A Randomized Comparison Between 0.67 mcg/kg, 1 mcg/kg, and 1.33 mcg/kg of Perineural Dexmedetomidine for Ultrasound-Guided Infraclavicular Block
Trial Parameters
Brief Summary
This study will compare three different doses of perineural dexmedetomidine 0.67 mcg/kg, 1 mcg/kg, and 1.33 mcg/kg as adjuvants to local anesthetics for ultrasound-guided infraclavicular brachial plexus blocks (ICBs). Our research hypothesis is that 1.33 mcg/kg will provide a 15%-longer duration than 1mcg/kg, which in turn will provide a 15%-longer duration than 0.67 mcg/kg. Since analgesic duration and sensory duration can be influenced by intake of pain medications and surgical trauma to small cutaneous nerves, respectively, we will select motor block duration as the main outcome to better target the action of dexmedetomidine on the brachial plexus.
Eligibility Criteria
Inclusion Criteria: * patients undergoing upper limb surgery at or below the elbow * age between 18 and 75 years * American Society of Anesthesiologists classification 1-3 * body mass index between 18 and 35 kg/m2 Exclusion Criteria: * adults who are unable to give their own consent * allergy or contraindication to dexmedetomidine * exposure to dexmedetomidine during the previous 48 hrs * pre-existing neuropathy (assessed by history and physical examination) * coagulopathy (assessed by history and physical examination and, if deemed clinically necessary, by blood workup i.e. platelets ≤ 100, International Normalized Ratio ≥ 1.4 or partial prothrombin time ≥ 50) * renal failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work-up i.e. creatinine. eGFR \< 90) * hepatic failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work-up i.e. transaminases ≥ 100) * allergy to LA * pregnancy (as instituti