Dexamethasone Versus Dexmedetomidine as Adjuvants for Nerve Blocks

University of Chile120 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Enrollment

120

Conditions

Pain, Postoperative Pain, Acute Upper Extremity Injury

Interventions

DexamethasoneDRUG

Dexamethasone as perineural local anesthetic adjuvant

DexmedetomidineDRUG

Dexmedetomidine as perineural local anesthetic adjuvant

Eligibility

Sex: ALLMin age: 18 YearsMax age: 75 Years

Medical Language ↔ Plain English

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

Locations (1)

Hospital Clínico Universidad de Chile

Santiago, Santiago Metropolitan, Chile

Outcomes

Primary Outcomes

Motor block duration

Elapsed time since the end of LA injection until return of hand and fingers movement

Time frame: 24 hours after block

Secondary Outcomes

Sensory block duration

Elapsed time since the end of LA injection until return of hand and fingers sensation

Time frame: 24 hours after block

Analgesic block duration

Elapsed time since the end of LA injection until first sensation of pain in surgical area

Time frame: 24 hours after block

Block performance time

Elapsed time from skin desinfection until the end of LA injection

Time frame: 1 hour before surgery

Intensity of pain during block procedure

Evaluated with a numeric rating score from 0 to 10

Time frame: 1 hour before surgery

Block onset time

Time required to reach a minimal sensorimotor composite score of 14 points out of a maximum of 16 points

Time frame: 1 hour before surgery

Sensory and motor block score

Sensorimotor block assessed every 5 minutes until 30 minutes using a 16-point composite score evaluating sensory and motor block of musculocutaneus, medium, radial and ulnar nerves. Sensation will be assessed with ice in each nerve territory with a 0 to 2 point scale. 0= no block, patients can feel cold; 1= analgesic block, patient can feel touch but not cold; 2= anesthetic block, patient cannot feel cold or touch. Motor function will be assessed for each nerve with a 0 to 2 points scale where 0= no motor block; 1= paresis; 2= paralysis. Succesfull blocks at 30 minutes correlate with a final score ( sum of all individual sensory and motor scores) of at least 14 points out of 16.

Time frame: 30 minutes post injection

Incidence of complete block

Percentage of blocks with a minimal sensorimotor composite score of 14 points out of a maximum of 16 points at 30 minutes post injection

Time frame: 30 minutes post injection

Perioperative glycemic levels

Capillary dextrose measurements at pre block, 1 hour post-surgery and 6 hours post-surgery

Time frame: Perioperative period

Perioperative median artery pressure (MAP)

Average of MAP and HR registered during preblock, intraoperative and up to 2 hours of postoperative period