Ultrasound-guided combined infraclavicular-anterior suprascapular block of the brachial plexus, injecting 20 ml of bupivacaine 0.5% plus epinephrine 5 micrograms per ml dorsal to the axillary artery in the infraclavicular fossa plus an ultrasound-guided injection of 3 ml of bupivacaine 0.5% plus epinephrine 5 micrograms per ml under the omohyoid muscle. If the anterior suprascapular nerve could not be identified after five minutes of insonation time, an upper trunk block will be carried out with the same amount of local anesthetic.

Patients will receive dexamethasone 4 mg intravenously and an ultrasound-guided intermediate cervical plexus block (5 ml of bupivacaine 0.5% plus epinephrine 5 micrograms per ml).

Pain intensity at rest using a NRS ranged from 0 to 10 (0 = no pain and 10 = worst imaginable pain)

Pain intensity at rest using a NRS ranged from 0 to 10 (0 = no pain and 10 = worst imaginable pain)

Pain intensity at rest using a NRS ranged from 0 to 10 (0 = no pain and 10 = worst imaginable pain)

Pain intensity at rest using a NRS ranged from 0 to 10 (0 = no pain and 10 = worst imaginable pain)

Pain intensity at rest using a NRS ranged from 0 to 10 (0 = no pain and 10 = worst imaginable pain)

Time from skin disinfection until the end of local anesthetic injection

Evaluated with the Numeric Rating Scale for Pain. This scale is graduated from 0 to 10 points. A 0-point score represents the absence of pain, and a 10-points score represents the worst imaginable pain. Patients will be asked to rate their pain verbally with this scale. The blinded assessor will register the score reported.

Determined by the presence of paresthesia, local anesthetic systemic toxicity, vascular puncture, Horner syndrome, or hoarseness after the block.

The sensorimotor block will be assessed every 5 minutes until 30 minutes after the end of local anesthetic injection using a 14-point composite score that encompasses the sensory functions of the axillary and supraclavicular nerves as well as the motor functions of the axillary, suprascapular, subscapular and lateral pectoral nerves

Sensation will be assessed with ice in each nerve territory with a 0 to 2 point scale. 0= no block, patients can feel cold; 1= analgesic block, the patient can feel touch but not cold; 2= anesthetic block, the patient cannot feel cold or touch.

The motor function will be assessed for each nerve with a 0 to 2 points scale where 0= no motor block; 1= paresis; 2= paralysis.

Successful blocks at 30 minutes correlate with a final score ( sum of all individual sensory and motor scores) of at least 12 points out of 14, with a sensory score of at least 3 points (out of 4 points).

Time required to reach a minimal sensorimotor composite score of 12 points out of a maximum of 14 points. The sensorimotor score is described in outcome 12.

Diaphragmatic function evaluated before the nerve block

HDP will be defined as the absence of diaphragmatic motion during normal respiration coupled with absent or (paradoxical) cranial diaphragmatic movement when the patient forcefully sniffs

HDP will be defined as the absence of diaphragmatic motion during normal respiration coupled with absent or (paradoxical) cranial diaphragmatic movement when the patient forcefully sniffs

Time between skin incision and closure (min)

Presence of postoperative nausea, vomiting, pruritus, urinary retention, respiratory depression.

Total amount of fentanyl required during general anesthesia

Total amount of morphine required during the first 48 hours after surgery

Patient satisfaction at 24 hours using a 0-10 scale (0 = not satisfied; 10 = very satisfied)

Presence of persistent sensory or motor postoperative deficit. The patients will be contacted by telephone and inquired about any sensory or motor deficit in the operated extremity.