Oral Dexamethasone as an Adjunct to a Brachial Plexus Block in Patients Undergoing Orthopaedic Surgery of the Forearm and Hand

Oral Dexamethasone as an Adjunct to a Brachial Plexus Block in Patients Undergoing Orthopaedic Surgery of the Forearm and Hand. A Randomised, Blinded, Placebo-controlled, Parallel, Triple-arm Clinical Trial.

The investigators will assess the beneficial and harmful effects of oral dexamethasone (12 mg or 24 mg) versus placebo in patients undergoing orthopaedic surgery of their hand or forearm with a lateral infraclavicular brachial plexus block as the means of providing anaesthesia and analgesia.

This is a randomised, blinded, placebo-controlled, multicentre, parallel, 3-arm clinical trial assessing the effects of adjunct oral dexamethasone (12mg or 24mg) versus placebo on time to first pain (i.e. block duration) in patients undergoing surgery of the forearm or hand. At the initiation of the trial, no other trials had examined the effects of oral dexamethasone as an adjunct to peripheral nerve blocks.

The investigators will randomise participants to either oral dexamethasone 12mg, oral dexamethasone 24mg, or placebo. Participants will be allocated according to a computer-generated random allocation sequence with random permuted blocks and stratification by site. Glostrup Pharmacy produced the trial medication and sequentially numbered the drug containers, thereby concealing the allocation.

All involved will be blinded for the entire duration of the trial (participant, carers, investigators, people delivering the intervention, observers/outcome assessors, statisticians). Blinding will not be broken until agreement has been reached within the steering committee regarding the statistical analysis. The trial medication is produced as identically appearing opaque capsules containing either dexamethasone or placebo. The trial medication is contained within identically appearing, sequentially labelled containers.

The investigators expect little to no attrition bias since the intervention is simple with a short follow-up. The investigators expect some missing data for duration of the motor block, as most participants will have the affected limb immobilized post-surgery, thereby making assessment of return of motor function difficult.

The investigators pre-defined the statistical analysis plan prior to unblinded data becoming available. The analysis plan can be found on: https://doi.org/10.6084/m9.figshare.22491214.

Inclusion Criteria:

• Scheduled for unilateral osseous surgery of the hand or forearm.
• Anaesthesia with an infraclavicular brachial plexus block
• Age of 18 or above
• American Society of Anaesthesiologists Physical Status Score of 1 to 3
• Body Mass Index of 18 to 40, but a minimum weight of 50 kg.
• For fertile women, negative urine humane choriongonadotropine test and use of safe anti-conception
• Ability to understand the trial protocol, risks and benefits, and provide signed informed consent

Exclusion Criteria:

• Inability to read and understand Danish
• Uncooperativeness (as judged by investigators)
• Participation in another trial involving medication
• Allergy to study medication
• Daily use of opioids above 30 mg/day morphine (or equivalents)
• Daily use of corticosteroids of more than 5 mg prednisolone equivalents within the past one month
• Neurological or musculoskeletal disease making block performance impossible (as judged by investigators)
• Dysregulated diabetes (as judged by investigators)
• Dysregulated anti-coagulants (as judged by investigators)
• History of drug or alcohol abuse
• Glaucoma
• Contraindications for paracetamol or opioids
• Other concomitant conditions needing surgery
• Other concomitant traumatic injuries