Low Dose Dexamethasone in Supraclavicular Blocks

• Status: Unknown status
• Trial end date: 2021-02-01
• Target enrollment: 0
• Participant gender: All

Summary

Brachial plexus nerve blocks provide superior analgesia over opioids while avoiding unwanted side effects. Single shot blocks with local anesthetic alone usually do not last the duration of the acute post-surgical pain period. This has led to the exploration of multiple adjuvants to increase the duration of single shot blocks, the most promising adjuvant being dexamethasone.

Peri-neural administration is an off-label use of dexamethasone. While no adverse events have been reported in human clinical studies, logic would dictate that we minimize the dose needed to produce the desired effect. Most studies thus far have used peri-neural dexamethasone doses ranging from 4-10 mg. However, Albrecht et al. found no difference in block duration comparing 4 mg and 8 mg doses while Liu et al. reported equivalent block duration using doses of 1, 2 and 4 mg.

Recent studies have evaluated whether systemic and peri-neural administrations of dexamethasone are equivalent, which would in turn imply a site of action. Results have been mixed. Four studies concluded peri-neural and intravenous administration are equivalent at prolonging analgesia, though one study had methodological errors, including the administration of intravenous dexamethasone to all patients. All of these studies used dexamethasone doses of 8 to 10 mg. One study where a lower dose (4 mg) was used found that peri-neural administration prolonged block duration whereas intravenous did not.

With that, the rationale of our study is to determine if equivalent block-prolonging analgesia can be achieved using low dose (1 mg) dexamethasone given peri-neural or intravenous. Clinical experience at our centre has been that 1 mg dexamethasone added to 20 mL produces similar block duration to that reported in published studies using higher doses.

• Phase: N/A
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: University of Calgary
• Treatments: BB 1101; Dexamethasone; Dexamethasone 21-phosphate; Dexamethasone acetate

Criteria

Inclusion Criteria:

• Adult 18 - 80 years

• BMI equal to or less than 35

• Upper limb surgery

• Normal pre-operative sensation in the operative limb

Exclusion Criteria:

• Pre-operative opioid greater than 4 Tylenol #3 per day (or equivalent)

• Pre-existing, fluctuating neurologic injury involving operative upper limb

• Patient refusal or patient inability to provide consent

• Suspected inability to comply with study procedures, including language difficulties or medical history and/or concomitant disease (skin infection at site of needle insertion) as judged by the investigator or attending anesthesiologist, reason for exclusion will be recorded.

• Patient pregnancy

• Patient BMI > 35

• Patient allergy to any of the drugs used in the protocol

• Surgical concern of postoperative neurological injury from surgical manipulation.

• Brittle diabetics

• Other contraindication to receiving a block (coagulopathy, significant respiratory risk, etc.)

• Surgeon refusal (e.g. concerns about compartment syndrome); reason for exclusion will be recorded