The effects of additive intrathecal fentanyl on time to first analgesic requirement in unilateral inguinal hernia surgery

Abstract

          Background: Spinal anesthesia has been found to be commonly technique for inguinal hernia surgery because it is easy to perform, provides fast onset of action, effective blockage of sensory and motor in awake patient and useful for reduce postoperative pain. Bupivacaine was local anesthetic that frequently used in spinal anesthesia, when it is combined with Fentanyl can produce synergestic effect and prolonging duration of sensory block without sympathetic block or delaying recovery.

          Objectives: The aim of prospective study is to compare effectiveness of Fentanyl combined in hyperbaric bupivacaine with hyperbaric bupivacaine alone in spinal anesthesia for inguinal herniorrhaphy.

          Method: The study designed was prospective, randomized, double blinded controlled study. Patients were randomly divided two groups of 22 each. Group BF received 0.5% hyperbaric bupivacaine 10 mg and Fentanyl 25 µg for spinal anesthesia. Group B received 0.5% hyperbaric intrathecal Bupivacaine 12.5 mg. Parameter such as level of sensory and motor blockage were assessed. Duration of full sensory or motor recovery, postoperative pain score  and time to first analgesia requirement were recorded. Side effects produced during perioperative and postoperative period were observed and noted.

          Results: No significant difference were observed in time to first analgesic requirement (group BF = 450.41 ± 250.13 min, group B = 400.50 ± 209.55 min, P = 0.477). Patients in group BF were faster recovery of motor and sensory function (recovery of motor block group BF = 209.05 ± 52.63 min VS  group B = 281.73 ± 115.86 min, P=0.012 recovery of sensory block group BF = 247.73 ± 58.89 min VS group B = 327.41 ± 110.81 min, P=0.005). The common adverse effects after spinal injection were hypotension, bradycardia and urinary retention but no significant differences in both groups.

          Conclusion: Bupivacaine in combination with Fentanyl has returned of motor function faster than Bupivacaine alone but not extending time of first postoperative analgesic requirement after spinal anesthesia for inguinal herniorrhaphy.