Comparison of different routes of administration of clonidine for analgesia following anterior cruciate ligament repair

BACKGROUND AND AIMS: A high percentage of patients undergoing arthroscopic repairs on day care basis complain of inadequate postoperative pain relief. Clonidine was evaluated for the best route as an adjuvant in regional anesthesia in anterior cruciate ligament (ACL) repair to prolong analgesia. MATERIAL AND METHODS: A prospective randomized double-blinded study was planned in a tertiary care hospital in North India in which 85 American Society of Anesthesiologists I and II patients undergoing ACL repair were enrolled. All groups received 0.5% hyperbaric bupivacaine intrathecally as in control group C. Group IT received intrathecal 1 μg/kg of clonidine along with hyperbaric bupivacaine, group IA received 0.25% bupivacaine and 1 μg/kg clonidine intra-articularly, and group NB received 0.25% bupivacaine and 1 μg/kg clonidine in femoro-sciatic nerve block (FSNB). Postoperative pain free interval and block characteristics were the primary outcomes studied. RESULTS: Pain-free duration was 546.90 (±93.66) min in group NB (P < 0.001) in comparison to 234.90 (±20.99), 367.80 (±47.40) and 172.20 (±54.82) min in groups IA, IT and C, respectively. Sensory block and motor blockade in NB were 474.90 (±43.80) and 267.40 (±34.59) min, respectively, and were significantly prolonged (P > 0.001) in comparison to other groups. The mean rescue analgesic requirement and cumulative frequency of rescue analgesia were least in group NB, followed by groups IT, IA and C. CONCLUSION: Clonidine is safe and effective adjuvant with bupivacaine in prolonging analgesia through various routes employed for post knee surgery pain. The maximum prolongation of analgesia is achieved through FSNB with a risk of prolonging postanesthesia care unit stay.