NEW YORK (Reuters Health) – New research suggests that the time it takes for an ambulance to transport a cardiac arrest patient from the field to the hospital has no significant effect on survival.

Therefore, the researchers speculate, it might be better to bypass a nearby local hospital in favor of bringing the patient to a specialized cardiac arrest center.

Prior research has shown that the care delivered at the scene of a cardiac arrest can affect outcomes. The impact of the transport time following scene interventions, however, was unclear, according to the report in the Annals of Emergency Medicine for August.

To investigate, Dr. Daniel W. Spaite, from The University of Arizona, Tucson, and colleagues analyzed data from the Ontario Prehospital Advanced Life Support (OPALS) study, which was conducted from 1991 to 2002 and featured cardiac arrest patients from 21 communities. Included in the current analysis were 15,559 patients with complete data.

Overall, 14.8% of patients had return of spontaneous circulation and 4.4% survived to hospital discharge, Dr. Spaite’s team reports. For survivors, the median transport interval was 4.0 minutes, not significantly different from the 4.2 minutes seen in non-survivors.

On regression analysis, several independent predictors of survival were identified. These included witnessed arrest, bystander CPR, initial rhythm of ventricular fibrillation/tachycardia, and shorter emergency medical services response interval, which increased the odds of survival by 2.61-, 2.22-, 2.22-, and 1.26-fold, respectively.

By contrast, the hospital transport interval did not affect survival, a finding seen in the group as a whole and in members of the subgroup who had a return of spontaneous circulation.

“Given the growing evidence showing major effect from specialized postarrest care, these findings support conducting clinical trials that assess the effectiveness and safety of bypassing local hospitals to take patients to regional cardiac arrest centers,” Dr. Spaite’s team concludes.

An accompanying editorial suggests that the transport interval may not matter, provided that the times are fairly short, as in the present study.

The current research “suggests that longer durations of transport for patients may be safe when transport intervals are relatively short,” Dr. Jon C. Rittenberger and Dr. Clifton W. Callaway, from the University of Pittsburgh, write. “However, the risk of deterioration during the prolonged transports that may be required to reach regional centers still warrants further investigation.”

Reference:
Ann Emerg Med 2009;54:248-255.