Systemic Steroids for Peripheral Nerve Blocks

The Effects of Systemic Steroids on the Duration of a Psoas Compartment Block.

This study will investigate the ability of systemic dexamethasone to prolong the sensory block duration for lumbar plexus nerve blockade.

The purpose of this randomized, double-blinded, placebo-controlled trial is to examine the equivalency of two different doses of dexamethasone when given intravenously as an adjuvant medication for postoperative pain management. Specifically, this study will investigate the prolongation of time to recovery of sensation following a lumbar plexus block in patients undergoing total hip arthroplasties. The investigators hypothesize that dexamethasone will prolong the sensory block time when compared to placebo and that similar results will be obtained in the 4 mg arm when compared to the 8 mg arm. The primary end point will be time to sensory recovery in the femoral nerve cutaneous distribution (part of the lumbar plexus) as determined by pin-prick sensation assessment. Secondary endpoints will include, but are not be limited to: time to first opioid administration, total opioid consumption over 30 hours, and rest and incident verbal numerical pain scores at 6,12,18,24 and 30 hours post block placement.

Inclusion Criteria: Primary elective total hip arthroplasty surgery

• must be a candidate for placement of a lumbar plexus block under anatomic landmark technique using electrical stimulation
• must give written informed consent for anesthesia
• must also be reliable and able to give accurate verbal pain scores postoperatively

Exclusion Criteria:

• contraindications to regional anesthesia including, allergy to amide local anesthetics, presence of peripheral neurologic dysfunction, pre-existing coagulopathy or infection in the area of interest will be excluded.
• insulin and non-insulin dependent diabetes mellitus
• preoperative use of systemic corticosteroids within 30 days of surgery
• chronic opioid use (defined as daily opioid dose of greater than 40 mg of oxycodone equivalents or any long-acting opioid)
• pregnancy
• failure to effectively place the lumbar plexus block.
• known prior adverse reaction to dexamethasone (for example: psychosis) or an allergy to dexamethasone