Over the last two weeks there has been a lot of buzz around the NEJM study on targeted temperature management in out of hospital cardiac arrest (OHCA) with return of spontaneous circulation (ROSC). This blog has been no exception. This article we’re going to discuss here addresses the care of a very different population: the patient with OHCA without ROSC in the field.
Over four years, 398,121 adults with OHCA and no ROSC in the field were prospectively entered into a database. The overall survival was dismal (1.89%) with even fewer patients having a good neurologic outcome (0.49%). Neurologic outcome was defined using the Cerebral Performance Category (CPC) scale with a CPC 1 or 2 as a good neurological outcome. Using logistic regression, the authors identified nine factors that were associated with a CPC 1 or 2 outcomes. The authors further stated that there were four critical factors predictive of a good neurological outcome in these patients: initial non-asystole rhythm; age < 65 years, EMS witnessed arrest and hospital arrival time (from call) < 24 minutes. They further broke down the outcomes by type of non-asystolic rhythm:
There are a number of interesting findings in this study. If there’s no ROSC in the field, the chance of achieving good neurologic status is minimal. Survivors were 3-4 times more likely to have a poor neurologic outcome (i.e. severe cerebral disability, coma or brain death) than a good one (1.89% vs. 0.49%). The presence of the previously mentioned four factors was associated with a higher incidence of better outcomes. In particular, a presenting rhythm of ventricular fibrillation had an adjusted OR of 9.37 for a good outcome. Additionally, this study showed, as others have in the past, that epinephrine use increased the rate of ROSC but did not increase the rate of good neurological outcomes (see also Stiell 2004, Hagihara 2012).
How does this change what we do? We’ve all been working when EMS brings in an unwtinessed arrest patient that never had ROSC. The entire ED team mobilizes to care for this patient even though we know the potential for a good outcome is miniscule. This study provides preliminary information on which patients are more likely to have a good neurologic outcome. It should be the basis of further studies looking at protocols to stop resuscitation in the field and avoid transport to the hospital.
References
Goto Y, Maeda T, Nakatsu-Goto, Y. Neurological outcomes in patients transported to hospital without prehospital return of spontaneous circulation after cardiac arrest. Critical Care 2013; 17:R274 doi: 10.1186/cc13121 [Open Access]
Stiell IG et al. ACLS in OHCA. NEJM 2004; 351: 647-56.
Hagihara A et al. Prehospital Epinephrine Use and Survival Among Patients with OHCA. JAMA 2012; 307(11): 1161-68