Postoperative Pain After Pediatric Umbilical Hernia Repair

Recent studies on adult patients' perceptions of their hospital care have shown that improvements are needed in pain management (Jha, Orav, Zheng, and Epstein). The use of regional anesthetic techniques to block specific peripheral nerves in adult patients has increased in recent decades as an alternative to general anesthesia or to decrease opioid use during and after surgery. Decreased postoperative complications have been observed, with fewer ambulatory patients requiring prolonged recovery room stays and/or costly unplanned hospital admissions (Chan, Peng, Kaszas, Middleton, Muni, Anastakis, and Graham).

Regional anesthetic techniques have not been widely performed in pediatric patients because of the challenge in requiring children to report paresthesias during needle placements. However, pediatric anesthesiologists have recently begun to use ultrasound to identify anatomy, and to guide needle insertion and local anesthetic infiltration, thereby enabling peripheral nerve blocks to be performed safely in children under general anesthesia. Several studies have illustrated that umbilical nerve blocks (Jose Maria, Götzens, and Mabrok) and rectus sheath blocks (Willschke, Bosenberg, Marhofer, Johnston, Kettner, Wanzel, and Kapral) can be used safely and effectively with ultrasound guidance in pediatric outpatient surgery. To date, few studies have explored whether ultrasound-guided regional blocks of the abdomen in children have the desired outcome of reducing postoperative pain and/or decreasing opioid use.

The use of ultrasound to guide the deposition of local anesthetic in the posterior sheath of the rectus muscle containing the peripheral nerves that innervate the abdomen may decrease postoperative pain, opioid and non-opioid analgesic consumption, as well as minimize opioid-related complications. Currently, at Children's Hospital Boston, the most common regimen for pain control after umbilical hernia repair performed under general anesthesia (i.e. standard of care) has been surgeon-administered nonspecific local anesthetic infiltration in the wound at the conclusion of surgery, followed by opioids in the Post-Anesthesia Care Unit and an oral opioid/acetaminophen combination post-discharge. In sporadic cases over the past year, several pediatric surgeons have collaborated with anesthesiologists from the pain service to allow ultrasound-guided bilateral rectus sheath blocks to be performed in patients undergoing umbilical hernia repair, usually prior to the surgical repair, and often concomitantly with surgeon-administered local anesthetic infiltration in the wound. Because of the anecdotal nature of these practices, specific conclusions regarding improvements in post-operative pain or decreased need for post-operative opioid use cannot be drawn. However, anecdotal reports from parents at the time of outpatient post-operative follow-up visits have been encouraging regarding perceived success in achieving adequate post-operative pain control in patients receiving the regional block.

We propose an interdisciplinary, prospective, randomized, single-blinded clinical trial of the use of ultrasound-guided bilateral rectus sheath blocks versus local anesthetic infiltration in a pediatric population of patients undergoing ambulatory umbilical hernia repair at Children's Hospital Boston and Children's Hospital Boston at Waltham.

Inclusion criteria

• Any patient who is 3 to 12 years of age
• Any patient undergoing outpatient umbilical hernia repair
• Any patient capable of expressing pain using the Faces Pain Rating Scale
• Patient has provided assent (if age 10 or older)
• Parents/guardians have provided informed consent

Exclusion criteria

• Any patient classified as ASA III, IV, or V by the American Society of Anesthesiologists
• Any patient with a history of Complex Regional Pain Syndrome
• Any patient with a history of chronic analgesic use
• Any patient who has used an analgesic including opioids, acetaminophen, and/or NSAID's within 24 hours prior to surgery
• Wards of the state
• Any patient with an incarcerated umbilical hernia requiring emergent surgery
• Any patient who does not speak English or Spanish
• Any patient whose primary caregiver does not speak English or Spanish
• Any patient who cannot express pain using the Faces Pain Rating Scale due to a disability
• Any patient whose primary caregiver is unable to comply with home instructions due to a disability
• Any patient less than 3 years of age or greater than 12 years of age
• Any patient with renal insufficiency
• Any patient with a bleeding disorder