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