Editor-in-Chief: Kenneth D. Candido, MD
BACKGROUND: Chronic pain is a significant health challenge, and targeted drug delivery (TDD) is increasingly utilized to manage patients who have failed several treatment modalities. An intrathecal trial is mandatory prior to permanent implantation, with current guidelines recommending inpatient observation of 23 hours or inpatient admission for a continuous intrathecal infusion opioid trial.
OBJECTIVES: TDD is an established method of the delivery of opioids, and in this study, we aim to provide a safe methodology using an outpatient protocol.
STUDY DESIGN: The study is designed as a retrospective analysis on all non-malignant chronic pain patients who were candidates for TDD, who underwent an outpatient catheter trial from January 1, 2015 to December 31, 2016.
SETTING: The study took place in an outpatient-based community practice.
METHODS: A retrospective chart review and patient experience questionnaire were utilized to assess the safety and efficacy of 98 patients who underwent an intrathecal continuous infusion catheter trial as an outpatient. The patients underwent an intrathecal catheter placement at the L2/3 interlaminar space with the catheter tip at T10, regardless of pathology. The patients were connected to an ambulatory pump and were monitored as an outpatient for up to 3 days.
RESULTS: Ninety of the 98 patients had greater than 50% pain relief and proceeded to a permanent intrathecal pump implant. The average effective dose of morphine or hyrdromorphone was 480 mcg/day. Using our outpatient and dosage methodology, 0 patients had serious adverse events which include infection, self-reported or caregiver-reported respiratory difficulty, or an emergency room (ER) visit during the trial.
The most common adverse events were post-dural-puncture headache (PDPH), which occurred in 41% of the patients, nausea/vomiting in 28% of the patients, and catheter dislodgment in 18% of the patients.
LIMITATIONS: The sample size can be increased to further prove safety. A multicenter study would also prove to be a benefit.
CONCLUSION: Based on this study, we have devised a safe and efficacious methodology for performing an outpatient intrathecal trial using a continuous infusion catheter, using low doses. Implanted drug delivery systems are being increasingly utilized for chronic non-malignant pain, and this study implements a safe methodology. This study hopes to provide better patient access or an alternative to inpatient intrathecal infusion trials, which can be cumbersome.
Key words: Targeted drug delivery, pump trial, intrathecal opioid, intrathecal infusion, outpatient trial, chronic non cancer pain