Background: Patients who achieve a return of spontaneous circulation (ROSC) with prolonged cardiac arrest have been recognized to have a poor prognosis. This might lead to reluctance in the provision of post-resuscitation care. Hence, we evaluated the impact of cardiac arrest time on neurologic outcomes in out-of-hospital cardiac arrest (OHCA) patients. Methods: This cross-sectional study used a hospital-based nationwide registry of OHCAs in Korea between 2012 and 2016. All witnessed OHCA patients aged ≥ 15 years and treated with targeted temperature management were included. We collected the time from collapse to sustained ROSC, which was defined as the downtime. The primary outcome was a favorable neurological outcome at hospital discharge. A multiple logistic regression analysis was conducted to determine independent factors for primary outcome in patients with downtime > 30 minutes. Results: Overall, neurologically favorable outcome rates were 30.5% in 1,963 patients. When the downtime was stratified into categories of 0-10, 11-20, 21-30, 31-40, 41-50, 51-60, and > 60 minutes according to 10-minute intervals, neurologically favorable outcome rates were 58.

This study compared the effects of extracorporeal cardiopulmonary resuscitation (ECPR) using propensity-score matching (PSM) analyses. A nationwide registry of out-of-hospital cardiac arrest (OHCA) patients in Korea between 2013 and 2016 was used. Patients with OHCA aged ≥15 years with cardiac etiology and resuscitation time >30 minutes were enrolled. Resuscitation-related variables before the initiation of ECPR were included. Two PSM analyses were performed separately, with and without post-ECPR variables. The primary outcome (PO) was a favorable neurologic outcome at hospital discharge. The rate of PO was 8.1% (13/161) in the ECPR group and 1.5% (247/16,489) in the conventional CPR (CCPR) group. In the matched cohort with post-ECPR variables, there was no significant difference in the rate of PO between the ECPR and CCPR groups (7.9% vs. 7.9%; p = 0.982). In the matched cohort without post-ECPR variables, the rate of PO was higher in the ECPR group than that in the CCPR group (8.3% vs. 3.6%; p = 0.012). PSM analysis without post-ECPR variables compared outcomes of all patients experiencing OHCA and treated with ECPR versus CCPR, which showed better neurologic outcomes for ECPR. PSM analysis with post-ECPR variables compared outcomes between ECPR survivors and CCPR survivors, which exhibited similar neurologic outcomes.

Out-of-hospital cardiac arrest (OHCA) is a global public health problem. 1 In patients who are resuscitated from OHCA, hypoxic brain injury is an important cause of morbidity and mortality. [2][3][4] Targeted temperature management (TTM) ameliorates hypoxic brain damage after OHCA. 5,6 Currently, TTM is the standard treatment for postresuscitated patients. However, it is unclear whether the cooling time (CT) in TTM is a time-sensitive issue. Several studies have shown that early achievement of the target temperature is associated with a favorable neurological prognosis. 7-10 However, other studies have found that reaching the target temperature too quickly increases mortality. [11][12][13] In a recent study comparing targeted hypothermia at 33°C and targeted normothermia at 37.5°C, there was no significant difference