The Effect of Intrathecal Clonidine as an Adjuvant to Hyperbaric Bupivacaine on Postoperative Analgesic Requirements in Patients Undergoing Lower Abdominal Surgeries - A Randomised Controlled Trial

Abstract

Background ABSTRACT Postoperative pain besides its psychological effects, causes restlessness, excitability, tachycardia and increased oxygen consumption. Opioid analgesics commonly used to provide analgesia are associated with sedation, respiratory depression and PONV. Intrathecal clonidine prolongs spinal anaesthesia by its potent anti nociceptive effect mediated by α-2 adrenergic receptors. We investigated the effect of the addition of clonidine ( 30µg ) to hyperbaric bupivacaine on postoperative pain relief and the analgesic requirement in postoperative period. Objective To determine the effect of intrathecal clonidine as an adjuvant to hyperbaric bupivacaine on postoperative analgesic requirements in patients undergoing lower abdominal surgeries. Study design A randomized controlled trial. Methods Sixty ASA I-II posted for various lower abdominal surgeries under spinal anesthesia using hyperbaric 0.5% bupivacaine were randomly allocated into two groups of thirty each. Group B received 3ml of hyperbaric 0.5% bupivacaine with 0.2 ml of normal saline and Group BC received 3ml of hyperbaric 0.5% bupivacaine with 0.2ml of clonidine ( 30µg ) . Pain was assessed in the PACU and later in the ward by a trained nursing staff blinded to the study for a period of 24 hrs. Pain scores were assessed every hourly and when it exceeded 3 on VAS injection IX Diclofenac 50mg IM as rescue analgesic was administered. The time to first rescue analgesic administration and total analgesic dose for 24 hrs was noted. Results The mean duration of analgesia in Group B and Group BC were 4.91±1.41 and 7.46±2.18 hrs respectively and the mean analgesic requirements in Group B and BC were 170.83±54.57 and 121.67±49.01 mgs respectively. There was significant difference between two groups with P value <0.001. Conclusion From our study we conclude that administration of clonidine as adjuvant to hyperbaric bupivacaine spinal anaesthesia for abdominal surgeries increases the duration of analgesia and reduces the postoperative analgesic requirements.