regional anesthesia of the shoulder

Question 1

where do nerves C3 and C4 arise from

Answer 1

cervical plexus via the supraclavicular nerves

Question 2

what are the roots of the brachial plexus

Answer 2

C5 to T1

Question 3

what 5 nerves arise from the brachial plexus

Answer 3

musculocutaneous
axillary
median
radial 
ulnar

Question 4

what is Hilton’s law

Answer 4

a joint receives innervation from the same nerves as those supplying muscles around that joint

Question 5

what is supraspinatus supplied by

Answer 5

suprascapular nerve

Question 6

what is deltoid supplied by

Answer 6

axillar nerve

Question 7

what is subscapularis supplied by

Answer 7

superior and inferior subscapular nerves

Question 8

what is pectoralis major supplied by

Answer 8

lateral pectoral nerve

Question 9

what is the cervical nerve root value of the muscles supplying the glenohumeral joint

Answer 9

C5/6

Question 10

what parts of the brachial plexus would be best to block in order to anaesthetise the shoulder

Answer 10

C5 and C6 nerve roots or the superior trunk

Question 11

what is an interscalene block

Answer 11

targets the superior roots and superior trunk of the brachial plexus as they pass between the anterior and middle scalene muscles (posterior triangle)

Question 12

what functions would you check to ensure that an interscalene block had been effective

Answer 12

motor function - the patient shouldn’t be able to abduct or flex the shoulder

sensation- loss of temp sensation over the dermatomes (pain and temp carried the same way)

lack of articular pain (pain on movement)

Question 13

what structures could be damaged in an interscalene block procedure

Answer 13

sympathetic chain
apex of the lung
phrenic nerve