Anesthesia & Clinical Research
Open Access

Abstract

Can Intravenous Dexmedetomidine Prolong Bupivacaine Intrathecal Spinal Anesthesia?

Anbarasu Annamalai, Sanjeev Singh, Arti Singh and Deigheidy Ehab Mahrous

Background and objectives: Different adjuvants have been used to prolong intrathecal spinal anesthesia, with the possible advantages of delayed onset of post-operative pain, delayed and reduced analgesic requirements. The aim of this study was to evaluate the effect ofintravenous dexmedetomidine on prolongation of intrathecal spinal anesthesia, level of sedation, post-operative analgesic requirement.

Methods: Ninety adult patients classified as American Society of Anaesthesiologists physical status (ASA) I or II scheduled for various elective surgical proceduresbelow umbilicus under intrathecal spinal anesthesia were doubleblind randomized to one of three groups. Each patient received 0.5% hyperbaric bupivacaine 2.5 ml intrathecal spinal anesthesia. Group C (control): Patient receiving intravenous normal saline 10 ml over 10 mins (as placebo) 10 minutes before intrathecal spinal anesthesia with 0.5% hyperbaric bupivacaine 2.5 ml and normal saline 10 ml over 10 mins (as placebo) after 30 minutes of spinal anesthesia. Group D1: Patient receiving intravenous dexmedetomidine 1 μg/kg over 10 mins, 10 minutes before intrathecal spinal anesthesia. Group D2: Patient receiving intravenous dexmedetomidine 1 μg/kg over 10 mins after 30 minutes of intrathecal spinal anesthesia.

Results: Sensory block was higher in group D2 (T-4.1 ± 0.7) than D1 (T-4.5 ± 0.5) and C (T-6.3 ± 0.8). Time for sensory regression of two blocks was 145 ± 32, 142 ± 28 and 94 ± 26 min in group D2, D1 and C respectively. Duration of motor block was similar in all groups. GroupD2 and D1 increased the time to first request for postoperative analgesia by 190.3 ±13.3 and 174 ± 19.5 min whereas in group C 133.40 ±10.4 min. The maximum Ramsay sedation score was greater in the group D1 and D2 than in C.

Conclusion: Intravenous dexmedetomidine prolonged spinal bupivacaine sensory blockade in both the groups. It also provided sedation and additional analgesia.