Optimal dose of dexmedetomidine for sedation during epidural anesthesia

ABSTRACT

BACKGROUND: Sedation during epidural anesthesia can reduce patients' anxiety and discomfort. Dexmedetomidine has sedative, hypnotic, and analgesic effects, with minimal respiratory depression. However, the use of dexmedetomidine is associated with prolonged recovery. This study investigated the optimal dose of intravenous dexmedetomidine for proper sedation with minimal recovery time in epidural anesthesia. METHODS: Sixty-three patients (American Society of Anesthesiologists physical status I/II) were randomized into two groups. Following epidural anesthesia, a loading dose (1 µg/kg) of dexmedetomidine was administered for 10 min followed by maintenance infusion as follows Group A (n = 32; dexmedetomidine 0.6 µg/kg/h) and Group B (n = 31; dexmedetomidine 1.0 µg/kg/h). Heart rate, blood pressure, and bispectral index score (BIS) were recorded during surgery. The length of stay and modified Aldrete score (MAS) were measured in the postanesthesia care unit (PACU). RESULTS: Length of stay in the PACU was longer in Group B than in Group A (P < 0.05). The MAS was higher in Group A after 30 min in the PACU (P < 0.05). The BIS did not significantly differ between the two groups from baseline to 150 min after infusion of dexmedetomidine. BIS values were significantly higher in Group A at 160 min (P < 0.05). The mean arterial pressure in Group B was significantly lower in the PACU. CONCLUSIONS: Length of stay in the PACU was longer in Group B than in Group A (P < 0.05). The MAS was higher in Group A after 30 min in the PACU (P < 0.05). The BIS did not significantly differ between the two groups from baseline to 150 min after infusion of dexmedetomidine. BIS values were significantly higher in Group A at 160 min (P < 0.05). The mean arterial pressure in Group B was significantly lower in the PACU.