A Comparative Study of the Block Characteristics of Spinal Bupivacaine Alone and Spinal Bupivacaine with Dexmedetomidine for Lower Abdominal Surgeries

Abstract

Background: Spinal anaesthesia with a local anaesthetic alone is often associated with relatively short duration of action. This study investigated the effect of intrathecal dexmedetomidine on duration of spinal bupivacaine during lower abdominal surgeries.
Patients and Method: Seventy two patients aged 18 - 55 years and ASA Class I or II scheduled for elective nonobstetric lower abdominal surgeries were recruited into the study. The patients were randomly allocated to receive spinal anaesthesia in sitting position using either 3ml of 0.5% hyperbaric bupivacaine plus 0.5ml sterile water (group B) or same dose of hyperbaric bupivacaine plus 0.5ml of 5ug dexmedetomidine (group D). The haemodynamic parameters, sensory and motor block characteristics, sedation scores and side effects during and immediately after the surgery were assessed and recorded. ·
Results: The mean time to reach T7 sensory level and Bromage score 3 were significantly longer among group B patients (6'.2 ± 2.4 and 6.8 ± 4.8 minutes respectively) as compared to group D (3.6 ± 1.2 and 2.9 ± 1.0 minutes respectively); p<0.0001. Time to first request for analgesic in Group 8 and Group D was 210 ± 29.7 and 360.1± 31.0 minutes respectively, p<0.0001. For most of the study period, group D exhibited significantly lower mean blood pressures compared to group B. The differences in the occurrence of adverse etfects were not statistically signiticant in both groups.
Conclusion: This study has shown that spinal anaesthesia using hyperbaric bupivacaine plus dexrnedetomid ine provided adequate and prolonged sensory and motor block than hyperbaric bupivacaine alone but it also resulted in lower blood pressure readings during most of the study periods.

Key words: Dexmedetomidine, spinal anaesthesia, bupivacaine, lower abdominal surgeries