It is estimated that over 60% of out-of-hospital cardiac arrest (OHCA) patients with a shockable rhythm are refractory to current treatment, never achieve return of spontaneous circulation, or die before they reach the hospital. Therefore, we aimed to identify whether field resuscitation time is associated with survival rate in refractory OHCA (rOHCA) with a shockable initial rhythm. This cross-sectional retrospective study extracted data of emergency medical service (EMS)-treated patients aged ≥ 15 years with OHCA of suspected cardiac etiology and shockable initial rhythm confirmed by EMS providers from the OHCA registry database of Korea. A multivariable logistic regression analysis was conducted for survival to discharge and good neurological outcomes in the scene time interval groups. The median scene time interval for the non-survival and survival to discharge patients were 16 (interquartile range (IQR) 13-21) minutes and 14 (IQR 12-16) minutes, respectively. In this study, for rOHCA patients with a shockable rhythm, continuing CPR for more than 15 min on the scene was associated with a decreased chance of survival and good neurological outcome. In particular, we found that in the patients whose transport time interval was >10 min, the longer scene time interval was negatively associated with the neurological outcome.
Keywords: out-of-hospital cardiac arrest; refractory; scene time; survival.