Intravenous and Perineural Dexamethasone for Ultrasound-Guided Axillary Blocks
Condition: Brachial Plexus Block Duration
Study type: Interventional
Phase: Phase 2/Phase 3

Summary: 
      Dexamethasone prolong the duration of brachial plexus blocks, but the optimal route,
      intravenous (IV) or perineural (PN), remains controversial.

      This Multi-centric trial compare IV and PN dexamethasone for ultrasound-guided axillary
      brachial plexus blocks (AXBs). Research hypothesis is that PN modality will outlast its IV
      counterpart. Since analgesic duration and sensory duration can be influenced by intake of
      pain medications and surgical trauma to small cutaneous nerves, the investigators will select
      motor block duration as the main outcome.
    

Detailed description: 
      After Ethics Committee of the McGill University Health Centre, a total of 150 patients
      undergoing upper extremity surgery (below the elbow) will be recruited.

      All AXBs will be supervised by one of the coauthors and conducted preoperatively in an
      induction room. This area will have full access to an oxygen source, resuscitative equipment
      and drugs.

      All patients will have fasted for at least eight hours. An IV cannula will be placed prior
      the block and will be monitored and given oxygen at 2-4 L/min through nasal cannulas.

      Light sedation will be provided for patient comfort if needed.Patients will be placed supine
      with the shoulder abducted and the elbow flexed. The AXB will have a puncture site superior
      to the axillary artery. After skin disinfection and draping, a skin wheal will be raised with
      3 mL of lidocaine 1.5%.

      In both groups, 30 mL of lidocaine 1.0%-bupivacaine 0.25% with epinephrine 5 µ/mL will be
      used. A 22-gauge, 5 cm block will be advanced under direct US vision toward the
      musculocutaneous nerve. Six mL of LA will be deposited in this location. The needle will then
      be directed posterior to the artery, at 6 o'clock position and twenty-four mL of LA will be
      deposited to obtain a spread around the artery.

      Patients will be randomized to receive 8 mg of IV or PN dexamethasone. In the IV group,
      patients will receive 0.8 mL of dexamethasone (10 mg/mL) intravenously and 0.8 mL of normal
      saline will be added to the injectate through the block needle. In the PN group, patients
      will receive 0.8 mL of normal saline intravenously and 0.8 mL of dexamethasone (10 mg/mL)
      will be added to the injectate through the block needle.

      A research assistant will prepare the IV and PN injectates. The operator, patient and
      investigator assessing the block will be blinded to group allocation.

      If placement of the needle tip in the desired location is unsuccessful after 15 minutes, the
      procedure will be stopped and the patient excluded from the study. Brachial plexus blockade
      will be carried out using an alternative method. If the alternative method fails as well, the
      patient will be given general anesthesia and intravenous narcotics will be used for
      postoperative analgesia
    

Intervention name(s): intravenous 8 mg dexamethasone and perineural 0.8 ml of saline solution; intravenous 0,8 ml of saline solution and perineural 8 mg of dexamethasone
Intervention type(s): Other; Other
Intervention MeSH terms: Dexamethasone; Dexamethasone acetate; Pharmaceutical Solutions; BB 1101
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Outcomes Assessor)
Primary purpose: Supportive Care