Continuous local anesthetic infusion for children with spina bifida undergoing major reconstruction of the lower urinary tract

Abstract

Objective: While many options for postoperative analgesia are available to the general patient population, choices are limited for individuals with spinal dysraphism. We hypothesized that the use of continuous local anesthetic infusion following major reconstruction of the lower urinary tract in children with spina bifida would significantly decrease need for opiate use, while maintaining adequate pain control.

Materials and methods: Children with spina bifida who underwent major reconstruction of the lower urinary tract at Children's Hospital Colorado were identified from January, 2003 through January, 2013 were identified. In addition to enterocycstoplasty, procedures included Mitrofanoff or Monti creation, bladder neck reconstruction, and Malone antegrade continence enema. Patients who had local anesthetic infusion catheters placed in the incision were compared to patients without catheters. Opioid consumption was calculated by conversion of any opiates into IV morphine (mg/kg) on postoperative days (POD) 0-3. Pain was assessed by mean and maximum FLACC scores on POD 0-2. Use of antiemetic medications and wound related complications were recorded as secondary metrics. Patients with other etiologies for neurogenic bladder and bowel were excluded. Patients whose pain was assessed by other assessment scales were excluded. Chi-squared analysis was used for nominal variables, students t-test was used for analysis of continuous variables. P values <0.05 were considered significant.

Results: 36 myelomeningocele patients who underwent primary enterocystoplasty met the inclusion criteria. All surgeries were open procedures. 24 patients in the infusion catheter group were compared to 12 patients who received primary analgesia by PCA or IV narcotics. There were no significant differences in age, sex, weight or spinal defect level between the two groups. Opioid use, as defined by IV morphine equivalents, was significantly less in the wound soaker group on all PODs. The total opioid use after POD #0-3 was 0.55 mg/kg in the wound soaker group vs 1.66 mg/kg in the IV/PCA group (p = 0.03). FLACC scores were uniformly lower in the wound soaker group, but were not significantly different. There was a significant decrease in need for postoperative antiemetic use in the wound soaker group (36.5% vs 83.3%, p = 0.014). Complications and hospital stay were similar between both groups.

Discussion: The advantage of local anesthesia is the reduction of systemic opioids and their subsequent adverse side effects. Our results suggest that in children with spina bifida undergoing major reconstruction of the lower urinary tract narcotic consumption is approximately 1/3 when continuous local anesthetic catheters are placed into the incision. The need for antiemetic medication is also significantly less. While this technique has been validated in a variety of other settings, it may be most beneficial in patients with myelomeningocele or other spinal dysraphism where epidural placement is generally contraindicated and narcotic use may have a particularly deleterious effect on preexisting neurogenic bowel function. The primary limitation of our study is that it is a retrospective review of a limited number of patients. Patients were not randomized and subject to other management differences that could have influenced our results in unknown ways.

Conclusions: Continuous local anesthetic catheters are a simple, effective alternative strategy to provide postoperative analgesia while reducing systemic opiate use and associated adverse effects.

Keywords: Bladder augmentation; Continuous local anesthetic infusion; Enhanced recovery after surgery; Pediatrics; Spina bifida.