The quality of chest compressions by trained personnel: the effect of feedback, via the CPREzy, in a randomized controlled trial using a manikin model.

Even after training, the ability to perform effective cardiac compressions has been found to be poor and to decrease rapidly. We assessed this ability with and without a non-invasive feedback device, the CPREzy, during a 270s CPR session in an unannounced, single-blinded manikin study using 224 hospital employees and staff chosen at random and using a non-cross over design. The two groups self-assessed their knowledge and skills as adequate. However, the control group (N=111) had significantly more difficulty in delivering chest compressions deeper than 4 cm (25 versus 1 candidate in the CPREzy group), P=0.0001. The control group compressed ineffectively in 36% (+/-41%) of all compressions as opposed to 6+/-13% in the CPREzy group (N=112, P=0.0001). If compressions were effective initially, the time until >50% of compressions were less than 4 cm deep was 75+/-81s in the control group versus 194+/-87 s in the CPREzy group (P=0.0001 [-180 to -57.5]). After a few seconds of training in its use, our candidates used the CPREzy effectively. Against the background knowledge that estimation of compression depth by the rescuer or other team members is difficult, and that performing effective compressions is the cornerstone of any resuscitation attempt, our data suggests that a feedback device such as the CPREzy should be used consistently during resuscitation.