Predictive value of NoSAS questionnaire combined with the modified Mallampati grade for hypoxemia during routine sedation for gastrointestinal endoscopy

BACKGROUNDː To date, there is no recognized simple method to predict hypoxemia in digestive endoscopic anesthesia, and the utility of the NoSAS questionnaire, an objective and simple assessment scale, used to assess obstructive sleep apnea (OSA), combined with the modified Mallampati grade (MMP) in screening for hypoxemia during routine sedation for gastrointestinal endoscopy. METHODSː A total of 2207 patients admitted to our hospital for painless gastrointestinal endoscopy were studied. All patients were measured for age, height, weight, body mass index, neck circumference, snoring, MMP, and other parameters. Patients were divided into hypoxemia and non-hypoxemia groups based on intraoperative oxygen saturation of less than 95% for 10 s. The ROC curve was plotted to evaluate the screening value of the NoSAS questionnaire separately and combined with MMP for hypoxemia. The total NoSAS score was evaluated at cut-off points of 8 and 9. RESULTSː With a NoSAS score ≥ 8 as the critical value for analysis, the sensitivity for hypoxemia was 58.3%, the specificity was 88.4%, and the area under the ROC was 0.734 ( P < 0.001, 95%CI:0.708–0.759). With a NoSAS score ≥ 9 as a critical value, the sensitivity for hypoxemia was 36.50%, the specificity rose to 96.16%, and the area under the ROC was 0.663 ( P < 0.001, 95% CI:0.639–0.688). With the NoSAS Score combined with the MMP for analysis, the sensitivity was 78.4%, the specificity was 84%, the area under the ROC was 0.859 ( P < 0.001, 95% CI:0.834–0.883). CONCLUSIONSː As a new screening tool, the NoSAS questionnaire is simple, convenient, and has a certain screening value for hypoxemia. Combined with the modified Mallampati grade (MMP), it can obviously improve the screening sensitivity of hypoxemia and has a higher application value.