Study of Wound Instillation Technique for Effective Postoperative Analgesia using Ropivacaine in Lumbar Spine Surgery

BACKGROUND: Instillation of local anaesthetics over incision site is a simple technique done as a part of multimodal analgesia targetting incisional pain for post-operative pain relief following lumbar laminectomy. AIM: To determine postoperative analgesic effect of ropivacaine in wound instillation for lumbar laminectomy. STUDY DESIGN: Prospective, randomised, double blind study. METHODOLOGY: Forty patients scheduled for elective lumbar laminectomy under general anaesthesia were enrolled and randomly allocated into two groups namely Group R (n=20 receiving 20ml of 0.25% ropivacaine) and Group N (n=20 receiving 20ml normal saline) as instillation over incision site. If the NRS exceeded ‘4’ at any point of time, rescue analgesia with inj. Diclofenac 75 mg deep intramuscular was administered. Post- operative pain score, duration of analgesia and total rescue analgesic required in 24 h were compared between the groups. RESULTS: The pain score was less in ropivacaine group as compared to normal saline group (p value 0.0001). Duration of analgesia in normal saline group (N) is 4.3± 1.03 and in ropivacaine group(R) is 12.15±1.49. Mean amount of rescue analgesic required in normal saline group was 191.25± 38.28mg and in ropivacaine group was 97.5± 35.26 mg. CONCLUSION: The patients who received ropivacaine wound instillation had better pain control, longer duration of analgesia and less analgesic requirement as compared to patients who received normal saline wound instillation.