A Retrospective Study of ICU Readmission of Cardiothoracic Surgery Patients

Transfer from the cardiovascular intensive care unit (CVICU) to a lower level of care represents a high-risk transition. Patients who survive critical illness are likely to have complex care needs and are at risk for adverse events and poor outcomes. Readmission to the CVICU is associated with increased morbidity, mortality and hospital length of stay (LOS). Cardiothoracic (CT) surgery patients are a particularly vulnerable population for adverse events when transitioning from the CVICU to an acute care floor due to increasingly complex surgical procedures and chronic disease. A knowledge gap exists as to why readmissions occur in this patient population and what can be done to prevent their occurrence. A review of the literature to assess the current body of knowledge of ICU readmission revealed common causes, risk factors, and other variables associated with readmission in the general ICU population. For the general ICU population, readmission rates are between two and four percent. However, very few studies have focused directly on the complexities of the CT surgery patient population. The purpose of this scholarly project was to determine primary reasons for CVICU readmission of CT surgery patients, and compare characteristics to non-readmitted patients in order to guide the development of targeted interventions. Project objectives included: 1) Determine primary reasons for readmission of CT surgery patients with an unplanned readmission to the CVICU, 2) Analyze and compare risk factors to non-readmitted patients, 3) Present findings to project stakeholders and 4) Disseminate findings to a broader audience in a national peer-reviewed forum. Implementation of this project was conducted through a retrospective chart review of all CT surgery patients admitted to the CVICU at an academic hospital from March 2010 to November 2015, and were subsequently transferred to a lower level of care. A statistical analysis was done to assess the association of clinical factors with readmission. Findings, as well as a proposal for the development of targeted interventions were presented to project stakeholders. An abstract for poster presentation was also submitted to the 40th Annual Snowbird CME Conference. Primary reasons for CIVCU readmission included respiratory insufficiency (27.6%), arrhythmias (18.1%), and GI bleed (9.6%). Mortality, in-hospital events and hospital LOS were significantly increased with readmitted patients. Independent preoperative risk factors as predictors of CVICU readmission included increased age and chronic lung disease. Post-operative risk factors as predictors of CVICU readmission include pleural effusion requiring draining, pneumonia, reintubation, cardiac arrest, bleeding with return to the operating room, and GI events. Recommendations include cautious optimization of patients with known readmission risk factors prior to and following transfer from the CVICU. Interventions should be targeted toward improving respiratory status. Future research should include multivariate analysis of risk factors and the development of a CVICU readmission prediction tool or discharge protocol in a prospective study.