# Effect of supraglottic endotracheal tube inserted transorally on preventing hypoxemia in obese patients undergoing sedated bidirectional endoscopy: a prospective randomized controlled clinical trial

## TL;DR

A transorally inserted supraglottic endotracheal tube reduces hypoxemia in obese patients during sedated endoscopy compared to a nasopharyngeal airway.

## Contribution

Demonstrates that a modified oropharyngeal airway using an endotracheal tube improves oxygenation in obese patients undergoing sedated endoscopy.

## Key findings

- The oropharyngeal airway group had a significantly lower incidence of hypoxemia (4.1%) compared to the nasopharyngeal group (14.6%).
- Severe hypoxemia occurred in six patients in the nasopharyngeal group but none in the oropharyngeal group.
- Anesthesiologists and endoscopists reported higher satisfaction with the oropharyngeal airway.

## Abstract

Prevention of hypoxemia in obese patients undergoing sedated gastroscopy is challenging, mainly due to upper airway obstruction. This study used a transorally inserted supraglottic endotracheal tube as an oropharyngeal airway to improve ventilation during sedated bidirectional endoscopy (esophagogastroduodenoscopy followed by colonoscopy) in patients with obesity.

Patients with mild-to-moderate obesity (body mass index: 30–39.9 kg/m2) underwent bidirectional endoscopy during deep sedation and received supplemental oxygen via a modified oropharyngeal airway using an endotracheal tube (ETT-OA) (n = 97) or a nasopharyngeal airway (n = 96). An endotracheal tube was inserted through the side port of the endoscopic bite block into the supraglottic area under gastroscopic guidance. The primary outcomes were the incidence of hypoxemia and severe hypoxemia.

The minimum SpO2 was comparable between the two groups. The incidence of hypoxemia was significantly lower in the oropharyngeal airway group than in the nasopharyngeal airway group (4.1% vs. 14.6%, P = 0.012). Severe hypoxemia occurred in six patients in the nasopharyngeal airway group but not in the other group (P = 0.037). The distal end of the nasopharyngeal airway was not inserted into the supraglottic area in eight patients because the tube was short and could not be replaced with a larger-sized tube due to rhinostenosis. Epistaxis occurred in 12 (12.5%) patients in the nasopharyngeal airway group. Anesthesiologists and endoscopists were more satisfied with the oropharyngeal airway.

An ETT-OA reduced the incidence of hypoxemia, especially severe hypoxemia, in patients with mild-to-moderate obesity during sedated bidirectional endoscopy compared with a nasopharyngeal airway.

Chinese Clinical Trial Registry (ChiCTR2200064417), first registered on 07/10/2022.