Clinical trial NCT02322242: The Effects of Dexamethasone on Low Dose Interscalene Brachial Plexus Block
Official title: Comparison of the Effects of Perineural Versus Systemic Dexamethasone on Low Dose Interscalene Brachial Plexus Block: A Randomized Control Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Shoulder Surgery
Nerve Block
Lead sponsor: Sunnybrook Health Sciences Centre
Sponsor class: OTHER
Collaborators: name: The Physicians' Services Incorporated Foundation
First posted: 2014-12-23
Enrollment: 182
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: A standard interscalene nerve block is performed with long acting local anesthetic (bupivacaine or ropivacaine in concentrations varying from 0.25% to 0.75%). The purpose of this study is to investigate the effect of the addition of perineural dexamethasone (4mg) to a standard ropivacaine solution (0.5%) on analgesic duration of low dose interscalene block compared to ropivacaine alone for interscalene block with systemic dexamethasone.

Ropivacaine is not an intervention as a local anesthetic is pre-requisite to performing a nerve block.

Detailed description: Interscalene brachial plexus block (ISB) is regarded as the standard of care for analgesia after shoulder surgery providing superior analgesia and reducing opioid consumption. Shoulder surgery, previously requiring inpatient admission for pain control, is now commonly performed on an ambulatory basis facilitated by ISB analgesia. The effects of single injection ISB dissipate after several hours unmasking the moderate to severe pain of the surgical insult and require strong opioid analgesia. Efforts to prolong ISB duration by increasing local anaesthetic (LA) dose are limited by their pharmacodynamics and narrow therapeutic window. To address some of these issues faced with prolonging ISB analgesia the addition of perineural adjuvants to local anesthetic (eg. clonidine, dexmedetomidine), have been investigated in an attempt to prolong peripheral nerve block duration with limited success. However, the corticosteroid dexamethasone, has been added to local anesthetic solutions for ISB and has demonstrated promise in preliminary studies. Perineural dexamethasone (8-10mg) in conjunction with local anesthetic prolongs the duration of ISB with an effect sizes ranging from 40% to 75% (absolute effect \~ 6 to 10 hours). Dexamethasone, however, is only approved for intramuscular or intravenous administration and therefore perineural use is currently off-label. There are several reasons that warrant a new randomized trial. Chiefly, all of the previous trials do not reflect modern regional anesthetic practice. These trials utilized peripheral nerve stimulation (PNS) and local anesthetic volumes of 30 to 40 ml. Modern ultrasound guided ISB (US-ISB) allows for more accurate, targeted deposition of local anesthetic with volumes ranging from 5 to 10 ml with no difference in block efficacy or duration compared to larger volumes (≥20ml). An ideal solution would be a local anesthetic with adjuvant mixture that allowed administration of lower volumes but with prolonged analgesic duration. The use of low dose local anesthetic with dexamethasone could be one such solution. A trial that demonstrates enhanced block quality and duration associated with perineural dexamethasone added to low dose local anesthetic may allow us to achieve both prolonged duration of effect and reduced side effects due to unwanted local anesthetic spread. This would create further significant benefits for patients and further promote the use of low dose local anesthetic techniques to anesthesiologists who do not currently use this technique.

Eligibility criteria: Inclusion Criteria:

1. Patients undergoing arthroscopic shoulder surgery at Sunnybrook Health Sciences Centre, Toronto Western Hospital and Women's College Hospital.
2. ASA functional status class I to III
3. Age 18 to 80 years
4. BMI ≤ 35 kg/m2

Exclusion Criteria:

1. Lack of patient consent
2. Allergy to dexamethasone or ropivacaine
3. BMI \> 35 kg/m2
4. Contraindications to low dose dexamethasone including peptic ulcer disease, systemic infection, glaucoma, active varicella/herpetic infections, diabetes mellitus
5. Contraindications to ISB including severe Chronic Obstructive Pulmonary Disease (Forced expiratory volume \< 40% predicted), coagulopathy, pre-existing neurologic deficit in ipsilateral upper extremity, localized infection
6. Pregnant or nursing females
7. Chronic opioid use defined as \> 30mg oral morphine or equivalent per day
8. Unable to take acetaminophen or celecoxib

Primary outcomes:
measure: Duration of Sensory Block
timeFrame: 1 day postoperative
Secondary outcomes:
measure: Time to First Opioid Consumption
timeFrame: 1 day postoperative
measure: Duration of Motor Block
timeFrame: 1 day postoperative
measure: Post-operative Oxygen Saturation on Room Air
timeFrame: 1 hour postoperative
measure: Opioid Consumption
timeFrame: 7 days postoperative
measure: Numeric Rating Scale for Pain (NRS 0-10)
timeFrame: 7 days postoperative
measure: Postoperative Serum Blood Glucose
timeFrame: 1 hour postoperative
measure: Number of Participants With Nerve Damage From Interscalene Block
timeFrame: 7 Days postoperative
measure: Infection
timeFrame: 7 Days postoperative
measure: Number of Participants With Postoperative Nausea and/or Vomiting
timeFrame: 7 days postoperative
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: Sunnybrook Health Sciences Centre
state: Ontario
Study officials:
affiliation: SunnybrookHealth Sciences Centre
name: Stephen Choi, MD,FRCPC,MSc
role: PRINCIPAL_INVESTIGATOR
References:
citation: McHardy PG, Singer O, Awad IT, Safa B, Henry PDG, Kiss A, Au SK, Kaustov L, Choi S. Comparison of the effects of perineural or intravenous dexamethasone on low volume interscalene brachial plexus block: a randomised equivalence trial. Br J Anaesth. 2020 Jan;124(1):84-91. doi: 10.1016/j.bja.2019.08.025. Epub 2019 Oct 5.