Anatomy Flashcards
The axillary brachial plexus block targets the brachial plexus at the level of the branches, and provides anesthesia to which nerves?
Median n.
Radial n.
Ulnar n.
some Musculocutaneous n. (but is often missed bc it branches off plexus prior to the other nerves)
*block is named after the approach, but doesn’t actually include axillary n.
The musculocutaneous n. is most commonly visualized between which two muscles?
Biceps
Coracobrachialis
Which nerve blocks do not cover the medial upper arm, so additional coverage of the intercostobrachial n may need to be performed?
Axillary brachial plexus block or Supraclavicular brachial plexus block or Infraclavicular brachial plexus block
*intercostobrachial is not a branch of the brachial plexus
How to perform intercostobrachial n block
subQ injection of local anesthetic just distal to axilla.
How to perform U/S guided interscalene block (shoulder and upper arm)
U/S placed at level of cricoid cartilage, Identify carotid artery, move probe laterally and posteriorly, the roots of the brachial plexus is found between the ANTERIOR and MIDDLE scalene muscles.
With the interscalene brachial plexus block, the ____ n is frequently spared.
Ulnar n.
The lumbar plexus block, aka psoas compartment block, covers which nerves?
Spares which nerves?
Femoral,
lateral femoral cutaneous,
obturator
Spares sciatic n.
Sciatic n. is responsible for innervation of which muscles?
Gastrocnemius
Soleus
Plantaris
Digital flexors
How to perform lumbar plexus block
Pt is in lateral decubitus position
Needle is inserted at L4 transverse process
Once contacted, needle is redirected in cephalad manner and advanced until stimulation of quadriceps femoris occurs (knee extension)
Femoral n innervates which muscles? What are their actions?
Iliopsoas
- Hip flexion
Quadriceps femoris
- Extension of lower leg at knee
In adults, the conus medullaris ends at ____ and the dural sac terminates at _____
L1-L2
S1-S2
In infants, the conus medullaris ends at ____ and the dural sac terminates at _____
L3-L4
S3-S4
*shifted down one interspace than adults
Transtracheal injection of lidocaine, blocks ____ nerve, which anesthetizes sensation to _____, and motor function of ______, during awake intubations
recurrent laryngeal n.
s) - vocal cords and trachea
(m) - laryngeal muscles (EXCEPT cricothyroid m
In pts with complex regional pain syndrome (CRPS) of the lower extremity, a _____ block may offer significant relief
Lumbar sympathetic plexus block
- located at anterolateral aspect of lumbar vertebral bodies (L1-L5)
The _____ n. alone innervates the pharynx, and can be anesthetized by injecting LA at the _______ through the peri-oral approach, which will help prevent the gag reflex
glossopharyngeal n (CN IX)
base of each of the anterior tonsillar pillars (palatoglossal fold)
The internal (sensory) branch of the superior laryngeal n. innervates the mucosa from the _________ to the _______.
It can be blocked by injecting LA at ______
epiglottis
vocal cords
Greater cornu of hyoid bone
Superior cornu of thyroid cartilage
The transtracheal block, will anesthetize the ______ nerves, which provides motor innervation to ______
recurrent laryngeal n.
all intrinsic muscles in the larynx
- posterior cricoarytenoids (vocal cord abduction)
- lateral cricoarytenoids (vocal cord adduction)
- thyroarytenoids (vocal cord relaxation)
A (meningocele / myelomeningocele) is associated with a tethered spinal cord, hydrocephalus and a latex allergy
myelomeningocele
*tethered spinal cord is a relative contraindication to neuraxial anesthesia d/t high potential for spinal cord injury
a ______ is where the meninges alone protrude through the defect in the vertebral column
meningocele
a ______ is where the meninges, nerve roots, and CSF, protrude through the defect in the vertebral column
myelomeningocele
Medial to lateral, what are the neurovascular structures in the antecubital fossa?
Median n, brachial a, radial n.
Subclavian vein central line
- approach and landmarks?
Insert needle 1 cm below mid-clavicle angled towards sternal notch
L IJ central line has higher risk of what?
- Pneumothorax (high-riding cupola of L lung)
2. Thoracic duct cannulation
Femoral vein central line
- approach and landmarks?
palpate femoral artery,
insert needle medial to artery and 1-2cm below inguinal ligament
Supraclavicular approach to central line placement
- approach and landmarks?
Lateral border of Sternocleidomastoid at its insertion point on clavicle
The MEDIAL lower leg is innervated by the _____ n., which is a branch of the femoral n.
saphenous
medial crural
The sciatic n innervates the LATERAL lower leg and the skin of the foot through its 2 branches: ____ and ____
common peroneal
and
tibial n.
The ______ n. provides sensory innervation to the lateral posterior portion of the leg.
Sural n (S1-2)
The tibial n. is a branch of the ______ n. and provides sensory innervation to the _____
sciatic n.
heel and plantar regions of the foot
How long do you have to wait to perform neuraxial anesthesia if the pt is on:
- Therapeutic LMWH
- Prophylactic LMWH
- Therapeutic LMWH: 24h after last dose
- Prophylactic LMWH: 12h after last dose
When performing caudal epidural, ______ is the structure that is transversed just prior to the epidural space.
Sacrococcygeal ligament
3 landmarks for caudal block
2 PSIS and sacral hiatus (directly superior to coccyx)
Sciatic n. block is performed between which 2 bony landmarks?
Greater trochanter and ischial tuberosity
gluteal approach
The LATERAL lower leg is innervated by the _____ n. and the MEDIAL lower leg is ______,
sciatic.
saphenous
The sciatic n. block provides anesthesia to which n?
sciatic n and its two components
- Tibial .
- Common peroneal
The common peroneal n. is a branch of the ______ n. and provides sensory innervation to the _____
sciatic
lateral lower leg
Infraclavicular n. block traverses the pec major and minor (NOT serratus anterior bc the lung is immediately deep to it) and targets _____
the brachial plexus at the level of the cords
Advantage of infraclavicular block over axillary block?
Disadvantage?
Includes the musculocutaneous and axillary n.
Higher risk of pneumothorax
Pts with (low/high) baseline vagal tone at increased risk of bradycardia and cardiac arrest.
high
- they would have lower resting baseline HR
- baseline ANS favors parasympathetics
- benefit from pretreatment with antimuscarinic (glycopyrolate or atropine)
Motor stimulation with ____mA is associated with intraneural injection
< 0.2
Benefits to retrobulbar blocks as opposed to peribulbar block?
Cons?
- Requires less LA
- Denser block
_____
- Higher risk of:
- intravascular and intradural injection
- retrobulbar hematoma
- penetration of globe
Femoral n. block: contraction of the _____ m. indicates correct placement of the needle
quadriceps (posterior division - main trunk of leg)
The lumbar plexus block aka the psoas compartment block is primarily used for femoral shaft and neck fractures, as it covers which key nerves?
femoral n.
obturator n.
LFCN
genitofemoral n.
*spares the sciatic n.
Which lung lobe is most prone to collecting secretions in the supine pt?
R lower lobe - posterior segment
most inferoposterior
The R coronary artery supplies which walls of the heart?
Inferior and inferoseptal walls of the LV
When is coronary circulation described as R or L dominant?
Right:
- If Posterior descending a. arises from RCA
Left:
- If Posterior descending a. arises from LCx
The lateral femoral cutaneous n contains fibers from the _____ n roots, and provides sensory innervation to the anterolateral thigh down to the knee
L2-L4
Femoral triangle to the adductor canal
Anteromedial wall: sartorius, posterior wall
Posterior wall: adductor longus and adductor magnus
Lateral wall: vastus medialis
(counterintuitive)
2/3 of the blood from the bronchial circulation drains into the ______, and 1/3 drains into the _____
Pulmonary vein
RV through pleurohilar veins or Pulmonary arteries
The R bronchial tree gets its circulation from _______, and the L bronchial tree gets it from ______
R: intercostal arteries
L: Bronchial circ arising Directly from aorta
Superficial cervical plexus block procedure are often used for carotid endarterectomy. How is it performed?
insert needle over posterior border of SCM and injecting LA along C2-C4 nerve roots.
The ______ is the fusion of the C7-T1 cervical sympathetic ganglia and lies on the anterior surface of the C7 vertebral body.
Stellate ganglion
What level is the stellate ganglion block performed?
C6 at Chassaignac tubercle
close proximity to the ganglion, which lies anterior to C7
How do you perform stellate ganglion block?
- Neck extension
- Locate cricoid cartilage (at C6)
- Run fingers laterally until you palpate anterior tubercle of C6 transverse process
- Push carotid a and jugular v laterally
- Insert 25g 1.5in needle until you reach bone and inject 5-10mL of LA
Benefits of TAP blocks
Limited side effects
Goal of TAP blocks
Block anterior rami of T7-L1
- Analgesia to skin, m, and parietal peritoneum of abd wall
(Cardiac MRI / 2-D ECHO) is best at determining ventricular EF.
Cardiac MRI
- std error 5%
- No radiation or contrast
- Habitus is not an issue
(Echo std error 10%)
Femoral n. contains divisions of L ____. It courses through the _____ m. and then between the psoas and ilacus m., covered by the _______
L2, L3, L4
Psoas major m.
Fascia iliaca
The historical “three-in-one” block provides blockade of which n?
femoral n.
lateral femoral cutaneous n.
obturator n.
Femoral n, a, v, which is more lateral?
Lateral to medial:
Nerve -> arterty -> vein
Injecting LA at the greater cornu of the hyoid bone blocks which nerve?
- What sensory innerv. does it block?
Internal branch of the superior laryngeal n.
- sensory innervation to the base of the tongue, epiglottis, aryepiglottic folds and arytenoids
*can prevent laryngospasm
Transtracheal LA injection at the cricothyroid membrane blocks which n?
Recurrent laryngeal n.
- vocal cords ABduction and trachea
(Short axis / long axis) and towards the direction of flow is the best way to obtain red signal on color doppler US
Short axis