Effect of low-dose dexmedetomidine to prolong spinal anesthesia in elderly patients: a prospective randomized controlled study.

Abstract

Spinal anesthesia for transurethral resection of the prostate (TURP) has a short duration, which poses challenges for postoperative pain management. The present study aimed to investigate the effects of intravenous (IV) dexmedetomidine at a dosage of 0.4µg/kg in prolonging the duration of spinal anesthesia and minimizing postoperative pain in elderly patients undergoing TURP. This prospective randomized controlled trial enrolled 38 patients aged 60-80 years who underwent elective TURP with spinal anesthesia. The patients were randomly assigned to two treatment groups: Group D received IV 0.4µg/kg dexmedetomidine, whereas Group C received IV normal saline after spinal anesthesia administration. The primary outcome was the time to 2-dermatome regression. The 2-dermatome regression time was longer in Group D than in Group C (104.44 ± 16.97min vs. 80.63 ± 15.59min, p < 0.05). The peak sensory block levels were significantly higher in Group D [T7 (T6-T8)] than in Group C [T10 (T7-T10)] (p = 0.017). The incidence of hypotension and bradycardia and postoperative pain at 0, 6, 12, and 24h were not different between two groups. Intravenous dexmedetomidine at a dosage of 0.4µg/kg significantly prolongs the duration of spinal sensory blockade. Although postoperative analgesia was not different, it provided hemodynamic stability without increasing the side effects.