Nasal cannula can achieve apneic oxygenation during emergency intubation. However, pre-procedure nasal cannula placement may be difficult in patients undergoing non-invasive positive pressure ventilation (NPPV) prior to intubation. Our objective was to compare mask leak during NPPV with versus without simultaneous application of nasal cannula. We hypothesized mask leak would be no worse with concomitant use of nasal cannula (non-inferiority design).Methods
We performed a randomized crossover non-inferiority study of healthy volunteers. We randomized subjects undergoing 60 s trials of NPPV (10 cm H2O continuous positive airway pressure) to either NPPV alone (NPPV-a) or NPPV with nasal cannula at 15 L/min (NPPV-nc). After a brief rest period, all subjects underwent the alternative intervention. The primary outcome was time averaged mask leak over 60 s (L/min). We defined a non-inferiority margin of 5 L/min.Results
We enrolled 64 subjects. Mean time-averaged mask leak was 2.2 L/min for NPPV-a versus 4.0 L/min for NPPV-nc for a difference of 1.7 L/min (one-sided 95% CI −∞ to 3.2 L/min). NPPV-a resulted in higher mean minute volume received (13.5 versus 12.2 L) and higher mean respiratory rates (14.8 versus 13.5 breaths per minute).Conclusion
The addition of nasal cannula during NPPV does not significantly increase mask leak. The simultaneous application of nasal cannula with NPPV may be a useful strategy to streamline airway management among patients undergoing NPPV prior to intubation.