The effect of dexmedetomidine on spinal anesthesia quality and hemodynamic changes in patients undergoing inguinal hernia repair surgery: intravenous versus intrathecal

Purpose The aim of this study was to evaluate the quality of spinal anesthesia and hemodynamic parameters of intravenous versus intrathecal dexmedetomidine in patients undergoing inguinal hernia repair surgery under spinal anesthesia. Methods Fifty male patients aged 18-70 years with ASA I and II were randomly divided into two groups of 25 patients receiving either intravenous (1 mu g/kg infused during 10 min before blockade) or intrathecal (5 mu g, added to local anesthetics) dexmedetomidine. The duration of analgesia, sensory and motor blockade levels, the score of pain intensity, post-operative analgesic usage and the level of sedation as well as hemodynamic changes, and complications were recorded. Results The duration of analgesia in the intrathecal group was significantly longer than intravenous group (403.588 +/- 93.706 vs. 274.048 +/- 47.266 min; P < 0.001). Duration of the sensory and motor blockade were significantly longer in intrathecal than intravenous group (230.440 +/- 26.494 vs. 181.400 +/- 28.850 min; P < 0.001 for sensory block, and 253.800 +/- 32.637 vs. 205.400 +/- 30.921 min; P < 0.001 for motor block). The score of pain intensity was lower in the intrathecal group in the post-operative period (3.680 +/- 1.680 vs. 5.520 +/- 1.901; P = 0.001 and 2.360 +/- 1.320 vs. 3.24 +/- 1.69; P = 0.041, respectively, for the time 6 and 12). Ramsay sedation score was higher in the intravenous group during surgery but it was higher in intrathecal group during recovery room period (P < 0.05). Moreover, the incidence of bradycardia was significantly lower in the intrathecal group (0% vs. 36% respectively; P = 0.002). Conclusion Administration of intrathecal dexmedetomidine along with local anesthetics can be recommended to increase the quality of spinal anesthesia with minimal complications.