A Controlled Study in CPR—Survival in Propensity Score Matched Full-Code and Do-Not-Resuscitate ICU Patients

Abstract

Background Cardiopulmonary Resuscitation (CPR) causes significant injuries and increased cost among transiently resuscitated patients that do not survive their hospitalizations. Descriptive studies show zero and near-zero percent survival for CPR recipients with high Apache II scores. Despite these factors, no controlled studies exist in CPR to guide patient selection for CPR candidacy. Our objective was therefore to perform a controlled study in CPR to inform recommendations for CPR candidacy. We hypothesize that the protective effects of CPR decrease as illness severity increases, and that Full-Code status provides no survival benefit over Do-Not-Resuscitate (DNR) status for patients with the highest predicted mortality by Apache IV score. Methods We performed propensity-score matched survival analyses between Full-Code and DNR patients after stratifying by predicted mortality quartiles using Apache IV scores. Primary outcomes were mortality hazard ratios. Secondary outcomes were Median Survival Differences, ICU LOS, and tracheostomy rates. Results Among 17,710 propensity-score matched ICU encounters, DNR status was associated with greater mortality in the first through third predicted mortality quartiles. There was no difference in survival outcomes in the fourth quartile (HR 0.99, p = .96). There was a stepwise decrease in the mortality hazard ratio for DNR patients as quartiles increased. Conclusion Full-Code status provides no survival benefit over DNR status in individuals with greater than 75% predicted mortality by Apache IV score. There is a stepwise decrease in survival benefit for Full-Code patients as predicted mortality increases. We propose that it is reasonable to consider a very high predicted mortality by Apache IV score a contraindication to CPR given the lack of survival benefit seen in these patients. Larger studies with similar methods should be performed to reinforce or refute these findings.