Determining the Prognostic Value of Continuous Intrathecal Infusion
Condition: Lumbar Post-Laminectomy Syndrome; Chronic Low Back Pain; Vertebral Compression Fracture; Failed Back Surgery Syndrome
MeSH terms: Syndrome; Back Pain; Low Back Pain; Failed Back Surgery Syndrome; Fractures, Compression
Intervention: Continuous intrathecal prognostic infusion test; Bupivacaine; Fentanyl; Placebo; Intrathecal Drug Delivery System (IDDS)
Intervention description: The patient is infused with solution through the percutaneous intrathecal catheter at a rate of 0.5-1.0 ml/hr for approximately 14-18 hours; Bupivacaine 0.625 mg/ml and fentanyl 1 mcg/ml continuous infusion at a rate of 0.5-1.0 ml/hr for approximately 14-18 hours; Bupivacaine 0.625 mg/ml and fentanyl 1 mcg/ml continuous infusion at a rate of 0.5-1.0 ml/hr for approximately 14-18 hours; Intrathecal infusion of normal saline at a rate of 0.5-1.0 ml/hr for approximately 14-18 hours; 40-mL IDDS containing a solution of fentanyl 50 mcg/mL with bupivacaine 30 mg/mL
Intervention MeSH terms: Fentanyl; Bupivacaine
Phase: Phase 4
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Patients who are considered candidates for intrathecal pump implant fulfilling the inclusion/exclusion criteria and who elect to participate in the study will be randomly assigned to two groups:
Group A tested with continuous infusion of intrathecal bupivacaine 0.625 mg/ml and fentanyl 1 mcg/ml for 14-18 hours followed by a trial with normal saline for another 14-18 hours; separated by a 4-6-hr infusion of preservative-free saline.
Group B tested with intrathecal normal saline for 14-18 hours followed by intrathecal Bupivacaine 0.625 mg/ml and fentanyl 1 mcg/ml for another 14-18 hours; separated by a 4-6-hr infusion of preservative-free saline.
Masking: Triple (Participant, Care Provider, Investigator)
Masking description: The drugs will be delivered by the pharmacy to a blinded physician and labeled as Intrathecal solution 1 and Intrathecal solution 2 to be administered sequentially, separated by a 4-6-hr infusion of preservative-free saline. 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.
Enrollment: 36.0
Sex: All
Minimum age: 30 Years
Healthy volunteers: No
Keywords: intractable chronic low back pain; lumbar post-laminectomy syndrome; vertebral compression fracture; intrathecal drug delivery system

Summary:

      The purpose of this study will be to determine the efficacy and the prognostic value of a
      continuous intrathecal prognostic infusion test in an in-hospital setting for selecting
      patients who would have better long term outcomes for treatment with intrathecal implantable
      devices. The investigators will compare the primary outcomes [changes in pain intensity score
      (NRS), patient global impression of change (PGIC)] before and after intrathecal infusion of
      an admixture of bupivacaine 0.625 mg/ml and fentanyl 1 mcg/ml versus normal saline.

      The study will include 36 patients with intractable chronic low back pain in the setting of
      lumbar post-laminectomy syndrome or vertebral compression fracture who failed conservative
      management and are considered candidates for IDDS.

      Prior to the implant, the patients will undergo an intrathecal prognostic infusion test with
      an externalized catheter. Baseline NRS pain scores will be assessed and documented on all
      patients upon admission to the preoperative area. An intrathecal catheter will be placed in
      the outpatient procedure suite at the appropriate level for target dermatomes. The needle
      entry point will occur in the upper lumbar spine and catheter tip will be placed in the lower
      thoracic spine, under local anesthesia with the patient awake and with minimal or no
      sedation. The intrathecal infusion will be started using an external pump once patient is in
      the PACU. The research component is to perform the intrathecal test with normal saline
      (inactive placebo solution) in addition to a test with fentanyl and bupivacaine (active
      solution). Patients will be randomly assigned to either Group I (continuous infusion of
      bupivacaine and fentanyl followed by saline) or Group II (continuous infusion of saline
      followed by bupivacaine and fentanyl).

      In PACU, patients will be started on an infusion rate of 0.5 ml/hr and titrated to pain
      relief greater than 50% of baseline or up to 0.8-1.0 ml/hr within 6-8 hrs after start of the
      infusion. A clinician blinded to the treatment arm will assess NRS and PGIC on the patients
      after approximately 12 hours. Assessment will include changes in pain intensity score at rest
      and upon ambulating or performing maneuvers that normally elicit patient's low back pain. A
      4-6-hour washout period will be allotted with infusion of preservative-free normal saline at
      a rate of 0.2 ml/hr, after which the physician will document a return of the NRS to baseline
      before switching therapies.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Previous lumbar or thoracic spine surgery or lower thoracic/lumbar vertebral
             compression fracture

          -  Intractable pain of trunk (more than limbs)

          -  Patient who passed psychological evaluations as part of the usual clinical care prior
             to consideration of IDDS and are stable with current pain condition and medications

          -  Failed more conservative management.

        Exclusion Criteria:

          -  Untreated coagulopathy or infection.

          -  Immune compromised state precluding having an implant.

          -  Allergic reactions to bupivacaine or fentanyl.

          -  Pregnancy

          -  Patients using more than 30 mg oral equivalents of morphine daily or who are unable to
             wean down below that dosage for more than 4 weeks before the prognostic intrathecal
             infusion test.

          -  Neurological deficits characterized as weakness in lower extremities with evidence of
             nerve damage

          -  Patients with cognitive disorders who would not be able to provide meaningful outcome
             responses