Background & Aims

A few cases of postoperative spinal syndrome (PSSS) provide very little pain relief even with standard treatment. Intrathecal morphine therapy (ITMT) has fewer side effects and can be used to improve pain control compared to systemic analgesic monotherapy, but ITMT-related complications may occur.

Methods

Thirty patients with PSSS were retrospectively evaluated. All patients had a visual analogue scale (VAS) score of 7 or higher and pain persisted for more than 6 months. If the VAS score decreased by more than 50% after a single dose of the ITM trial and there were no adverse events in the trial, ITM pump (ITMP) implantation was performed for continuous morphine injections for pain control. Of the 30 patients, 22 received only the ITM trial, and 8 patients received ITMP implantation, with a VAS reduction of more than 50% after the trial. Patients who received the trial only were observed for an average of 5.8 days (range: 4–15 days), while patients who received ITMP transplantation were observed for an average of 53.3 months (range: 16–123 months). We analysed adverse events after ITM injections or complications associated with ITM procedures or ITMP implants.

Results

Adverse drug events (n=12) were the most common complication, followed by procedural adverse events (n=1) and equipment adverse events (n=1). Dysuria (n = 9) was the most common side effect of the drug, followed by pruritus (n = 3). A rare but serious complication included a large lumbosacral subdural hematoma (n=1). There was catheter occlusion (n=1) by precipitated morphine crystals and skin infection at the implantable pulse generator (IPG) site (n=1). Skin necrosis was observed at the lumbar surgery site (n=1). Adverse drug events (n = 12) were the most common complications, followed by procedural adverse events (n = 1) and equipment adverse events (n = 1).

Conclusions

The most common drug-related side effect was difficulty urinating. Drug side effects recover within a few days after the ITM trial. In rare cases, complications related to the procedure may also occur, such as subdural hemorrhage or blocked IT catheter. An understanding of IT opioids, equipment, and meticulous procedural techniques is required to reduce complications associated with ITMT.

References

1. Pendi A, Acosta FL, Tuchman A, Movahedi R, Sivasundaram L, Arif I, et al. Intrathecal morphine in spine surgery: a meta-analysis of randomized controlled trials. Spine (Phila Pa 1976) 2017;42:E740–E747.
2. Ruan X. Drug-related side effects of long-term intrathecal morphine therapy. Pain Physician 2007;10:357–366.
3. Webster LR. The relationship between the mechanisms of action and safety profiles of intrathecal morphine and ziconotide: a review of the literature. Pain Med 2015;16:1265–1277.

Presenting Author

Kwanho Park

Poster Authors

Kwanho Park

MD, PhD

VHS Medical Center

Lead Author

Tae Wan Kim

MD

VHS Medical Center

Lead Author

Topics

  • Specific Pain Conditions/Pain in Specific Populations: Neuropathic Pain - Peripheral