Study Design: Prospective randomized double blind trial.
Objective: To assess the effectiveness of intrathecal fentanyl in the relief of post operative pain in patients undergoing lumbar decompression or fusion.
Summary of Background Data: Morphine has been shown to be effective intrathecally in spinal surgery but there is an increased incidence of respiratory complications. Fentanyl has not been formally evaluated in this setting.
Methods: All patients received our standard analgesic regime with PCA via a syringe driver. They were also randomised to receive either 15 micrograms of fentanyl intrathecally, or nothing. The fentanyl was administered by the operating surgeon under direct vision one or two levels above the site of operation at the end of the procedure.
Subjects: 30 patients undergoing lumbar spinal surgery were prospectively recruited.
Outcome measures: VAS pain scores were taken at 2, 4, 24 and 48 hours post operatively. Time to first bolus delivery of morphine from the PCA was also recorded as was the total dose of morphine required.
Results: The patients randomized to receive fentanyl showed a significant increase in the time to first bolus delivery of morphine as well as a 40% reduction in the total morphine dose delivered. There was also a decrease in their mean VAS scores. There was no increased incidence of side effects in the group receiving fentanyl. No patients suffered respiratory compromise requiring treatment and only two patients required HDU observation overnight. The remainder of the cohort left recovery after 2 hours to be nursed on an open ward.
Conclusion: Intrathecal fentanyl is effective at reducing morphine use via a PCA and mean pain VAS scores after lumbar spinal surgery. We would support its use over intrathecal morphine because of the reduced incidence of respiratory complications and the ability to nurse patients on the open ward.