Pain Control in Pediatric Posterior Spine Fusion Patients: The Effect of Gabapentin
Pain Control in Pediatric Posterior Spine Fusion Patients: The Effect of Gabapentin
The purpose of this study is to evaluate the patient experience when using gabapentin with
 other pain control medications after posterior spinal fusion surgery for scoliosis in
 adolescents. These results will be compared to patients who underwent the same procedure
 during the study period and received the same standardized pain control regimen excluding
 gabapentin. Effects on pain level, opioid use, and satisfaction will be measured. Opioid side
 effects including nausea, sedation and urinary retention (inability to empty one's bladder)
 will also be recorded.The null hypotheses are as follows:

 1. There is no significant difference in pain control when adding gabapentin to a
 multimodal pain management protocol in pediatric post-operative posterior spinal fusion
 patients.

 2. There is no significant difference in the amount of opioid medication required for pain
 control in pediatric post-operative posterior spinal fusion patients.
Patients aged 10-19 years with idiopathic scoliosis, and classified as American Society of
 Anesthesiology (ASA) class I to III who intended to undergo posterior spinal fusion for
 deformity correction were enrolled. Prior to surgery, subjects were randomized into either
 the experimental or control group by the OHSU research pharmacy using an online randomization
 tool, which utilized block randomization upon patient enrollment to result in equal sized
 groups at study completion. Patients, caretakers and providers remained blinded to the group
 assignments.

 Patients filled out the Scoliosis Research Society, SRS-22 standardized form at a
 pre-operative clinic appointment. Following hospital admission, patients recorded initial
 pain level with the Visual Analog Scale (VAS) prior to receiving standardized pre-operative
 medications. The VAS scale used in this study was a 10 cm line with anchors of "no pain" at
 the left and "worst pain imaginable" at the right; each point was measured to the nearest
 millimeter. In the post-operative period, nursing staff assessed patient pain using the VAS
 at 4-hour intervals from 06:00 until 22:00 for the duration of hospitalization for a minimum
 of 4 daily scores recorded per patient. After the third post-operative day, but before
 discharge, the parent or guardian of each subject was asked to complete an IRB-approved
 survey to measure parent demographics and parental satisfaction with the patient's
 hospitalization and pain control.

 Each patient received standardized medications according to our multimodal pain protocol.
 Following hospital admission, patients in both groups received one 12.5 mg/kg dose of
 intravenous (IV) acetaminophen. Patients in the experimental group received one 15 mg/kg dose
 of liquid gabapentin while the control group received a placebo, formulated to match the
 volume, color, taste, and smell of the experimental medication. The gabapentin or placebo was
 prepared by the OHSU research pharmacists so that providers and investigators remained
 blinded to treatment assignment. Several intraoperative anesthetic medications were given to
 subjects in both groups including: IV ketamine at 5mcg/kg/min for 120 minutes and IV
 Ketorolac 0.5mg/kg up to 15mg. Intra-operative IV propofol and IV hydromorphone were titrated
 to desired effect.In the post-operative period, gabapentin was administered to the
 experimental group at 10mg/kg PO q8h, beginning at Phase II and continued through
 postoperative day four. The control group received equivalent volume doses of placebo at the
 same intervals. Post-operative medication was administered according to the following
 protocol for both groups: ketorolac continued at 0.5mg/kg up to 15mg IV q6h for 12 total
 doses. Once ketorolac doses were complete, the patient may have received Ibuprofen 10mg/kg up
 to 600mg PO as needed. Hydromorphone was given through patient-controlled analgesia (PCA) at
 a basal dose of 0.002mg/kg/hr for 24 hours and demand dose of 0.004mg/kg with an 8-minute
 lockout. Once basal PCA was discontinued, administration of oxycodone 0.1-0.2mg/kg PO up to
 15mg PO q4h as needed supplemented the PCA demand dose. If the patient tolerated PO oxycodone
 without emesis, the PCA hydromorphone was discontinued after 24 hours, but a rescue dose of
 hydromorphone 0.002mg IV q4 was available if needed. Other as needed medications included
 diazepam 0.15mg/kg up to 5mg PO q6h for muscle spasms, ondansetron 0.1mg/kg up to 4mg IV q12h
 for nausea, and IV acetaminophen 12.5mg/kg up to 1000mg q6h. Acetaminophen 12.5mg/kg up to
 650mg PO q6h hours was administered after the IV was removed. All patients received one
 Senokot-S tablet and Miralax 0.8 g/kg up to 17g daily for bowel regimen.

 For the entire hospitalization, nursing staff monitored vital signs and assessed sedation
 using the standardized Pasero Opioid-induced Sedation Scale (POSS) protocols at 4-hour
 intervals.16 Any POSS score of 3 or greater resulted in more frequent monitoring of
 respiratory status and sedation level, decreased opioid dosing, and administration of
 naloxone as needed. All patients were routinely monitored for known adverse gabapentin drug
 reactions including: peripheral edema, nausea/emesis, viral disease, ataxia, dizziness,
 nystagmus, somnolence, hostile behavior, fatigue and fever, Stevens-Johnson syndrome, drug
 hypersensitivity reactions, drug induced coma/seizure, and suicidal thoughts. Any perceived
 adverse reaction would have resulted in the gabapentin or placebo being stopped at the
 clinicians' discretion
Inclusion Criteria:

 -  Patients of age 10-19 with an American Society of Anesthesiologists patient
 classification of I to III undergoing surgery to correct idiopathic or neurogenic
 scoliosis.

 Exclusion Criteria:

 -  Patients who require a surgical approach or technique differing from posterior spinal
 fusion and/or have allergies to any of the standardized or experimental study
 medications: acetaminophen, gabapentin, hydromorphone, ketorolac or oxycodone.