Physiological stability of the extremely low birth weight infant impact of a reduced intervention nursing caregiving environment

This study was designed to analyze the impact of a reduced-intervention nursing caregiving environment (RINCE) on the physiologic stability of extremely low birth weight (ELBW) (weighing < 1000 g) infants. The specific research hypotheses were (a) the experimental RINCE will minimize caregiver disruptions when compared to a control-bed environment; (b) physiological stability, as measured by optimal heart rate variability and reduced skin temperature variability will be superior among ELBW infants who are placed into the experimental RINCE when compared to a control-bed environment; and (c) variability in ambient temperature and ambient humidity during caregiving will be reduced in the experimental RINCE when compared to a control-bed environment. The sample consisted of 10 ELBW neonates. Infants were selected according to the selected inclusion criteria and informed consent. A small n intensive within-subject crossover design explaining the patterns of physiological stability tested the hypotheses. The independent variable was the bioinstrumented RINCE, and the dependent variables measured by continuous computer recordings were (a) heart rate/R-R interval, (b) skin temperature (abdominal and extremity), (c) dry ambient temperatures, (d) ambient relative humidity, and (e) caregiving interventions. Sampling occurred every 60 s for the first 12-24 hr of life. The frequency of caregiver disruptions and frequency and duration of caregiver interventions (minutes) were not significantly different in both environments. The mean heart rate among the 10 infants was not significantly different; however the magnitude of mean heart rate standard deviations (long-term beat to beat SD/minute) were significantly less in the RINCE. The need for body position changes was reduced by 28% in the RINCE. Mean abdominal skin temperatures outside the clinical thermal range were not found to be significantly different. Heel extremity temperatures outside the clinical thermal range were significantly increased in the control-bed environment (m = 80.8 min versus m = 21.1 min). Variability in ambient temperature and humidity were both found to be significantly superior in the RINCE. This study improved on the 'environmental mismatch' experienced by the ELBW infant by designing and analyzing the physiologic impact of a RINCE on autonomic and thermal physiologic stability.