The Analgesic Efficacy of Continuous Wound Instillation With Diclofenac or Ropivacaine Following Cesarean Section: a Randomized, Double-blind, Placebo Controlled Study

Study Objective: To assess the analgesic efficacy of diclofenac or ropivacaine when administered via wound infusion.

Design: Prospective, randomized, double-blind, placebo-controlled study. Setting: Large referral hospital. Patients: 75 women recovering from Cesarean section performed via a Pfannenstiel incision.

Interventions: On completion of the surgical procedure, a 15 cm 19G infusion catheter (PAINfusor™, Baxter) will be placed below the fascia. According to a computer generated randomization schedule, patients will be divided into one of three treatment groups (n = 25).

• In Group Control water for injection will be administered.
• In Group Ropivacaine 0.2 % ropivacaine will be administered.
• In Group Diclofenac diclofenac (300 mg/240 ml of water for injection) will be administered.

During the first 6 postoperative hours, a co-investigator will administer "rescue" analgesia (10 ml bolus of infusion drug or rescue morphine). Thereafter, the catheter will be connected to an elastometric pump (LV 10 Infusor, Baxter) filled with either water for injection, ropivacaine 0.2 %, or diclofenac (300 mg/240 ml water for injection). The fluid will be administered as a constant infusion rate (10 mL/hr). Continuous wound infusion will be continued for the subsequent 18 postoperative hours. During this 18 hour period, subcutaneous morphine 4 mg will be administered on patient request for additional analgesia.