Crit Care Med. 2019 Mar;47(3):e222-e226

# Six Hours of Manual Ventilation With a Bag-Valve-Mask Device Is Feasible and Clinically Consistent.

Halpern P, Dang T, Epstein Y, Van Stijn-Bringas Dimitriades D, Koenig K

OBJECTIVES: Manual ventilation of intubated patients is a common intervention. It requires skill as well as physical effort and is typically restricted to brief periods. Prolonged manual ventilation may be unavoidable in some scenarios, for example, extreme mass casualty incidents. The present study tested whether nurses are capable of appropriately manually ventilating patients for 6 hours.

DESIGN: Volunteers performed ventilation on an electronic simulator for 6 hours while their own cardiorespiratory variables and the quality of the delivered ventilation were measured and recorded. The volunteers scored their perceived level of effort on a standard Borg Scale.

SETTING: Research laboratory at the Emergency Department, Tel Aviv Medical Center.

SUBJECTS: Ten nursing staff members of the Tel Aviv Sourasky Medical Center, 25-43 years old.

INTERVENTIONS: Volunteers ventilated manually a lung simulator for 6 hours.

MEASUREMENTS AND MAIN RESULTS: The subjects' physiologic states, including blood pressure, heart rate, respiratory rate, and oxygen saturation, showed no significant changes over time. The quality of delivered ventilation was somewhat variable, but it was stable on the average: average tidal volume ranged between 524.8 and 607.0 mL (p = 0.33). There was a slight but significant increase (7.3-10.9 L/min [p = 0.048]) in minute volume throughout the test period, reaching values consistent with mild hyperventilation. The subjects scored their perceived working effort as very light to fairly light, with a nonsignificant gradual increase in the Borg score as the study progressed.

CONCLUSIONS: Manual ventilation of intubated patients can be performed continuously for 6 hours without excessive physical effort on the part of the operator. The quality of delivered ventilation was clinically adequate for all of them. There was a mild but significant trend toward hyperventilation, albeit within safe clinical levels, which was due to an increasing ventilatory rate rather than an increase in tidal volume.