status. The groupings are discussed in relation to their suggest impact or lack thereof on the growth progress of children having survived neonatal necrotizing enterocolitis.

NECROTIZING ENTEROCOLITIS: LONG-TERM FOLLOW UP OF HEIGHT AND WEIGHT by Kristina Hedin A thesis submitted to the faculty of The University of Utah in partial fulfillment of the requirements for the degree of Master of Science College of Nursing The University of Utah June 1979 Copyright (S) Kristina Hedin 1979 All Rights Reserved THE UNIVERSITY OF UTAH GRADUATE SCHOOL SUPERVISORY COMMITTEE APPROVAL of a thesis submitted by Kristina Hedin 1 have read this thesis and have found it to be of satisfactory quality for a master's d g � :;� l 19, 1979 D:m � Sue Huether Chairman. Supervisory Committee 1 have read this thesis and have found it to be of satisfactory quality for a master's degree. Apri 1 19, 1979 Date Linda Book Member. Supervisory Committee I have read this thesis and have found it to be of satisfactory quality for a master's degree. April Date 19, 1979 Celia Woodcock :\1ember. Supervisory Committee THE UNIVERSITY OF UTAH GRADUATE SCHOOL FINAL READING APPROVAL To the Graduate Council of The University of Utah: Kristina Hedin I have read the thesis of WIts final form and have found that (I) its format, citations. and bibliographic style are consistent and acceptable; (2) its illustrative materials including figures. tables, and charts are in place; and (3) the final manuscript is satisfactory to the Supervisory Committee and is ready for submission to the Graduate School. April 26, 1979 Dale Sue Huether Member. Supervisory C0mminec App rp ved for the Majorfcpartme�.!.----.,.".\ ! / , i /; . ) Chairman: Dean Approved for the Graduate Council �tkV ;(: �ArJ? . i/ James L. Clayton DC3n of Thc Graduate School ABSTRACT A cross-sectional study was made of height and weight growth in children having survived neonatal necrotizing enterocolitis. Values were compared to standardized growth norms. height was noted in 23 of the 30 NEC survivors. was noted in 21 of 30 NEC survivors. Retardation in Retardation in weight Retardation in height and weight was of greater frequency and severity in girls than in boys. A normal relative body weight, revealing proportionate weight for height, was demonstrated in all NEC survivors. The findings were interpreted in relation to a number of groupings including: gestational age, birth weight, disease management, part of intestine affected by NEC, complicating persisting disease, duration of initial hospitalization with NEC, and family socioeconomic status. The groupings are discussed in relation to their suggested impact or lack thereof on the growth progress of children having survived neonatal necrotizing enterocolitis. CorHENTS Page ABSTRACT . . . iv LIST OF TABLES vii LIST OF FIGURES viii ACKNOWLEDGMENTS ix Chapter I. INTRODUCTION II. REVIEW OF THE LITERATURE History . . . . . . Etiology . . . . . . Diagnosis . . . . . . . . . . . Management: Medical and Surgical Nursing Management . . . . . . Complications .. . Follow-up . . . . . Related Growth Patterns Summary . . . . . III. CONCEPTUAL FRAMEWORK The Problem . . . Hypotheses . . . . Definition of Terms IV. METHODOLOGY AND RESEARCH DESIGN Purpose . . . Population Sample . . . . Instruments Methodology Groupings . . . . . . Statistical Procedures 3 3 4 6 7 9 13 15 18 20 22 25 25 26 27 27 27 27 28 28 30 31 Chapter V. Page RESULTS 33 Height of NEC Survivors Weight of NEC Survivors . . . . Sex of Survivors . . . Relative Body Weights. Gestational Age . . . . . Birth Weights . . . . . . . . . . Small for Gestational Age (SGA) . . . Management of NEC: Surgical and Medical Areas of Intestine Affected by NEC . . . Complicating Persisting Disease . . . . . . Duration of Initial Hospitalization with NEC Family Socioeconomic Status . 33 36 39 39 41 42 44 45 47 50 52 52 VI. DISCUSS ION 55 VII. LIMITATIONS 65 SUMMARY AND RECOMMENDATIONS. 67 VIII. Significance of Findings to Nursing . Recommendations . . . . . . . . . . . . 68 70 Appendix A. INFORMED CONSENT FORM 72 B. DATA COLLECTION FORM FOR NEC STUDY 74 REFERENCES 77 VITA . . . 84 vi LIST OF TABLES Table Page 1. Results of Student t-Test: Variance in Mean Heights 34 2. Results of Student t-Test: Variance in Mean Weight 37 3. Profile of the 12 NEe Survivors with Growth Progress Below the 3rd Percentile. . . . . . . . . . . . . . . . . . . . 53 LIST OF FIGURES Figure Page 1. Height Measurements of NEC Survivors. 35 2. Weight Measurements of NEC Survivors 38 3. Relative Body Weights of NEC Survivors (Sexes Combined) 40 4. Birthweights for Gestation Age of NEC Survivors 43 5. Management of NEC: Surgical and Medical 46 6. Part of Intestine Affected in NEC Survivors in Relation to Growth Progress . . . . . . . . . . . . . . . . . . . .. 49 ACKNOWLEDGEMENTS The author is indebted to the Supervisory Committee, Chairperson Ms. Sue Huether, Dr. Linda Book, and Ms. Celia Woodcock for their skillful guidance, patience and support. Appreciation is ex- tended to the Office of Surgery, Primary Children's Medical Center for their cooperation with data collection, the Division of Pediatric Gastroenterology at The University of Utah for their financial support and continued cooperation and assistance, and the staff of the Pediatric Intensive Care Unit, Primary Children's Medical Center for their knowledgeable contributions on nursing management. A special thanks is extended to Ms. Pauline Heaton, Office of Pediatric Gastroenterology, University of Utah Medical Center for her patience and assistance with data collection. The author is further indebted to Mr. Steven Goldsmith for his thesis editing and continued support. CHAPTER I INTRODUCTION Necrotizing enterocolitis (NEC) is a highly critical disease of the newborn infant with documented mortality rates varying from 27 - 75 percent (Bergman, 1976; Toulakian, 1976). It;s character- ized by ischemic necrosis of the gastrointestinal tract wi th a cl inical picture of gastric retention, abdominal distention, bilious vomit ing, and gastrointestinal bleeding (Bergman, 1976; Mizrahi, 1965). Necrotizing enterocolitis occurs primarily in low-birth-we;ght and premature infants who suffered some severe perinatal physiological stress. With the significant increase in incidence reported to be three to eight percent of all premature infants (Bergman, 1976; Santuilli, 1974), necrotizing eneterocolitis is now recognized as a serious disease entity. Etiology, recognition, and management of the acute phase of NEC, also termed neonatal necrotizing enterocolitis, has been the basis for most past studies pertaining to the disease (Bell, Graham & Stevenson, 1971; Bunton, Durbin, r·1cIntosh, Shaw, Taghizadeh, Rey- nolds, Rivers & Urman, 1977; Cohn, Sunshine &deVries, 1972; Franz, L'Heureux, Engel, Leonard & Hunt, 1974; Mizrahi, 1965; Richmond & r~ikity, 1975; Santuilli, 1974; Stevenson, Graham, Oliver & Goldenberg, 1969; Torma, Delemos, Rogers & Discrens, 1973; Toulakian, 1976; Yu, Tudehope &Gill, 1977). The lonn-term effects of NEC on physical 2 growth are not known to date. This study examines the sequellae of neonatal necrotizing enterocolitis in terms of physical growth specifically height and weight. The results of the study provide a basis for health care planning in terms of growth expectations for children having suffered the disease. There are 56 children, ages 15 months to 6 years, 3 months, in the Intermountain West who have survived NEC as recorded by the Intermountain Newborn Intensive Care Unit (INBICU), the Division of Pediatric Gastroenterology at The University of Utah Medical Center, Salt Lake City, Utah, and the office of Surgery, Primary Children's ~1edical Center, Salt Lake City, Utah. This investigator measured the physical growth of these children in terms of height and weight and utilized standard growth norms for a comparison group. CHAPTER II REVIEW OF THE LITERATURE The literature on necrotizing enterocolitis focuses on the acute phase of the disease. There are no reported studies of long-term follow-up of NEC survivors. Comprehension of the potential and exist- ing long-term consequences of neonatal necrotizing enterocolitis necessitates an understanding of this disease. History Genersich (1891) first described necrotizing enterocolitis of the newborn in a 45-hour-old premature infant with cyanosis, vomiting, and abdominal distention who died within 24 hours. morteum exam revealed areas of inflammation and ileum without mechanical obstruction. The post perforation of the Since that time there have been several articles that describe similar disease entities (Agerty, Ziserman & Shalenberger 1943; Dunn, 1963; Herman, 1965; Mizrahi, 1965; Thelander, 1937). The first comprehensive study of necrotizing enter- ocolitis was reported in Babies Hospital, New York in 1964-1965 by Santulli. Since that time many more cases and review studies have been reported (Bell et al., 1971; Cohn et al., 1972; Franz et al., 1974; Hopkins, Gould, Stevenson &Oliver, 1970; Rabinowitz &Siegle, 1976; Torma et a1., 1973), reflecting a true increase in incidence as well as an increase in awareness of this disease (Fetterman, 1971). 4 Etiology The etiology of necrotizing enterocolitis is basically unknown although many theories are becoming more strongly emphasized. There are certain factors which appear important in determining the precipitation of the disease in the susceptible neonate: (1) Stress induced circulatory ischemia of the gastrointestinal mucousa, (2) bacterial colonization in the gut with invasion of the intestinal mucosa, (3) formula feeding resulting in a reduction or absence of the inherent protective imnunological activity (secretory IgA) in the intestine. Physiological stressors can precipitate detrimental changes in the intestine. Lloyd (1965) described "selective circulatory ischemia as a defense mechanism to asphyxia based on the concept of ll the living reflex in which blood, in response to the stress of hypoxia, is shunted away from the mesenteric bed to the brain and heart. A similar reflex is assumed to occur during delivery of the premature or low-birth-weight infant who has a decreased tolerance to physical stress (Bell et al., 1971; r·1izrahi, 1965; Santuilli, 1974; Toulakian, 1976). Stresses other than hypoxia, such as cold, umbilical artery catheterization, cyanotic congenital heart disease, respiratory distress syndrome, or erythroblastosis fetalis, can also initiate decreased blood perfusion in the intestine (Santulli, 1974; Toulakian, 1976). Hypoxia and other stresses are believed to precipitate ischemic changes in the intestine of the neonate which may eventually lead to necrosis or perforation (Toulakian, 1976). 5 Bergman (1976) postulated that following diminished blood flow to the mesenteric bed the mucosa undergoes decreased mucin production with proteolytic damage to the intestinal wall. The proteoly- sis and ischemic necrosis result in a breakdown in the mucosal integrity of the intestine. This breakdown allows for the gas forming organisms to invade the intestinal wall. The gas generated may accumulate and rupture the intestinal wall producing pneumoperitoneum (Bergman, 1976; Santuilli, 1974). Thus, the diminished blood flow to the intestine, precipitated by various stresses, results in a structural and functional change in the intestinal mucosa. For the first few days of life, newborn infants lack secretory IgA, the principle immunoglobulin in intestinal secretions. With initiation of feeding, food antigens and endogenous flora colonize in the intestine and stimulate local antibody production. The colostrum of the mother's milk is the only known source of IgA during these first few days of life (Tou1akian, 1976). Breast milk also provides living macrophages as a protective agent for the newborn infant (Barlow, Santulli, Heird, Pitt, Blanc &Schu1linger, 1974). Barlow et al., (1974) demonstrated the protective effects of breast milk in experiments with physiologically stressed newborn rats. Breast milk pro- tected nursing rats from hypoxia, hypothermia and orally ingested Klebsiella while formula-fed rats who received no breast milk developed NEC and died. Premature and low-birth-weight infants, the primary candidates for NEC, are most often unable to tolerate any oral feedings due to the lack of maturity of intestinal function. predisposition of these infants to r~EC Thus, the is further increased due to 6 the lack of immunological defenses from breast milk. Premature in- fants have decreased immunocompetence compared to full-term infants with decreased ability to manufacture IgA, a decrease of transplacentally acquired IgG, and depressed phagocytosis (Bergman, 1976). It is generally postulated that in this premature immunodeficient infant the selective intestinal ischemic necrosis leads to bacterial inv~­ sion of the bowel mucosa and results in necrotizing enterocolitis in the neonate. Diagnosis The newborn, at risk for developing NEe, is a premature infant or low-birth-weight infant of less than 1,500 9rams who has suffered significant perinatal, pre- to postnatal, physiological stress. Lowrey (1978) defines prematurity as gestational age of 37 weeks or less, and low-birth-weight as less than 2,500 grams. Prenatal stres- ses include placenta previa, premature rupture of the membranes, and sepsis. Identified postnatal stresses are apnea, respiratory dis- stress syndrome, temperatlJre instabilities, cyanotic congenital heart disease, umbilical artery catheterization, thrombocytopenia and exchange transfusion (Bell et a1., 1971; Santuilli, Schull inger, Heird, Gongaware, Wigger, Barlow, Blanc &Berdon, 1975; Stevenson, Oliver, Graham, Bill & Goold, 1971; Toulakian, 1976). Roback (1974) has re- ported that at least 75 percent of NEe patients have respiratory distress syndrome (RDS). Hyaline membrane disease also commonly heralds a predisposition to NEe. The first observable clinical signs of necrotizing enterocolitis are abdominal distention. gastric retention. bilious vomiting. 7 guaiac positive stools and gross blood in stools which indicate intestinal malfunction. Less definitive clinical signs indicative of systemic malfunction are temperature instability, lethargy and apnea (Bergman, 1976; Hodson, 1975; Toulakian, 1976, rJayne, 1975). The diagnosis of necrotizing enterocolitis is confirmed by the following roentgen findings, listed in order of frequency: intestinal is, (1) Pneumatosis (2) nonspecific intestinal dilation, (3) pneumoperi- toneum indicating perforated intestine and abnormal barium enema (Hodson, 1975; Mizrahi, 1965; Rabinowitz et al., 1976; Santuilli et al., 1975; \~ayne, 1975; Wilson & Wooly, 1969). Laboratory findings are nonspecific but reflect the infant's response to sepsis caused by bowel necrosis. The corollary findings include platelet counts of less than 75,OOO/mm 3 , variable total white cell counts, academic arterial blood samples and low urine output with high specific gravity (Wayne, 1975). The occurrence of these signs and symptoms indicates that the neonate is suffering from necrotizing enterocolitis. Management: Medical and Surgical At the earliest signs of abdominal distention and gastrointestinal distress in the newborn, the medical treatment protocol for acute necrotizing enterocolitis, clearly outlined by Santulli (1974), must be instituted. Oral feedings are withheld and intravenous fluids are begun, along with blood transfusion as necessary. suction is initiated to decompress the abdomen. Nasogastric At this time, acid- base balance and electrolyte disturbances must be corrected. terial cultures are collected from the blood, nose, throat, Bac- 8 cerebrospinal fluid, stool and urine. Roentgenographic exams of the abdomen are taken every four to six hours to detect early perforation, signs of free air, obstruction and peritoneal fluids. Anti- biotic therapy is begun. Ampicillin and Kanamycin are the parenteral antibiotics of choice and topical antibiotics, Kanamycin and Gentamycin, given every four hours via the nasogastric tube can help prevent perforation (Bell, t;1artin, Schubert, Partin & Burke, 1973). LO\'1 molecular weight dextran can be used for 48 hours for its effect in countering platelet adherence and aggregation, and the development of microthrombosis in the small vessels of the intestinal circulation (Santulli, 1974; Toulakian, 1976). Treatment is continued for 48 hours after the resolution of both radiographic and clinical findings (Martin, 1975). Medical treatment of infants with NEC has proven to be significantly effective (Toulakian, 1976). Successful management of NEC may include surgical interventions. Indications for surgery are pneumoperitoneum, intestinal obstruction, and signs of peritonitis including: well-localized signs of abdominal resistance, or cell ul itis of the abdominal wall, and (l) Persistent or (2) induration, edema (3) abdominal mass (Santull i, 1974; Tou1akian, 1976). The surgical procedure is excision of the necrotic bowel through a lower abdominal transverse incision. The most frequently involved areas of bowel are the ileum and ascending colon. At present, there is controversy as to whether primary end anastomosis of viable bowel or exteriorizing the bowel ends with ileostomy or colostomy is most effective (Bergman, 1976; Wayne, 1975). A gastrostomy is constructed initially to aid in gastrointestinal 9 tract decompression and later for ease in feeding (Wayne, 1975). Early diagnosis of necrotizing enterocolitis and prompt institution of appropriate medical and surgical therapy are essential for survival and can be reflected in the long-term effects of the disease. Nursing Management Management in the acute phase of the disease is besf handled in a newborn intensive care unit where the nursing staff is familiar with care of acutely ill newborn infants. sease entity. NEe is an insidious di- Nurses must know the risk criteria and clinical signs of disease onset. The nurse, as a constant care provider, has the best opportunity to recognize necrotizing enterocolitis in the neonate. The nurse plays an active part in assessing the tolerance of a feeding regime by an infant. Any baby who consistently does not absorb glucose or formula feedings should be suspected as a potential NEe victim. Nasogastric secretions can be aspirated and examined for undigested formula; frequent, watery stools should be noted. Providing adequate nutrition for a neonate susceptible to NEe is a significant problem. Premature and low-birth-weight infants, especially those with respiratory problems, often have initial feeding difficulties along with increased metabolic demand. These infants also have an inability to completely assimilate usual infant formulas and breast milk due to the immaturity of intestinal function. There- fore, elemental formulas which are more easily absorbed can be used. However, a controversy exists in the literature as to the establishment of feeding regimes. Although elemental formulas are more easily 10 absorbed, an elemental diet for the neonate susceptible to NEe may increase the risk of developing the disease (Book, Herbst, Atherton & Jung, 1975). Aggressive oral alimentation, parenteral nutrition and nasogastric feeding have also been reported to increase the incidence of NEe in the infant at risk (Book, Herbst &Jung, 1976; Bliss, 1976). Abdominal evaluation is an on-going process with the infant at risk for NEe. On inspection, the nurse should be suspicious of abdominal distention, especially if associated with rigidity. Once distention is discovered, abdominal girth measurements should be taken An increase in one centimeter or greater since the every four hours. last measurement should be repoted to the physician immediately (Bliss, 1976). ItShininess of peritonitis. ll or reddening of the abdominal wall may be a sign Auscultation of bowel sounds should be checked at least every four hours, and their absence brought to the physician's attention. Percussion and palpation should be held at a minimum be- cause of the friable intestinal wall in the NEe victim. Stools of infants suspected of NEC should be tested daily for occult blood to evaluate gastointestinal bleeding. Book et al., (1976) reports carbo- hydrate malabsorption in 10 to 14 formula-fed premature infants who developed NEe with greater than 2+ reducing substances detected in their stools. Therefore, stools should be tested for reducing sub- stances to evaluate carbohydrate absorption. Once the disease has been recognized and medical management initiated, continual and careful nursing care is essential. Enteric isolation of the infant is advised although an infectious agent for NEC has not been identified or conclusively documented (Book, Overall, 11 Herbst, Britt, Epstein &Jung, 1977). Abdominal trauma should be avoided while handling and diapering the infant. Since the babies have diarrhea, care for the rectal and adjacent areas is needed to prevent skin excoriation; zinc oxide and A & 0 o'intment are helpful. The naked infant should be kept in a heated isolette to allow for continual assessment of the abdomen, skin probe monitoring and color evaluation. Observations by the Pediatric rcu nurses at Primary Children's Medical Center suggest that infants become dusky or exhibit a peculiar gray color before their vital signs change significantly. Vital signs should be taken everyone to two hours as needed. Rectal temperatures are contraindicated, however, axillary temperatures provide an adequate measure of temperature variation. in temperature may be a sign of sepsis. A sudden drop Bradycardia or sudden list- lessness should be reported (Bliss, 1976). Apnea and signs of cardio- vascular shock may herald perforation, the major indication for surgery. Postoperative nursing care for the infant with NEC is the same as that for any infant who has had bowel resection with an and gastrostomy tube. ileosto~y The incision is often close to the stoma and continual effort should be made to keep the incision clean to prevent infection. Stoma care is required, along with prevention of surround- ing skin excoriation. Nursing management of the infant who survives the acute phase of the disease pertains to the assessment of nutrition maintenance. Parenteral hyperalimentation is provided initially following the acute stage, until an alternative feeding method can be initiated. The gastrostomy tube facilitates the assessment of gastrointestinal 12 secretion tolerance. When the gastrostomy residual is minimal, less than 5cc's, and secretions are moving through the intestine, frequency of stools will increase and diarrhea may be common. For medically treated patients with no gastrostomy tube, gastrointestinal evaluation is made on the basis of stool quality and quantity. When regular stools are apparent, feeding is started progressing from water to halfstrength formula to full strength. Post surgical patients are commonly given dilute elemental formulas via the gastrostomy tube where as medical patients are given regular low calorie formula via the nasogastric or nasojejunal tube. Calorie intake is increased with tolerance as evi- dence by stools and weight gain. Oral feeding is finally initiated based on feeding tolerance and weight gain. The nasogastric or naso- jejuenal tube is removed \vhen oral feedings are tolerated and weight gain is evidenced. The gastrostomy tube is removed when oral alimenta- tion is successful and the infant has achieved a weight of five pounds or two to three kilograms. Parental support and counseling during the onset and the acute phase of NEC is essential for family well-being. A general but arti- culate explanation and overview of the infant's condition and acute expectations is mandatory in family and psychological intervention. During the acute stage visiting should be planned to allow maximal rest and optimal personal attention for both the patient and the parents. If surgery is required, the parents should be given an explana- tion of the general surgical procedure and prepared for what to expect postoperatively. Survival of the acute phase of NEC introduces the possibility of complications during the initial hospitalization. 13 These complications should be described to the parents to provide a realistic profile of the expectations for the duration of the neonate's hospital ization. When preparation for discharge occurs, planning for home care of the infant and follow-up coordination must be established. Instruc- tion of colostomy and ileostomy care must be given when appropriate. Signs and symptoms of gastrointestinal malfunction or bowel obstruction must be reviewed in lieu of complications occurring at home. The use of medications, dosage and side effects must be understood by the family. Nutrition counseling must be provided and a regime of home care should be established. As the long-term effects of necrotizing enterocolitis have not been documented, a review of referenced expectations for the NEC survivor is not yet possible. However, expecta- tions should be presented from a hypothetical perspective. Complications Infants who have survived the acute phase of necrotizing enterocolitis with or without surgical intervention face the risk of several intestinal complications within the first few months following the disease. Koloske and Martin (1973) delineated the surgical and medical complications of NEC in 22 infants. Late surgical complica- tions were one high jejunal stricture, three colonic strictures, two entercolonic fistulas, and one pericolonic abscess, wound dehiscence occurred twice. Krasna, Beck, Becker and Schneider (1970).also report three cases of colonic stenosis following surgery and one incident of stricture of the terminal lieum. Bell, Ternberg, Askin, 14 McCallister and Schake1ford (1975) more recently cite that 18 percent of patients surviving NEC with and without surgical intervention developed intestinal strictures usually noted within the first few months after the acute involvement but sometimes manifested as late as one and one-half years thereafter. Intestinal stenosis of the colon versus the small intestine following neonatal NEC was described by Chiba, Watanabe and Kasai (1975) in children from one to 32 months of age after surgery for NEC. Complete intestinal obstruction, or acquired atresia, following this disease is rare. Santulli et al., (1975) re- ports three cases of intestinal strictures out of 64 patients, five to seven weeks after the acute episode of NEC. ~1alabsorption and short bowel syndrome were also reported in the postoperative period (Santulli et al., 1975). tion can also ccur. Sepsis from bowel contamination and catheterizaPulmonary complicatiJons including pneumonia, pneumothorax, edema, atelectasis and pulmonary hemorrhage have also been reported as postoperative complications (Dudgeon, Coran, Lauppe, Hodgman & Rosenkrantz, 1973). The medical complications of NEC described by Krasna et al., (1970) are two cases of dissacharide intolerance manifested by watery stools and acid stools positive for reducing substances when infants were fed infant formulas with lactose. Nutrition and malabsorption problems were seen in seven to 22 cases in Koloske and r~artin's (1973) study; three of these seven were endangered by one or a combination of the following entities: gram negative sepsis, acute renal failure, disseminated intravascular coagulation, seizure, questionable superior vena cava thrombosis and various body rashes. Generalized bleeding 15 disorders are dangerous and fatal complications of NEC. Leake, Thanopoulous and Neiberg (1975) describe a single case of hyperviscosity syndrome associated with NEC. Less common complications such as lymphoid polyposis (Rabinowitz, Wolfe, Feller & Krasna, 1968), and enterocyst formation (Lloyd &Cywes, 1973) occur. Koloske et a1., (1973) states that hyperalimentation has permitted infants to survive long enough to develop an impressive array of late complications. Follow-Up The minimal documented follow-up of newborns with necrotizing enterocolitis limits the knowledge of the long-term effects of this disease. There are no comprehensive studies on the long-term results of NEC reported in the literature; however, a few reports have mentioned follow-up of patient status. Herman (1965) reported one case of an infant with bowel perforation from NEC whose growth and development were "normal ll within the first year of life. Cohn et al., (1972) cite an infant with NEC who was treated medically, then surgically for perforation. After 80 days, the infant continued to grow and develop "normally" with an "uneventful course,lI Some investigators hypothesize that if the patient can survive five days following the diagnosis of i~EC, the prognosis should be excellent and the long-term sequellae rare (Bell et al., 1971). Others believe that there ;s a distinct possibility of long-term complications from NEC and are recalling their survivors for clinical and possible radiographic study (Hopkins et al., 1970). A nursing care study by Gamble (1974) describes a survivor of necrotizing enterocolitis with a progressively normal 16 weight gain of a doubling of birth weight by six months of age. It is difficult to assess growth in many of the reported cases because children are simply described as "normal" without specific parameters del ineated. There have been a number of studies which report the longterm results of extensive small intestine resection in the neonatal and infancy periods. . These studies, not specifically involving UEC, are significant since the surgical procedure for NEC, when indicated, is often small and large bowel resection. Wilmore, Burrington and Hutter (1972) report that survival following massive intestinal resection is related to the length of remaining bowel. A relatively minimal length of small gut is necessary for survival, growth and development. The critical length of small intestine which must remain for adequate development probably lies between 20 - 30 em. but varies considerably. Benson, Lloyd and Krabbenhoft (1966), in a study of 10 patients who underwent resection of more than 50 percent of the small intestine, observed that the clinical and nutritional status of survivors, three years post resection, was within normal limits. In re- view of nine survivors of extensive small intestine resection as neonates cited by Rickham, Irving and Shmarling (1977), 10 - 18 years post surgery, all but one case were normal with heights and weights within normal limits. The effect of massive bowel resection was evaluated in 18 children by Hilmore et a1., (1972). An initial lag in body weight was noted during the first year of life followed by an accelerated weight gain which placed most of the children within normal limits of weight 17 distribution after the first year following surgery. Most of the children were reported as functioning "up to their potential ,II Young, Swain and Pringle (1969) also reported two cases of major bowel resection in infancy who, after a catch up phase of accelerated gain in weight and growth, presented in normal health (age not mentioned). Depending on the length of remaining bowel, resection of the small and large intestine, the surgical procedure for necrotizing enterocolitis, may result in growth progress within normal limits. Conclusively, investigators report that children who have had intestinal resections as infants must be given intensive care the first two to three years of life with regard to nutrition. Infants with small intestine resection cannot be maintained by enteral feeding alone. Careful and studied dietary management and parenteral mentation are required. hyperali~ Full parenteral nutrition may continue for four to six months after intestinal resection (Rickham et al., 1977). Bell et a1., (1973) explained that in the infant and growing child who have had intestinal resection, certain intrinsic compensatory changes may occur in the intestine that may eventually allow such a patient to support, for the most part, his own nutrition. When a large portion of the intestine is resected, adaption of the intestine involves an increase in caliber and longitudinal growth of the remaining intestine (Benson et al., 1966; Rickham, 1967). Further- more, a gradual enhancement of digestive function of the resected intestine is indicated by a positive nitrogen balance, and the increased ability to absorb fat and tolerate monosaccharides. Malabsorption of vitamins K and B12 persists but can be readily managed. 18 Valman (1976), in a study of the growth and fat absorption after ileum resection, found that during recovery from early severe malnutrition there was a largefood,intake which results in a rapid weight increase until the expected weight and height was reached. food intake then fell rapidly. The There was only a slight reduction in final height of the children that Valman (1976) studied. Their growth in general demonstrated that a degree of malabsorption persisted in some older children after major bowel resection in infancy. However, Valman (1976) found that most survivors seldom had handicaps which they needed to be aware of in later childhood. Suggested areas of supervision and investigation of children suffering massive small bowel resection in infancy, as with NEC, include bowel function, dietary advice, untoward symptoms and retardation in growth and development (Young et al., 1969). Related Growth Patterns Necrotizing enterocolitis occurs primarily in low-birth-weight and premature infants, therefore, a review of growth patterns evidenced in these babies is applicableto the survivors of NEC. Follow-up studies of growth and development of low-birth-weight and premature infants indicate that following an initial growth lag within the first month of life these infants show an accelerated rate of weight gain and linear growth in the first one to two years of life. The standard growth curve is paralleled by three to five years of life often on a lower level (Lubchenco, 1976; Pape, Buncic, Ashby &Fitzhardinge, 1978). Smith (1977) reports that premature birth is not a cause for more than 19 a transient postnatal growth deficiency. Usually there is an initial period of slow growth but once the infant is able to ingest an adequate caloric intake, there is a Ucatch up" to the normal growth rate for biological age. Pape et al., (1978) reports a study of low-birth- weight infants that achieved the 3rd to 10th percentile in weight and the 10th to 25th percentile in length by two years postterm. Lub- chenco (1962) cites that in a sample population of children born preterm with birth weights less than 1,500 grams, one-half of the sample were below the 10th percentile of height and weight at birth and also at the age of 10 years. Goldstein (1971) found that on the average, prematurely born children were only 0.5 Cill. less in height than full- term babies at 7 years of age. It is evident that there are many factors that can affect growth progress in the premature and 10w-birth-weight infant such as those causing early fetus expulsion. birth trauma, and postnatal factors of nutrition. There is a question as to whether later growth pat- terns relate more to intrauterine growth than to postnatal nutrition. Those who believe they are related to intrauterine growth have reasoned that the infant is stunted by this experience and will not catch up. • Small for gestational age (SGA) infants are determined by external physical characteristics, including weight, and neurological evaluation (i(;aus & Fanaroff, 1973). An infant whose birth weight is on or below the 10th percentile is considered small for gestational age (Klaus et al., 1973). If a child is small for gestational age and below the lOth in weight, length, and head circumference at birth, percentil~ he or she is more likely to remain small throughout his or her 20 childhood (Lubchenco, 1976). If there are congenital anomalies or congenital infections as associated with intrauterine growth, later growth is not predictable (Lubchenco, 1976). Birth weight is a major factor in determining the growth curve during early childhood. Children with birth weights of 1,500 to 2,000 grams usually approximate the average for a full term infant by three to six years of age, while those with birth weights between 1,000 to 1,500 grams may require from five to eight years longer (Hess & Lunden, 1949). Conclusively, it is noted that with an increase in prema- turity and decrease in birth weight, the rate and level of growth progress decreases in comparison to normal growth standards. Summary Neonatal necrotizing enterocolitis mayor may not result in impaired physical growth in children 1 1/2 to 6 1/2 years of age. There are factors which may contribute to altered growth progress. NEC may effect the intestine itself in such a way as to alter the ability of the bowel to absorb nutrients efficiently which would precipitate a decreased weight gain and linear growth. Carbohydrate or protein malabsorption can parallel starvation in the body, altering weight gain and growth progress. Resection of the small intestine results in a decrease in absorptive area which may result in a decrease in nutrients absorbed precipitating a decreased rate of weight gain and linear growth. Most infants who develop NEC are born preterm or low-birth-weight and, therefore, may be predisposed to below average growth patterns if their premature or birth weight status was 21 significant. These aspects of NEG signify that survivors of the dis- ease may have altered growth patterns indicated by lower percentile height and weight. The' body system of a chi 1d survivi ng NEG may compensate for the massive physiologic insult in infancy. nate is resilient. The intestine of the neo- The intrinsic compensatory changes that may occur" such as the increase in caliber and the longitudinal growth of the intestine, increase in ability of the resected small bowel to absorb fats and to tolerate monosaccharides may allow weight gain and growth progress comparable to normal growth standards. Studies indicate that neonates having had small intestinal resection demonstrate a lag in weight gain in the first few months of the postoperative period. This lag is followed by a significant acceleration of weight gain in the first one to two years of life which eventually allows normal growth progress to be achieved. Infants with necrotizing enterocol His are primarily premature and low-birth-weight. It is reported that prematurity and low-birth- weight are no cause for long-term deficiency in growth progress and that the growth achieved is determined by the degree of prematurity and weight at birth. Once a child having suffered NEG is able to tolerate adequate caloric intake and ma'intain adequate nutrition in the first years of life, growth progress can achieve a rate and level comparable to normal growth standards. At this time, there is no documentation of growth progress of children having survived neonatal necrotizing enterocolitis. CHAPTER I I I CONCEPTUAL FRAMEWORK liThe physical" growth progress of the NEC survivors can be assessed in terms of height and weight. The literature indicates that progress of growth is measured in terms of height and weight (Lowrey, 1978; Stuart, 1934; Whipple, 1966). Lowrey (1978) states that in any group of measurements body weight sums up all the increments in size, and is the best index of growth and nutrition. Height, most commonly measured after 18 months, is also an index of physical size and is used as a means of assessing growth progress and health in children (Smith, 1977; Whipple, 1966). to height and/or weight growth. Growth progress in this study refers These measurements of physical growth may give a very general indication of a subject's health, although deviations from the norm usually follow or accompany rather than herald a disease (Lowrey, 1978). However, once a health practitioner has detenlli ned that a chi 1dis growth pattern dev i ates from the norm by other than normal physiologic variations the cause of the deviant growth should be investigated (Whipple, 1966). Necrotizing enterocolitis ;s a disease of the intestine, an organ responsible for nutrient absorption and, therefore, growth maintenance. If NEC alters the intestine's function, possibly precipitat- ing a malabsorption problem, the physical growth of the survivor, especially weight, could be deterred. The measurement of height and weight as an index of physical growth progress ;s a means of assessing 23 the potential problems, such as malabsorption, and the long-term effects of necrotizing enterocolitis. It has become common practice to use percentile as a standard of growth progress comparison and means of assigning an individual some point of reference to the group of his age (Lowrey, 1978). Harold C. Stuart, School of Public Health, Boston, Massachusetts, established growth percentile charts for height and weight of boys and girls from birth to 12 years of age. The percentiles on the growth charts are based upon repeated measurement of a large number of children under comprehensive studies of health and development and are considered "norms" for height and weight (Whipple, 1966). The values on the growth charts are interpreted as normal values in the sense that deviations from these values are to be regarded as deviations from the nor~s (00ssing, 1952). The Stuart growth charts are used in the meci- cal centers and hospitals of Salt Lake City for evaluation of height and weight growth progress and are used in this study as a basis for comparison. When a large population is used to establish physical growth norms, as with the Stuart growth charts, height and weight are normally distributed so that the 50th percentile corresponds to both the mean and the mode (Cooper, 1969; Tanner, 1978). Lowrey (1978) states that children with height and weight measurements which (1) fall in varying percentile groups; (2) shift percentile groups, or (3) fall near or to the outside of the 10th or 90th percentiles should be reviewed for growth abnormalities. Tanner (1978) reports, however, that the 3rd and 97th percentiles are the conventional limits of normality with 24 the remaining three percent above and below those norms considered a significant number. Further, Tanner (1978) states that the truly pathological children lie considerably below the third percentile. In a cross-sectional study, one executed for the first time on a population, the 3rd and 97th percentiles should be regarded as normal (Tanner, 1978). However, children measured in a longitudinal study, examined over a significantly long period of time, who fall in the 3rd to 97th percentile on the first measurement and are considered normal,. should move toward the 10th and 90th percentiles in subsequent measurements (Tanner, 1978). In this cross-sectional baseline study of NEe survivors, the 3rd and 97th percentile groups are considered the limits of normality. The establishment of growth norms, such as those of the Stuart growth charts, allow direct comparison of the place an individual holds in relation to the usual distribution of measurements. A number of useful impressions can be made regarding the physical characteristics of a particular child by comparing his growth to the established norms (Lowrey, 1978). Tanner (1978) identifies three distinct ways that collections of growth data and growth standards may be used: (1) As a screening device or community care resource for investigating not overtly ill children to see if they may benefit from special education, medical, nursing or social care, or counseling; the response to treatment of an ill child; and (2) for studying (3) as an index of the general health and nutrition of a population or subpopulation. The growth data collected from this study can be used as Tanner has described most effectively by the family nurse clinician and 25 other primary health care providers. Much of what Tanner has de- lineated is intrinsic to the role of the family nurse clinician such as a referral base for special education, social care or further medical aid, and investigation of the child's response to treatment as well as to his illness. Use of a general health index as a resource for health education, preventive medicine and health maintenance is also intrinsic to the role of the family nurse clinician. Furthermore, and of great importance, growth data can provide the nurse clinician with a reference on which her psychological and health oriented family intervention can be based. Some needs of the families of children having survived necrotizing enterocolitis may be suggested by the implications of the growth data. The Problem The problem exists that there is no data on growth expectations of children having survived necrotizing enterocolitis. Related management assessment, follow-up care and family guidance for NEe survivors is, therefore, speculative. Hypotheses Hypothesis 1 The height of children having survived necrotizing enterocolitis will not differ significantly from the height of normal children. Hypothesis 2 The weight of children having survived necrotizing enterocolitis will not differ significantly from the weight of normal children. 26 Definition of Terms Height The distance from the heel to the top of the head of a child standing upright against a wall as measured in centimeters and inches. Weight The relative heaviness of a child without c10thing as ascertained by a portable standing scale measured in kilograms and pounds. Necrotizing Enterocolitis (NEe) A disease of the newborn characterized by ischemic necrosis of the gastrointestinal tract with a clinical picture of gastric retention, abdominal distention, bilious vomiting and gastrointestinal bleeding. The diagnosis of NEC at infancy was documented on each sub- ject's hospital chart at the time of the acute phase of the disease. CHAPTER IV METHODOLOGY AND RESEARCH DESIGN Purpose The purpose of this study is to describe the growth progress of children having survived necrotizing enterocolitis, in terms of height and weight. The results of this study can be used to establish a baseline for growth expectations and health care planning for children having suffered the disease. The design of this study is descrip- tive. Population The population for this study consists of 56 survivors of neonatal necrotizing enterocolitis who were diagnosed with the disease at the Intermountain Newborn Intensive Care Unit (INICU), University of Utah Medical Center, Salt Lake City, Utah, and the Primary Children's Medical Center, Salt Lake City, Utah,from August 1972 to July 1977. The ages of these children range from 1 1/2 years to 6 1/2 years. Re- cords of the cases of NEC were obtained from the Pediatric Gastroenterology Office and INICU at the University of Utah Medical Center and the Surgical Office at the Primary Children's Medical Center. Sample The sample group the stated population. (~) consisted of 30 survivors of NEC from The ages range from 1 1/2 years to 6 1/2 years. 28 They are all Caucasians. Twenty-six of the subjects lived in Utah, two subjects lived in Idaho and two subjects lived in Montana. Popula- tion members were excluded from the sample on the basis of patient expiration, physical trauma requiring or resulting in amputation of extremities, inability to locate, and inability to come within a 350 mile radius of Salt Lake City, Utah. Instruments A Lufkin pocket steel tape nubian blade was used to measure the height of each subject in centimeters and inches. A Teraillon portable standing scale was used to measure the weight of each subject in kilograms and pounds. Methodology The parents or legal guardian of each subject was contacted by phone. The investigator identified herself as a University of Utah College of Nursing graduate student conducting a follow-up study of survivors of neonatal necrotizing enterocolitis. Consent for a home visit to measure the height and weight of the NEC survivor was obtained. If the home was outside the 350 mile radius, a place was es- tablished within the radius where the visit could be made. time for measurement was established. A date and Information for contacting the investigator was provided. A home visit was made at the time established, Introductions were made and review of the study was provided for the family and subject. Informed written consent (see Appendix A for complete deriva- tion) was signed by the parents or legal guardian of each subject. The confidentiality of the data obtained was explained. 29 For measurement of height, each subject stood barefoot on an uncarpeted floor with heels, buttocks, shoulders and head against a wall. A metal carpenters "LI! square was placed on the top of the child's head and extended to touch the wall perpendicularly. mark was made where the square touched the wall. A pencil The distance from the floor to the mark was measured with the steel tape and recorded on the data collection form (see Appendix B for complete derivation) in centimeters and inches as the subject's height. Prior to the measurement of weight the scale was calibrated with a l5-pound weight at the place of visit. on an uncarpeted floor for weight measurement. The scale was placed Each subject was al- lowed to wear only underclothing when measured for weight. The child was asked to stand on the scale and the measure of weight was recorded on the data collection form in kilograms and pounds. Data obtained following the measurement of height and weight included the age, sex and race of subject; age, sex, race, height and weight of the subject's siblings, mother and father; family socioeconomic status; birth weight and gestation age of the subject; type of management of NEC during the acute phase, either medical or surgical; part of intestine affected (if unknown by family, this data was obtained from the patient's chart); duration of initial hospitalization with NEC; other complicating persisting disease and the number of hospitalizations since discharge with NEC (see Appendix B, Data Collection Form). Following completion of the data collection forms, four questions were asked: (1) Did your child, or does he, have a problem with 30 nutrition or feeding? If so, how often? (2) Did your child, or does he, have diarrhea? (3) Is your child, or has he been, constipated? If so, how often does he have a bowel movement? or does he, suffer nausea and vomiting? (4) Did your child, If so, how often? These questions were asked as a prelimin9ry survey for a future study and will be commented on in the discussion only. were recorded on the data collection form. All of the above data All of the above data are identified by random number Code 1-30 rather than by name to protect anonymity. Groupings The data obtained was grouped for analysis. The major group- ings were height and weight for age and sex, growth measurements within normal limits, and those below normal limits. include: Additional groupings (1) Relative body weight which indicates appropriate weight for height; (2) gestational age which identified premature infants; (3) birth weight which designates low-birth-weight infants and infants small for gestational age (SGA) by weight. (4) disease management, either surgical or medical, which may identify one more successful than the other; (5) the part of intestine affected by NEC either small or large intestine; (6) complicating persisting diseases which may deter growth progress; (7) duration of initial hospitalization with NEC with relation to growth progress; and (8) family socio- economic status according to estimated annual income which may affect growth progress by financial capabilities for care. The data on the number of hospitalizations since discharge with NEe (see Appendix B, Data Collection Form), was not analyzed. The 31 question was not valid or reliable as indicated by the varying responses received. For future investigation the question should be revised to assess the number of complications related to NEG since discharge, which was the information desired by the original question. Statistical Procedures The Student i-test is the statistical procedure commonly employed to identify whether two sample means are significantly different or if the similarity is so close that there is reasonable probability that the means do not differ in the larger population (Cooper, 1969; Klecka, Nie &Hull, 1975). When two different variables are being examined, such as height and weight, from two different samples, the form of t-test used is the t-test for paired observations (Cooper, 1969; Klecka et a1., 1975). The Student i-test for paired observations was performed on the data of height and weight measurements for age and sex to identify the mean variances between the height and weight of the NEC survivors and the height and weight of normal children. The mean height and weight of the NEC survivors was calculated from the data obtained. The 50th percentile was employed as the mean height and weight for the sample of normal children. The level of signifi- cance was set at a level of 0.05, the most typically used value with the Student t-test (Klecka et al., 1975). Two growth records were used to analyze the obtained data. The growth measurements were plotted on the Stuart growth charts to assess where the growth of the NEC survivors fell in relation to the growth of normal children. The 3rd and 97th percentiles are considered 32 the limits of normal growth for this cross-sectional study. A growth record of weight for gestational age, of Caucasian infants born at high altitude, constructed by Lubcheno, Hansman, Dressler, and Boyd in 1963, was used to plot and graphically illustrate the birth weight for gestational age of the NEC survivors. The re1atiye body weight was analyzed to assess the growth of the NEC survivors. The relative body weight is the weight of each NEC survivor expressed as a percentage of the "ideal II weight for height (Sohar, Scapa &Ravid, 1973). The "ideal" weight for height was calculated with the Stuart growth chart percentiles. "Normal" relative body weight is considered 100 percent ideal weight, 1/1, in that weight and height percentiles are the same. The limits of normal have been arbitrarily assigned at 120 percent ideal weight for obesity (Sohar et al., 1973) and 80 percent ideal weight for underweight. CHAPTER V RESULTS Height of NEC Survivors Hypothesis 1 states that the height of children having survived necrotizing enterocolitis will not differ significantly from the height of normal children. The results of the Student t-test indicate (see Table 1) that the absolute mean height of all NEC survivors is 4.2 cm. less than that of normal children. The mean height for males only is 2.4 cm. less than normal males and the mean height of female subjects only is 3.9 cm. less than normal females. The differences between the means is statistically significant at the 0.05 level of significance and null Hypothesis 1 is disproven. The heights of the NEC survivors, sexes combined, were plotted on the Stuart growth charts (see Figure 1). Examination of the charts reveals that there are seven subjects (23%), six males and one female, whose height is on or above the 50th percentile. There are 12 subjects (40%), seven males and five females, whose growth is below the average mean but within normal limits of growth, Therefore, 19 NEC survivors (63%) have height within normal limits of growth, 55 percent of the females and 63 percent of the males. There are 11 NEC survivors, six males and five females, whose height is below the 3rd percentile of growth. The height of one child, a 1 1/2 year-old, male, was not included on the growth chart, since he ;s below two 34 Table 1 Results of Student t-Test: Variance in Mean Heights Males and Females Males On1~ Females On1~ t @ .05 level of significance + t = difference of means - 4.2 cm. - 2.4 cm. - 3.9 cm. Average difference - 5.2 cm. - 3. 1 cm. - 8.8 cm. Degrees of freedom 2.0 6.8 - 5.2 2.1 + 18 29 Standard deviation (SO of differences) 95% confidence interval + + 18 5.6 2.6 - 3.1 2.2 7.5 + 2.7 - 8.8 + 5.0 35 em ,/ 97% 150 Height Chart Both Sexes 140 130 3°/""'" /0 120 110 100 90 x 80 70 2 I I I 3 4 5 Figure 1 . I I 7 Age in Years 6 I I I I 8 9 10 11 Height Measurements of NEG Survivors o = males x = females 36 years of age; his height plotted on the growth chart for his age fell below the 3rd percentile. Weight in NEG Survivors Hypothesis 2 states that the weight of children having survived necrotizing enterocolitis will not differ significantly from the weight of normal children. The absolute mean weight of the 30 NEG survivors is 3.7 kg less than the mean weight of normal children, as indicated by the results of the Student t-test (see Table 2). The mean weight of the male subjects only is 2.4 kg. less than the mean weight of normal males and the mean weight of the female subjects only is 3.1 kg. less than the mean weight of normal females. All of the dif- ferences in the means are statistically significant at the 0.05 level of significance, and null Hypothesis 2 is disproven. The weights of the NEG survivors, sexes combined, were plotted on the Stuart growth chart (see Figure 2). Examination of the charts reveals that there are eight children (27%), five boys and three girls, whose weight is on or above the 50th percentile. There are 14 subjects (46%), 11 boys and three girls, whose weight is below the average mean but within normal growth limits. Therefore, 22 of the 30 NEG survi- vors (73%) have weight measurements within normal limits. There are eight children, three boys and five girls, with weight below the 3rd percentile of growth. The weight of one NEG survivor, a 1 1/2 year- old male, was not included on the growth chart, since he is below two years of age; his weight was below the average mean but within normal limits of growth. 37 Table 2 Results of Student t-Test: Variance in Mean Weight Males and Females t @ .05 level of significance t = difference of means Average differences Degrees of freedom Males Onl~ Females Onl~ + 2. 1 + 2.1 + 2.2 - 3.7 kg - 2.4 kg - 3. 1 kg - 1.9 kg - 1.2 kg - 3.2 kg 29 Standard deviation (SO) of differences 2.8 95% confidence interval -1.9+1.1 18 2.2 -1.2+1.0 10 3.5 - 3.2 + 2.4 38 kg Weight Chart Both Sexes 50 / 45 97% 40 35 / 3% 30 25 20 o X X x 15 11 I 2 3 Figure 2. 4 I I I 567 Age in Years I I I I 8 9 10 11 Weight Measurements of NEC Survivors a = rna 1es x = females 39 Sex of Survivors Males. There are 19 male NEG survivors. In terms of height, six achieved height on or above the 50th percentile, while seven have heights below the average mean but within normal limits, and six males have height below the 3rd percentile. In terms of weight, six males have weight on or above the 50th percentile, while 10 have weights below the average mean but within normal limits, and three have weight below the 3rd percentile. Seven in 19 male NEG survivors (37%) have height and/or weight growth below the 3rd percentile. Females. There are 11 female NEG survivors. In terms of height, one female achieved height on or above the 50th percentile, while five females have height below the average mean but within normal growth limits, and five females have growth below the 3rd percentile. In terms of weight, three girls have weight on or above the 50th percentile, while three girls have weight below the average mean but within normal limits, and five girls have weight below the 3rd percentile. Five in 11 female NEG survivors (45%) have height and weight growth below the 3rd percentile. Relative Body Weights The lIideal" weight for height of each NEG survivor was calculated with the Stuart growth chart percentiles. The relative body weight is the weight of each NEG survivor expressed as a percentage of the lIideal" weight. The distribution of the relative body weights of the children having survived necrotizing enterocol itis is summarized in Figure 3. The distribution of the relative body weights of the NEG 15 13 VI 5 11 > > or- S- ::l U1 9 7 20% 18% 5 13% . 13% 10% 3 . 1 13% 3% - [ 1 6 4 I 80-84 4 5 4 3 7% 3% 2 r 85-89 Figure 3. 90-94 95-99 100-104 105-109 Percent of Ideal Body Weights 110-114 115-119 1 I 120-124 Relative Body Weights of NEC Survivors (Sexes Combined) Number in column is number of NEC survivors the column represents. Percentage on top of column is percent of NEC survivors the column represents. ..J::;:. a 41 survivors form a bell-shape curve about the norm, slightly skewed to the right. This illustrates a normal distribution of ' relative body weights, with the greatest number, six, of subjects having an ideal body weight of 105 percent to 109 percent, one subject having an ideal body weight of 80 percent to 84 percent and one subject having an ideal body weight of 120 percent to 124 percent. Gestational Age With an increase in prematurity or a decrease in gestational age, the rate and level of growth progress may decrease in relation to normal growth standards. The mean weeks of gestation of the sub- jects is 31.2 weeks, for males only it is 31.0 weeks, and for females only it is 31.4 weeks. Twenty-eight of the 30 NEC survivors (93%), 18 males and 10 females were delivered at 37 weeks less, with a range of 26 to 37 weeks and a mean of 33.6 weeks. In relation to growth progress in terms of height, seven of the subjects born premature, six males and one female, have height on or above the average mean, or 50th percentile, and 21 of the subjects born premature, 12 males and nine females, have height below the average mean. Nine of the subjects born premature, five males and four females, have weight below the 3rd percentile. In terms of weight achievement, seven of the subjects born premature, four males and three females, have weight on or above the 50th percentile, while 19 of the subjects born premature, 11 ~a1es and eight females, are below the average mean, seven of which, three males and four females, are below the 3rd percentile for weight. Sexes combined, 10 of the 28 NEC survivors born premature have growth progress ECCLES UEALTH SCIEN,CES LIBRARY 42 of height and weight or both below the 3rd percentile (see Figure 4). The two NEe survivors with gestational ages of 43 weeks have growth progress in terms of height and weight below the 3rd percentile. Birth Weights With a decrease in birth weight the rate and level of growth progress may decrease in relation to normal growth standards. The mean birth weights of the NEe survivors was 1,757 grams, the mean for males being 1,756 grams, and for females, 1,759 grams. Twenty-seven of the 30 NEe survivors (90%) had birth weights less than 2,500 grams and are, therefore, considered low-birth-weight infants. The range in birth weights of these infants is 820 grams to 2,240 grams with an average mean weight of 2,021 grams. In relation to growth progress in terms of height, seven of the low-birth-weight subjects, six males and one female, have height on or above the average mean, or 50th percentile and 20 of the low-birth-weight subjects, 11 males and nine females, have height below the average mean. In terms of weight, nine of the low-birth-weight subjects, six males and three females, have weight on or above the 50th percentile, while 18 of the low-birthweight subjects, 10 males and eight females, have weight below the average mean, seven of which, three males and four females, are below the 3rd percentile for weight. Sexes combined, 10 of the 27 NEe sur- vivors with low-birth-weights have growth progress of height and/or weight below the 3rd percentile (see Figure 4). Infants with birth weights of 1,500 grams or less are more susceptible to NEe (Book, 1979), and are predisposed to a greater 43 Intrauterine Weights Both Sexes (From Lubchenco Et. A1., 1963) Grams 4000 3600 3200 2600 2400 2000 1600 1500 1200 800 400 I I I 25 27 29 Figure 4. o x I I I 31 33 35 37 Weeks of Gestation 39 I I 41 43 Birthweights for Gestation Age of NEe Survivors = NEe survivors with growth within normal limits. = NEe survivors with height and/or weight or both below the third percentile. 44 decrease in growth progress than other low birth weight infants. Thirteen NEG survivors (48%), eight males and five females, have birth weights less than 1,500 grams, with a range of 820 grams to 1,450 grams and an average mean of 1,108 grams. With regard to height, two of these subjects, one male and one female, have height above the 50th percentile, while 11, seven males and four females, have height below the average mean, and five, two males and three females, have height below the 3rd percentile. With respect to growth progress in terms of weight, three NEG survivors with birth weights less than 1,500 grams, two males and one female, have weight on or above the 50th percentile, 10, six males and six females, have weight below the average mean, four of which, one male and three females, have weight below the 3rd percentile. Sexes combined, six of the 13 NEG survivors with birth weights below 1,500 grams, have growth progress in terms of height and/or weight below the 3rd percentile (see Figure 4). Small for Gestational Age (SGA) Infants small for gestational age are determined by physical characteristics, and neurological evaluation. determination is birth weight. Significant to that Infants with birth weights on or below the 10th percentile are considered small for gestational age (Klaus, 1973). There are six NEG survivors, five males and one female, with birth weight below the 10th percentile and are considered to be SGA. In relation to height growth, one SGA male has height above the 50th percentile, while two SGA males have height below the average mean but within normal limits and one SGA male and one SGA female have 45 height below the 3rd percentile. In terms of weight achievement, two SGA males have weight above the 50th percentile, while three SGA ma1es have weight below the average mean but within normal limits. One female NEe survivor born small for gestational age has weight below the 3rd percentile. Sexes combined, two of the NEe survivors born small for gestational age have height and/or weight growth be10w the 3rd percentile (see Figure 4). Management of NEe: Surgical and Medical Necrotizing enterocolitis can be managed either surgically or medically. Eleven NEe survivors (37%), seven males and four fe- males, were treated surgically with intestinal resection. With respect to growth in terms of height, three surgically managed NEe survivors, all males, achieved growth on or above the 50th percentile. Five surgical patients, two males and three females, have height below the average mean, but within norma1 limits, and three surgical patients two males and one female, have height below the 3rd percentile. In terms of weight achievement, three NEe survivors surgically managed, two males and one female, have weight on or above the 50th percentile, five surgical patients, three males and two females, have weight below the average mean but within normal limits, and three surgical patients, two males and one female, have weight below the 3rd, percentile. Sexes combined, there are 11 surgica1ly managed NEe survivors, seven with growth progress of height and/or weight within normal limits, and four with growth progress below the 3rd percentile (see Figure 5). There- fore, 36'% of NEe survivors surgically treated have growth below the 3rd percentile. 46 Total number of patients surgically managed 11 Surgical patients with normal growth 7 Surgical patients with growth below the third percentile Surgical Management 4 -----------------------------------------------------------------------Total number of patients medically managed 19 Medical patients with normal growth 15 Medical patients with growth below the third percentile Medical Management 4 o1 Figure 5. 3 5 7 9 11 13 15 17 19 21 NEC Survivors Management of NEC: Surgical and Medical Growth = height and/or weight 23 25 47 Nineteen of the 30 NEG survivors (63%), twelve males and seven females, were medically managed. With regard to growth progress in terms of height, four medically managed patients, three males and one female, have height on or above the 50th percentile, 15 medically managed patients, nine males and six females, have height below the average mean, eight of which, four males and four females, have height below the 3rd percentile. In terms of weight achievement, six medi- cally managed NEG survivors, four males and two females, have weight on or above the 50th percentile, 13 medical patients, eight males and five females, have height below the average mean, five of which, one male and four females, have weight below the 3rd percentile. Sexes combined, there are 19 medically managed NEG survivors, 15 of which have growth in terms of height and/or weight within normal limits, and four of which have growth progress below the 3rd percentile (see Figure 5). Therefore, 21 percent of NEG survivors medically managed have growth progress below the third percentile. Areas of Intestine Affected by NEG The most frequently involved area of intestine in necrotizing enterocolitis are the ileum and ascending colon. The area of bowel affected is identified by surgical evaluation, autopsy and occasionally by radiographic determination. The data available on the NEG survi- vors did not specify the particular part of small intestine or colon affected by the disease, therefore, the categories given are small intestine and colon. Surgical evaluation indicated that of the 11 surgically managed patients, four had small intestinal involvement, 48 three boys and one girl, five had colon involvement, four boys and one girl, and two surgical patients, one boy and one girl, have both small and large intestinal involvement. Radiographic evaluation de- termined the area affected in four medically managed patients, two of which had colon involvement, one boy and one girl, and two of which had small and large intestinal involvement, one boy and one girl. There were 15 NEe survivors in total, nine males and six females, in which the area of affected intestine was identified. In terms of height specific growth, one male with small intestinal involvement has height above the 50th percentile and two patients with small intestinal involvement, one male and one female, have height below the average mean but within normal limits, and one male has height below the 3rd percentile. In terms of weight achievement, one male with small intestinal involvement achieved weight above the 50th percentile, and two males and one female have weight below the average mean but within normal limits. There were no patients with small intestinal involvement with weight below the 3rd percentile. Of the 15 NEe sur- vivors in which the area of intestine affected was identified, seven patients had colon involvement, four males and three females. In terms of height achievement in these patients, two males have height on or above the 50th percentile, while five patients, two males and three fellales, have height below the average mean, three of which, two males and one female, have height below the 3rd percentile. In terms of weight achievement in the NEe survivors with identified colon involvement, one male has weight above the 50th percentile, while three males and three females have weight below the average mean, Patients with small intestinal involvement Total number I 4 With growth within normal limits Small intestine I 3 With growth below third percentile OJ Patients with colon involvement Total number 7 With growth within normal limits Colon I 4 With growth below third percentile I I 3 Patients with colon & small intestinal involvement Total number f---. 4 With growth within normal limits J Colon and small intestine J 3 With growth below third percentile OJ - - - - L. ___ I t . 1 2 3 -- I I I I I I I I I I I 4 5 6 7 8 9 10 11 12 13 14 NEC Survivors Figure 6. Part of Intestine Affected in NEC Survivors in Relation to Growth Progress Growth = height and/or weight or both .t::\.0 50 two of which, one male and one female, have weight below the 3rd percentile. There are four subjects, two males and two females who suffered both large and small intestinal involvement. In terms of height speci:fic growth progress, none have height above the 50th percentile, thus all four have height below the average mean, one male of which has height below the 3rd percentile. With regard to weight achieve- ment, one male and two females achieved weight on or above the 50th percentile and one male has weight below the 3rd percentile. Three summary statements can be made with regard to growth progress of height and weight or both, and with sexes combined (see Figure 6). One in four (25%) NEC survivors with small intestinal in- volvement achieve growth progress below the 3rd percentile. One in 2.33 (43%) NEC survivors with colon involvement had growth progress below the 3rd percentile. One in four (25%) NEC survivors with small and large intestinal involvement had growth progress below the 3rd percentile. Complicating Persisting Disease The most frequently occurring complicating disease for the children surviving necrotizing enterocolitis were respiratory distress syndrome (RDS) and hyaline membrane disease. These two diseases are grouped together for statistical purposes because of their similar characteristics and are often considered the same disease entity (Vaughn &McKay, 1975). These disease entities were suffered by 18 of the 30 NEe survivors (60%), 10 males and eight females. In terms of 51 height specific growth, six children who had RDS, five males and one female, have height on or above the 50th percentile. Nine of the subjects who suffered RDS or hyaline membrane disease have height below the average mean but within normal growth limits, and three subjects, one male and two females, have height below the 3rd percentile. In terms of weight achievement, six of the children who had RDS or hyaline membrane disease have weight above the 50th percentile, three males and three females, while nine of the children, six males and three females, have weight below the average mean but within normal limits, three of which, one male and two females have weight below the 3rd percentile. Five of the 18 children who had RDS (28%) have height and/or weight below the 3rd percentile. The second most common complicating disease was patent ductus arteriosis, found in five of the NEC survivors, two males and three females. One of these females achieved height above the 50th per- centile, one male and two females have height below the average mean but within normal limits, and one male has height below the 3rd percentile. In terms of weight in the subjects with PDA's, one male and one female achieved weight above the 50th percentile, and three subjects have weight below the average mean, two of which, one male and one female, have weight below the 3rd percentile. There were five incidences of other complicating persisting diseases in the NEC survivors. One child had persistent fetal circu- lation, his height and weight are below the average mean, but within normal limits. Two female children have cerebral palsy and both now have height and weight below the 3rd percentile. Two children, one 52 male and one female, suffer significant neurological deficits and both have height and weights below the 3rd percentile. In total, 23 NEe survivors had or have a complicating persisting disease. Fifteen of these children are within normal growth limits, while eight have growth which falls below the 3rd percentile (see Table 3). There are seven NEe survivors who did not suffer any complicating disease, three of which have height and weight measurements within normal limits, three fall below the 3rd percentile for height, but are within normal limits for weight, and one girl is below the 3rd percentile for height and weight (see Table 3). Duration of Initial Hospitalization with NEe The duration of initial hospitalization with neonatal necrotizing enterocolitis was evaluated in terms of weeks. pital stay was two weeks to 16 weeks. weeks. The range in hos- The mean average stay was 8.06 The mean average hospitalization for the NEe survivors whose growth, height and weight, is within normal limits, was 7.75 weeks. Those 12 children whose growth, height and/or weight, is below the 3rd percenttle had a mean average hospitalization of 8.06 weeks (see Table 3). The mean average hospital stay for male NEe survivors was 7.36 weeks and the mean average hospital stay for female NEe survivors was 9.32 weeks. Family Socioeconomic Status Family socioeconomic status was evaluated according to estimated annual income in lieu of that status affecting the ability of Table 3 Profile of the 12 NEe Survivors with Growth Progress Below the 3rd Percentile Code Number 3 9 10 14 17 Sex Age M 5 Yr. M 3 M 1 M 3 M 2 Height +3% 1/2 Yr "'3% 1/2 Yr 4-3% 1/2 Yr WNl Yr "'3% Weight *3% WNl WNl 4-3% +3% Percent Ideal Weight (Relat he Body Weight) 102 109 111 88 114 Birth Weight (Grams)1180 1530 3750 2130 1760 Gestational Age (Weeks) 38 34 43 34 32 Management Medical Surgical Medica 1 Surgical Med ica 1 Part of Intestine Affected ? Small Int. ? Colon POA Uyaline Mem. Small & large Ints. Neuro Deficit Colon Hyaline Mem. 11 M 31/2Yr H% M 3 Yr 1 Mot3% F 5 1/2 Yr 4-3% f 5 1/4 Yr "'3% WNl WNl "3% t3% 109 111 100 85 1140 1220 852 3665 29 32 28 43 Medical Medical Medical Medical 15 f 5 1/4 Yr +3% t3% 104 2100 29 Medical ? 16 F 19 5 1/4 Yr +3% 4 Yr 1 Mo +3% +3% +3% 92 F 110 820 1050 29 29 Medica 1 Surgical Colon 21 29 2 WNL ? Within normal limits Unidentified Compl icating Oiseasel SGA ROSol ISgA 1 ? ? ? ROS Respi rator'y 01 stress Syndrome POA = Patient Ductus Arteriosis SgA Snml1 for Gestational Age POAI Neuro. Deficit Cereb. Palsy Uya 1i ne Mem. Cereb. Palsy ISgA RUSI fami ly Weeks of Annua 1 Income Hospita 11 za tion ._-$12,000 7 10 20,000 2 10,000 4 12,000 16 10,000 10 8 10.5 2.5 15,000 21,000 25,000 12,000 9 20,000 10 20,000 12,000 12 01 W 54 a family to provide care, i.e., nutrition, and thus affecting growth progress. The range in annual income for the families of all the NEe survivors is $9,000 to $35,000. The average mean income is $17,250. The range in annual income of the NEe survivors whose growth is within normal limits for height and weight is $9,000 to $35,000, with an average mean of $18,000. The range in annual income of the NEe survivors whose growth in height or weight or both is below the 3rd percentile is $10,000 to $27,000, with a mean average of $16,250 (see Table 3). The average income of families with male NEe survivors is $18,000, while that of families with female NEe survivors is $19,500. CHAPTER VI DISCUSSION The literature is inconclusive as to whether necrotizing enteroco1ities does or does not impair physical growth progress. fore, the null hypothesis was chosen for this study. There- The results indicate, however, that the height and weight of the children having survived neonatal necrotizing enterocolitis differ significantly from those of normal children in that the absolute mean height and weight measurements of the subjects fall below the absolute mean height and weight of normal children. Thus, the null hypotheses are disproven. These results suggest that NEC may impair physical growth progress. However, there are a number of factors associated with NEC that may also deter physical growth of height and weight such as prematurity, low-birth-weight (Lubchenco, 1962; Lubchenco, 1976; Pape et al., 1978), intestinal complications (Wilmore et al., 1972; Young et al., 1969), and adequate nutrition (Book et al., 1975; Book et a1., 1976; Bliss, 1976). It is, therefore, difficult to pinpoint NEC as the main de- terrentofgrowth progress although the data suggests it is a contributing factor. Although the growth of the NEC survivors falls below the 50th percentile, 18 of the 30 NEC survivors (60%) achieved growth of height and weight within normal limits of the 3rd to 97th percentiles. terms of height, 19 subjects (63%) achieved normal growth. In In terms 56 of weight, 22 subjects (73~&) achieved normal growth. The two percent- ages for height (63%) and weight (73%) growth suggest a range for growth achievement of NEe survivors. The generalization can be made that 63 percent to 73 percent of NEe survivors may achieve growth of height and weight within normal limits. Since the absolute mean height and weight of NEe falls below the absolute mean of normal children and 63 percent to 73 percent of NEC survivors achieve normal growth progress, it is apparent that the growth progress of children having suffered neonatal necrotizing enterocolitis have growth patterns on the lower limits of normal. There are 23 NEC survivors with height below the average mean, 11 of which have height below the 3rd percentile. There are 21 NEe survivors with weight below the average mean, eight of which have weight below the 3rd percentile. The results indicate that height retardation is slightly more frequent among NEe survivors than weight retardation. The growth measurements were examined according to sex. The results reveal that in terms of height, six out of 19 male NEe survivors (32%) have height below the 3rd percentile, while five out of 11 female NEC survivors (45%) have height below the 3rd percentile. With regard to weight, three out of the 19 male NEe survivors (16%) have weight below the 3rd percentile, while five out of 11 girls have weight below the 3rd percenttle. With growth of height and/or we; ght combi ned, in rati 0 fOnTI, 37 percent of rna 1e NEe surv; vors have growth retardation, while 75 percent of female NEC survivors have growth retardation. The generalization can be made that female 57 survivors of necrotizing enterocolitis are more predisposed to growth retardation than male NEe survivors. Further evaluation of the growth of the NEe survivors was done in terms of proportionate growth and relative body weight. These children have a high incidence of 90 percent to 110 percent ideal body weight and all relative body weights for height were normal. There- fore, although the growth progress of these NEe survivors is on the lower limits of normal, their growth has proportionately normal weight for height as indicated by the relative body weight index. This nor- mal relative body weight could also suggest that the small stature of these children may be precipitated by a factor that effects overall growth progress, such as low-birth-weight or prematurity versus an intestinal insult, such as NEe, which would more likely effect carbohydrate and fat absorption and thus primarily weight gain. The results were interpreted in relation to a number of groupings including prematurity, low-birth-weight, small for gestational age, disease management, part of intestine affected, complicating persisting disease, duration of hospitalization and family socioeconomic status. These categories will be discussed in relation to their sug- gested impact or lack thereof on the growth progress of children having survived neonatal necrotizing enterocolitis. The cross referencing of these categories produced no significant correlations. Premature and low-birth-weight infants, high risk infants for NEC are predisposed to some degree of growth deficiency (Lubchenco, 1976; Pape et a1., 1978, Smith, 1977). It is, therefore, important to note the high numbers of premature and low birth weight infants 58 among the NE.e survivors. prematurely. Twenty-eight (93%) of the subjects were born Twenty-seven, (90%) of the subjects were low-birth-weight infants with birth weights less than 2,500 grams, 13 of which had birth weights less than 1,500 grams. The degree of prematurity and the de- ficiency in birth weight do not coincide in all cases (see Figure 3). Since premature and low-birth-weight infants are known to be predisposed to some degree of growth deficiency, and 90 percent to 93 percent of the sample of NEe survivors were premature and/or low-birthweight it is not surprising to find the growth progress of the sample on the lower limits of normal. Without controls of gestational age and birth weight, it is difficult to say what effect NEe alone has on growth progress. However, there are two children, one male and one female, of 43 weeks gestation and of normal birth weights who suffered NEe that now have growth progress below the 3rd percentile. Smith (1977) reports that premature and low-birth-weight infants suffer an initial lag in growth but once the infant is able to ingest an adequate caloric intake there is a "catch up" to normal growth rate for biological age. Therefore, a premature or low-birth- weight infant who suffers NEe is subject to an initial growth lag due to his prematurity and low-birth-weight. However, the premature and low-birth-weight infant with NEe may be unable to "catch Upll to nor-. mal growth rate due to the impedance of adequate caloric intake as a result of NEe. The expected growth spurt for premature and low- birth-weight infants occurs within the first one to two years of life (Pape et al., 1978). 59 During the first year and often the second year of life, infants with NEe are adjusting to different formulas, increasing caloric intake, and compensatory intestinal changes. The intestine is overcoming a severe insult during a time of initial intestinal maturation. The generalization may be made that although the initial small stature of premature and low-birth-weight infants with NEe may be attributed to the decrease in gestational age and birth weight, the low but normal growth pattern at a later age may be due to NEe induced inhibition of the catch up phase at an earlier age. Therefore, the growth patterns of NEe survivors appear less than that of normal premature and low-birth-weight infants. Premature and low-birth-weight infants are also allotted various time spans and certain ages by which normal growth progress should be achieved. Following the one to two year growth spurt, three to eight years are allowed for infants of varying degrees of prematurity and low-birth-weights to reach normal limits (Lubchenco, 1976; Page et a1., 1978; Smi th, 1977; Hess & Lunden, 1949). I n accordance with these ages and time spans, four to ten years would be appropriate for evaluation of growth progress of the NEe survivors. The ages of the 30 reported NEe survivors range from 1 1/2 to 6 1/2 years. There are 16 children with ages greater than four years, six of which have growth progress below the norm. Perhaps these NEe survivors are too young to be compared vii th average growth means. Surgical versus medical management of necrotizing enteroco1i ti s does have some beari ng on the outcome of growth progress. results indicate that 36 percent of survivors of NEe surgically The 60 treated with intestinal resection have growth progress below the 3rd percentile, where 21 percent of survivors of NEe medically managed have growth progress below the 3rd percentile. It is significant to note, however, that patients requiring surgery for NEe have a more extensive case of the disease than a patient who can be managed medically. Furthermore, the intestinal resection causes further insult to an already suffering intestine. therefore, somewhat lengthened. The rehabilitation phase is, The results indicate that surgical management of necrotizing enterocolitis predisposes the survivor to an increased incidence of growth progress below the 3rd percentile. The data on the area of intestine affected by NEe revealed some interesting outcomes. Those patients with small intestine in- volvement, the area of intestine with the greatest nutrient absorption, or with small and large intestinal involvement were less likely to have growth progress below the 3rd percentile than those patients with colon involvement alone. This includes the fact that two of the pa- tients with colon involvement were medically managed and would be less likely to have retarded growth. Two of the four patients with small and large intestinal involvement were medically managed which may contribute to their increased ratio of normal growth rate. Interestingly, all four patients with small intestinal involvement alone were surgically managed, yet only one patient suffered growth progress below the 3rd percentile. Thus, there is a tendency for NEe survivors with colon involvement alone to have a greater incidence of growth progress below the 3rd percentile. 61 The most frequently occurring complicating disease (60%) among NEC survivors was RDS or hyaline membrane disease. Kamper (1978) reports that mean values for height and weight of children having suffered idiopathic RDS, hyaline membrane disease, showed no significant difference from normal growth means. It is assumed, therefore, that the retarded growth of the five·NEC survivors who had RDS is not attributable to the complicating disease process. It is interesting to note that six or seven NEC survivors with height on or above the 50th percentile had RDS or hyaline membrane disease and six in nine NEC survivors with weight on or above the 50th percentile had RDS or hyaline membrane disease. This rinding supports the assumption that RDS does not retard growth progress. Patent ductus arteriosis occurred in five of the 30 NEC survivors, two of which have growth below the 3rd percentile. Since chil- dren with cardiac disease are known to be predisposed to growth retardation (Linde, Dunn, Schireson & Rasof, 1967), the retarded growth of the two NEC survivors with PDAs may be attributed to the cardiac disease. However, two of the five NEC survivors with PDAs achieved growth above the 50th percentile. Another complicating cardiac disease entity found in one NEC survivor who had growth below the average mean but within normal limits was persistant fetal circulation. From these results it is difficult to determine the impact of complicating cardiac disease on the growth of NEC survivors. It is apparent, however, that this complicating disease entity should be a controlled variable. Cerebral palsy and significant neurological deficiencies were described in three NEC survivors all with height and weight below the 62 3rd percentile. These neuro1oigcal disease entities have some contri- bution to growth retardation since they also retard motor development. Therefore, neurological complicating disease should also be controlled variables in studies of growth and development. The mean average duration of hospitalization for NEC survivors was 8.06 weeks. The average length of initial hospitalization for the children with growth progress below the 3rd percentile was 8.06 weeks, or .31 weeks (2.17 days) longer than the average mean of 7.75 weeks of hospita1i"zation for those children with normal growth progress. The slightly increased duration of initial hospitalization would not herald potential growth retardation for NEC survivors since the difference in value does not appear significant. Family socioeconomic status was evaluated by estimated annual income. These results indicate the NEC survivors come from a wide variety of socioeconomic backgrounds although middle class status seemed most prevalent. The mean average income of families of NEC survivors with growth progress below the 3rd percentile is $16,350 or $1,750 less than the $18,000 annual income of the families of NEC survivors with growth progress within normal limits. Although only slightly less and still middle class standing, the estimated annual income of families with NEC survivors with growth progress below the 3rd percentile is less than that of families of NEe survivors with normal growth patterns. In these days of inflation the stated dif- ference does not seem significant enough to affect care for an NEe survivor though that is a subjective observation. 63 According to the preliminary survey, the incidence of diarrhea, constipation, nausea and vomiting was not significantly increased as might be expected following :the intestinal insult of necrotizing enterocolities. Nutrition and feeding habits were found to be a slight problem, especially with relation to formula adjusunent and increasing caloric intake in the first and early second years of life; this was an expected finding for children having suffered NEe. The preliminary survey information on intestinal follow-up also suggests that the threat of malabsorption syndrome in NEe survivors is negligible. A number of generalizations have been made with regard to the findings of this study. Growth progress of children having suffered neonata 1 NEe have growth patterns on the lower 1imi ts of normal, as indicated by the absolute mean height and weight of the NEe survivors falling below the average mean and the 63 percent to 73 percent of NEG survivors with normal growth patterns. Female NEe survivors have a higher incidence of growth below this 3rd percentile than male NEe survivors. retardation. Height retardation is slightly more frequent than weight The growth of NEe survivors has proportionately normal weight for height as indicated by the high incidence of normal relative body weight. There is high incidence of premature and fants among the NEe survivors. low~birth-weight in- The initial small stature of the NEe survivors may, therefore, be attributed to prematurity and low-birthweight and the lower normal growth progress at their present age may Ii be due to the NEe induced inhibition of the "catch Up" at an earlier age. This may be the rationale for growth patterns of NEe survivors 64 appearing less than that of normal premature and low-birth-weight infants. The NEC survivors may be too young to compare with normal growth standards. Further evaluation of the data indicates that NEC survivors surgically managed have an increased incidence of growth progress below the 3rd percentile. Also, NEC survivors with colon involvement have a greater incidence of growth progress below the 3rd percentile. The results also reveal that complicating, persisting disease mayor may not contribute to growth retardation, depending on the disease entity. RDS is not known to have a growth retardant effect. Cardiac disease and neurological complications can effect growth achievement and should, therefore, be controlled variables in studies of growth and development. Additional generalizations were that NEC survivors with growth progress below the 3rd percentile are found to have had an initial hospitalization longer than NEC survivors without growth retardation. Also, family income, although middle class for families of all NEC survivors, was somewhat less for those with growth progress below the 3rd percentile than those subjects with normal growth patterns. Since there have been on previously reported studies describing growth and development of survivors of NEe, the findings of this study make a significant contribution toward the establishment of baseline criteria for growth expectations of children surviving necrotizing enterocolitis. The criteria will serve as a useful clinical tool for nurse clinicians and other health professionals. CHAPTER VII LIMITATIONS There are limitations to the study that need to be considered when evaluating the baseline data. The Stuart growth charts, used as the standard norm, were compiled by measurements of children in the eastern United States. Falkner (1977) reports that the samples from which growth standards are derived should match the subjects of a sample being studied with regard to race,geography, and time. Since the sample of NEC survivors used in this study is composed entirely of Caucasians from the Intermountain West, comparison with the Stuart growth charts, although used throughout Utah, may be an inaccurate comparison. There are no existing growth charts specific for the In- termountain West. This study was of descriptive design which in itself is a limitation to the interpretation of the findings. The NEC survivors were compared to standard norms in which birth weight, gestational age, and complicating disease could not be controlled as variables. Sources of invalidity that are controlled, however, by the posttest descriptive design are the effect of history, testing instrumentations, regressions, selection and mortality (Campbell & Stanley, 1966). Statistical limitations to this descriptive design study are, therefore, negligible. 66 Another limitation is imposed by the design which was a crosssectional, one-time study. Growth trends may vary from individual to individual with relation to growth spurts and rates of maturation (Lowrey, 1978). A cross-sectional study does not allow for analysis of growth trends and rates of maturation in relation to growth progress because the sample is examined only once. As mentioned earlier, the sample may also be too young to evaluate growth patterns with relation to normal growth standards. A longitudinal study of the sample group is recommended to account for these limitations. There was also a geographic limitation to the study. jects are mainly from Utah with a few from Montana and Idaho. The subBesides, the environmental effect on growth trends (Whipple, 1966), a further geographic limitation was imposed on the available population by the investigator. A limit of a 350-mile radius from Salt Lake City, Utah, was established as a means to select the sample population. tation excluded 12 population members. This limi- CHAPTER VIII SUMMARY AND RECOMMENDATIONS Summary Necrotizing enterocolitis is a highly critical disease of the newborn. It is characterized by ischemic necrosis of the gastroin- testinal tract with a clinical picture of gastric retention, abdominal distention, bilious vomiting and gastrointestinal bleeding. It occurs primarily in premature and low-birth-weight infants who have suffered some perinatal stress. Etiology, recognition, and management of NEC have been the basis for most studies of NEC in the past. The long- term effects of NEC have not yet been reported in the literature. It is the intent of this study to describe the physical growth effects in terms of height and weight of children having survived necrotizing enterocolitis. There are 56 children in the Intermountain West, ages 1 1/2 to 6 1/2 years, who have survived NEC as recorded by the Intermountain Newborn Intensive Care Unit, the Division of Pediatric Gastroenterology at the University of Utah Medical Center, Salt Lake City, Utah, and the Office of Surgery, City, Utah. Pr;m~ry Children's Medical Center, Salt Lake The sample consisted of 30 of these children, ages 1 1/2 to 6 1/2 years, all Caucasian, who were diagnosed with necrotizing enterocolitis from August 1972 to July 1977. 68 The findings indicate that the height and weight of the children having survived neonatal NEe differ significantly from those of normal children in that the absolute mean height and weight of the subjects falls below the absolute mean of nornlal children. hypotheses chosen for this study are thus disproven. The null However, 63 per- cent to 73 percent of NEe survivors have growth progress within normal limits. Thus, children having survived neonatal necrotizing enteroco- litis, ages 1 1/2 to 6 1/2 years, have growth patterns on the lower limits of normal. Female NEe survivors have a higher incidence of growth below the third percentile than male NEe survivors. Height of NEe survivors has proportionately normal weight for height as indicated by the high incidence of normal relative body weights. There is a high incidence of prematurity (93%) and low-birth-weight (90%) among the NEe survivors, however, the growth patterns of the NEe survivors appears less than that of normal premature and low-birth-weight infants. Significance of Findings to Nursing Since there are no previously reported studies describing the growth and development of NEe survivors, the findings of this study make a significant contribution toward the establishment of baseline criteria for growth expectations of children surviving NEe. The cri- teria can serve as a useful clinical tool for hospital nurses, family nurse clinicians and other health care providers. In consideration of the hospital setting, for the nursing and medical staff who work so closely with infants during the acute newborn 69 phase of NEe, it is enlightening to know that the growth potential of the survivors can be within normal limits, even though below the average mean. This is also an encouraging note for the often depressed morale of the nurses in the newborn and pediatric intensive care units. This growth data indicates that the response of the NEe survivors to the present medical and nursing management needs continued focus on the nutrition and other factors of care that may potentiate growth progress. During hospitalization, following the acute phase of NEe, when the significance of weight gain and growth become more apparent, there are countless questions from the family of the NEe survivors including: Will my child be normal? What can we expect now? What can we expect in the future? This collection of growth data provides a reference on which the answers to such questions can be based. Nurses and other health professionals will find this resource of benefit in preparation of a family and infant for hospital discharge and future follow-up. The role of the family nurse clinician involves the primary comprehensive health care of families. The family nurse clinician can contribute to the family's deve'lopment, from the time of the parentis decision to have children through the development of those children. Therefore, if a newborn were to develop NEe, the family nurse clinician would be aware of the prenatal course, perinatal events, and may be involved in the hospital care of the infant. The family nurse clini- cian would assure continuity of care for the infant with NEe and the family before and after hospitalizations. 70 Follow-up care of the NEC survivor and family may be the primary responsibility of the family nurse clinician. It is for this reason that knowledge of growth expectations of NEC survivors is so important to the nurse clinician. She may be the one responsible for understanding the growth deviations that would herald the need for special medical care, social assistance, health education, nutrition assessment, or family counseling. The family nurse clinician and other primary health care providers can use this baseline criteria as a resource when assessing a child's and family·s response to illness, recovery, health and life situation. Recommendations In order to account for some of the previously designated limitations some additive changes in study design are recommended for further growth evaluation. The use of a control group is recommended to alleviate the limitations imposed by the use of standardized growth norms. The use of a control group would also control for variables such as gestational age, birth weight, complicating diseases, and other entities which may have an impact on growth progress. Control group design would also allow fqr further evaluation of the possibility of NEC inhibiting the IIcatch up phase ll in infants with growth retardation. A longitudinal study of this sample of NEC survivors is recom- mended to allow for the variation in individual growth trends and growth spurts and prov;de'more conclusive data. Two additional groupings are recommended for growth evaluation. The incidence and type of complications in the NEC survivor should be 71 evaluated to determine the impact of complications, or lack thereof, on growth achievement. Age specific grouping of the growth of NEC survivors should be included in data analysis. Since growth progress is determined according to age, an age specific group would be a valid approach to data analysis. Perhaps children having suffered acute and critical diseases as infants, such as NEC, should be periodically recalled for physical assessment to facilitate the collection of growth data. Compiled nationwide for neonatal diseases, the data would contribute to the establishment of criteria for growth assessment of children having suffered neonatal diseases. Family nurse clinicians and other health professionals could use such data to educate and counsel families on the future of their critically ill newborn and to further validate pediatric health care. APPENDIX A INFORMED CONSENT FORM 73 As the parent and/or legal guardian of ~~~~~~~ (middle initial) ____~~~__~_____ ' r (last name) ~(m-l~·d~d~l-e-l~·n~i~t~ia~l~)----~(~la-s~t~n-am-e-)~--- ~(~fl~·r-s~t--na-m-e~)-------- ~~~ __~___________ (first name) , hereby grant authorization for the above-named child to serve as a subject in the investigation of "Necrotizing Enterocolitis: A study of the long-term physical growth consequences in terms of height and weight," under the supervision of Kristina Hedin, R.N. This investigation aims to establish a baseline of growth progress in height and weight of neonatal necrotizing enterocolitis survivors. The procedures to which the above- named child will be subjected are the measurement of height and weight and the completion of a personal data form. risks. There are no expected The benefits of these procedures include the knowledge of ac- curate height and weight of the subject as well as contributing to the improvement of follow-up health care and family counseling, with reference to growth expectations, for children survivors of neonatal necrotizing enterocolitis. r understand that confidentiality will be protected and that the above-named child is free to withdraw from participation in the investigation at any time. r have read and fully understand the forgoing information. Date Signature of Subject's Parent or Guardian APPENDIX B DATA COLLECTION FOR~1 FOR NEC STUDY 75 Code - - - - - 1. Name of Subject Address 7(~la-s~t--na-,m-e~)------~(~f~i-rs~t--n-am-e~)--~(m~i~d~d~le~i-n~;t~i~a~l) ----rc-rty ) ~("""'n-o-.-a-n-;-d-s--:-t-re-e--:"t""T") Home Phone Number (s ta te ) (zip code) --(~a-r-e-a-c-o~d-e~)----(~t-e~le-p~h-o-n-e-n-u-m~be-r~) 2. Date of Phone Contact 3. Date and 4. Informed ---------------------------------Time of Home Visit ----------------------------Consent Signed --------------------------------- Subject's: 5. Height cms 6. Weight kgms ins Fami ly IS: 10. r·1other 11 . Father 7. Age 9. 1bs a. Height b. Weight Race c. 8 Sex --- ---------------Age d. Sex e. Race 12. Siblings No. No. No. No. No. 13. Family Socioeconomic Status 14. Birth Weight 16. Management of NEC f·1edi ca 1 17. Part of Intestine Affected 15. Ges ta ti ona 1 Age _ _ _ _ __ Surgical 76 18. Duration of Hospitalization with NEC 19. Other Complicatory Persisting 20. Number of Hospitalizations Since Discharge for NEC ______ ---------------------Disease --------------------- REFERENCES 78 Agerty, H. A., Ziserman, A. J. &Shalenberger, C. L. A case of perforation of the ileum in a newborn infant with operation and recovery. Journal of Pediatrics, 1943, 22, 233. Barlow, B., Santulli, T., Heird, ~J. C., Pitt, J. Blanc, ~L A. & Schull inger, J. N. 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