Effects of anesthetic nasal masks on hypoxemia in overweight/obese patients undergoing gastroscopy: a randomized controlled trial.

BACKGROUND

Overweight and obese patients are at a higher risk of hypoxemia during sedated gastroscopy due to impaired respiratory function. The aim of this study was to investigate whether an anesthetic nasal mask could have a positive outcome in preventing hypoxemia in such patients compared with a conventional nasal catheter.

METHODS

This prospective, randomized controlled trial enrolled 146 overweight/obese patients (BMI ≥ 25 kg/m) who underwent sedated gastroscopy from February 15, 2022, to December 31, 2022. Patients were randomly assigned (1:1) to receive oxygen via nasal masks or nasal cannulas using a computer-generated randomization sequence. The sample size was calculated based on an expected reduction in hypoxemia incidence from 40 to 15%, with a significance level of 0.05 and a power of 90%. Statisticians responsible for data analysis were blinded to group assignments. Both groups received standardized oxygen delivery with initial flow rates (5 L/min) to minimize procedural variability. The primary outcome was the incidence of hypoxemia (SpO ≤ 90%). Secondary outcomes included the incidence of severe hypoxemia, rescue airway interventions, and adverse events.

RESULTS

Of the 146 patients, 73 were assigned to the nasal mask group and 73 to the nasal cannula group. The incidence of hypoxemia was significantly lower in the nasal mask group (13.7%) compared with the nasal cannula group (37.0%; absolute risk reduction [ARR] = 23.3%, 95% CI 9.7-36.9%%, p = 0.002; relative risk reduction [RRR] = 63.0%). In addition, the nasal mask group required fewer rescue airway interventions, such as jaw thrusts and noninvasive ventilation. No significant differences were observed in adverse events between the two groups.

CONCLUSIONS

Nasal masks significantly reduce hypoxemia (with a 63% relative risk reduction) and the need for airway interventions during sedated gastroscopy in overweight/obese patients, without increasing adverse events. These findings support the use of nasal masks as an effective and safe airway management strategy for this patient population. Clinical trial registration number ChiCTR2100053388.