SHAC block: block the capsule, not the neck

Question 1Why is the SHAC block considered phrenic-sparing?

1. aIt is placed on the front of the shoulder joint, far from the brachial plexus roots and the phrenic nerve
2. bIt uses a local anaesthetic which does not affect nerves
3. cIt is always given with a nerve stimulator
4. dIt blocks the phrenic nerve and the shoulder together

Question 2Which bony landmark must you keep medial to your needle during a SHAC block?

1. aThe greater tuberosity
2. bThe acromion
3. cThe spine of the scapula
4. dThe coracoid process

Question 3Where should the local anaesthetic spread in a SHAC block?

1. aDeep to subscapularis, along the anterior capsule over the humeral head
2. bUnder the deltoid on the back of the shoulder
3. cAround the C5 and C6 roots
4. dInside the subscapularis tendon

Question 4During a SHAC block, the tendon swells and the injection needs high pressure. What does this mean?

1. aYou have reached the brachial plexus
2. bYou have entered the joint
3. cThe needle tip is inside the tendon, so stop and reposition
4. dThe block is working well

Question 5How strong is the evidence for the SHAC block in emergency shoulder dislocation?

1. aIt is the recommended first-line analgesia in national guidance
2. bSeveral large emergency department trials prove it superior to sedation
3. cLimited to small reports, so use it as an advanced option under local governance
4. dIt has been abandoned because it does not work