Perioperative gabapentin reduces 24 h opioid consumption and improves in-hospital rehabilitation but not post-discharge outcomes after total knee arthroplasty with peripheral nerve block.

BACKGROUND: This study was designed to determine whether a 4 day perioperative regimen of gabapentin added to celecoxib improves in-hospital rehabilitation and physical function on postoperative day 4 and 6 weeks and 3 months after total knee arthroplasty (TKA).

METHODS: After Research Ethics Board approval and informed consent, 212 patients were enrolled in a randomized, double-blinded, placebo-controlled study. Two hours before surgery, patients received celecoxib 400 mg p.o. and were randomly assigned to receive either gabapentin 600 mg or placebo p.o. Two hours later, patients received femoral, sciatic nerve blocks, and spinal anaesthesia. After operation, patients received gabapentin 200 mg or placebo three times per day (TID) for 4 days. All patients also received celecoxib 200 mg q12 h for 72 h and i.v. patient-controlled analgesia for 24 h. Pain and function were assessed at baseline, during hospitalization, on postoperative day 4 (POD4), and 6 weeks and 3 months after surgery.

RESULTS: The gabapentin group used less morphine in the first 24 h after surgery [G=38.3 (29.5 mg), P=48.2 (29.4 mg)] (P<0.0125) and had increased knee range of motion compared with the placebo group in-hospital (P<0.05). There were no differences between groups in favour of the gabapentin group for pain or physical function on POD 4 [95% confidence interval (CI): pain: -1.4, 0.5; function: -6.3, 2.0], 6 weeks (95% CI: pain: 0.1, 1.9; function: -0.2, 6.5) or 3 months (95% CI: pain: -0.2, 1.7; function: -2.2, 4.3) after TKA.

CONCLUSIONS: In the context of celecoxib, spinal anaesthesia, femoral and sciatic nerve blocks, a dose of gabapentin 600 mg before operation followed by 4 days of gabapentin 200 mg TID decreased postoperative analgesic requirements and improved knee range of motion after TKA. Gabapentin provided no improvement in pain or physical function on POD4 and 6 weeks or 3 months after surgery.