Effect of Sedation on Diagnostic Injections

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.

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