Two minutes CPR versus five cycles CPR prior to reanalysis of the cardiac rhythm: A prospective, randomized...

While the 2005 cardiopulmonary resuscitation (CPR) guidelines recommended to provide CPR for five cycles before the next cardiac rhythm check, the current 2010 guideline now recommend to provide CPR for 2 min. Our aim was to compare adherence to both targets in a simulator-based randomized trial.

119 teams, consisting of three to four physicians each, were randomized to receive a graphical display of the simplified circular adult BLS algorithm with the instruction to perform CPR for either 2 min or five cycles 30:2. Subsequently teams had to treat a simulated unwitnessed cardiac arrest. Data analysis was performed using video-recordings obtained during simulations. The primary endpoint was adherence, defined as being within ±20% of the instructed target (i.e. 96-144s in the 2 min teams and 4-6 cycles in the fivex30:2 teams).

22/62 (35%) of the "two minutes" teams and 48/57 (84%) of the "five×30:2″ teams provided CPR within a range of ± 20% of their instructed target (P<0.0001). The median time of CPR prior to rhythm check was 91s and 87s, respectively, (P=0.59) with a significant larger variance (P=0.023) in the "two minutes" group.

This randomized simulator-based trial found better adherence and less variance to an instruction to continue CPR for five cycles before the next cardiac rhythm check compared to continuing CPR for 2 min. Avoiding temporal targets whenever possible in guidelines relating to stressful events appears advisable.