Automatic Mechanical Ventilation versus Manual Bag Ventilation during Cardiopulmonary Resuscitation: A Pilot Randomized Controlled Trial.

BACKGROUND: There is insufficient evidence supporting that mechanical ventilation can replace the manual ventilation method during cardiopulmonary resuscitation (CPR).

RESEARCH QUESTION: Is using automatic mechanical ventilation feasible and comparable to the manual ventilation method during CPR?

STUDY DESIGN AND METHODS: This is a pilot randomized controlled trial comparing automatic mechanical ventilator (MV) and manual bag ventilation (BV) during CPR of out-of-hospital cardiac arrest (OHCA). Patients with medical OHCA arriving at the emergency department were randomly assigned to two groups: an MV group using a mechanical ventilator and a BV group using Ambu-bag. Primary outcome was any return-of-spontaneous circulation (ROSC). Secondary outcomes were changes of arterial blood gas analysis results during CPR. Tidal volume, minute volume, and peak airway pressure were also analyzed.

RESULTS: A total of 60 patients were enrolled and 30 patients were randomly assigned to each group. There were no statistically significant differences in basic characteristics of OHCA patients between the two groups. The rate of any ROSC was 56.7% in the MV group and 43.3% in the BV group, showing no significant (p = 0.439) difference between the two groups. There were no statistically significant differences in changes of PH, PCO2, PO2, HCO3, or lactate level during CPR between the two groups either (p-value: 0.798, 0.249, 0.515, 0.876. and 0.878, respectively). Significantly lower TV (p < 0.001) and minute volume (p = 0.009) were found in the MV group.

INTERPRETATION: In this pilot trial, the use of MV instead of BV during CPR was feasible and could serve as a viable alternative. A multicenter RCT is needed to create sufficient evidence for ventilation guideline during CPR.