Purpose: Recent reports on the use of in-hospital cardiopulmonary resuscitation (CPR) have failed to provide an applicable method to identify patients who have little chance of surviving CPR. We prospectively evaluated the clinical characteristics and outcome of 140 consecutive hospitalized patients who had cardiopulmonary arrest and received CPR, and we propose a method for predicting survival in this setting.
Patients and methods: The study period was July 1 through December 31, 1985, and the patient population consisted of 91 men and 49 women (age range, 18 to 92 years). We devised a multifactorial scoring system, the Pre-Arrest Morbidity (PAM) Index, to evaluate pre-arrest morbidity in individual patients.
Results: Seventy-seven (55%) of these patients were successfully resuscitated, 34 (24.3%) were discharged from the hospital alive, and 29 (20.7%) were long-term survivors (alive three months after discharge). Multivariate analysis of pre-arrest clinical variables demonstrated a significant association with mortality for hypotension, azotemia, and age 65 years or older, although none of these factors was absolutely predictive of a fatal outcome. The PAM Index was found to correlate inversely with the frequency of successful resuscitation, and the probability of short-term and long-term survival after CPR. Patients with PAM scores of 7 or greater had an extremely low likelihood of long-term survival (less than 15%), and no patient with a score of more than 8 survived to discharge. When the PAM score was considered in multivariate analysis of pre-arrest variables, it became the only significant independent predictor of mortality.
Conclusion: The PAM Index may be useful in identifying patients in whom CPR may be ineffective.