Ventilation during chest compressions can lead to an increase in peak inspiratory pressure. High inspiratory pressure can raise the risk of injury to the respiratory system and make it challenging to deliver the required tidal volume. The utilization of mechanical devices for chest compression has exacerbated this challenge. The aim of this narrative review was to summarize the different mechanical ventilation strategies applied during mechanical cardiopulmonary resuscitation (CPR). To this end, we searched the PubMed and BioMed Central databases from inception to January 2020, using the search terms "mechanical ventilation," "cardiac arrest," "cardiopulmonary resuscitation," "mechanical cardiopulmonary resuscitation," and their related terms. We included all studies (human clinical or animal-based research studies, as well as studies using simulation models) to explore the various ventilation settings during mechanical CPR. We identified 842 relevant articles on PubMed and 397 on BioMed Central; a total of 38 papers were judged to be specifically related to the subject of this review. Of this sample, 17 studies were conducted on animal models, 6 considered a simulated scenario, 13 were clinical studies (5 of which were retrospective), and 2 studies constituted literature review articles. The main finding arising from the assessment of these publications is that a high FIO2 must be guaranteed during CPR. Low-grade evidence suggests turning off inspiratory triggering and applying PEEP ≥ 5 cm H2O. The analysis also revealed that many uncertainties persist regarding the ideal choice of ventilation mode, tidal volume, the ventilation rate setting, and the inspiratory:expiratory ratio. None of the current international guidelines indicate the "best" mechanical ventilation strategy to apply during mechanical CPR. We propose an operating algorithm worthy of future discussion and study. Future studies specifically addressing the topics covered in this review are required.
