Does Perineural Dexamethasone Increase the Duration of an Ulnar Nerve Block When Controlling for Systemic Effects?

Healthy volunteers will have bilateral ulnar nerve blocks performed with bupivacaine on two different days with a minimum of 14 days wash-out. On one day, the participants will also receive dexamethasone in one arm and placebo in the other. On the other day, the participants will also receive placebo in one arm and lidocaine in the other. By this using this design, the investigators will be able to assess if perineural dexamethasone can increase the duration of an ulnar nerve block when controlling for the systemic effects. Furthermore, to ensure blinding, the investigators have also incorporated the lidocaine group which also allows for the assessment of the effects of adding lidocaine to a peripheral nerve block with bupivacaine. The order of which the participant will receive dexamethasone and lidocaine will be random. It will also be random in which arm the participant receives dexamethasone and lidocaine.

Inclusion criteria

• Age of 18 years or above
• Must fully understand the protocol and sign written informed consent
• American Society of Anaesthesiologists Physical Status Classification System of 1 or 2
• Body Mass Index above 18 kg/m^2
• For fertile women, safe contraceptives for the last month and negative urine human chorionic gonadotropin is required

Exclusion criteria

• Participants unable to cooperate
• Participants unable to speak or read Danish
• Age above 65 years
• Cardiovascular disease
• Allergy to study medication
• History of alcohol or substance abuse
• Intake of corticosteroids within the last 14 days
• Daily intake of prescription analgesia within the last four weeks
• Intake of over-the-counter analgesia within the last 48 hours
• Neuromuscular diseases or wounds on the arms or hands preventing adequate test or block performance.
• Diabetes mellitus