8 Regional Flashcards
Borders of epidural space
Foramen magnum to sacrococcygeal lig, posterior long lig, vertebral pedicle, lig Flavum and vertebral lamina
What is batsons plexus
Epidural venous veins that drain blood from SC. No valves, pass through anterior and lateral epidural space
Where subarachnoid space ends in adult and in infant
S2 Adult S3 infant
Structure that correlates w dural sac
Superior iliac spines
Interspace: conus medullaris, tuffiers line (correlates w what), dural sac, sacral hiatus/coccygeal lig
L1, L4-5/iliac crests, S2, S5
Dermatomes: C6, C7, C8
Thumb, 2nd and 3rd digits, 4th and 5th digits
Dermatomes: T4, T6, T10
Nipple line, xiphoid, umbilicus
Dermatomes: T12, L4
Pubic symphysis, anterior knee
Factors that affect spread in spinal
Baricity of LA, pt position, dose, injection site
Factors that do NOT affect spread in spinal
Barbotage, inc abd p, speed of injection, bevel orientation, addition of vasoconstrictor, weight, gender
Spinal anesthesia: where autonomic and sensory blocks occur in relation
Autonomic block= 2-6 dermatomes higher than sensory. Sensory= 2 dermatomes higher than motor
Epidural anesthesia: sensory block in relation to motor
2-4 dermatomes higher
CV effects of neuraxial anesthesia, reflex
Decrease venous return, CO, and BP. Bezold jarisch
Cns fx neuraxial
Dec sensory input to RAS leading to drowsiness
When at risk for bleeding w neuraxial
Plt <100k, or PT/aPTT/bleeding time 2x nml value
Contraindications to neuraxial
Bleeding risk, inc ICP, sepsis, infec at site, valve lesions w fixed SV (as/ms/HOCM), scoliosis/fusion/OA, difficult a/w, full stomach, peripheral neuropathy, mult sclerosis
Conditions that inc specific gravity
Hyperglycemia, uremia, high protein content, adv age, colder temp
Conditions that dec sp gravity. Nml csf sp grav
Liver dis, jaundice, warmer temp. 1.002-.009
Only solution in water that is hyperbaric, why
Procaine 10%, contains a lot of molecules
Hypobaric: what happens if sitting or supine after injection
If sitting will go to brain. If supine will go to lumbar region
Needle angle of epidural needles
Crawford 0, hustead 15, touhy 30
Contraindications to caudal anes: absolute
Spina bifida, meningomyelocele of sacrum, meningitis
Relative contraindications to caudal anes
Pilonidal cyst, abn superficial landmarks, hydrocephalus, IC tumor, degenerative neuropathy
Landmarks to caudal
Superior iliac spines and sacral hiatus
Positions for caudal anes
Lateral pos w top leg flexed (Simms pos) or prone w frog legs
Additives to caudal anes
Epi 1:200,000 or clonidine 1 mcg/kg
Caudal block dosing: sacral peds v adult
0.5 ml/kg or 12-15 ml in adult
Caudal block dosing: sacral to t10 peds v adult, to mid thoracic
T10: 1 ml/kg peds 20-30 ml adult. To mid thoracic 1.25 ml/kg peds, n/a in adults
Most to least lipophilic to hydrophobic opioids neuraxial
Sufent, fent, demerol, dilaudid, morphine
Most common SE neuraxial opioids. Other 3
Most common is pruritis. Other= resp dep, Nv, urine ret
How neuraxial opioids cause pruritis, tx
Stim of opioid receptors in trigeminal nucleus. Not by mast cells. Narcan will work, Benadryl wont
Hydrophilic opioid v lipophilic fx w resp dep
Hydrophilic= early <6h or late 6-12 h. Lipophilic= only early
What reduces efficacy or epidural opioids
2 chlorprocaine
How long to wait before doing block w glyco IIB/A antagonists: itrofiban, eptifibatide, abciximab
Hold 8 hrs, 8 hrs, hold 1-2 days
How long to wait before block w plavix or ticlid
Plavix 7 days, ticlid 14 days
How long to wait for block/after block/after indwelling catheter removal w iv heparin
Before block 2-4hr. After block 1 hr. After indwelling removed 2-4 hours
LMWH (lovenox, -Parin ending) how long to wait before placing if once or twice daily. How long before removing indwelling cath. How long after cath removed or after single shot block
Before: once wait 12h, twice wait 24h. Before removing: 12h. After removal: 2h. After single shot: once daily hold 6-8h, twice hold 24h
Warfarin: how long to wait before block placement, when can remove catheter
Hold 5 days. Can remove if INR <1.5
Thrombolytic implication on neuraxial
Absolute contraindication (tpa, alteplase, etc)
Where is conus medullaris
Adult l1-2, infant l3
Dural sac: what it is, where it is
Where subarachnoid space ends, S2 adult s3 infant
Cauda equina syndrome: cause, what inc risk, s/s
Neurotoxicity, inc conc of LA. 5% lido and spinal micro catheters. Bowel and bladder dysfunc, sensory deficit, weakness, paralysis
Transient neuro symptoms: cause, inc risk, doesnt inc risk
Pt positioning/sciatic nerve stretch/muscle spasm. Inc: lido, lithotomy, knee arthrosc. Doesn’t: early amb, LA conc, baricity, glucose conc
TNS: s/s
Back and butt pain radiating to legs. Develops 6-36h and lasts 1-7 days
Where SC ends in infant, highest point that you can do a spinal in them
L3. Highest= L4
Which nerve roots most resistant to fx of LAs
L5 and S1. Largest spinal nerves
After spinal recovery what comes back first to last
Motor, touch, sharp pain, temp
Order of being anesthetizzed in spinal
Pre gang sns, temp, pin prick, touch, motor
2 complications more common in spinal anes over epidural
Meningitis and cauda equina syndrome
2 complic more common after epidural than spinal
Epidural abscess, traumatic spinal cord injury, and spinal hematoma
Best method of decontam for neuraxial
Chlorhexidine and isopropyl alcohol
Brachial plexus: roots, trunks
Roots: c5-t1. Trunks: superior, middle, inferior
Brachial plexus: cords, branches
Cords: lateral, posterior, medial. Branches: musculocutaneous, axillary, median, radial, ulnar
Roots that contribute to each trunk
C5-6= superior. C7= middle. C8-t1= inferior
Roots with corresponding branches
C5-7/lat cord/musculocutaneous. C5-6/posterior/axillary. C5-t1/lateral and medial/median. C5-t1/posterior/radial. C8-t1/medial/ulnar
Sensory and motor test: axillary
Pinch lateral shoulder, arm abduction
Sensory and motor test: musculocutaneous
Pinch lateral FA, elbow flexion
Sensory and motor test: median
Pinch index finger. Thumb opposition
Sensory and motor test: radial
Pinch web between thumb and index finger.elbow extension, wrist and finger extension
Sensory and motor test: ulnar
Pinch pinky, pink abduction
Acceptable nerve twitch responses during interscalene block
Deltoid abduction, pec internal rotation, biceps flexion, tricep extension, any twitch of hand/forearm
Acceptable v unacceptable twitch responses in supraclavicular block
Acceptable: finger or wrist flexion or extension. Unacceptable: shoulder, biceps, or triceps (suggests upper or middle trunk)
Landmarks in supraclavicular
Clavicle and subclavian artery
Acceptable twitch response w infraclavicular block
Triceps or any muscle below the elbow
Area most likely to not get enough anesthesia after an axillary block w transarterial technique
Lateral fa
Risk with ulnar nerve block, avoid median block in who
Vol too high can compress ulnar and lead to ischemic injury. Median nerve- avoid if carpal tunnel syndrome
Bier block: steps from seeing arm to removing esmarch in inflating tourniquet
Elevate arm 1-2 min, wrap esmarch, inflate distal, inflate proximal, deflate distal, remove esmarch
Vol and conc LA for bier block
50 ml 0.5% lido
Bier block tourniquet pressure goal
250 or 100 above SBP
When tourniquet pain may occur. How long tourniquet needs to be up after iv regional. Max tourniquet inflation time
45-60 min. 20 min. 2 hrs
How to change out tourniquet if pain after bier block
Inflate distal cuff, deflate proximal cuff
If 20-40 min since LA injection how to deflate cuff
Deflate, immeadiately reinflate, then deflate after 1 min
Tourniquet pressure and vol: leg, calf
Leg= larger vol, p 350-400. Calf: same p and vol
Lumbar plexus: what it derives from, nerves that come off of it/pneumonic
L1-4. I (iliohypogastric) invariably (ilioinguinal) get (genitofemoral) lazy (lat fem cutaneous) on (obturator) Friday’s (fem)
How to remember lumbar plexus which nerves come from where, mnemonic
2 from 1 (I and I from L1), 2 from 2 (G and L from L2. G= L1+2, l= L2+3) and 2 from 3 (O and F from L2,3,4)
Sacral plexus: roots and what comes off from it (including ankle)
L4-S4. Post fem cutaneous and sciatic —> com per (sup per and deep per) + tibial (post tib). Com per and tibial converge into sural
Coccygeal plexus roots and branches from it
S4-co. Pudendal, inf anal, perineal
Lumbar plexus gives sensory and motor info where
Motor and sensory to anterior thigh. Sensory to medial aspect of lower leg below knee
Sensory and motor info from lat fem cutaneous and roots
L2-3, no motor, sensory to lateral thigh
Femoral roots, important branch, sensory and motor info
L2-4. Saphenous. Motor; anterior branch= sartorius, posterior branch= quadriceps. Sensory= ant thigh
Obturator: branches, injured when, sensory and motor info
L2-4. Pelvic sx. Motor to hip adductors. Sensory to distal inner thigh and pt of hip
Sacral plexus: where it originates from. Two pts of it
L4-5 and s1-4. Sciatic nerve and posterior fem cutaneous
Sciatic nerve roots, sensory, motor info
L4-S3. Motor to posterior thigh, motor and sensory to most of lower leg and foot by tibial and common peroneal nerves
Post fem cutaneous roots, sensory, motor info
S1-3. Sensory to posterior thigh
Psoas compartment block hits which nerves
Another word for lumbar plexus. Lat fem cutaneous, femoral (and saphenous), obturator
Landmarks for psoas block
Spinous processes, iliac crests, PSIS. Needle goes 3 cm caudad from L4 and 5 cm lateral from midline
Potential complications psoas block, contraindication to it
Sympathectomy of one or both legs. Retro hematoma, renal injection. Contra: coagulopathy
Borders of fem triangle
Sartorius muscle (lateral), adductor longus (medial), ingluinal ligament (superior)
Structures inside fem triangle medial to lateral
VAN
Fascia iliaca block: where LA deposited, layers traversed w needle
Inferior to fascia iiliaca superior to ilipsoas. Needle thru fascia lata then iliaca
How to inc tolerance of an upper leg tourniquet
3 in 1 block or sciatic and a psoas compartment block
Sensory and motor from saphenous nerve
No Motor. Sensory to medial knee and down the lower leg
What does sciatic nerve innervate (muscle wise)
Biceps femoris, semitendinosus, semimembranosus
Sciatic nerve arises from which roots, which nerves does it consist of
L4-5 and S1-3. Tibial and peroneal nerves
Stim of tibial nerve in popliteal fossa causes what
Plantar flexion and inversion of foot
Part of foot that it covers: tibial n, sural n, sup peroneal n, deep peroneal n
Tibia= heel. Sural= lateral foot. Sup per= dorsum of foot. Deep per= space b/w 1st and 2nd toe
Ankle block nerves, which ones pure sensory
Sup per, sural, saphenous, tibial, DP. All S’s= pure sensory
Motor func of tibial and DP
Tibial= plantar flexion and inversion. DP= Eversion and dorsiflexion
Sural nerve: where it is in ankle block, what it provides sensation to
Behind lateral malleolus. Sensation to posterior heel and sole of foot and pt of Achilles above ankle
Sup per nerve: where it is in ankle block, sensation to where
Anterior to lateral malleolus. Dorsum of foot
Dep per nerve: where it is in block, sensory to where
In between dorsalis pedis a and tibialis anterior tendon of foot. Skin on lateral side of hallux, medial side of second toe
Saphenous nerve: sensory to where, where it is in ankle block
Medial aspect of lower leg below the knee. Between midpoint of distal tibia and medial malleolus
Terminal branches of plexus, pneumonic
MARMU, mcn, ax, radial, median, u temp lunar
How many RTDCB
5 C5-T1, 3, 6, 3, 5
Which nerves supplied by medial and lateral cords. Which nerves supplied by posterior
Med/lat: median, ulnar, musculocutaneous. Posterior: radial and axillary
If pt c/o sensation in anterolateral forearm which block most likely performed
Axillary
Which block has highest incidence of chylothorax
Infraclavicular
Where do roots become trunks
Lateral border of scalenes
Where do trunks become divisions
Under clavicle, over 1st rib
Where to divisions become cords
Under pec minor
Where do cords become terminal branches
Axilla
Which segments of brachial plexus targeted by: interscalene, supraclavicular, infraclavicular, axillary
Interscalene: roots. Supra: trunks and divisions. Infra: cords. Axillary: branches
Blockade of which nerve will enhance tolerance of an upper arm tourniquet
Intercostobrachial
