Abstract
BACKGROUND: Hypoxemia is a common adverse event during propofol sedation for gastrointestinal endoscopy. Maintaining a sufficiently slow infusion rate is known to reduce respiratory depression caused by propofol, but achieving this consistently is challenging due to variations in manual techniques. This study evaluated the use of a narrow-bore extension tube to administer propofol, which passively slows infusion, to reduce hypoxemia during gastroscopy sedation. METHODS: A randomized controlled trial was conducted among patients undergoing propofol sedation for gastroscopy. Participants were assigned to either the narrow-bore extension tube group, which restricts infusion rates, or the control group receiving a standard-bore extension tube with unrestricted infusion rates. The primary outcome was the incidence of hypoxemia (SpO(2) < 90%), with secondary outcomes including severe hypoxemia (SpO(2) < 90% for ≥ 60 s or SpO(2) < 75%), time to achieve deep sedation, total propofol dosage, and the incidence of pain on propofol injection (POPI). Subgroup analyses by age and BMI were performed. RESULTS: The incidence of hypoxemia was significantly lower in the narrow-bore extension tube (11.7% vs. 27.0%, p = 0.001), and there was a corresponding decrease in severe hypoxemia (7.3% vs. 19.7%, p = 0.003). The median time to achieve deep sedation was longer in the narrow-bore group (70 vs. 54 s; p < 0.001). The greatest reduction in hypoxemia was observed in overweight patients (BMI 25-28 kg/m(2), p = 0.029). CONCLUSIONS: Using a narrow-bore extension tube to control propofol infusion rates significantly reduces hypoxemia during gastroscopy sedation. This cost-effective strategy is especially beneficial for higher-risk patients, such as those who are overweight. TRIAL REGISTRATION: The clinical trial was registered on Chinese Clinical Trial Register on December 16, 2024 (ChiCTR2400094042).