Associations between Clinicopathological Characteristics and Intraoperative Opioid Requirements during Endoscopic Submucosal Dissection with Monitored Anesthesia Care: A Retrospective Study.

Background and study aims: Endoscopic submucosal dissection is used to treat early gastric neoplasms. Compared with other endoscopic procedures, it requires higher doses of opioids, leading to adverse events during monitored anesthesia care. We investigated the correlations between clinicopathological characteristics and intraprocedural opioid requirements in patients who underwent endoscopic submucosal dissection under monitored anesthesia care. Patients and methods: The medical records of patients who underwent endoscopic submucosal dissection under monitored anesthesia care were retrospectively reviewed. The dependent variable was the total dose of fentanyl administered during the dissection, while independent variables were patient demographics, the American Society of Anesthesiologists physical status classification, preoperative vital sign data, and the pathological characteristics of the neoplasm. Correlations between variables were examined using multiple regression analysis. Results: The study included 743 patients. The median total fentanyl dose was 100 mcg. Younger age (coefficient -1.37; 95% confidence interval [CI] -1.78 to -0.95), male sex (16.12; 95% CI 6.99-25.24), baseline diastolic blood pressure (0.44; 95% CI 0.04-0.85), neoplasm length (1.63; 95% CI 0.90-2.36), and fibrosis (28.59; 95% CI 17.77-39.42) were positively correlated with the total fentanyl dose. Total fentanyl dose was higher in the differentiated (16.37; 95% CI 6.40-26.35) and undifferentiated cancers group (32.53; 95% CI 16.95-48.11) than in the dysplasia group; no significant differences were observed among the others. The mid-anterior wall (22.69; 95% CI 1.25-44.13), mid-posterior wall (29.65; 95% CI 14.39-44.91), mid-greater curvature (28.77; 95% CI 8.56-48.98), and upper groups (30.06; 95% CI 5.01-55.12) had higher total fentanyl doses than the lower group, whereas doses did not significantly differ for the mid-lesser curvature group. Conclusions: We identified variables that influenced opioid requirements during monitored anesthesia care for endoscopic submucosal dissection. These may help predict the needed opioid doses and identify factors affecting intraprocedural opioid requirements.