Study Comparing Plasma Levels of Bupivacaine and Dexamethasone After Interscalene Nerve Block with Different Dexamethasone Methods

What this Trial Is About

Researchers are studying the effects of dexamethasone when given either around the nerve perineurally or through the vein intravenously during a single-shot interscalene nerve block for shoulder surgery. The study focuses on comparing blood levels of the local anesthetic bupivacaine and dexamethasone to better understand their absorption and effects. This research is important because previous findings suggest perineural dexamethasone may safely extend pain relief, but its exact action and systemic absorption are not well known. Participants will receive 20 mL of 0.25% bupivacaine combined with 8 mg of dexamethasone administered either perineurally or intravenously. The study is randomized and double-blind, involving 40 patients undergoing shoulder surgery that requires a single-shot interscalene block. Blood samples will be taken multiple times after the block to measure plasma concentrations of bupivacaine and dexamethasone. The trial compares these levels between the two groups to assess pharmacokinetics and block effectiveness. During the study, participants will have venous blood samples collected at several time points up to four hours post-block, plus one sample at discharge. Researchers will evaluate the plasma levels of both enantiomers of bupivacaine and dexamethasone, block duration, and opioid use. The study is conducted under medical supervision with careful monitoring of participants responses and safety throughout the trial period.

Effect of Dexamethasone on Plasma Levels of Bupivacaine and Dexamethasone After a Single-injection Interscalene Nerve Block.