Can width of lower tongue base preoperative sonography measurements predict hypoxemia during esophagogastroduodenoscopy under sedation?

Background: The most common complication during esophagogastroduodenoscopy (EGD) under sedation is a decrease in pulse oxygen saturation (SpO 2 ) and even the development of hypoxemia. The width of the lower tongue base measured by ultrasound is considered to be a significant predictor of the presence and severity of obstructive sleep apnea syndrome (OSAS). This study aimed to observe the capability of the width of the lower tongue base measured by ultrasound to predict hypoxemia during EGD under sedation. Methods: : Adult patients undergoing EGD under sedation at our hospital after assessment in the anesthesia clinic were enrolled in the study. The width of the lower tongue base was measured as the distance between the lingual arteries (DLA) on both sides of the inferior lateral margin of the tongue by ultrasound. Beside weight and height were recorded. The primary outcome was hypoxemia defined as the SpO2 < 90% at any time during EGD under sedation. Results: : A total of 304 patients were successfully included, and hypoxemia was reported in 32 patients. The DLA prediction criterion for hypoxemia was ＞31 mm. The DLA was correlated with hypoxemia (Spearman correlation coefficient, 0.455; P <0.001) and owned the highest area under the receiver operating characteristic curve (0.927; 99% CI, 0.891 to 0.953, compared with that of the other predictors, P < 0.001) with hypoxemia. Conclusions: : The width of the lower tongue base, measured as the DLA by ultrasound examination can be used to predict the risk of hypoxemia during EGD under sedation effectively. In addition, compared with BMI, DLA measured by ultrasound examination exhibits improved predictive capabilities. Trial registration: ChiCTR, ChiCTR2000032940, 16/05/2020. https://www.chictr.org.cn/index.aspx