Atropine sulfate for patients with out-of-hospital cardiac arrest due to asystole and pulseless electrical activity

Background: The 2005 guidelines for cardiopulmonary resuscitation (CPR) have recommended that administration of atropine can be considered for non-shockable rhythm, but there are insufficient data in humans. Methods and Results: The effects of atropine were assessed in 7,448 adults with non-shockable rhythm from the SOS-KANTO study. The primary endpoint was a 30-day favorable neurological outcome after cardiac arrest. In the 6,419 adults with asystole, the epinephrine with atropine group (n=1,378) had a significantly higher return of spontaneous circulation (ROSC) rate than the epinephrine alone group (n=5,048) with an adjusted odds ratio of 1.6 (95% confidence interval (CI) 1.4-1.7, P<0.0001), but the 2 groups had similar 30-day favorable neurological outcome with an adjusted odds ratio of 0.6 (95%CI 0.2-1.7; P=0.37). In the 1,029 adults with pulseless electrical activity (PEA), the 2 groups had similar rates of ROSC and 30-day favorable neurological outcome, and the epinephrine with atropine group had a significantly lower 30-day survival rate than the epinephrine alone group with an adjusted odds ratio of 0.4 (95%CI 0.2-0.9, P=0.016). Conclusions: Administration of atropine had no long-term neurological benefit in adults with out-of-hospital cardiac arrest due to non-shockable rhythm. Atropine is not useful for adults with PEA.