Determinants and Prediction of Transport Ventilators' Oxygen Consumption

This study investigates the determinants of oxygen consumption in transport ventilators, a critical factor for patient safety, especially during long-distance transfers and in resource-limited settings. A bench study was conducted on 4 ventilators to measure oxygen consumption under various ventilation settings. The main factor influencing oxygen consumption was the bias flow, a specific flow not contributing to patient ventilation. A formula incorporating bias flow was assessed to estimate oxygen consumption. The accuracy of this formula was then compared with clinical data assessed during a long-distance air medical evacuation with mechanically ventilated patients. The high heterogeneity of oxygen consumption observed between the ventilators was mainly explained by the different levels of bias flow. The clinical experience revealed that including this parameter in the prediction may permit to improve oxygen consumption accuracy.