A Randomized Double Blind Cross-over Trial of Continuous Intrathecal Infusion for Assessing Patients With Chronic Non-cancer Pain Who Would Benefit From Treatment With Intrathecal Drug Delivery System (IDDS) Implant

Recruitment: Subjects will be recruited from patients seen at the University Hospitals Pain Medicine clinics by attending physicians. Screening will be done before obtaining consent by an investigator. If patients are deemed appropriate for an intrathecal device they will undergo normal procedures and guidelines in place prior to being considered candidates for an implantable device. No subject will be compensated for participation.

Consent Process: Subjects will be consented by one of the investigators. An explanation in lay terms for the reasons of the study and the proposed prognostic benefits will be used to promote patient understanding. If interested, eligible individuals will be given the opportunity to ask and have all questions addressed before signing the informed consent document. The procedure will occur at their next visit, and continued consent of study participation will be confirmed.

Study Design: This is a randomized, double-blind, placebo controlled cross over study comparing prognostic intrathecal testing with an admixture of bupivacaine and fentanyl versus saline. None of the procedures in this study deviate from usual clinical care that patients receive at UHCMC or nationally. Baseline scores using the numerical rating scale (NRS) for pain (a scale form 0-10, where 0 signifies no pain at all, and 10 the worst possible pain) will be recorded, both in the sitting or supine position (least pain) and with ambulation or standing (worst pain). Patients will be given weight based cefazolin (or vancomycin if indicated) prior to placing the externalized intrathecal catheter. Placement of the percutaneous intrathecal catheter will be done in the operating room with minimal or no sedation in the prone or lateral decubitus position under fluoroscopic guidance. Needle entry will occur in the mid-upper lumbar spine and through the needle an intrathecal catheter will be advanced until its tip is positioned in the posterior intrathecal space in the lower thoracic spine. The needle is then removed and the catheter is secured in place with steri-strips and a clear sterile bio-occlusive dressing will be placed. Patients will then be transferred to the PACU where they will be initiated on one of two solutions that will be prepared for each patient by the investigational pharmacy staff at UHCMC. The solutions will be labeled as "Intrathecal solution 1" and "Intrathecal solution 2" and will be contained in a sterile 50 ml bag. Solution 1 and 2 may contain either:

1. Preservative-free normal saline
2. Fentanyl 1 mcg/ml and bupivacaine 0.625 mg/ml

The content of Intrathecal solution 1 and 2 will be unknown to all investigators and participants in the study with the exception of the investigational pharmacy. The order of the Intrathecal solution (1 or 2) will be determined by pharmacy using a computer generated random sequence allocation. The intrathecal catheter will be attached to a pump delivering solution 1 or 2 at around noon time, in the recovery area on the day the catheter is placed. A bolus of 1cc will be given through the infusion pump at initiation of therapy and the patient will then be started on an infusion rate of 0.5 ml/hr. After 3-4 hours (around 3-4 pm) and similarly around 6-7 pm the rate will be titrated depending on patient's response up to a maximum of 0.8-1.0 ml/hr. If the patient has achieved > 50% pain relief compared to baseline, no up-titration will occur; i.e. the rate will be increased only if the patient has not had 50% or more reduction in baseline pain on the NRS. The intrathecal rate will be kept the same provided the patient had 50% or greater decrease in pain scores or has reached the 1.0 ml/hr rate (whichever comes first). The rate will be unchanged from 6-7 pm until around 6-7 am the next morning when the infusion will be stopped and the patient will be assessed for pain relief. In the morning, the patient will be asked to rate the pain score at rest (in bed or chair) and with ambulation/standing. The pain scores will be recorded and the catheter will be aspirated at the hub to ensure continued cerebrospinal fluid flow and the patient will be started on a solution of preservative-free normal saline at 0.2 ml/hr to keep the catheter patent. After 6 hours, around noon time, the patient will be crossed over to Intrathecal solution 1 or 2, depending on what she/he had the day before, given 1.0 ml of that solution as a bolus and then infusion will be started at 0.5 ml/hr and the same protocol as the day before will be repeated with the patient discharged the next morning. Patients who experience greater than 50% pain relief (relative to baseline) with either intrathecal solution will be offered the implant of a permanent IDDS that will deliver a combination of bupivacaine and low-dose fentanyl. Patients not responding to both solutions with greater than 50% pain relief will be considered to have failed the intrathecal test and would not proceed to implant. The patients will be asked to pick which solution provided better pain relief: solution 1 or solution 2 and responses will be recorded. Additionally, pain scores obtained periodically as part of patients' usual clinical care vital signs and recorded by the nursing staff on the hospital ward will be collected throughout the study. Un-blinding for patients who had a successful intrathecal prognostic infusion test with greater than 50% pain relief will not occur until 12 months have elapsed since the pump implant.