Dexamethasone Versus Dexmedetomidine as Adjuvants for Nerve Blocks

A Randomized Comparison Between Perineural Dexamethasone and Perineural Dexmedetomidine as Adjuvants for Ultrasound-Guided Infraclavicular Blocks

When used as perineural (PN) adjuvants to local anesthetics (LAs), dexamethasone (DX) and dexmedetomidine (DXD) have been well documented to prolong the duration of peripheral nerve blocks. These drugs have important differences in terms of cost and safety profiles. This randomized controlled trial (RCT) will compare PN DX and PN DXD for ultrasound-guided infraclavicular brachial plexus blocks (ICBs).

Since analgesic and sensory duration can be influenced by factors different to block, motor block duration is the main outcome. The protocol is designed as an equivalency trial and hypothesize that both drugs result in similar durations. The equivalency margin is set at 3 hrs.

Inclusion Criteria:

• age between 18 and 75 years
• American Society of Anesthesiologists classification 1-3
• body mass index between 20 and 35

Exclusion Criteria:

• adults who are unable to give their own consent
• pre-existing neuropathy (assessed by history and physical examination)
• coagulopathy (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. platelets ≤ 100, International Normalized Ratio ≥ 1.4 or prothrombin time ≥ 50)
• renal failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. creatinine ≥ 100)
• hepatic failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. transaminases ≥ 100)
• allergy to local anesthetics (LAs)
• pregnancy
• prior surgery in the infraclavicular region
• chronic pain syndromes requiring opioid intake at home