The anesthetic technique of choice for surgical treatment of CTS varies among surgeons. In the last decade some studies have described the performance of this surgery using local anesthesia with adrenaline without the necessity of sedation or the use of pneumatic garrote, having good effectiveness and substantial reduction of costs. However there is need for studies with an appropriate design and methodology to evaluate the actual effectiveness of this kind of anesthesia for the surgical treatment of CTS.

Objective: To evaluate the effectiveness and cost of open surgery for CTS in a randomized trial comparing two anesthesia methods: intravenous regional anesthesia (Bier) and local anesthesia with adrenaline without limb garroting (Lalondi).

Methods: This study was developed in the Group of Hand Surgery and Upper Limb; Department of Orthopedics and Traumatology, Federal University of São Paulo, UNIFESP / EPM with co-participation of the Hand Surgery and Microsurgery Department of Hospital Alvorada. This study will be a Randomized Clinical Trial. The previous calculation of the sample resulted in 78 patients. The following primary outcomes will be assessed: Pain through visual analogue scale (VAS). Costs: Costs related to anesthetic and surgical procedures will be recorded. The secondary outcomes will be: Use of Analgesics, Anxiety and Depression through the HADS (Hospital Anxiety and Depression Scale) scale. Quality of life through the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ). Remission of paresthesia after surgical intervention, complications and failures.

Surgical treatment of CTS is most often performed under hospital conditions, with the use of anesthesia. The anesthetic technique of choice varies among surgeons. In the last decade some studies have described the performance of this surgery using local anesthesia with adrenaline without the necessity of sedation or the use of pneumatic garrote, having good effectiveness and substantial reduction of costs for the procedure with this anesthetic method. However, when we evaluated the level and strength of the evidence from these studies, we notice that there is a need for studies with an appropriate design and methodology to evaluate the actual effectiveness of this kind of anesthesia for the surgical treatment of CTS.

Objective: To evaluate the effectiveness of open surgery for CTS in a randomized trial comparing two anesthesia methods: intravenous regional anesthesia (Bier) and local anesthesia with adrenaline without limb garroting (Lalondi).

Methods: This study was developed in the Group of Hand Surgery and Upper Limb; Department of Orthopedics and Traumatology, Federal University of São Paulo, UNIFESP / EPM with co-participation of the Hand Surgery and Microsurgery Department of the Medical Residency Service in Hand Surgery of Hospital Alvorada. This study will be a Randomized Clinical Trial. The previous calculation of the sample resulted in the need for total inclusion of 35 patients in each group, total of 70 patients, considering a loss of 10% during follow-up we will include 78 patients. The following primary outcomes will be assessed: Pain through visual analogue scale (VAS), that, will be measured in the pre-operative, transoperatory, immediate postoperative, 2 hours, 4 hours, 6 hours, 8 hours, 12 hours after surgery. Costs: Costs related to anesthetic and surgical procedures will be recorded. The secondary outcomes will be: Use of Analgesics, Anxiety and Depression through the HADS (Hospital Anxiety and Depression Scale) scale. Quality of life through the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ). Remission of paresthesia after surgical intervention, complications and failures.

Inclusion Criteria:

• Patients older than 18 years of age, with idiopathic Carpal Tunnel Syndrome with indication for surgery due to failure of conservative treatment for at least three months or that presented at the initial diagnosis with motor impairment detected by clinical examination (hypotrophy) and/or by electromyography (ENMG) examination.
• The diagnosis of CTS will be made through the clinical evaluation in which CTS patients will be considered, those who present at least four of the clinical criteria proposed and proven by the electromyography examination.

Clinical Criteria for CTS - (At least 4 criteria will be required for clinical confirmation of the diagnosis)

1. Paresthesia in the territory of the median nerve

2. Night paresthesia of the hand

3. Decreased strength with hypotrophy of the musculature tenar

4. Positive tinnitus sign on the wrist

5. Positive Phalen test

6. Loss of 2-point discrimination in the region innervated by the median nerve

   • Patients who agree to participate, after having been adequately informed about the nature of the study, and have reading and signed the informed consent form.

Exclusion Criteria:

• Patients with prior history of cervical spine diseases (radiculopathies, arthrosis),
• Pregnant women and puerperal women,
• Patients with sequelae of previous wrist and hand surgeries,
• Other upper limb compressive syndromes and scapular girdles will be excluded

open label