A Clinical Evaluation of Intravenous Sedation of Dexmedetomidine Combined with Butorphanol and Midazolam for Implant Surgery

Abstract

Dexmedetomidine (DEX), a highly selective α₂-adrenergic agonist, produces a sedative effect through a central mechanism. However, DEX may not be the sedative agent of choice in dental procedures, in which its plasma half-life is 2 to 3 hours. Sedation by a combination of DEX and other select drugs may reduce the total dosage of DEX and strengthen the amnesic action. We evaluated the amnesic action and recovery process under DEX sedation combined with butorphanol and midazolam for implant surgery.
Fifteen patients scheduled for implant surgery were enrolled in this study. They were administered with 0.01 mg/kg butorphanol and 0.05 mg/kg midazolam, and DEX infusion started. They were managed with 0.2 to 0.7μg/kg/h DEX to keep patientʼs level of being within 2 or 3 according to the Richmond Agitation-Sedation Scale Score. DEX infusion discontinued at the end of each operation. To assess an amnesic action, memory of local anesthesia, auditory memory (calling at the start of suture) and visual memory (watches or syringes etc. shown at the end of each operation) were verified at three hours after the operation. To determine psychomotor function and recovery of equilibrium in the recovery process, Trieger Dot Test (TDT) plot error ratio and a one-leg standing test with eyes closed (OL-test) were performed. Before leaving the hospital, a questionnaire regarding patientʼs feeling during and after the operation and a questionnaire regarding the management of sedation were taken.
The results were summarized as follows;
1. In intravenous sedation, the amnesic action of memory of local anesthesia, auditory memory and visual memory was 87%, 80% and 80% respectively.
2. TDT plot error ratio (24.5±25.3%) at one hour after the end of each operation showed a significant increase and all patients were successful in the OL-test at three hours after the end of the operations.
3. In a questionnaire for patients, 14% had uncomfortableness during and after sedation. However, all patients hoped that they would be managed with sedation in the present study if they were sedated again. In a questionnaire for Surgeons, they could operate smoothly. For this reason, 67% of them answered that patients hardly choked on irrigation saline. All surgeons hoped to operate under such a sedation environment in our study if they had an opportunity to repeat this procedure.
These results indicated that sedation with butorphanol, midazolam and DEX has a quality amnesic action, produces a smooth operation and satisfies both surgeons and patients. Therefore, this combination is available for sedation on the day surgery.