Related Experiment Video
Updated: Aug 19, 2026

Normothermic Negative Pressure Ventilation Ex Situ Lung Perfusion: Evaluation of Lung Function and Metabolism
Published on: February 14, 2022
Peak pressures during manual ventilation
Mohamed Turki1, Michael P Young, Scott S Wagers
1Vermont Lung Center, Fletcher Allen Health Care, University of Vermont, College of Medicine, Burlington 05405-0075, USA.
Introduction:
Manual (bag) ventilation sometimes achieves better oxygenation than does a mechanical ventilator. We speculated that clinicians might generate very high airway pressure during manual ventilation (much higher than the pressure delivered by a mechanical ventilator), and that the high airway pressure causes alveolar recruitment and thus improves oxygenation. Such high pressure might injure alveoli in some patients.
Methods:
We tested the hypothesis that manual ventilation may involve substantially higher pressure than is delivered by a mechanical ventilator. We asked experienced respiratory therapists to manually ventilate a lung model that was set to represent several typical clinical scenarios.
Results:
We found that the peak airway pressure generated by the therapists was sometimes in excess of 100 cm H(2)O.
Conclusions:
The high airway pressure during manual ventilation would be considered extreme in the context of conventional mechanical ventilation, which raises questions about whether manual ventilation causes barotrauma.
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