Association between interval between call for ambulance and return of spontaneous circulation and survival in out-of-hospital cardiac arrest☆
Received 6 October 2005; received in revised form 2 March 2006; accepted 10 March 2006.
Summary
Aim
To describe the association between the interval between the call for ambulance and return of spontaneous circulation (ROSC) and survival in out-of-hospital cardiac arrest.
Patients
All patients suffering an out-of-hospital cardiac arrest in whom cardiopulmonary resuscitation (CPR) was started, included in the Swedish Cardiac Arrest Registry (SCAR) for whom information about the time of calling for an ambulance and the time of ROSC was available.
Results
Among 26,192 patients who were included in SCAR and were not witnessed by the ambulance crew, information about the time of call for an ambulance and the time of ROSC was available in 4847 patients (19%). There was a very strong relationship between the interval between call for an ambulance and ROSC and survival to one month. If the interval was less than or equal to 5min, 47% survived to one month. If the interval exceeded 30min, only 5% (n=35) survived to one month. The vast majority of the latter survivors had a shockable rhythm either on admission of the rescue team or at some time during resuscitation.
Conclusion
Among patients who have ROSC after an out-of-hospital cardiac arrest, there is a very strong association between the interval between the call for ambulance and ROSC and survival to one month. However, even if this delay is very long (>30min after calling for an ambulance), a small percentage will ultimately survive; they are mainly patients who at some time during resuscitation have a shockable rhythm. The overall percentage of patients for whom CPR continued for more than 30min who are alive one month later can be assumed to be extremely low.
ABSTRACT