A Comparative Study of the Efficacy of Intrathecal Injection of Hyperbaric Bupivacaine with Fentanyl Versus Hyperbaric Bupivacaine with Dexmedetomidine in Lower Abdominal Surgeries: A Prospective Randomized Study

Spinal anaesthesia is the most common technique used for lower abdominal surgeries. Spinal anaesthesia using plain hyperbaric bupivacaine has disadvantages like delayed onset, shorter duration etc. Adding adjuvants like fentanyl, dexmedetomidine has overcome these disadvantages and improve post operative analgesia and stable hemodynamic condition with minimal side effects. Aim of the study was to determine the time of onset and duration of sensory and motor block, sedation score and postoperative analgesic efficacy of Fentanyl and Dexmedetomidine as adjuvant to bupivacaine in lower abdominal surgeries.

This prospective, double blind, randomized study included total 100 patient-divided equally in 2 groups (group F-fentanyl and group D-dexmedetomidine) after matching the inclusion and exclusion criteria. Group F received 3ml of 0.5 % injection Hyperbaric Bupivacaine + 25 mcg Fentanyl and Group D received 3ml of 0.5 % injection Hyperbaric Bupivacaine + 5mcg Dexmedetomidine intrathecally. The onset and duration of sensory and motor block, sedation score, duration of postoperative analgesia and need of rescue analgesia along with haemodynamic parameters were recorded.

The mean time for onset of sensory block in group D was (3.5 ± 0.88 mins) significantly lower than group F (4.4 ± 1.2 mins) (p=0.001). And the mean time of onset of motor block in group D (3.23 ± 1.0mins) was significantly lower than in group F (4.3 ± 1.1 mins). Duration of sensory and motor block was significantly higher in group D as compared to group F. The mean analgesic dose in group D was 1.4 ± 0.78 and in group F was 3.6 ± 0.73(p<0.005).

From our study we concluded that Dexmedetomidine is a better adjuvant than Fentanyl as it provides rapid onset and prolonged sensory and motor block, hemodynamic stability with excellent post operative analgesia.