Background: Total Knee Replacement (TKR) surgery is associated with moderate to severe pain post-operatively. Multimodal analgesic regimens have been the mainstay of pain therapy after TKR. ACB is a highly successful approach favouring reduced post-operative opioid requirements and facilitates in earlier ambulation. Method: In this prospective randomized, double-blind, placebo-controlled, parallel group study, 110 ASA class I–II adult patients of either sex, scheduled for Unilateral Total Knee Arthroplasty(TKA) under spinal anesthesia, were included. Out of which 62 patients were recruited and randomly assigned to their treatment group. ACB was performed immediately postoperatively. Patients were randomized to receive nociception level-guided analgesia by either Ropivacaine or placebo based infusion in orthopaedic ICU. Infusion was given at 8ml/ h, and rescue local analgesic was given if pain score of ≥3, if not relieved then opioid supplementation was done. Result: Both continuous and intermittent group showed no statistically significant results in terms of pain score ≥3 (2/28 vs. 5/28 p=0.21), rescue Ropivacaine boluses requirement (5/28 vs. 2/28; p=0.21) or morphine consumption (0/28 vs. 2/28; p=0.491) in 24 h postoperatively. We observed significant differences between the groups in outcomes like Ropivacaine consumption and motor blockade. At 16th h, bromage score ≥ 1 was 20/28 vs. 2/28 (p= 0.000) hence, limiting ambulation. But, at 24th h, only 1 patient in the continuous group had a motor blockade. Ropivacaine consumption of 24h was (193.43 ± 5.25 ml) vs. (4.29 ± 9.97 ml), (p= 0.000). Conclusion: Intermittent ACB during TKA is favourable over continuous ACB in terms of pain, opioid requirement, and motor blockade.
Kavita Kadyan,Padma Puppala and Dinesh Kumar Kataria