Active compression-decompression cardiopulmonary resuscitation in standing position over the patient (ACD-S), kneeling beside the patient (ACD-B), and standard CPR: comparison of physiological and efficacy parameters.

The purpose of this investigation was to compare the efficacy of three different cardiopulmonary resuscitation techniques: (a) standard cardiopulmonary resuscitation (CPR), (b) active compression-decompression cardiopulmonary resuscitation (ACD-CPR) with the rescuer standing beside the patient (ACD-B), and (c) ACD-CPR with the rescuer in a standing position over the patient (ACD-S). The physiological responses of the rescuers when performing these techniques were also evaluated. A total of 14 experienced professional rescuers of a mobile intensive care unit (32+/-6 years), participated in this investigation. On 3 different days (randomised order), each of them performed on a manikin (a) CPR, (b) ACD-B, and (c) ACD-S. Parameters indicative of both CPR performance (time to exhaustion, compression depth and efficacy), and rescuers' physiological responses (blood lactate; minute ventilation (VE); heart rate (HR); oxygen uptake VO2; respiratory exchange rate (RER); and percentage of VO2max) were monitored during the trials. The main findings of this investigation were: (a) the evidence of a greater physiological load for the rescuers during the ACD-CPR techniques compared to CPR, which caused a longer performance time with CPR as compared to ACD-CPR; (b) the overall absence of physiological differences between ACD-B and ACD-S; and (c) a modest decrease in mechanical efficacy for ACD-S when compared to ACD-B.