Effect of intravenous dexmedetomidine on spinal anaesthesia with 0.5% hyperbaric bupivacaine in lower abdominal...

Regional anesthesia is the preferred technique for most of lower abdominal and lower limb surgeries. For decades, lignocaine had been the local anesthetic of choice for spinal anesthesia. Recent studies show that intravenous clonidine and dexmedetomidine can prolong the duration of the spinal anesthesia. Dexmedetomidine is a more suitable adjuvant compared to clonidine due to its more selective α2A receptor agonist activity.

The study was undertaken to evaluate the effects of intravenous administration of dexmedetomidine on spinal anesthesia with 0.5% hyperbaric bupivacaine in lower abdominal surgeries.

Prospective randomized, double-blind control study.

Sixty patients of American Society of Anaesthesiologists Grades I and II, 20-60 years age, undergoing lower abdominal surgeries under spinal anesthesia were randomized into two groups by computer-generated table. Group 1: Bupivacaine and dexmedetomidine group; and Group 2: Bupivacaine and saline group. Spinal anesthesia was given with 15 mg of 0.5% bupivacaine. Patients in Group 1 received dexmedetomidine 1 μg/kg over 20 min followed by 0.5 μg/kg/h, intravenously till the end of surgery. Patients in Group 2 received normal saline. Observations were analyzed using Student's unpaired t-test.

The mean duration of analgesia in group 1 was 219.7 ± 2.55 minutes and in group 2 was 150.2 ± 5.7 minutes. The prolongation in duration of analgesia in dexmedetomidine group was statistically significant. The mean durations of motor blockade in Group 1 and Group 2 were 189.6 ± 2.14 and 158.2 ± 5.31 min, respectively.

Intravenous dexmedetomidine is useful to maintain hemodynamic stability and prolong spinal analgesia.