Determination of the 90% Effective Dose of Dexmedetomidine for Treating Postoperative Catheter­related Bladder Discomfort During Recovery: An Open-label, Single-group Study.

PURPOSE: Catheter-related bladder discomfort (CRBD) is an unpleasant experience for patients during postoperative recovery. Dexmedetomidine is an effective therapy for CRBD; however, little is known about dexmedetomidine administration for treating CRBD during recovery. This study was conducted to determine the 90% effective dose (ED90) of dexmedetomidine to provide adequate treatment for CRBD during recovery. DESIGN: Prospective, single-blind dose-finding study. METHODS: This open-label, single-group trial included severe postoperative CRBD patients aged 18 to 80 years and the American Society of Anesthesiologists' physical status class I or II in the postanesthesia care unit. All patients were assigned to receive intravenous dexmedetomidine. The dose of dexmedetomidine was determined using the modified Dixon's up-and-down method. The first patient was treated with 0.4 mcg/kg dexmedetomidine. An increment or decrement of 0.05 mcg/kg dexmedetomidine was used based on the response of the previous patient. A successful treatment was defined as the transition from severe CRBD to mild CRBD. Probit regression was applied to calculate the ED90 of dexmedetomidine. FINDINGS: A total of 29 patients were recruited, of whom 14 patients (48.3%) underwent successful treatment. The ED90 of dexmedetomidine required for successfully treating postoperative CRBD was 0.55 mcg/kg (95% confidence interval: 0.49-1.54 mcg/kg). CONCLUSIONS: The ED90 of dexmedetomidine for the successful treatment of severe postoperative CRBD during recovery is 0.55 mcg/kg.