Comparison of NaPSflex and standard nasal cannula during sedation for gastrointestinal endoscopy in obese patients: a randomized cohort trial

Background: Obese patients (BMI ≥30 kg/m 2 ) are at high risk of hypoxemia during sedated endoscopy due to tongue fallback compromising airway patency. Standard nasal cannulas fail to prevent pharyngeal collapse, raising serious safety concerns. This trial evaluated the efficacy and safety of a novel Nasal Pharyngeal Set-flexible (NaPS flex ) for oxygenation maintenance. Methods: In this prospective, randomized controlled trial, obese patients scheduled for propofol-sedated gastrointestinal endoscopy were randomly assigned to receive oxygen via either the NaPS flex or the standard nasal cannula. The primary outcome was the incidence of hypoxemia (SpO₂ ≤ 92%). Secondary outcomes included the incidence of moderate (SpO₂ ≤ 90%) and severe (SpO₂ ≤ 85%) hypoxemia, the need for airway interventions, satisfaction scores from endoscopists, anesthesiologists, and patients, as well as the incidence of sedation-related adverse events. Results: A total of 122 patients were enrolled. Compared with the standard nasal cannula group, the NaPS flex group showed a significantly lower incidence of hypoxemia (11.7% vs. 32.3%, P = 0.006) and moderate hypoxemia events (5.0% vs. 22.6%, P = 0.005). No cases of severe hypoxemia occurred in the NaPS flex group, whereas the standard nasal cannula group reported a 6.5% incidence ( P = 0.045). Conclusion: Compared to the standard nasal cannula, the NaPS flex device more effectively maintains oxygenation stability during sedation for painless gastrointestinal endoscopy in obese patients, reduces hypoxemia and the need for airway interventions, and demonstrates promising clinical utility.