Continuous ventilation versus 30:2 strategy in mechanical cardiopulmonary resuscitation - a manikin-based simulation study.

backgroundThere is conflicting data about which ventilation strategy is better when performing external chest compressions with mechanical devices. During manual cardiopulmonary resuscitation, continuous ventilation is recommended when the airway is secured and a ventilation rate of 10/min is maintained. However, during mechanical cardiopulmonary resuscitation, some expert groups and various data have raised concerns about ineffective ventilation with continuous ventilation due to the high intrathoracic pressure generated by the devices without pauses for effective ventilation. This study compares the two possible ventilation strategies - continuous ventilation and 30:2 (30 compressions followed by 2 ventilations) - during mechanical cardiopulmonary resuscitation. We analysed the effects of the two resuscitation strategies on ventilatory parameters measured during cardiopulmonary resuscitation and compared mechanical with manual cardiopulmonary resuscitation with both ventilation strategies.

methods30 students of human medicine performed cardiopulmonary resuscitation on endotracheally intubated resuscitation training manikins. The chest compressions were performed manually or by using mechanical chest compression devices (LUCAS®, EASY PULSE®). Tidal volume, respiratory minute ventilation volume, ventilation frequency, compression frequency, and chest compression depth were recorded by sensors built into the manikins. Cardiopulmonary resuscitation was performed with either continuous ventilation (ventilations every 6 s; 10/min) or 30:2 in two resuscitation runs of 3 min each.

resultsRespiratory minute ventilation volume was significantly higher with continuous ventilation than with 30:2 cardiopulmonary resuscitation (4.8 l/min vs. 3.1 l/min, p<.001). Tidal volume was lower with continuous ventilation than with a 30:2 cardiopulmonary resuscitation (521 ml vs. 565 ml; p = .013). There were no significant differences between manual and mechanical cardiopulmonary resuscitation with both ventilation strategies.

conclusionThis study showed that ventilation during mechanical cardiopulmonary resuscitation using mechanical chest compression devices was efficient with both ventilation strategies. Interestingly, the respiratory minute ventilation volume was even higher with continuous ventilation than with 30:2 due to the higher respiratory rate. In addition, there was no significant difference in ventilation outcome between manual and mechanical chest compressions.