Brachial Plexus Flashcards
intensity of nerve stimulation
low intensity, up to 5 mA
blocks of the brachial plexus
interscalene, supraclavicular, infraclavicular, axillary
roots-trunks-divisions-cords-terminal branches
duration of nerve stimulation
0.05-0.1 ms
nerve stimulation helps avoid…
intraneural intrafascicular injection and subsequent nerve injury
C5, C6
axillary, upper and lower subscapular, suprascapular
C5, C6, C7
musculocutaneous, long thoracic, lateral pectoral
C5
dorsal scapular, to subclavious muscle
C5, C6, C7, C8
to longus colli and scalene muscles
C5, C6, C7, C8, T1
radial, median
C8, T1
ulnar, medial pectoral, medial cutaneous nerve of forearm
T1
medial cutaneous nerve of arm
C6, C7, C8
thoracodorsal (middle subscapular)
acceptable twitches
pectoralis major, deltoid, biceps, triceps, forearm , hand
advantages of ISB
landmarks easy to find in obese patients, shoulder surgery, small risk of pneumothorax
ISB disadvantages
paresthesias usually elicited
ulnar nerve frequently spared
not appropriate for the pulmonarily compromised
phrenic nerve blockade typically ensues (only 10%)
ISB complications
unintentional spinal/epidural anesthesia
vertebral artery puncture
phrenic nerve block
LAST
ISB technique
head contralateral, HOB slightly elevated
sternocleidomastoid palpated
roll fingers off posteriorly
intersection at C6
ISB insertion
22/23g needle almost perpendicular to the floor
45 degrees caudad, posterior, and medial
watch out for EJ
paresthesias are elicited and injection performed (30 ml)
drugs and dosages for ISB
lidocaine 20-30ml
mepivacaine 20-30ml
bupivacaine 20-30ml
ropivacaine 20-30ml
advantages SCB
3 trunks of the brachial plexus (most compact here)
arm can be in any position
most homogenous block of brachial plexus (ulnar nerve not spared)
disadvantages of SCB
difficult to teach
considerable experience required
major risk of pneumo
SCB complications
puncture of subclavian artery
pneumo
phrenic nerve block
LAST
SCB dosages
Lidocaine 30ml
Bupivacaine 30ml
Ropivacaine 30ml
Mepivacaine 30ml
ICB advantages
nerves frequently missed with axillary approach are blocked
musculocutaneous nerve blocked
does not require positioning of the arm like axillary approach
phrenic nerve blockade not a possibility
ICB disadvantages
no pulse to assist in blocking bundle
if injection too far proximal to clavicle, musculocutaneous and axillary nerves will be missed
needle insertion too medial can result in pneumothorax
ICB dosages
Lidocaine 30 ml
Bupivacaine 30 ml
Mepivacaine 30 ml
Ropivacaine 30 ml
Median nerve in quadrants…
1 & 8 in 56% of subjects
ulnar nerve in quadrants…
2 in 59% of subjects
radial nerve in quadrant…
3 in 38% of subjects
advantages of AxB
surgery on forearm and wrist
fewer complications than SCB
safest and most reliable for the patient
AxB disadvantages
arm abducted for surgery
not for shoulder or upper arm surgery
musculocutaneous nerve lies outside of perivascular sheath, need separate block
AxB technique
supine head contralateral
arm abducted 90 degrees
forearm flexed 90 degrees
palpate brachial artery as far proximal
Dosages AxB
Lidocaine 20-30ml
Bupivacaine 20-30ml
Ropivacaine 20-30ml
Mepivacaine 20-30ml
elbow blocks technique
flex elbow 90 degrees
ID medial condyle of humerus
insertion point is between medial condyle of humerus and olecranon process of ulna
Inject 4 ml LA (3-5 ml)
median nerve block
draw a line from the medial to lateral condyles of the humerus on anterior surface
insert B bevel needle slightly medial to the brachial artery
inject 4 ml (3-5 ml)
radial nerve block
elbow extended
locate brachioradialis muscle and biceps brachii insertion (tendon)
radial nerve is in the groove between the muscles mentioned above
inject 4 ml (3-5 ml)
movements in response to radial nerve stimulation
extension at elbow
supination of forearm
extension of wrist and fingers
movement in response to ulnar nerve stimulation
flexion of wrist
adduction of all fingers
flexion and opposition of medial two fingers towards thumb
movement in response to median nerve stimulation
pronation of forearm
flexion of wrist
opposition of middle, forefinger, and thumb
flexion of the lateral three fingers
movement in response to musculocutaneous stimulation
flexion at elbow
