Peak pressures during manual ventilation.
BACKGROUND
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.
Turki
Mohamed
M
Vermont Lung Center, Fletcher Allen Health Care, University of Vermont, College of Medicine, Burlington 05405-0075, USA.
Young
Michael P
MP
Wagers
Scott S
SS
Bates
Jason H T
JH
D000403:Airway Resistance; D005260:Female; D006801:Humans; D008170:Lung Compliance; D008297:Male; D008954:Models, Biological; D011312:Pressure; D012123:Pulmonary Ventilation; D012119:Respiration; D012138:Respiratory Therapy / Q000379:methods*; D012737:Sex Factors; D013990:Tidal Volume