Effects of low-dose esketamine on hypoxemia during gastroscopy in patients with moderate-to-high risk obstructive sleep apnea: protocol for a prospective, randomized, controlled trial.

In patients at moderate-to-high risk of obstructive sleep apnea (OSA) undergoing painless gastroscopy, adding a low dose (0.25 mg/kg) of esketamine to propofol sedation may reduce dangerous oxygen drops (hypoxemia) compared to propofol alone. Esketamine, an NMDA receptor antagonist, is expected to lower the amount of propofol needed while keeping breathing more stable, and its side effects (like brief high blood pressure) should be mild. This single-center, double-blind, randomized controlled trial will enroll 294 adults with a STOP-Bang score of 3 or higher. The main outcome is the rate of hypoxemia (oxygen saturation below 90% for at least 10 seconds). The protocol aims to fill a gap in safer sedation for OSA patients.

Study at a glance

Abstract

Propofol sedation in patients with Obstructive Sleep Apnea (OSA) frequently induces hypoxemia, posing significant clinical risks. Esketamine, an N-Methyl-D-Aspartate (NMDA) receptor antagonist, may reduce propofol requirements while preserving respiratory stability, but its efficacy in OSA patients remains unproven. At the studied dose (0.25 mg/kg), esketamine's potential side effects (transient hypertension) are expected to be mild and self-limited. Therefore, we aimed to test whether low-dose esketamine (0.25 mg/kg) can reduce the incidence of hypoxemia in moderate-to-high risk OSA patients during propofol-based painless gastroscopy. This single-center, double-blind, randomized controlled superiority trial will enroll 294 patients (STOP-Bang score ≥ 3, 18-90 years, STOP-Bang = Snoring, Tiredness, Observed apnea, Pressure [blood], Body Mass Index [BMI], Age, Neck size, Gender.) undergoing gastroscopy. Participants will be randomized 1:1 to receive either esketamine (0.25 mg/kg) plus propofol or saline placebo plus propofol, stratified by age (18-65 vs. > 65 years) and OSA severity (STOP-Bang 5-6 vs. ≥ 7). The primary outcome is the incidence of hypoxemia (Peripheral Oxygen Saturation [SpO2] 10 s). Secondary outcomes include severe hypoxemia (SpO2 ≤ 75% or ≤ 90% for ≥ 60 s), duration of hypoxemia, emergency airway management, propofol consumption, hemodynamic stability, involuntary body movements, procedure/recovery times, and clinician satisfaction (measured via 10-cm Visual Analog Scale [VAS]). This protocol rigorously evaluates esketamine's potential to improve sedation safety in OSA patients, addressing a critical gap in peri-procedural care. Chinese Clinical Trial Registry (ChiCTR2500099420). Registered on March 24, 2025 (Supplementary File 2). Si-Qi Hao is a co-first author with the same contribution as the first author. The corresponding author is Li-Xin An.