Carpal Tunnel Release Under Local Anaesthesia With or Without Distal Median Nerve Block

Carpal Tunnel Release Under Local Anaesthesia With or Without Distal Median Nerve Block - a Protocol of a Double Blinded Randomised Controlled Trial

Carpal tunnel syndrome (CTS) is the most commonly appearing entrapment neuropathy of the upper extremity. Treatment options include both non-operative and operative methods. Surgical treatment, carpal tunnel release (CTR), involves division of the transverse carpal ligament. Surgery can be performed under axillary or intravenous block, or general anaesthesia. There are no prior randomised controlled trials (RCT) comparing local infiltration anaesthesia to local infiltration anaesthesia augmented with a distal median nerve block in CTR.

The aim of this trial is to investigate whether adding a distal median nerve block to local anaesthesia reduces the patient's perceived pain level for up to 72 hours after CTR, compared to using only local anaesthesia, i.e., an anaesthesia mixture injected solely in and around the planned incision and nerve release. The null hypothesis is that the use of distal median nerve block with local anaesthesia does not reduce pain after CTR compared to pure local anaesthesia.

PERSONNEL (carPal tunnEl ReleaSe lOcal iNfiltratioN mEdian bLockade) is a double-blinded, i.e., patient and investigators, RCT in patients with CTS. Patients will be randomly divided into two parallel trial groups, 1:1 in size to each other. Fifty-nine patients will be needed for each group to have adequate power. The primary outcome is the pain level perceived by the patient after the procedure during the first 72 hours using the Visual Analogue Scale (VAS). Secondary outcomes include patient-rated outcome measures, safety, the entire consumption of pain killers after the surgery during the first 72 hours postoperatively, pain of performing the anaesthesia, and pain during and after the operation.

No trial comparing local anaesthesia to local anaesthesia augmented with distal median nerve block has been published before. There is also no trial noting individual tolerance to pain. The quality of the median nerve block at the wrist has been achieved by using sensory or sensory-motor nerve stimulation and has been proven effective. This increases trust in the effectiveness of the treatment method, but it still needs to be adequately proven which is the goal of this trial.

Inclusion Criteria:

• ≥18 years of age
• CTS verified by nerve conduction studies
• Symptoms suitable for CTS

Exclusion Criteria:

• Recurrent CTS
• Peripheral neuropathies
• Known allergy to the trial drugs
• Profound cognitive impairment
• Pregnancy