Effect of Sedation on Diagnostic Injections

Not Applicable

Completed

Brief Summary: Interventional pain procedures have diagnostic, prognostic and therapeutic value. It is well-documented that the reference standard for identifying a pain generator is a low-volume block performed with local anesthetic, with or without steroid. Many factors may increase the false positive (FP) rate of diagnostic and prognostic nerve blocks; however, the use of sedation is the most controversial and remediable. Proponents of sedation argue that it has little effect on the rate of positive diagnostic blocks, and may even reduce the false-negative rate. The purpose of this study is to determine the effect of intravenous sedation on pain relief and the "false-positive rate" after diagnostic nerve blocks.

Detailed Description: Sixty-eight patients with sacroiliac (SI) joint or sympathetically-maintained pain will be randomized in a crossover fashion to receive diagnostic nerve blocks either with or without intravenous sedation. Among those who obtain some benefit and return for a 2nd block, this 2nd procedure will be done with sedation if the first was done without sedation, and vice versa. Midazolam and fentanyl will be used for intravenous sedation, titrated to anxiolysis and analgesia. Pain scores (0-10 numerical rating scale, or NRS) and an activity log will be recorded over the 8-hours following the blocks via a pain diary. The first follow-up visit will be 4 weeks after the procedure. Patients who obtain some benefit but continue to report significant pain or who might otherwise benefit from a repeat procedure will have this second procedure performed with sedation if no sedation was given for the first procedure, and without sedation if sedation was administered for the first procedure. The post-procedure pain data will be recorded in the same fashion as the initial nerve block. The second follow-up visit will be 4 weeks after the 2nd block.

Recruitment & Eligibility

Inclusion Criteria

Chronic pain > 4 weeks but < 10 years in duration
Suspected SI joint or sympathetically-maintained pain based on history and physical exam
May benefit from a sacroiliac joint or sympathetic block
Pain on 0-10 NRS scale > 3/10 in intensity

Exclusion Criteria

No previous interventional pain-alleviating injections for the same condition within the past 3 years
Uncontrolled coagulopathy
Pregnancy, which will be ruled out by a urine pregnancy test in women of childbearing age
Allergy to contrast dye or amide local anesthetics
Unstable medical or psychiatric condition (e.g. unstable angina, congestive heart failure or severe depression) that could preclude an optimal treatment response
Systemic infection
Age < 18 or > 75 years

Arm && Interventions

Group	Intervention	Description
Sedation	Midazolam	Pt will receive sedation with their procedure
Sedation	Fentanyl	Pt will receive sedation with their procedure

Primary Outcome Measures

Name	Time	Method
Pain Score	through 6 hours after injection	pain diary using 0-10 scale, with 0 being no pain and 10 being the worst pain imaginable

Secondary Outcome Measures

Name	Time	Method
Procedure-related Pain Score	1 day	0-10 pain scale, with 0 being no pain and 10 being the worst pain imaginable
Oswestry Disability Index	1-month	Measure of functional capacity on a scale ranging from 0% to 100%, with 0% signifying no disability
Satisfaction	1 day	5-point Likert scale. The scale is from 1-5. 1 being very unsatisfied and 5 being very satisfied.
Pain Score	1-month	0-10 numerical rating scale (NRS) pain scale. 0 being no pain and 10 being the worst possible pain.