Regional Flashcards
Termination of
- Spinal cord (conus medullaris)
- Dural sac
In neonate
L2/3 for conus medullaris
Cauda equina + filum terminal remains
Dural sac terminates at S3/S4
PECS 1 block target nerves
Between pec major and minor
Targeting lateral and medial pectoral nerves
PECS 2 block target nerves
B/w pec minor + serratus anterior
Blocks lateral cutaneous spinal nerves + long thoracic nerve +/- intercostal nerves
Which ligament do you pierce to reach the paravertebral space?
costotransverse ligament
Location of serrates plane block
aim between lat dorsi serratus anterior at the mid axillary line
Location of the
- Anterior thoracolumbar fascia (TLF)
- Middle TLF
- Posterior TLF
anterior TLF anterior to quadratus lumborum, posterior to kidney
Middle TLF posterior to QL, lateral to erector spinae
Posterior TLF superficial to erector spinae
Location of TAP block
Between IOM and TA, lateral abdomen, probe immediately caudal to costal margin
Location of rectus sheath block
Through the oblique muscles laterally, aiming medially under the rectus abdominis
Lateral to the superior epigastric artery branch
Which part of brachial plexus does long thoracic nerve come off?
What does it innervate?
At the C5,6,7 roots
Serratus anterior (motor nerve)
Where does dorsal scapular nerve come off? what does it supply?
C4,C5 roots
motor supply for rhomboid, levator scapula
origin of the supraclavicular nerve?
C3/C4
Sensory supply to skin of the upper chest
Where are lateral and medial pectoral nerves come off?
Lateral pectoral nerve comes off lateral cord
Medial pectoral nerve comes off medial cord
Supply of
- Medial brachial cutaneous nerve
- Medial ante-brachial cutaneous nerve?
Where do they come off?
Both nerves come of medial cord.
Medial brachial cutaneous nerve supplies the medial surface of the arm, along with intercostal brachial (tourniquet)
Medial ante-brachial cutaneous nerve supplies medial surface of both arm and forearm, extending to wrist.
Where does intercosto-brachial nerve originate?
T2 intercostal nerve
Which part of the upper limb does a interscalene block frequently miss?
C8-T1 roots - not good for distal surgery - does not cover medial surface
Specific risks of interscalene block?
Phrenic nerve palsy
Horner’s syndrome
RLN palsy
Dorsal scapular nerve
Vertebral artery puncture
Pneumothorax
Location of
- Interscalene block target
- supraclav nerve
- Long thoracic nerve
- Dorsal scapular nerve
Block target is between C5 and C6 nerve roots (looking for the traffic light sign), between the anterior and middle scalene muscles
Three nerves surround the middle scalene
Supraclav = superficial to MS
long thoracic within the MS
dorsal scap posterior to MS
Describe the surrounding features of the IJV
IJV situated within the carotid sheath, containing carotid artery, vagus nerve
Carotid sheath lies deep the SCM, anterior to anterior scalene. Phrenic nerve can be found between SCM and anterior scalene
Thyroid, trachea, oesophagus medial to IJV
Sympathetic trunk medial and deep to carotid sheath (closer to vertebral body)
Where is intermediate cervical plexus block performed?
Similar probe placement as interscalene block
Identify spinal transverse processes.
Block performed at C4/C5
Identify posterior border of SCM, target plane between levator scapulae muscle + SCM
- Middle scalene is anterior to levator Scap
Which nerves does a cervical plexus block achieve?
Neck area divided into four quadrants
- Greater auricular nerve: ear region, upper portion of SCM
- Lesser occipital nerve: lateral scalp
- Transverse cervical nerve: anterior neck, lower SCM
- Supraclavicular nerve: lateral neck, skin above clavicle
Interscalene nerve block misses?
Suprascapular nerve
Can get sparring of the very inferior trunk (ulnar)
Describe the surrounding structures of supraclavicular nerve bundle
Needle approaches lateral to medial
Medial: subclavian artery, anterior scalene, subclavian vein
Lateral: middle scalene
Superficial: omohyoid, platysmus
Deep: 1st rib, pleura
SCM medial to omohyoid.
Supply of the musculocutaneous nerve?
sensory supply via lateral cutaneous nerve to the lateral forearm
Motor supply to biceps, coracobrachialis, brachialis
Describe the surrounding structures of the axillary artery, relevant for a axillary brachial plexus block
3 nerves surround the artery - ulnar posterior, radial deep, medial anterior
Corocobrachialis anterior to bundle, within it is musculocutaneous nerve, biceps further anterior
Axillary vein posterior to ulnar nerve
Conjoint tendon of lat dorsi and teres major diagonally, anterior -> posterior
Femoral triangle border?
inguinal canal
adductor Magnus medial
sartorius lateral
Osteotome of the proximal femur
medial surface - obturator nerve
sacral plexus - greater trochanter
Femoral nerve for the rest
Hip joint capsule innervation?
Posterior capsule by sacral plexus nerves (superior gluteal + musculo articulares)
Anterior capsule into 4 quadrants
- Femoral nerve main supply
- Obturator nerve inferior quadrants
- Accessory obturator nerve medial quadrants
Where are the sensory branches of the hip capsule nerves consistently found? (target of PENG block)
Between anterior inferior iliac spine (AIIS) and iliopubic eminence of the superior rami
These nerves are FN, ON, AON
PENG block structures
Target plane between AIIS, along superior pubic ramus, and iliopubic eminence
Look for iliopsoas tendon within iliacus, aim needle just deep to it
FV, FA, FN lie superficial to iliacus.
Muscular structures that can be visualised during a infra-inguinal FI block?
satorius lateral, iliacus deep
Pectineus medial and deep to femoral vein
Describe the trajectory of the fascia iliaca
Separates femoral vein and artery from pectineus medially
Runs between femoral artery and femoral nerve, then deep to satorius and superficial to iliacus
Neural supply for the anterior knee capsule ?
nerve to the vests medialis
Saphenous nerve
Neural supply for the posterior knee capsule?
Branches of obturator nerve (medial part of the distal femur)
Tibial nerve and CPN
Describe the surrounding anatomy of an adductor canal block
Target is the saphenous nerve, which is lateral to the femoral artery and vein
Satorius lies superior, adductor longus medial, vastus medialis lateral
Note NVM above the vastus-adductor membrane, need to find this to avoid neuropraxia
Describe the surrounding anatomy for a popliteal sciatic block
Needle approach lateral to medial, with probe on the posterior knee surface.
Biceps femoris lateral. Semimembranosis medial
Skin -> neural bundle (CPN and TN) -> pop vein -> pop artery
Motor nerves for the ankle/foot?
deep peroneal for anterior leg compartment (dorsiflexion)
tibial nerve for posterior compartment
Plantar osteotome supply? ankle
Mainly tibial nerve
Sural lateral ankle
Dorsum osteotome? ankle
Mainly deep peroneal, sural nerve lateral ankle
Sensory supply to plantar surface ankle ?
Tibial nerve mainly
Saphenous nerve mid medial surface
sural nerve lateral surface
Sensory supply to dorsal surface ankle?
Superficial peroneal mainly
Saphenous medial foot around the sole
sural lateral small patch
deep peroneal 1st webber space
Describe tibial nerve ankle block
identify medial malleolus
aim between achilles tendon, posterior to the posterior tibial artery
advance needle to hit tibia in a posterior to anterior direction, hit tibia, withdrawal few mm, inject
Describe saphenous nerve block
Identify medial malleolus
Nerve located anterior to the MM
Just lateral to great saphenous vein
SC block just superior to MM, lateral to GSV
Describe superficial peroneal block
ring block from anterior tibial ridge to lateral malleolus
If US guidance, go 10cm up the ankle and identify nerve between EDL and peroneus
Describe deep peroneal nerve block
Lateral to tibialis anterior, medial to anterior tibial artery
Inject lateral to TA, hit bone, withdrawal few mm, inject
Describe sural nerve block
Field block lateral malleolus to achilles tendon
Located anterior to small saphenous vein
7 nerves of scalp block
supraorbital
supratrochlear
zygomaticotemporal
auriculotemporal
greater auricular
lesser occipital
greater occipital
Location of supraorbital block
just above the supraorbital notch
location of supratrochlear block
just medial to the supraorbital nerve site, above the eyebrow line
Location of zygomaticotemporal block?
Deep and superificial block at the lateral edge of zygomatic arch
Deep - hit bone then inject
Superficial - on the way out, aiming more laterally.
Location of auriculotemporal block?
1cm anterior to the auditory meatus, immediately posterior to the superficial temporal artery
Line drawn from occipital protuberance to mastoid
Alone this line, which blocks can be performed?
Lateral third - lesser occipital nerve (posterior border of SCM)
Medial third - greater occipital nerve
Greater auricular nerve block location?
2cm posterior to the auricle at the level of the tragus
Spinal tracts for motor control?
Later corticospinal tract
Anterior corticospinal tract - truncal stability
Cross at level of brain stem
Brown Seckar Syndrome pattern at T8
Ipsilateral loss of sensory and motor
- Motor pattern: lower motor neuron at the level (flaccid paresis), spastic paresis below as upper motor neuron loss.
Contralateral loss of pain and temperature - starts a few levels below (i.e T8 injury = T10 loss)
Spinal cord segmental supply
Aorta -> segmental -> dorsal branch -> epidural and spinal arteries.
Radicular medullary branch (main branch of concern) joins the ASA and PSA.
Damage to flow of Artery of Adamkewtiz (syndrome)
Anterior spinal syndrome
- Flaccid paresis at the level of damage.
- Spastic paresis below
- Loss of pain 2 levels below (tracts of Ls are spared)
- Sparring of the dorsal column (proprioception not affected)
- SNS loss due to lateral horn cells.
Venous supply to the epidural space
Anterior and posterior epidural plexus
Draining laterally —-> azygous
Spinal level of dural sac termination?
S2 in neonate.
Doesn’t tend to change in adults.
L1/2 - Conus, L4/5 - Tuffier’s line
Major terminal branches of posterior cord?
Axillary nerve C5,6
Radial nerve C5 - T1
Subscapular nerve (for rotator cuff muscle)
Median nerve course
Lateral to axillary artery, then medial to brachial / radial artery
Middle of the forearm -> under the carpel tunnel into the hand.
Ulnar nerve course
Between axillary artery and vein
Groove on the back of medial epicondyle
Medial to ulnar artery at the wrist
Cross the flexor retinaculum
Radial nerve course
direct continuation of the posterior cord
Between heads of triceps
Superficial branch - purely sensory
Travels through the snuff box
Measures to reduce nerve injury
- Equipment
- Technique
- LA
- Patient factor
- Surfical factor
Equipment: blunt needle, US, nerve stim, injection pressure monitor
Technique: awake, slow injection, feel the resistance, visualise on US
LA - lower LA dose, lower volume
Patient - note comorbidities (T2DM, BMI, smoker), caution in anticoagulation
Surgical - optimal positioning while numb, minimise tourniquet.
Which upper limb block is considered deep?
infraclavicular block
Interscalene block - how can one tell the spinal process level?
C7 only has posterior tubercle visible.
C6 above will have double hump - anterior and posterior tubercles.
Deposit location of superficial cervical plexus block?
5-10ml LA between the posterior edge of SCM and MSM.
Describe the superior trunk block
Trace interscalene a bit more distal
Reliably block the supra scapular nerve
Reason to do this is phrenic nerve being further away
Specific complications of supraclavicular block>
pneumothorax
Ulnar sparing
Damage to subclavian artery
Phrenic nerve palsy
Dorsal scapular artery or transverse cervical artery injury
Describe infraclavicular block
hand behind head to move clavicle superior
Linear probe just medial to coracoid process to identify axillary artery
10cm short bevelled needle IP cephalic to caudal
Specific risks of infraclavicular block
Pneumothorax
Axillary artery injury
3% phrenic nerve block
Which cords give rise to which terminal nerves?
Meidal cord - median / ulnar
Posterior - radial, axillary
Lateral - median, musculocutaneous
Testing upper limb distal nerves
Median nerve - thumb opposition
Ulnar - spread fingers against resistance
Radial - wrist extension
MCN - elbow flexion
Describe digital nerve block
Each digit by 4x digital nerves
(2x palmar, 2x dorsal)
Inject the web space dorsum
Palmar surface, inject midpoint at the base of the digit.
Which division of the femoral nerve gives rise to the saphenous nerve?
Posterior
Which nerves need to be blocked for the skin incision component of hip arthroplasty
LFCN + skin infiltration to the superior component
Surrounding structures of suprainguinal FI block
Bowtie - AIIS deep to it, iliopsoas overlying
Caudad - satorius muscle
Internal olblique cephalad, with deep circumflex iliac artery sometimes visible.
Local spread under the fascia iliaca, superficial to the iliopsoas muscle, pushing the internal oblique away
Optimal location for adductor canal block
At the point when adductor Magnus and adductor longus both visible
- AM, when more proximal, is in close proximity to sartorius.
- Lower down, AL takes over.
muscles surrounding the pop-sci nerve
Laterally, biceps femoris
Medially, semi-tendonosus superficial, and semi-membranosus deep
Vein immediately deep to nerve bundle, then artery.
pop-sci block, needle goes lateral to medial, through the semi-tendenosus muscle
What are the three hyoid muscles?
MSG
Mylohyoid
Stylohyoid
Geniohyoid
Abductors of vocal cord?
Posterior cricoarytenoids, supplied by RLN
Which muscle does the RLN not supply?
Cricothyroid (tensor),
Supplied by external SLN
Which nerves are you numbing for AFOI in the nasal cavity
Greater and lesser Palatine (from M2)
Olfactory bulb -> anterior ethmoid (C1) for nares and anterior third of nasal septum
Course of subclavian vein
Continuation of axillary vein, commences at the lateral border of the first rib
Travels posterior to the clavicle
Anterior scalene muscle posteriorly separating it from the subclavian artery
Travels over the superior surface of the first rib, forming a slight groove, then joins the internal jugular vein to form the brachiocephalic
Which coronary artery supplies the
- AV node?
- SA Node?
AV node by whichever branch supplies the PDA (85% RCA, 15% LAD)
SA node - 60% RCA, 40% Cx
Segments of right middle lobe?
Medial and lateral segments
Orientation of the right lung - where would you find each lobe on lateral CXR
Most of the anterior chest wall by upper lobe
Most of the posterior chest wall by lower lobe
Right middle lobe anterior and inferior
Segments of the upper right lobe?
Apical, anterior and posterior segments
Segments of the lingual lobe?
part of left lung, upper lobe division
Superior and inferior segments
