Review of: Pellis T, Kette F, Lovisa D, et al. "Utility of pre-cordial thump for treatment of out of hospital cardiac arrest: A prospective study." Resuscitation. 80(1):17-23, 2009.
The authors of this study prospectively reviewed the effect, if any, of the precordial thump (PT) on out-of-hospital cardiac arrest victims in a rural system in Italy. The EMTs weren't specifically trained in the delivery of the PT, but their protocol was amended to have them deliver it upon arrival at the scene if no prior treatment had been performed or if they witnessed the patient arrest.
The authors reviewed 144 cases. The initial rhythm was ventricular fibrillation (V Fib) in 23 cases and ventricular tachycardia (V Tach) in 1 (16.7%), pulseless electrical activity (PEA) in 42 (29.2%), and asystole in 78 (54.2%). They felt the relatively low fraction of tachyarrhythmias observed here may be related to the long response time (mean less than nine minutes, which is not untypical for rural areas).
In the unwitnessed arrests, only two patients had changes in their rhythm associated with PT. One was in PEA that converted to asystole, and no return of spontaneous circulation (ROSC) was achieved. The second was in V Tach and converted to PEA without ROSC.
PT was performed three times in witnessed arrests, and all three had ROSC. In all three cases the patients developed asystole, and PT resulted in the spontaneous return of a pulse. They subsequently received pacemakers.
In no instance did the performance of PT delay the delivery of defibrillation, and the authors concluded that "PT can make a contribution to overall ROSC and survival, in particular in witnessed early asystolic cardiac arrest. PT had neither positive nor detrimental effects in non-EMS-witnessed cardiac arrests, and it was ineffective in tachyarrhythmic cardiac arrest and pulseless electrical activity."
The debate continues to rage regarding the value of the precordial thump. This study is interesting and enlightening for two reasons. First, studies have shown the maneuver generates very little electrical energy. This study confirms the amount of energy certainly isn't enough to terminate V Fib. However, there are several problems using this study alone to condemn PT. The very low number of patients in V Tach is concerning. It's far fewer than what is generally reported in most U.S. systems. This is most likely a reflection of long response times in this system. The energy required to terminate fresh V Tach is much less than V Fib, and PT continues to be employed in the cardiovascular lab. So there still may be a place for its use. If you can do it without delaying care and the arrest is relatively fresh, there may be benefit.
Second, the fact that the cases where PT worked were on patients in asystole is astounding. Not only is this a remarkable finding, but one that would have otherwise generated several case reports. Most providers have been taught that PT is only for V Fib/V Tach and that a patient who goes into asystole gets CPR, pharmacology and pacing.
I don't think this study definitively answers the question of whether to abandon PT, but it certainly raises some interesting questions about its use in witnessed arrest from asystole.