Today we read and discussed a landmark article on preoxygenation:
Weingart SD, Levitan RM. 2012. Preoxygenation and prevention of desaturation during emergency airway management. Ann Emerg Med. 59(3):165-75.e1.
Take home points:
- Preoxygenation increases length of time for “safe apnea” (SpO2 >88-90%)
- Positioning is important- use 20-degree head-up or reverse Trendelenberg during preoxygenation; position patient’s head to maximize upper airway latency with external auditory meatus aligned with sternal notch (using padding under head and upper shoulders), then use jaw thrust or chin lift
- Recommended choice of modality for preoxygenation depends on patient’s risk:
- Low risk (SpO2 96-100%): Use non-rebreather at maximal oxygen flow for 3 minutes
- High risk (SpO2 91-95%): Use non-rebreather mask or CPAP or bag-valve-mask with PEEP for 3 minutes
- Hypoxemic (SpO2 <91%): Use CPAP or bag-valve-mask with PEEP for 3 minutes
- Apneic oxygenation using nasal cannula at 15 L/min can extend duration of “safe apnea”
