Association of transport time interval with neurologic outcome in out-of-hospital cardiac arrest patients without return of spontaneous circulation on scene and the interaction effect according to prehospital airway management

OBJECTIVE: This study analyzed the association of transport time interval (TTI) with survival rate and neurologic outcome in out-of-hospital cardiac arrest (OHCA) patients without return of spontaneous circulation (ROSC) and the interaction effect of TTI according to prehospital airway management. METHODS: A retrospective observational study based on the nationwide OHCA database from January 2013 to December 2017 was designed. Emergency medical service (EMS)-treated OHCA patients aged ≥18 years were included. TTI was categorized into four groups of quartiles (≤4, 5–7, 8–11, ≥12 minutes). The primary outcome was favorable neurologic outcome at discharge. The secondary outcome was survival to discharge from the hospital. Multivariable logistic regression was used to analyze outcomes according to TTI. A different effect of TTI according to the administration of prehospital EMS advanced airway was evaluated. RESULTS: In total, 83,470 patients were analyzed. Good neurologic recovery decreased as TTI increased (1.0% for TTI ≤4 minutes, 0.9% for TTI 5–7 minutes, 0.6% for TTI 8–11 minutes, and 0.5% for TTI ≥12 minutes; P for trend <0.05). The adjusted odds ratio of prolonged TTI (≥12 minutes) was 0.73 (95% confidence interval, 0.57–0.93; P<0.01) for good neurologic recovery. However, the negative effect of prolonged TTI on neurological outcome was insignificant when advanced airway or entotracheal intubation were performed by EMS providers (adjusted odds ratio, 1.17; 95% confidence interval, 0.42–3.29; P=0.76). CONCLUSION: EMS TTI was negatively associated with the neurologic outcome of OHCA without ROSC on scene. When advanced airway was performed on scene, TTI was insignificantly associated with the outcome.