Effects of intrathecal dexmedetomidine as an additive to low-dose bupivacaine in patients undergoing transurethral resection of prostate.

Abstract

Background and Aims:In patients undergoing transurethral resection of prostate (TURP), it is vital to restrict the level of block to T10dermatome during spinal anaesthesia. Low-dose bupivacaine causes minimum haemodynamic alterations, but may provide insufficient surgical anaesthesia. Dexmedetomidine, a selective α2-adrenoreceptor agonist, is a potent anti-nociceptive agent when given intrathecally. The aim of this study was to compare the adjuvant effects of intrathecal dexmedetomidine with low-dose bupivacaine spinal anaesthesia versus a higher dose of bupivacaine in patients undergoing TURP.Methods:The study was designed as a prospective, double-blind, randomised trial that included sixty patients of American Society of Anesthesiologists Grade I–III scheduled for TURP. They were allocated into two groups: Group I receiving only hyperbaric bupivacaine intrathecally and Group II receiving dexmedetomidine with low dose bupivacaine. The time to regression of two dermatomes from the peak sensory block level was the primary outcome of the study.Results:With comparable baseline and demographic attributes, both groups had similar peak sensory block levels (T9). Patients in Group II had quicker onset with the time to reach T10being faster (10.72 ± 3.50 vs. 12.72 ± 3.90 min, P = 0.041), longer duration of motor block (200 ± 18.23 vs. 190 ± 10.15 min, P = 0.011) and increased time to first analgesic requirement (300 ± 25.30 vs. 220 ± 15.12 min, P = 0.0001).Conclusion:Intrathecal dexmedetomidine with low-dose bupivacaine provides faster onset, prolonged sensory and motor block and reduced rescue analgesic requirement in patients undergoing TURP.