Brachial plexus block (BPB) is frequently used as the sole anesthestic technique for upper extremity surgery. However, the choice of injection can be made from different approaches that often depends on the site of surgery because the extent of sensory-motor blockade after a BPB varies with the approach used. The investigator is not aware of any single BPB technique that can consistently produce surgical anaesthesia of the whole ipsilateral upper extremity. However, occasionally surgery entails that the whole upper extremity is anesthetized, i.e. from the shoulder to the elbow, or even the forearm, wrist or hands. This clinical challenge has been addressed previously using a combination of BPB techniques. The investigator has recently demonstrated that it is feasible to accurately identify majority of the main components of the brachial plexus above the clavicle, including the three trunks, using ultrasound imaging. Since majority of the innervation of the upper extremity, i.e. shoulder, arm, elbow, forearm, wrist and hand, originates from the three trunks of the brachial plexus, the investigator hypothesized that selectively blocking upper, middle, and inferior trunks of the brachial plexus will produce surgical anesthetsia of the whole ipsilateral upper extremity. The aim of this study is to assess a novel brachial plexus block technique, the selective trunk block (SeTB), and provide preliminary clinical evidence of its effectiveness in producing surgical anesthesia of the whole ipsilateral upper extremity.

Brachial plexus block (BPB) is frequently used as the sole anesthetic technique for upper extremity surgery. The choice of technique often depends on the site of surgery because the extent of sensory-motor blockade after a BPB varies with the technique used. The investigator is not aware of any single BPB technique that can consistently produce surgical anesthesia of the whole ipsilateral upper extremity. However, occasionally surgery entails that the whole upper extremity is anesthetized, i.e. from the shoulder to the elbow, or even the forearm, wrist or hands. This clinical challenge has been addressed previously using a combination of BPB techniques. The investigator has recently demonstrated that it is feasible to accurately identify majority of the main components of the brachial plexus above the clavicle, including the three trunks, using ultrasound imaging. Since majority of the innervation of the upper extremity, i.e. shoulder, arm, elbow, forearm, wrist and hand, originates from the three trunks of the brachial plexus, the investigator hypothesized that selectively blocking upper, middle and inferior trunks of the brachial plexus will produce surgical anesthesia of the whole ipsilateral upper extremity, except for the area innervated by the intercostobrachial nerve (T2- medial aspect of the upper arm). In addition, there may be a potential advantage that phrenic nerve can be spared, so this blockade will not affect the respiratory function as it is common to see phrenic nerve palsy after interascalene BPB (100%) and supraclavicular BPB (50-67%). The aim of this study is therefore to assess a novel brachial plexus block technique, the "selective trunk block" (SeTB), and provide preliminary clinical evidence of its effectiveness in producing surgical anesthesia of the whole ipsilateral upper extremity.

Inclusion Criteria:

• Elective upper extremity surgery
• Emergency upper extremity surgery

Exclusion Criteria:

• Patient refusal
• Local skin site infection
• Allergy to local anaesthetics
• Peripheral neuropathy
• Brachial plexopathy