Empirical evidence for safety of mechanical ventilation during simulated cardiopulmonary resuscitation on a physical model

Background: Cardiac arrest is a critical event requiring adequate and timely response in order to increase a patient's chance of survival. In patients mechanically ventilated with advanced airways, cardiopulmonary resus-citation (CPR) maneuver may be simplified by keeping the ventilator on. This work assessed the response of an intensive care mechanical ventilator to CPR using a patient manikin ventilated in three conventional modes. Methods: Volume-controlled (VCV), pressure-controlled (PCV) and pressure regulated volume-controlled (PRVC) ventilation were applied in a thorax physical model, with or without chest compressions. The mechanical ventilator was set with inspiratory time of 1.0 s, ventilation rate of 10 breaths/min, positive end-expiratory pres-sure of 0 cmH(2)O, FiO(2) of 1.0, target tidal volume of 600 mL and trigger level of -20 cmH(2)O. Airway opening pres-sure and ventilatory flow signals were continuously recorded. Results: Chest compression resulted in increased airway peak pressure in all ventilation modes (p < 0.001), espe-cially with VCV (137% in VCV, 83% in PCV, 80% in PRVC). However, these pressures were limited to levels similar to release valves in manual resuscitators (similar to 60 cmH(2)O). In pressure-controlled modes tidal/min volumes de-creased (PRVC = 11%, p = 0.027 and PCV = 12%, p < 0.001), while still within the variability observed during bag-valve-mask ventilation. During VCV, variation in tidal/min volumes were not significant (p = 0.140). Respi-ratory rate did not change with chest compression. Conclusions: Volume and pressure ventilation modes responded differently to chest compressions. Yet, variation in delivered volume and the measured peak pressures were within the reported for the standard bag-valve-mask system. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

This study assessed the response of mechanical ventilation to CPR, showing that different ventilation modes have slight variations in response to chest compressions, but the delivered volume and peak pressures were within the range observed during bag-valve-mask ventilation.