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

ABSTRACT Background Cardiac arrest is a critical event requiring adequate and timely response in order to increase patient’s chance of survival. In patients mechanically ventilated with advance airways cardiopulmonary resuscitation (CPR) maneuver may be simplified by keeping the ventilator on. This work assessed the response of a 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/minute, positive end-expiratory pressure of 0 cmH2O, FiO2 of 1.0, target tidal volume of 600 ml and trigger level of -20 cmH2O. Airway opening pressure and ventilatory flow signals were continuously recorded.. Results Chest compression resulted in increased airway peak pressure in all ventilation modes (p<0.001), specially 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 (∼60 cmH 2 O). In pressure controlled modes tidal/minute volumes decreased (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/minute volumes were not significant (p=0.140). Respiratory rates were constant with and without chest compression. Conclusions A intensive care mechanical ventilator could provide adequate ventilation during compressions in a manikin model while using conventional ventilation modes.