Comparison of the Effectiveness of Nasal Cannula Versus Face Mask With Reservoir Bag in Postoperative Patients Undergoing General Anesthesia: A Prospective Randomized Controlled Trial.

Background: High-concentration oxygen delivery via a face mask (FM) with a reservoir bag is a common practice to prevent postoperative hypoxemia; however, it may also lead to atelectasis and other respiratory complications. Lower concentrations delivered via nasal cannula (NC) may be equally effective in preventing postoperative hypoxemia. The present study aimed to compare peripheral oxygen saturation (SpO_2) delivered via NC versus FM with a reservoir bag in patients who have undergone general anesthesia (GA).

Methods: Eighty-four patients scheduled for GA were randomized to receive either oxygen via NC (NC group, n = 42) or FM with a reservoir bag (FM group, n = 42) for 30 minutes after GA at a postanesthesia care unit (PACU). All patients were assessed based on SpO_2 value, adverse events, and patient satisfaction (measured using a 100-mm visual analog scale).

Results: The overall difference between groups in the change of SpO_2 over 30 minutes at the PACU was -0.004 (95% confidence interval, -0.015 to 0.008; P = 0.527). SpO_2 during the first five minutes was lower in NC group, but the difference was not statistically significant. No desaturation occurred in either group, and there was no observed difference between groups in terms of adverse events. Patient satisfaction scores were also similar (P = 0.612).

Conclusions: Oxygen supplementation via NC and via FM with a reservoir bag were equally effective in preventing postoperative hypoxemia after GA.