A pilot study of the rectus sheath block for pain control after umbilical hernia repair

Background: Umbilical hernia repair, a common day surgery procedure in children, is associated with significant postoperative discomfort. The rectus sheath block may offer improved pain management following umbilical hernia repair. In this pilot study, we compared the efficacy of the rectus sheath block with that of our current standard practice - local anesthetic infiltration into the surgical wound - for pain control after umbilical hernia repair in children. Methods: Fourteen children, aged 1-8 years, undergoing umbilical hernia repair were randomly assigned to receive either a rectus sheath block or local anesthetic infiltration into the surgical wound at completion of surgery. Anesthetic management was standardized. Each analgesic technique was performed using 0.8 ml.kg(-1) of 0.25% bupivacaine with epinephrine 1 : 200 000. Postoperatively, an investigator who was blinded to the analgesic technique recorded the Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) scores and sedation scores every 10 min, and administered intravenous morphine 50 mu g.kg(-1) for cases with CHEOPS scores >= 8. Total morphine dose was recorded. Parents were telephoned the day after surgery to determine the overall satisfaction with pain control. Results: Total postoperative morphine consumption did not differ significantly between groups, averaging 0.10 +/- 0.09 and 0.10 +/- 0.07 mg.kg(-1) for the local infiltration and rectus sheath groups, respectively. There were no significant differences in pain or sedation scores, and no complications related to either analgesic technique. Discussion: Our results suggest that the rectus sheath block has no advantage over infiltration of local anesthetic into the surgical wound for postoperative pain management in children undergoing umbilical hernia repair.