Continuous epidural morphine/butorphanol infusion following selective dorsal rhizotomy in children

Efficacy of intrathecal morphine administration in pediatric patients undergoing selective dorsal rhizotomy

PURPOSE

The purpose of this study was to evaluate the effectiveness of intrathecal morphine following selective dorsal rhizotomy in pediatric patients previously diagnosed with cerebral palsy.

METHODS

This was a retrospective, cohort analysis over the course of four years. The analysis consisted of a treatment group which received intrathecal morphine (5 mcg/kg) injection and a control group that did not receive the injection prior to dural closure. All patients underwent multilevel laminectomies for selective dorsal rhizotomy at Akron Children's Hospital. The effectiveness of the treatment was measured by total dose of hydromorphone administered on patient-controlled analgesia (PCA), number of days on oral narcotics, and cumulative dose of oral narcotic.

RESULTS

Of the analyzed 15 pediatric patients, seven patients received intrathecal morphine injection while the other eight did not receive the treatment prior to dural closure. There was a difference of 1135 mcg in total PCA dose between the study group (3243 mcg) and the control group (4378 mcg). The total PCA dose based on weight was lower in the study group (163 mcg/kg) than in the control group (171 mcg/kg).

CONCLUSION

Based on these findings, the administration of intrathecal morphine clinically reduces the opiate need in the first 96 hours post-operatively.

Epidural analgesia for reduction of postoperative systemic opioid use following selective dorsal rhizotomy in children

OBJECTIVE

Selective dorsal rhizotomy (SDR) requires significant postoperative pain management, traditionally relying heavily on systemic opioids. Concern for short- and long-term effects of these agents has generated interest in reducing systemic opioid administration without sacrificing analgesia. Epidural analgesia has been applied in pediatric patients undergoing SDR; however, whether this reduces systemic opioid use has not been established. In this retrospective cohort study, the authors compared postoperative opioid use and clinical measures between patients treated with SDR who received postoperative epidural analgesia and those who received systemic analgesia only.

METHODS

All patients who underwent SDR at Boston Children's Hospital between June 2013 and November 2019 were reviewed. Treatment used the same surgical technique. Postoperative systemic opioid dosage (in morphine milligram equivalents per kilogram [MME/kg]), pain scores, need for respiratory support, vomiting, bowel movements, and length of hospital and ICU stay were compared between patients who received postoperative epidural analgesia and those who did not, by using the Wilcoxon rank-sum test or Fisher's exact test.

RESULTS

A total of 35 patients were identified, including 18 females (51.4%), with a median age at surgery of 6.1 years. Thirteen patients received postoperative epidural and systemic analgesia and 22 patients received systemic analgesia only. Groups were otherwise similar, with treatment selection based solely on surgeon routine. Patients who received epidural analgesia required less systemic morphine milligram equivalents/kg on postoperative days (PODs) 0-4 (p ≤ 0.042). Patients who did not receive epidural analgesia were more likely to require respiratory support on POD 1 (45% vs 8%; p = 0.027). Reported pain scores did not differ between groups, although patients receiving epidural analgesia trended toward less severe pain on PODs 1 and 2. Groups did not differ with respect to postoperative vomiting or time to first bowel movement, although epidural analgesia use was associated with a longer hospital stay (median 7 vs 5 days; p < 0.001).

CONCLUSIONS

Patients who received postoperative epidural analgesia required less systemic opioid use and had at least equivalent reported pain scores on PODs 1-4, and they required less respiratory support on POD 1, although they remained in the hospital longer when compared to patients who received systemic analgesia only. A larger prospective study is needed to confirm whether epidural analgesia lowers systemic opioid use in children, contributes to a safer postoperative hospital stay, and results in better pain control following SDR.

Postoperative Pain Protocol in Children after Selective Dorsal Rhizotomy

INTRODUCTION

Selective dorsal rhizotomy (SDR) provides lasting relief of spasticity for children suffering from cerebral palsy, although controlling postoperative pain is challenging. Postoperatively, escalation of therapies to include a patient-controlled analgesia (PCA) pump and intensive care unit (ICU) admission is common.

OBJECTIVES

We developed a multimodal pain management protocol that included intraoperative placement of an epidural catheter with continuous opioid administration. We present the 3-year results of protocol implementation.

METHODS

With institutional review board approval, all patients who were subjected to SDR at our institution were identified for review. Hourly pain scores were recorded. Adverse effects of medication, including desaturation, nausea/vomiting, and pruritus, were also noted. Comparisons were made between patients treated with PCA and those treated with multimodal pain control using t and χ2 tests as appropriate.

RESULTS

Thirty-nine patients undergoing the procedure with protocolized pain control (average age 6.8 years, 57% male) were compared to 7 PCA-treated controls (average age 6.6 years, 54% male). Pain control was satisfactory in both groups, with average pain scores of 1.5 in both groups on postoperative day 0, decreasing by postoperative day 3 to 1.1 in the PCA group and 0.5 in the protocol group. No patients under the protocol required ICU admission; all patients with PCA spent at least 1 day in the ICU. Desaturations were seen in 16 patients in the protocol group (41%), but none required ICU transfer. Treatment for pruritis was given to 57% of PCA patients and 15% of protocol patients. Treatment for nausea and vomiting was given to 100% of PCA patients and 51% of protocol patients. Medication requirements for the hospitalization were decreased from 1.1 to 0.28 doses per patient for pruritis, and from 3 to 1.1 doses per patient for nausea.

CONCLUSIONS

Multimodal analgesia is an excellent alternative to PCA for postoperative pain after SDR. Actual analgesia is comparative to that of controls without the need for intensive care monitoring. Side effects of high-dose opiates were less frequent and required less medication. With the protocol, patients were safely treated outside the ICU.

Neuraxial opioid-induced itch and its pharmacological antagonism

Given its profound analgesic nature, neuraxial opioids are frequently used for pain management. Unfortunately, the high incident rate of itch/pruritus after spinal administration of opioid analgesics reported in postoperative and obstetric patients greatly diminishes patient satisfaction and thus the value of the analgesics. Many endeavors to solve the mystery behind neuraxial opioid-induced itch had not been successful, as the pharmacological antagonism other than the blockade of mu opioid receptors remains elusive. Nevertheless, as the characteristics of all opioid receptor subtypes have become more understood, more studies have shed light on the potential effective treatments. This review discusses the mechanisms underlying neuraxial opioid-induced itch and compares pharmacological evidence in nonhuman primates with clinical findings across diverse drugs. Both nonhuman primate and human studies corroborate that mixed mu/kappa opioid partial agonists seem to be the most effective drugs in ameliorating neuraxial opioid-induced itch while retaining neuraxial opioid-induced analgesia.

Scheduled oral analgesics and the need for opiates in children following partial dorsal rhizotomy

OBJECT

Postoperative epidural morphine is commonly used to control pain in children following dorsal rhizotomy for spasticity. The authors report their experience in using a regimen of scheduled minor analgesic drugs to manage postoperative pain, with the goal of avoiding opiate use following a spinal intradural procedure.

METHODS

Postoperative pain scores were analyzed in a group of 22 children who underwent a partial dorsal rhizotomy. According to a preestablished standard regimen for postoperative pain control after dorsal rhizotomy, in each patient an intraoperative epidural catheter was placed for the potential infusion of postoperative morphine. Additionally, this cohort underwent a scheduled regimen of acetaminophen (10 mg/kg) and ibuprofen (10 mg/kg), alternating every 2 hours. For comparison, a retrospective chart review was performed in 20 patients with rhizotomies completed prior to the use of this oral analgesic protocol. Only one patient received a postoperative dose of morphine epidurally. None of the remaining patients required postoperative epidural morphine for pain control. Pain scores were significantly lower in this group compared with a retrospective review of patients treated according to the standard regimen. Length of hospital stay was shorter in these patients and antiemetic requirements were lower.

CONCLUSIONS

A regimen of minor analgesic therapy, when given in alternating doses every 2 hours immediately after partial dorsal rhizotomy for spasticity and throughout hospitalization, significantly reduced postoperative pain scores, hospitalization, and antiemetic requirements in these patients.

Continuous epidural butorphanol relieves pruritus associated with epidural morphine infusions in children

We examined the efficacy of epidural butorphanol to either prevent or relieve pruritus associated with epidural morphine infusion in children. Forty-six children were randomized to receive either epidural morphine (M) or epidural M with butorphanol (B) for postoperative analgesia. They received bupivacaine and either M 50 microg.kg-1 or the same dose of M plus B 10 microg.kg-1. Following surgery, a continuous infusion of 0.1% bupivacaine with either M 20 microg.ml-1 or M 20 microg.ml-1 + B 4 microg.ml-1 was given at a rate of 0.3 ml.kg-1.h-1. Pain scores and pruritus scores were recorded every 4 h during epidural infusion. Subjects with a pruritus score=2 received diphenhydramine 0.5 mg.kg-1 i.v. and were switched to an alternate epidural infusion; subjects receiving M (group M) were switched to M+B while subjects receiving M+B (group B) were switched to hydromorphone (H) 4 microg.ml-1. There was no difference in the initial incidence of pruritus (group M 11/18; group B 13/28). No subject in group M required a second change of epidural infusion because of continued pruritus after being switched to M+B; five of 13 subjects in group B continued to experience pruritus after being switched to H and required a second change of epidural infusion or an alternate analgesic modality (P=0.038). The median pruritus score in the first 24 h after changing epidural infusions was 0 in subjects in group MDelta (changed from M to M+B) and 1 in subjects in group BDelta (changed from M+B to H; P=0.012). While the median sedation score in the first 24 h was 1 in both groups, there was a greater incidence of sedation scores of 2 in group B than group M (28% vs 12.3%; P=0.021). B 10 microg.kg-1 was not effective in preventing pruritus associated with bolus epidural administration of M 50 microg.kg-1 in children. B 1.2 microg.kg-1. h-1 was effective in relieving pruritus associated with continuous epidural infusion of M 6 microg.kg-1.h-1.