Which nerves are blocked in Interscalene block?

The interscalene block covers most of the brachial plexus, sparing the ulnar (C8-T1) nerve. It is a great block for distal clavicle, shoulder, and proximal humerus procedures. Under sterile conditions, the interscalene space is identified either by palpation or ultrasound visualization.

How does Interscalene block cause Horner syndrome?

Interscalene brachial plexus block (ISB) commonly produces Horner’s syndrome defined by ipsilateral miosis and ptosis, due to blockade of neighboring cervical sympathetic ganglia [1, 2]. The cervical sympathetic ganglia consist of superior, middle and inferior cervical sympathetic ganglia [3].

How do you assess Interscalene blocks?

The interscalene block is meant to target the brachial plexus, a network of nerves sectioned between two scalene muscles. These nerves send signals from the spine to the shoulder, arm and hand. To identify the area, the anesthesiologist will trace your nerves with a marker on your skin.

How is interscalene used to block the brachial plexus?

The interscalene approach to brachial plexus blockade results in reliable anesthesia of the shoulder and upper arm (Figure 3). The supraclavicular branches of the cervical plexus, supplying the skin over the acromion and clavicle, are also blocked due to the proximal and superficial spread of local anesthetic.

Are there ultrasound guided brachial plexus block techniques?

More recently, the introduction of ultrasound-guided techniques has allowed for additional refinements and improved block consistency with reduced local anesthetic volumes. (see Ultrasound-Guided Interscalene Brachial Plexus Block)

How big is an interscalene nerve block for the ulnar nerve?

FIGURE 3. Sensory distribution of the interscalene brachial plexus nerve block (in red). Ulnar nerve distribution area (C8-T1) can also be accomplished by using larger volume (e.g. 15-20 ml) and using low interscalene nerve block where the injection occurs between the ISB and supraclavicular nerve block.

What can ultrasound guided interscalene block do for You?

Interscalene block can provide anaesthesia and/or analgesia for operations on the distal clavicle, shoulder and proximal arm. Ultrasound guided interscalene block target the roots and proximal trunks of the brachial plexus as they are sandwiched between the anterior and the middle scalene muscle.