Effect of pre-emptive gabapentin on postoperative pain following lower extremity orthopaedic surgery under spinal anaesthesia

Panah Khahi M, Yaghooti AA, Marashi SH, Nadjafi A
Correspondence: Dr Panah Khahi, panahkha@sina.tums.ac.ir

ABSTRACT
Introduction Gabapentin has demonstrated efficacy in clinical trials as a pre-emptive analgesic and in acute postoperative pain management. However, our experience with the drug is still limited. The present study was conducted in order to evaluate the effect of gabapentin on reduction of postoperative pain in the first 24 hours after internal fixation of the tibia under spinal anaesthesia.
Methods In a double-blind, randomised controlled clinical trial, 64 American Society of Anesthesiologists Class I or II patients, who underwent internal fixation of the tibia, were administered 300 mg of gabapentin or a placebo two hours before surgery. The postoperative pain was assessed using Visual Analogue Scale two, 12 and 24 hours after surgery. The time from the end of surgery until the first bolus dose of morphine on demand (pain score > 4) and the total morphine requirement were recorded. Patients were also asked about the possible side effects of gabapentin.
Results The pain score was significantly lower in the gabapentin group at two hours post surgery (p-value is 0.004), while the scores at 12 and 24 hours post surgery were not significantly different between the two groups. No side effect of gabapentin was observed.
Conclusion Pre-emptive use of gabapentin 300mg orally significantly decreases postoperative pain two hours after surgery.

Keywords: gabapentin, morphine demand, orthopaedic surgery, postoperative pain, pre-emptive analgesia
Singapore Med J 2011; 52(12): 879-882