Clinical efficacy of high-flow nasal oxygen in patients undergoing ERCP under sedation.

Hypoxemia can occur during endoscopic retrograde cholangiography (ERCP) and it is difficult to achieve adequate ventilation with the prone position. High-flow nasal oxygen (HFNO) has been recommended to be more effectively help ventilation than conventional low flow oxygen. The aim of this study was to evaluate the effect of HFNO during sedated ERCP and to identify predictors of desaturation during ERCP. The investigated variables were age, gender, American Society of Anesthesiologists classes (ASA), duration of exam, and sedative used for midazolam or/and propofol of 262 patients with sedated ERCP. The differences between categorical and continuous variables were analyzed using the Student's t test and the chi-square test. Desaturation (SpO2 ≤ 90%) occurred in 9(3.4%) patients among 262 patients during sedated ERCP. The variables found to predict desaturation were older age (p < 0.01), higher sedation dose for midazolam or propofol (p < 0.01), and use of midazolam (p < 0.01). Desaturation rate was lower during sedated ERCP with HFNO compared to the preliminary study with conventional low flow nasal oxygen. Patients with older age, higher sedation dose, or the use of midazolam might require close monitoring for desaturation and hypoventilation by nursing staff. The study shows the use of high-flow nasal oxygen reduces the incidence of desaturation during ERCP.