UE blocks Flashcards
ID these structures
draw the brachial plexus
origin of roots of brachial plexus
originate from union of ventral rami of C5-T1 spinal nerves. roots pass between anterior and middle scalene muscles
origin of trunks of brachial plexus
roots converge to trunks just beyond lateral border of scalene muscles
C5-6 superior trunk
C7 middle trunk
C8-T1 inferior trunk
origin of divisions of brachial plexus
each trunk diverges into anterior and posterior divisions just under 1st rib
-anterior divisions innervate anterior (flexor) parts of arm
-posterior divisions innervate posterior (extensor) parts of arm
-C5-6 superior trunk- anterior and posterior divisions of superior trunk
-C7 middle trunk- anterior and posterior divisions of middle trunk
-C8-T1 inferior trunk- anterior and posterior divisions of inferior trunk
origin of cords of brachial plexus
divisions converge into cords when brachial plexus goes under pecs minor muscle
-C5-7 anterior division of superior and middle trunks- lateral cord
-C5-T1 posterior divisions of all 3 trunks- posterior cord
-C8-T1 anterior division of inferior trunk- middle cord
*cords are named in relationship to axillary artery
origin of branches of brachial plexus
cords diverge into branches in the axilla
-C5-7 MSK nerve
-C5-6 axillary n
-C5-T1 median n
-C5-T1 radial n
-C8-T1 ulnar n
MAMRU
supraclavicular nerves to be aware of in brachial plexus and their origin
-dorsal scapular nerve (C5)
-suprascapular nerve (C5-6)
-long thoracic nerve (C5-7)
what does dorsal scapular nerve innervate
comes off of C5, innervates levator scapula and rhomboid muscles
what does supra scapular nerve innervate
comes off C5-6, innervates supraspinatus and infraspinatus muscles, as well as posterior glenohumeral joint, subacromial bursa, acromioclavicular joint
what does long thoracic nerve innervate
C5-7, innervates serratus anterior muscle
infraclavicular nerves to be aware of and their origin
-lateral pectoral n (C5-7)
-medial pectoral n (C8-T1)
what does lateral pectoral n innervate
C5-7, innervate pecs minor muscle and acromioclavicular joint
what does medial pectoral n innervate
C8-T1, innervate pecs minor and lower region of pecs major muscle
phrenic nerve origin and specs
-originates from anterior rami of C3-5
-not part of brachial plexus but does get contribution form C5
-innervates diaphragm
supraclavicular nerve origin and specs
-C3-4
-arises from cerviccal plexus
-sensory innervation to “cape of the shoulder” and clavicle
-anesthetized with superficial cervical plexus block. ex) clavicle fx or CEA
intercostobrachial n origin and specs
-arises from T2
-not component of brachial plexus, arises from second intercostal nerve
-sensory innervation to medial aspect of upper arm
-field block may required for UE procedures
-total 5mL LA is sufficient
dermatome C4
sensory region
superior aspect of shoulder
dermatome C6
sensory region
lateral shoulder
dermatome C7
sensory region
3rd digit
dermatome C8
sensory region
5th digit
dermatome T1
sensory region
medial aspect of arm
dermatome T2
sensory region
axilla
peripheral nerve: axillary
sensory region
lateral upper arm at shoulder
peripheral nerve: intercostobrachial and medial brachial cutaneous
sensory region
medial upper arm to elbow
peripheral nerve: medial antebrachial cutaneous
sensory region
anterior upper arm, anterior and medial forearm to wrist
peripheral nerve: MSK (lateral antebrachial cutaneous)
sensory region
lateral forearm to wrist
peripheral nerve: radial
sensory region
lateral upper arm
posterior arm below shoulder
posterior FA
dorsum of hand lateral to axial line of 4th digit
radial side of thumb
peripheral nerve: median
sensory region
palmer side of 1st, 2nd, 3rd digits (palmar side and tips of dorsal side)
radial side of 4th digit (palmar side and tips on dorsal side)
peripheral nerve: ulnar
sensory region
hypothenar eminence
ulnar side of 4th digit and entire 5th digit
peripheral nerve: axillary
motor function
shoulder abduction (deltoid contraction)
peripheral nerve: intercostobrachial and medial brachial cutaneous
motor function
no motor function
peripheral nerve: medial antebrachial cutaneous
motor function
no motor function
peripheral nerve: MSK (and lateral antebrachial cutaneous)
motor function
elbow flexion (biceps contraction)
forearm supination (palm faces upwards)
LAC is an extension of MSK nerve and has no motor function
peripheral nerve: radial
motor function
elbow extension (triceps contraction)
wrist and finger extension
thumb abduction
peripheral nerve: median
motor function
forearm pronation
finger flexion (first 3.5 digits)
thumb opposition (brings thumb to contact a finger)
peripheral nerve: ulnar
motor function
wrist flexion
ulnar deviation
5th digit opposition (brings 5th digit to contact thumb)
finger flexion (4th and 5th digits)
thumb adduction (adductor policis, think NMB’s)
clinical assessment of brachial plexus blockade (4P’s)
pushER: elbow extension against resistance (triceps contraction) radial nerve
pulleM: elbow flexion against resistance (biceps contraction) MSK n
pinch Me: pinch index finger (2nd digit) median n
pinch U: pinch pinky finger (5th digit) ulnar n
ISB
targets which roots of brachial plexus
indications
C5-7 roots of brachial plexus
indications: surgical procedures of shoulder, upper arm, clavicle
-not ideal for surgeries below elbow
clavicular surgery may require which block on top of ISB
superficial cervical plexus block
ISB total volume LA needed
7-15mL
ISB US
landmarks for ISB landmark technique
cricoid cartilage
clavicle
lateral border of clavicular head of SCM muscle
ISB landmark technique steps
- after positioning patient, ID 6th cervical vertebra by drawing line laterally from cricoid cartilage towards clavicular head of SCM. often, you can feel transverse process of C6
- ask patient to slightly raise their head to accentuate clavicular head of SCM. place index and middle fingers in lateral border of this muscle
- when the patient relaxes, your fingers will rest on belly of ASM. move fingers to lateral edge of muscle to ID groove between anterior and MSM (inter scalene groove)
- now that your index and middle fingers straddle the cricoid line in the groove, you have your point of needle insertion.
- insert 1-2cm until you elicit acceptable response
another name for transverse process of C6
chassaignacs tubercle
acceptable responses for ISB landmark technique
deltoid (shoulder abduction)
pecs major (arm internal rotation)
biceps (elbow flexion)
triceps (elbow extension)
any twitch of the hand or forearm
unacceptable responses for ISB landmark technique
trapezius (cervical plexus stimulation)
diaphragm (phrenic n stimulation–> hiccups)
total volume for ISB landmark technique
25-30mL
30 minutes after ISB, patient c/o dyspnea and CP. SpO2 93% on .4 FiO2 via FM. he is otherwise stable. what is the BEST intervention at this time?
CXR. phrenic nerve is blocked 100% of time, PTX is still a risk
horners syndrome and sx
stellate ganglion located at C7
routinely blocked during ISB
often signifies successful block
sx: eyelid drooping (ptosis), pinpoint pupil (miosis), inability to sweat (anhidrosis)
describe MOA of hypotensive bradycardia episode during shoulder arthroscopy
from bezold jarisch reflex.
theory: venous pooling in LE’s reduces VR. unloaded ventricle + SNS + epi uptake from the block causes profound bradycardia to increase fill time
sx: bradycardia, HoTN, syncope
how to decrease risk of bezold jarisch reflex
preop BB
how to reduce risk of total spinal during ISB
make sure you dont get a motor response at <0.2mA
how to reduce risk of RLN injury during ISB
occurs from large volumes of LA (>30mL), causes hoarseness
s/sx PTX after ISB and who is at high risk
high risk: tall patients
s/sx: cough, CP, dyspnea
dx: CXR
ID this sonoanatomy
SCA
SCB
target
indications
non indications
why people prefer USG with this block
target: trunks/divisions of brachial plexus
indications: surgical procedures of upper arm, elbow, wrist, hand
non indications: shoulder surgery because C5-6 may be missed
-USG preferred r/t close proximity of SCA and pleura
ID this block
what it looks like on USG
type of needle
total volume
supraclavicular block
hypoechoic circles that looks like grapes
22g 5cm B bevel
20-25mL LA
landmarks for supraclavicular block landmark technique
clavicle
clavicular attachment of SCM
patients midline
steps for supraclavicular block landmark technique
- position patient in semi sitting position just like USG
- ID clavicle, clavicular attachment of SCM, patients midline
- ask pt to relax shoulder and flex elbow. allows forearm to rest on abdomen which will help you ID FA and hand movement during nerve stimulation
- lateral edge of SCM is drawn to the insertion point of the clavicle. positioning needle medial to this line increases risk of PTX.
- place finger 2.5cm lateral to to SCM insertion point directly above clavicle. insertion site should be directly above index finger
25-35mL total
acceptable response to supraclavicular block nerve stimulator
finger twitch (flexion or extension)
which artery could you inadvertently inject with ISB
vertebral
greatest risk of supraclavicular block and how to reduce risk
PTX. tilting the transducer slightly caudal will place first rib between brachial plexus and pleura reducing risk of PTX.
if the patient complains of what sensation, there may have been an intraneural injection (and nerve injury)
“crampy” sensation
obtain this image for which USG technique?
infraclav
infraclavicular block
target
indications
good alternative when
target: cords of brachial plexus below clavicle
indications: surgical procedures of upper arm, elbow, wrist, hand
good alternative to supraclav in patients with resp insufficiency and axillary block in patients with limited UE mobility
infraclav USG technique
- palpate coracoid process and place high freq transducer in saggital plane below clavicle and medial to coracoid process
- place transducer in parasaggital position distal to coracoid process. might need low freq transducer based on habitus
- ID axillary artery in cross section. ID 3 small hyperechoic cords in corresponding positions to axillary artery. unlike ISB and supraclav, nerves appear hyper echoic instead of hypo echoic
- 21-22g 9cm B bevel needle. advance through pecs major and minor and under axillary a. inject and it should go cephalad. total volume 20-30mL LA
3 most common errors during infraclavicular block that increase risk of PTX include
needle insertion too medial
direct needle medially
needle insertion depth exceeds 6cm
landmark technique for infraclav
- position patient supine with head turned to non operative side
- palpate lateral tip of coracoid process. draw line 2cm medial and 2cm caudal and mark the point
- after you obtain motor response (motor flexion or extension), reduce mA to .5 to make sure you still get that then inject 25-35mL in 5mL increments
most painful brachial plexus block
infraclav (d/t multiple muscle layers)
which region is most likely to be inadequately anesthetized via axillary nerve block
lateral forearm (musculocutaneous nerve)
axillary block
target
indications
does not cover
target: 4 of the 5 terminal branches: median, radial, ulnar, musculocutaneous (not axillary)
indications: surgery of FA and hand
-desirable in patients with a full stomach and those who want too avoid GA.
-does not cover: skin of medial upper arm (intercostobrachial nerve). skin over the deltoid (axillary n)
relationship of terminal nerves relative to axillary artery
median: anterior and medial
ulnar: posterior and medial
radial: posterior and lateral
musculocutaneous: anterior and lateral
USG axillary nerve technique
- position patient supine and abduct the operative arm 90 degrees. flex the FA upward and parallel to long axis of body
- place high frequency linear array transducer in axilla at the crease formed by biceps and pecs major
- 22g B bevel 5cm anterior to nerves using in plane technique until tip of needle is in close proximity to each nerve. do radial nerve first due to its deeper location
landmarks for landmark axillary artery
axillary artery pulse
coracobrachialis muscle
pecs major muscle
biceps muscle
triceps muscle
landmark technique for axillary artery
- positon patient supine and abduct arm 90 degrees. flex forearm upwards and parallel to long axis of body
- starting on lateral edge of pecs major, palpate axillary artery and then follow it distally in muscular groove between corachobrachialis and triceps muscle
- mark artery as high in the axilla as practical
- cleanse area and palpate proximal axillary artery with index and 3rd finger of non dominant hand
- block intercostobrachial and medial cutaneous nerves with SQ injection of 4-5mL LA. not part of axillary block will help patient tolerate block placement
- block median nerve (advance above axillary pulse until you stimulate median nerve aka forearm pronation and finger flexion. 10mL)
- block MSK nerve (bring needle back to skin, redirect needle to corachobrachialis muscle. advance until you stimulate MSK nerve aka elbow flexion or biceps twitching. 5-10mL)
- block ulnar nerve (remove needle, advance below axillary pulse until you stimulate ulnar nerve aka thumb adduction and 4th/5th digit flexion. 5-10mL)
- block the radial nerve (advance needle deeper until you encounter radial nerve aka elbow/wrist extension and forearm supination. 5-10mL)
for axillary block, if you puncture the axillary artery,
its ok to transition to trans arterial technique.
advance until blood is no longer aspirated.
after aspiration, inject 3mL and watch for signs of LAST. pull out and obviously inject as you go except when you are traversing back through the artery and getting blood in aspiration
what is the “corner pocket” referring to? (specific block)
inferior portion of plexus where first rib meets SCA (important in supraclav)
