Lidocaine vs. tramadol vs. placebo wound infiltration for post-cesarean section pain relief: a randomized controlled trial.

Objectives: In low-income settings, postoperative pain relief could be challenging as a high patient/nurse ratio limits pain assessment and adequate analgesics administration. The multi-center prospective double-blinded parallel randomized controlled trial was done to compare lidocaine, tramadol, and placebo (saline) intraoperative wound infiltration to relieve post-cesarean section wound pain during the first 24 h.

Methods: Ninety-nine cases were equally randomized into three groups, each containing 33 pregnant women undergoing cesarean section under general anesthesia. During operation, the wound was infiltrated subcutaneously with 20 mL of 2% lidocaine solution in the first group, 2 mg/kg tramadol in the second group, and saline in the third group. The primary outcome was to assess the postoperative pain at 2, 4, 6, 12, and 24 h by the Yes-No-Don't Know (YNDK) Scale, while the secondary outcome was to assess the need for further postoperative analgesia.

Results: Wound infiltration with lidocaine or tramadol was effective in pain relief, and both were superior to placebo. Wound infiltration with tramadol was superior to lidocaine in pain relief at 2 h and up to 24 h.

Conclusions: Wound infiltration with tramadol has a more prolonged pain relief effect than lidocaine in post-cesarean section pain relief in patients performing cesarean section under general anesthesia lasting up to 24 h, and both are superior to placebo in pain relief.