Letters Section Editor: Jody W. Zylke, MD, Senior Editor.
Author Affiliations: Emergency Department (Drs Carron and Hugli) (firstname.lastname@example.org), Institute of Social and Preventive Medicine (Dr Taffe), Lausanne University Hospital, Lausanne, Switzerland.
To the Editor: An association between the use of epinephrine prior to hospital arrival in patients with out-of-hospital cardiac arrest and both a decreased chance of survival and poorer long-term functional outcomes was demonstrated by Dr Hagihara and colleagues.1 We have several concerns about the statistical methods of the study.
First, their data show that the single most significant predictor of 1-month survival and good cerebral performance was the occurrence of ROSC (eTable 2 in article). The interval between the beginning of ventricular fibrillation and the occurrence of ROSC is a key predictor of these outcomes2; this time interval is not included in their analysis. Therefore, the use of epinephrine could be a surrogate marker of a more prolonged resuscitation and delayed ROSC in patients failing to respond to the initial defibrillation,3 and the time to ROSC a confounding factor for the effect of epinephrine. The time to ROSC is 1 of the core time events to be recorded in the Utstein template,4 allowing new analyses to be redone with the time from telephone call to ROSC as an additional factor.
Carron P, Taffe P, Hugli O. Use of Epinephrine for Cardiac Arrest Prior to Hospital Arrival. JAMA. 2012;308(1):29-31. doi:10.1001/jama.2012.5942