Feasibility of manual ventilation replacing mechanical ventilation

Abstract

BackgroundDuring the COVID-19 pandemic it is anticipated that there will be a shortage of mechanical ventilators available for patients in critical condition. This has sparked many discussions about rationing resources and withholding care; however, an alternative may be to implement manual ventilation in these situations instead. Manual ventilation and a safety device were assessed for efficacy of extended use, such as may be required during this pandemic.MethodsTo evaluate physical output characteristics of extended manual ventilation and efficacy of a barotrauma mitigation device, 47 medical students, nurses and medics completed two 1-hour manual ventilation sessions using the SmartLung 2000 Lung Simulator and 5300 Series Mass Flow Meter with a SPUR II resuscitator bag and endotracheal tube, mimicking a healthy adult with normal lung physiology, both with and without the Sotair device. Providers were randomised to complete their initial session either with or without the Sotair device.FindingsCollected data show wide variability in tidal volume and peak pressure in unmitigated manual breaths despite prior training and independent exploration of the resuscitation equipment prior to testing. The mean (±SD) tidal volume with bag only was 563.9±128.8 mL and with the safety device 536.1±80.9 mL (p<0.0001). The mean peak inspiratory pressure with bag only was 17.2±6.3 cm H2O and with the safety device 14.9±2.4 cm H2O (p<0.0001).InterpretationWhile extended manual ventilation cannot replace mechanical ventilation, it is feasible with a safety device, which may reduce barotrauma, underventilation and overventilation. These results also demonstrate that withholding care and rationing resources may not be necessary.