Prevalence and characteristics of disinhibition during bronchoscopy with midazolam

Background: Disinhibition is sometimes experienced during bronchoscopy with sedation. However, data on disinhibition during bronchoscopy are scarce. We examined the prevalence and characteristics of disinhibition during bronchoscopy with midazolam. Methods: This retrospective study analyzed consecutive patients who underwent bronchoscopy between November 2019 and December 2020. The severity of disinhibition was defined as follows: mild, disinhibition sometimes requiring restraints by assistants; moderate, disinhibition always requiring restraints by assistants; and severe, disinhibition requiring antagonization of sedation by flumazenil to continue bronchoscopy. Results: Among 251 eligible patients who were sedated using midazolam, 36 (14.3%; 95% confidence interval [CI], 10.5%-19.2%), 42 (16.7%; 95% CI, 12.6%-21.8%), and 7 (2.8%; 95% CI, 1.4%-5.6%) experienced mild, moderate, and severe disinhibition, respectively. Depression (odds ratio [OR] 2.77; 95% CI, 1.20-6.41), endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) (OR 10.23; 95% CI, 1.02-103.01, referred to brushing/bronchial washing/observation), and increased administration of midazolam (OR 1.20; 95% CI, 1.02-1.42, per 1-mg increase) were independently associated with moderate-to-severe disinhibition. Patients experiencing moderate disinhibition reported significantly better scores for discomfort during bronchoscopy. Besides the maximum systolic and diastolic blood pressures during bronchoscopy, the changes in hemodynamic and respiratory statuses during bronchoscopy or complications did not significantly differ between patients experiencing moderate-to-severe disinhibition and those experiencing none-to-mild disinhibition. Conclusions: Moderate-to-severe disinhibition occurred in 19.5% of patients during bronchoscopy with midazolam. We should focus on disinhibition when patients have depression or are planning to undergo EBUS-TBNA, and sparing the administration of midazolam might reduce the occurrence of disinhibition. Clinical trial registration: UMIN000038571 (c) 2021 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.