Critical Care/Resuscitation
Abstracts
Raoul Daoust, MD, MSc
Université de Montréal/Hôpital du Sacré-Coeur de Montréal
Disclosure Relationship(s): Nothing to disclose
Background: The initial rhythm is one of the main prognostic factors used for the selection of patients for extracorporeal resuscitation (E-CPR). However, among patients that can otherwise be considered eligible for E-CPR, the prognosis implications of converting from a non-shockable to a shockable rhythm, as compared to having an initial shockable rhythm, remains uncertain. The objective of this study was to evaluate the association between the initial rhythm and its subsequent conversion and survival following an out-of-hospital cardiac arrest (OHCA), among E-CPR candidates. It was hypothesized that such a conversion would be associated with a higher survival to discharge as compared to no conversion.
Methods: The present cohort study used a registry of adult OHCA between 2010 and 2015 in Montreal, Canada. Adult patients suffering from a non-traumatic OHCA of less than 65 years of age, for whom the initial rhythm was known, with a witnessed collapse and bystander cardiopulmonary resuscitation and without a return of spontaneous circulation after 15 minutes of prehospital resuscitation were included. The primary outcome measure was survival to hospital discharge. Univariates analyses were initially performed using Fisher’s exact test. Then, it was planned to construct a multivariable logistic regression, if appropriate.
Results: A total of 556 (male=73%, mean age = 53 years [SD 10], survival = 18%) patients were considered E-CPR candidates according to their clinical characteristics. Among these patients, 248 (27%) had an initial shockable rhythm (Survival = 37%), 175 (31%) had pulseless electrical activity (PEA) and no subsequent shockable rhythm (Survival = 4%), 26 (5%) had PEA and a subsequent shockable rhythm (Survival = 5%), 76 (14%) had asystole and no subsequent shockable rhythm (Survival = 0%), and 5 (1%) asystole and a subsequent shockable rhythm (Survival = 0%). Patients with an initial shockable rhythm had better odds of survival than patients in all other groups (p<0.001 for all comparisons). No other comparisons yielded significant results (p=0.09 to p=0.80). Given the small number of patients and events in some groups, only univariate analyses were performed.
Conclusion: The initial rhythm remains a much better outcome predictor than subsequent rhythms and should be preferred when evaluating the eligibility for advanced resuscitation procedures.