Dexametasone Versus Dexametasone Plus Dexmedetomidine in Nerve Blocks
Condition: Analgesia; Pain, Acute; Upper Extremity Injury
MeSH terms: Acute Pain; Arm Injuries
Study type: Interventional
Phase: Phase 4

Summary: 
      This study will compare perineural dexamethasone 2mg and perineural mixture of dexamethasone
      2mg plus dexmedetomidine 50mcg DX plus DXD as adjuvants to local anesthetics for
      ultrasound-guided infraclavicular brachial plexus blocks (ICBs). The protocol is designed as
      a superiority trial and hypothesizes that the mixture of both drugs results in longer block
      duration. Furthermore, since analgesic and sensory duration can be influenced by the intake
      of pain medications and surgical trauma to small cutaneous nerves, respectively, motor block
      duration was selected as the main outcome to better target the action of both adjuvants on
      the brachial plexus.
    

Detailed description: 
      With the approval of Ethics Committee of the Hospital Clínico Universidad de Chile, a total
      of 50 patients undergoing upper extremity surgery (elbow and below) will be recruited.
      Recruitment will be carried out by an investigator not involved in patient care in the
      preoperative clinic or during routine preoperative visits.

      All ICBs will be supervised by one of the coauthors and conducted preoperatively in an
      induction room.

      After skin disinfection and draping, the ICB will be performed with a previously described
      technique. In both groups, a proven 90% effective volume of 35 mL of local anesthetic
      solution will be injected. As LA solution, it will be used a mixture of lidocaine
      1.0%-bupivacaine 0.25% with epinephrine 5 µ/mL. The injectate will be slowly injected through
      the block needle.

      Patients will be randomized to receive the study drug, either PN 2 mg dexamethasone or a
      combination of PN 2 mg dexamethasone with 50 ug dexmedetomidine, mixed with the
      above-mentioned LA solution.

      A research assistant (licensed anesthesiologist) will prepare the local anesthetic solutions
      and will add the study drug following the randomization order. The operator, patient and
      investigator assessing the block will be blinded to group allocation.

      The primary outcome will be the duration of the motor block (defined as the temporal interval
      between the end of LA injection through the block needle and the return of movement to the
      hand and fingers) for patients with successful ICBs. Patients will be provided with a data
      sheet and asked to record the time at which motor function returns. An investigator blinded
      to group allocation will collect this data sheet in person (inpatients) or by phone
      (outpatients) on postoperative day 1.
    

Intervention name(s): Dexamethasone; Dexmedetomidine-Dexamethasone
Intervention type(s): Drug; Drug
Intervention description(s): dexamethasone 2 mg will be added to the local anesthetic used to block the cords of the brachial plexus with an infraclavicular approach.; A mixture of dexamethasone 2mg with dexmedetomidine 50mcg will be added to the local anesthetic used to block the cords of the brachial plexus with an infraclavicular approach.
Intervention MeSH terms: Dexamethasone; Dexamethasone acetate; Dexmedetomidine; BB 1101
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: blinded-randomized controlled trial
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Supportive Care
Keywords: dexamethasone; dexmedetomidine; nerve block; adjuvants