A Study of Intrathecal Hydromorphone for Pediatric Idiopathic Scoliosis Repair

Study Overview
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Brief Summary
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The purpose of this study is to identify a dose of intrathecal hydromorphone (opioid pain medicine) that optimizes pain control but minimizes side effects historically seen with this class of pain medications.

Detailed Description
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This study is a sequential coin based up-down dose allocation method with the goal of identifying the ED90 for intrathecal hydromorphone (ITH) in idiopathic adolescent scoliosis repair via the posterior approach. A starting dose of 3.5 mcg/kg of hydromorphone was determined by current practice at the institution as well as upon review of available literature of previously used ITM doses in pediatric spine patients. Subsequent participants will receive higher (step up) or lower (step down) from this starting dose. Steps down from the starting dose will be smaller than steps up to ensure maintenance of adequate analgesia and to allow more accurate estimate of the optimal dose should it decrease beyond our starting dose. Steps up from the starting dose were chosen based on commonly used weight-based doses in our current practice. A maximum dose of 400 mcg, despite patient weight, was determined based on expert consensus and review preparatory to research query. The anesthesiologist covering the case (high lumbar or thoracic corrections) or the surgeon (low lumbar corrections) will administer the medication at the low lumbar level. ITH dose adjustments for subsequent study patients will be based on the efficacy of the dose used with the prior patient. Efficacious ITH administration will be defined as all NRS scores ≤5 within the first 18 hours after administration (binary outcome). If the NRS score was >5 within 18 hours or if the patient required supplemental opioid administration for pain control (suggestive of insufficient analgesia), the dose will be increased for the next enrolled study patient. If the pain score remains ≤5 within 18 hours of opioid administration, the next patient will receive the next lower dose or the same dose as the previous patient. Patients excluded after randomization will be removed from the study.

Official Title
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Identification of the Optimal Analgesic Dose of Intrathecal Hydromorphone for Pediatric Patients Undergoing Posterior Spine Surgery for Idiopathic Scoliosis

Conditions
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Pain Control

Intervention / Treatment
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* Drug: Hydromorphone 2.5 mcg/kg
* Drug: Hydromorphone 2.75 mcg/kg
* Drug: Hydromorphone 3 mcg/kg
* Drug: Hydromorphone 3.25 mcg/kg
* Drug: Hydromorphone 3.5 mcg/kg
* Drug: Hydromorphone 4 mcg/kg
* Drug: Hydromorphone 4.5 mcg/kg
* Drug: Hydromorphone 5 mcg/kg


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - Undergoing spinal surgery with a posterior approach for idiopathic scoliosis. Exclusion criteria: Patients with pre-surgical elevated pain scores (≥ 3/10 on Numeric Rating Scale (NRS)), history of chronic pain, or pre-surgical opioid use will not be included. Patients with contraindications to spinal anesthesia (anatomical abnormality or elevated bleeding or infection risks) will not be included. Patients for whom the protocol is violated (inability to perform postoperative data collection), or the study/procedure was aborted will not be included in analysis.

Ages Eligible for Study
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Minimum Age: 10 Years
Maximum Age: 17 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Sequential Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Intrathecal Hydromorphone 2.5 mcg/kg<br>Subjects undergoing posterior spinal surgery will receive 2.5 mcg/kg hydromorphone in the intrathecal space at the low lumbar level | Drug: Hydromorphone 2.5 mcg/kg<br>* 2.5 mcg/kg intrathecal<br>|
| Experimental: Intrathecal Hydromorphone 2.75 mcg/kg<br>Subjects undergoing posterior spinal surgery will receive 2.75 mcg/kg hydromorphone in the intrathecal space at the low lumbar level | Drug: Hydromorphone 2.75 mcg/kg<br>* 2.75 mcg/kg intrathecal<br>|
| Experimental: Intrathecal Hydromorphone 3 mcg/kg<br>Subjects undergoing posterior spinal surgery will receive 3 mcg/kg hydromorphone in the intrathecal space at the low lumbar level | Drug: Hydromorphone 3 mcg/kg<br>* 3 mcg/kg intrathecal<br>|
| Experimental: Intrathecal Hydromorphone 3.25 mcg/kg<br>Subjects undergoing posterior spinal surgery will receive 3.25 mcg/kg hydromorphone in the intrathecal space at the low lumbar level | Drug: Hydromorphone 3.25 mcg/kg<br>* 3.25 mcg/kg intrathecal<br>|
| Experimental: Intrathecal Hydromorphone 3.5 mcg/kg<br>Subjects undergoing posterior spinal surgery will receive 3.5 mcg/kg hydromorphone in the intrathecal space at the low lumbar level | Drug: Hydromorphone 3.5 mcg/kg<br>* 3.5 mcg/kg intrathecal<br>|
| Experimental: Intrathecal Hydromorphone 4 mcg/kg<br>Subjects undergoing posterior spinal surgery will receive 4 mcg/kg hydromorphone in the intrathecal space at the low lumbar level | Drug: Hydromorphone 4 mcg/kg<br>* 4 mcg/kg intrathecal<br>|
| Experimental: Intrathecal Hydromorphone 4.5 mcg/kg<br>Subjects undergoing posterior spinal surgery will receive 4.5 mcg/kg hydromorphone in the intrathecal space at the low lumbar level | Drug: Hydromorphone 4.5 mcg/kg<br>* 4.5 mcg/kg intrathecal<br>|
| Experimental: Intrathecal Hydromorphone 5 mcg/kg<br>Subjects undergoing posterior spinal surgery will receive 5 mcg/kg hydromorphone in the intrathecal space at the low lumbar level | Drug: Hydromorphone 5 mcg/kg<br>* 5 mcg/kg intrathecal<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain intensity | Reported by the patient using an 11-point numeric visual analogue scale (NRS) with 0=no pain and 10=worst pain ever | 18 hours after intrathecal hydromorphone administration | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of need for dual anti-pruritic agents | Number of subjects needing dual anti-pruritic agents (Nubain or naloxone (beyond the protocol infusion rate of 0.25 mcg/kg/min)) | 24 postoperative hours | 
| Maximum pain scores | Highest pain score reported during the first 24 hours after intrathecal opioid administration. Reported by the patient using an 11-point numeric visual analogue scale (NRS) with 0=no pain and 10=worst pain ever. | 24 hours after intrathecal hydromorphone administration | 
| OME consumption | Total oral morphine equivalents (OME) consumption | 24 hours after intrathecal hydromorphone administration | 
| Incidence of antiemetic use postoperatively | Number of subjects to require antiemetic medications used to prevent or treat nausea and vomiting | 24 postoperative hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Posterior Spine Surgery, Pediatric Idiopathic Scoliosis Repair