Transnasal Humidified Rapid-Insufflation Ventilatory Exchange versus Oropharyngeal Airway-Assisted Face-Mask Ventilation for Gastric Insufflation During Induction of General Anesthesia in Patients at High Risk for Obstructive Sleep Apnea.

Abstract

Purpose: Obstructive sleep apnea (OSA) is an independent risk factor for gastric insufflation during the induction of general anesthesia. We aimed to compare the impact of oropharyngeal airway-assisted face-mask ventilation and transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) on gastric insufflation in patients with high-risk OSA.

Patients and methods: Patients at high risk for OSA scheduled for elective major abdominal surgery under general anesthesia were randomized 1:1 to either Group T (THRIVE throughout induction) or Group M (face-mask preoxygenation followed by oropharyngeal airway-assisted pressure-controlled ventilation). Gastric antrum ultrasonography was performed at baseline (T₁), after preoxygenation (T₂), and post-intubation (T₄) to assess changes of antral cross-sectional area (CSAa). Arterial blood gases were analyzed at T₁, T₂, after induction during ventilation/apnea (T₃), and T₄. Adverse events and patient comfort were recorded. The primary outcome was the incidence of gastric insufflation at T₄. Secondary outcomes included CSAa percentage change, oxygenation and arterial blood gas variables, adverse events, and patient comfort.

Results: Of 100 randomized patients, 94 completed the study (47 per group). Group T demonstrated a significantly lower incidence of gastric insufflation post-intubation compared to Group M (23.4% vs 44.7%; P = 0.030) and a smaller median percentage increase in antral cross-sectional area (7.62% vs 13.24%; P = 0.070). THRIVE provided superior preoxygenation (higher PaO₂ at T₂, P < 0.001). During apnea (T₃-T₄), Group T maintained adequate oxygenation (SpO₂ >92%) without mechanical ventilation but developed mild hypercapnia, which was expected to improve following continued mechanical ventilation after intubation. Adverse event rates were non-significant (P = 1.000). Patient comfort scores were significantly higher in Group T (P < 0.001).

Conclusion: In patients at high risk for OSA, THRIVE reduces the incidence of gastric insufflation during induction compared with oropharyngeal airway-assisted face-mask ventilation. THRIVE improves preoxygenation and patient comfort. Oxygenation was maintained during apnea, with a transient increase in PaCO₂ observed after intubation.