Continuous intravenous morphine infusion for postoperative analgesia following posterior spinal fusion for idiopathic scoliosis.
METHODS
A retrospective study of postoperative pain management.


OBJECTIVE
Evaluate the efficacy and safety of continuous intravenous morphine infusion for postoperative pain management in patients with idiopathic scoliosis (IS) undergoing posterior spinal fusion (PSF) and segmental spinal instrumentation (SSI).


BACKGROUND
Postoperative pain is a common problem following surgery for IS. There are no published reports regarding the use of a continuous intravenous morphine infusion for this patient population.


METHODS
We retrospectively reviewed data regarding 339 consecutive patients with IS who underwent PSF and SSI between 1992 and 2006. All patients received intrathecal morphine after the induction of general anesthesia. Following surgery, preordered morphine infusion (0.01 mg/kg/h) was started at first reported pain. The infusion rate was titrated based on vital signs, visual analog scale (VAS) pain scores (0-10), and clinical status. It was continued until patients were able to take oral analgesics. We reviewed intrathecal morphine dosage, VAS pain scores through the third postoperative day, interval to start of morphine infusion, total morphine requirements in the first 48 hours, and any adverse reactions (nausea/vomiting, pruritus, respiratory depression, and pediatric intensive care unit admission).


RESULTS
Mean intrathecal morphine dose was 15.5 +/- 3.9 microg/kg and mean interval to start of the intravenous morphine infusion was 17.5 +/- 5 hours. Mean VAS pain scores were 3.1, 4.5, 4.5, and 4.6 at 12 hours, 1, 2, and 3 days after surgery, respectively.The total mean morphine dose in the first 48 hours postoperatively was 0.03 +/- 0.01 mg/kg/h. Total morphine received was 1.44 +/- 0.5 mg/kg. Nausea/vomiting and pruritus, related to the morphine infusion occurred in 45 patients (13.3%) and 14 patients (4.1%), respectively. No patients had respiratory depression or required Pediatric Intensive Care Unit admission.


CONCLUSIONS
A low frequency of adverse events and a mean postoperative VAS pain score of 5 or less demonstrate that a continuous postoperative morphine infusion is a safe and effective method of pain management in patients with IS following PSF and SSI.
Poe-Kochert
Connie
C
Division of Pediatric Orthopaedics, Rainbow Babies and Children's Hospital, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, OH, USA.
Tripi
Paul A
PA
Potzman
Jennifer
J
Son-Hing
Jochen P
JP
Thompson
George H
GH
D000293:Adolescent; D000698:Analgesia / Q000379:methods*; D000701:Analgesics, Opioid / Q000008:administration & dosage; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D009020:Morphine / Q000008:administration & dosage*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy*; D011184:Postoperative Period; D012189:Retrospective Studies; D012600:Scoliosis / Q000601:surgery*; D013123:Spinal Fusion
D000701:Analgesics, Opioid; D009020:Morphine