Selective Use of Positive-Pressure Ventilation for Preoxygenation During Air Medical Rapid Sequence Intubation.

Background: Preoxygenation is critical to safe performance of rapid sequence intubation (RSI). The use of positive-pressure ventilation (PPV) has been advocated during preoxygenation but may increase the risk of aspiration.

Objective: To explore the risk-benefit analysis of using PPV during air medical RSI.

Methods: We performed a retrospective analysis of the Air Methods Airway Registry using patient data from over 175 bases across the U.S. over a 5-year period. Patients were separated into normoxemic (SpO2 ≥93%) and hypoxemic (SpO2 <93%) and compared in regard to demographics, clinical data, and use of PPV. Primary outcomes were first-attempt intubation success (FAS) and FAS without desaturation (FASWD). Chi-square, t-test, and logistical regression were used to analyze the data.

Results: There were 9778 patients who underwent intubations during the study period. FAS was 92% (8966 patients). FASWD was 90% (8775 patients). Mean SpO2 was 94.9%. There were 42% (4118 patients) of patients who received PPV prior to intubation and 1% (94) aspirated during RSI. Multivariate logistical regression showed an association between use of PPV and reduced intubation success for normoxemic patients but improved intubation success for hypoxemic patients. The use of PPV was associated with higher risk of aspiration events (p = 0.007).

Conclusion: The use of PPV during preoxygenation prior to RSI appears beneficial for hypoxemic but not normoxemic patients due to lower intubation success and increased aspiration risk with PPV. This data supports selective use of PPV prior to the initial intubation attempt in patients undergoing RSI.