Intrathecal pain treatment for severe pain in patients with terminal cancer: A retrospective analysis of treatment-related complications and side effects.

Abstract

Objectives: Two-thirds of patients with advanced cancer experience pain. Some of these patients have severe pain refractory to oral and parenteral medication, for whom intrathecal pain treatment could be an option. While intrathecal therapy is presently used with good results in clinical practice, the current evidence is limited. Hence, increased knowledge of intrathecal pain treatment is needed. This retrospective study aimed to assess complications and side effects related to intrathecal pain treatment in patients with terminal cancer.

Methods: A retrospective study on all patients who received intrathecal treatment with morphine and bupivacaine through externalized catheters for cancer-related pain at a single university hospital during a 5-year period.

Results: Treatment-related complications were reported in 24 out of 53 patients. The most common complications were catheter dislocation (13%), catheter occlusion (9%), falls due to bupivacaine-related numbness or weakness (9%), and reversible respiratory depression (8%). There were five serious complications, i.e., meningitis or neurological impairment, of which four were reversible. Side effects related to intrathecal drugs, or the implantation procedure were observed in 35 patients. The most common were bupivacaine-related numbness or weakness (57%) and reversible post-dural puncture headache (19%). Systemic opioid doses decreased during the first 3 weeks of intrathecal treatment, from a median daily dose of 681 to 319 oral morphine milligram equivalents. The median treatment duration time was 62 days.

Conclusions: Complications related to intrathecal treatment are common, but mostly minor and reversible. Side effects are predominantly related to unwanted pharmacological effects from intrathecal drugs. Intrathecal treatment enables the reduction of systemic opioid doses, which indicates a good treatment effect on pain. Hence, intrathecal therapy can be considered a safe pain-relieving treatment in patients with severe refractory cancer-related pain. Future research is warranted on patient acceptability and satisfaction of intrathecal pain treatment.