Intrathecal morphine for postoperative analgesia in patients with idiopathic scoliosis undergoing posterior spinal fusion.
METHODS
A retrospective study of postoperative pain management with intrathecal morphine.


OBJECTIVE
Identify the dosing regimen of intrathecal morphine that safely and effectively provides postoperative analgesia with minimal complications in patients with idiopathic scoliosis undergoing posterior spinal fusion (PSF) and segmental spinal instrumentation (SSI).


BACKGROUND
Postoperative pain after surgery for idiopathic scoliosis is a concern. Intrathecal morphine has been used to decrease pain. However, the most appropriate dose has not been determined.


METHODS
We retrospectively analyzed 407 consecutive patients with idiopathic scoliosis who underwent PSF and SSI at our institution from 1992 through 2006. Patients were divided into 3 groups based on the intrathecal morphine dose: no dose (n = 68); moderate dose of 9 to 19 microg/kg, mean 14 microg/kg (n = 293); and high dose of 20 microg/kg or greater, mean 24 microg/kg (n = 46). Data included demographics, Wong-Baker visual analog scale postoperative pain scores, postoperative intravenous morphine requirements, time to first rescue dose of intravenous morphine, and postoperative complications of pruritus, nausea/vomiting, respiratory depression, and pediatric intensive care unit (PICU) admission.


RESULTS
The demographics of the 3 study groups showed no statistical differences. The mean Wong-Baker visual analog scale pain score in the post anesthesia care unit was 5.2, 0.5, and 0.2, and the mean time to first morphine rescue was 6.6, 16.7, and 22.9 hours, respectively. In the first 48 postoperative hours, respiratory depression occurred in 1 (1.5%), 8 (2.7%), and 7 (15.2%) patients, whereas PICU admission occurred in 0 (0%), 6 (2%), and 8 (17.4%) patients, respectively. The majority of PICU admissions were the result of respiratory depression. Frequency of pruritus and nausea/vomiting was similar in all 3 groups.


CONCLUSIONS
Intrathecal morphine in the moderate dose range of 9 to 19 microg/kg (mean 14 microg/kg), provides safe and effective postoperative analgesia in the immediate postoperative period for patients with idiopathic scoliosis undergoing PSF and SSI. Higher doses did not result in significantly better analgesia and had a greater frequency of respiratory depression requiring PICU admission.
Tripi
Paul A
PA
Division of Pediatric Anesthesiology and Pediatric Orthopaedics, Rainbow Babies and Children's Hospital, University Hospitals Case Medical Center, Case Western reserve University, Cleveland, OH, USA.
Poe-Kochert
Connie
C
Potzman
Jennifer
J
Son-Hing
Jochen P
JP
Thompson
George H
GH
D000293:Adolescent; D000701:Analgesics, Opioid / Q000009:adverse effects / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007278:Injections, Spinal; D015278:Intensive Care Units, Pediatric; D008297:Male; D009020:Morphine / Q000009:adverse effects / Q000627:therapeutic use*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000503:physiopathology / Q000517:prevention & control*; D012131:Respiratory Insufficiency / Q000139:chemically induced / Q000503:physiopathology; D012189:Retrospective Studies; D012600:Scoliosis / Q000503:physiopathology / Q000601:surgery*; D013123:Spinal Fusion / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods
D000701:Analgesics, Opioid; D009020:Morphine