Comparison of an Oxygen-Powered Flow-Limited Resuscitator to Manual Ventilation With an Adult 1,000-mL Self-Inflating Bag

BACKGROUND: Positive-pressure ventilation of patients with unprotected airways during cardiopulmonary resuscitation can cause gastric dilation.

OBJECTIVE: Determine if there is a significant difference in volume delivered to lungs and stomach while using an adult 1,000-mL disposable bag-valve-mask (BVM) device and the oxygen-powered, flow-limited Oxylator EMX resuscitator.

METHODS: We used a bench model to simulate a patient with an unprotected airway, consisting of an intubation manikin, lung analog, and simulated lower esophageal sphincter set at an opening pressure of 20 cm H₂O. The BVM and the Oxylator were used to provide mask ventilation at a verbally prompted rate of 12 breaths/min.

RESULTS: The volumes delivered with the BVM and the Oxylator to the lungs and stomach were not significantly different: 262 ± 112 mL versus 297 ± 99 mL and 227 ± 199 mL versus 159 ± 73 mL, respectively.

CONCLUSION: Our study found no significant difference between the Oxylator and BVM when comparing tidal volume delivered to lungs and stomach during ventilation of a simulated unconscious nonintubated patient. More research on BVM use and the Oxylator should be done to validate the American Heart Association's guideline recommendations for ventilating unconscious patients with unprotected airways. Research on gastric dilation during cardiopulmonary resuscitation needs to be done with bench models using manikins that simulate chest excursion, bidirectional airway flow, lung impedance, and gastric compliance.