The participants will be randomly allocated to either SJOV or HFNO in a 1:1 ratio using block randomization with variable block sizes of four or six randomized. In the HFNO group, oxygen supplementation is delivered at 35 liters min-1 with a fraction of inspired oxygen (FiO2) of 100%. In the SJOV group, SJOV is conducted using a Wei nasal jet tube (WNJ, Well Lead Medical Co. Ltd, Guangzhou, China) which is connected to a manual jet ventilator (Well Lead Medical Co. Ltd, Guangzhou, China) via its jet port. The initial settings of SJOV were as follows: driving pressure (DP) 15 psi; respiratory rate (RR) 20 bpm; inspiratory-to-expiratory (I/E) ratio 1:2, and gas supply, 100% oxygen.
This study aims to compare the effect of the use of supraglottic jet oxygenation and ventilation (SJOV) with high-flow nasal oxygen therapy (HFNO) on reducing the rate of hypoxia during gastrointestinal endoscopic procedures in deeply sedated patients at high altitudes.