Regional Anesthesia and Anticoagulants Flashcards
examples of cox 1 inhibitors
NSAIDS, aspirin
criteria to consider for neuraxial block when patient takes COX1 inhibitors
coagulation status appears normal, no other blood thinners in use
MOA of glycoprotein IIb/IIIa antagonists
inhibits platelet aggregation via surface receptors
examples of glycoprotein IIb/IIIa antagonists
tirofiban
eptifibatide
abciximab
anesthetic management of patient on glycoprotein IIb/IIIa antagonists that requires neuraxial block
avoid until platelet function has recovered.
contraindicated within 4 weeks of surgery aka do not restart
hold tirofiban and eptifibatide how many hours before block placement?
4-8 hours
hold abciximab how many hours before block placement?
24-48
MOA of thienopyridine derivatives
inhibits platelet aggregation by blocking ADP transferase
examples of thienopyridine derivatives
clopidogrel
prasugrel
ticlopidine
post op anesthetic management of a patient on thienopyridine derivatives that require block placement
may restart 24h post op
how long to hold clopidogrel before a block is placed?
5-7 days
how long to hold prasugrel until block is placed?
7-10 days
how long to hold ticlodipine until block is placed?
10 days
MOA of unfractionated heparin
potentiates antithrombin, inhibits thrombin (factor 2) and factors 9, 10, 11, 12
anesthetic management of a patient on unfractionated heparin that requires a neuraxial block
coags are normal and no other blood thinners in use
obtain platelet count before block or removal of catheter if IV or SQ heparin for >4 days
how long after block placement can you restart heparin or catheter removal
1 hour
before block placement, hold low dose heparin (5000 units up to TID) for
4-6 hours
before block placement, hold higher dose heparin (less than or equal to 20,000 units daily) for
12 hours
before block placement, hold heparin doses > 20,000 units daily in pregnant patients for
24 hours
hold heparin SQ for how many hours after last dose or discontinuation of IV infusion for neuraxial catheter removal?
4-6 hours
MOA of LMW heparin
irreversibly inhibits 10a
examples of LMW heparin include
enoxaparin
dalteparin
tinzaparin
anesthetic management of a patient on LMW heparin that requires a neuraxial block includes
coags WNL and no other blood thinners in use
obtain platelet count if on LMWH for >4 days
before block or catheter placement, delay LMWH at least ___ hours after prophylactic dose
12 hours
before block or catheter placement, delay LMWH at least ______ hours after therapeutic dose
24 hours
after block placement, if LMWH is ordered-
delay first dose at least 12 hours after block and if single daily dosing, give second dose no sooner than 24 hours after first fose
MOA of anti vitamin K drugs
impairs factors 2,7,9,10
anesthetic management of a patient on warfarin that requires a neuraxial block
verify normal INR
hold warfarin for how long before block placement?
5 days
at what level should INR be before neuraxial catheter removal if patient is on warfarin
<1.5
examples of PO anti factor 10a agents
apixiban
betrixiban
edoxaban
rivaroxaban
how long should you discontinue anti factor 10a agents before catheter placement
at least 72 hours (3 days). if <72h, consider checking 10a
how long should you wait to dose anti factor 10a agents before neuraxial catheter removal
6 hours before first postop dose
MOA of thrombolytic agents
activates plasminogen
examples of thrombolytic agents
TPA
streptokinase
alteplase
urokinase
anesthetic management of patient on thrombolytic agent who requires neuraxial anesthesia
absolute contraindication to neuraxial
MOA of herbal therapies
inhibits platelet aggregation
examples of herbal therapies
garlic
ginkgo
ginseng
anesthesia management of patient on herbal therapies that requires neuraxial block
proceed with neuraxial anesthesia if patient is not on other blood thinning drugs
tx for PDPH
bed rest
NSAIDS
caffeine (cerebral vasoconstriction)
epidural blood patch
sphenopalantine ganglion block
if PDPH doesn’t get better after how many epidural blood patches, consider other etiologies
2
describe sphenopalatine ganglion block
-soak long cotton tipped applicator in LA (1-2% lido or .5% bupiv)
-place patient in sniffing
-insert cotton tip in each bare towards middle turbinate
-continue insertion until you each back wall of nasopharynx, which is the vicinity of the sphenopalantine ganglion
-leave applicator in place for 5-10m
-pt should notice sx improvement at this time
most common culprits for post spinal bacterial meningitis
streptococcus veridians
most effective preparation method to prevent post spinal bacterial meningitis
chlorhexidine and alcohol
what is the threshold for spinal induced HoTN
<90SBP
methods to minimize spinal induced HoTN risk
-vasopressors (neo)
-5HT3 antagonist (zofran) that inhibits bezold jarisch reflex
-“co loading” of IVF just after block with 15mL/kg IVF
-postioning (pelvic tilting)
cauda equina syndrome
cause
s/sx
tx
cause: neurotoxicity is result of exposure to high concentrations of LA
s/sx: bowel and bladder dysfunction, sensory deficits, weakness, paralysis
tx: supportive
transient neurological sx’s
cause
factors that increase risk
s/sx
tx
cause: patient positioning, stretching of sciatic nerve, myofascial strain, muscle spasm
factors that increase risk: lidocaine, lithotomy, ambulatory surgery, knee arthroscopy
s/sx: severe back and butt pain that radiates to both legs. generally develops within 6-36h and persists for 1-7d
tx: NSAIDS, opioid analgesics, trigger point injections
what can you do if you encounter resistance when removing epidural catheter?
lateral decubitus
taping catheter to skin under gentle traction and trying again later
using a stylet to thread the catheter
injecting wire reinforced catheter with saline
why is blood usually in epidural needle and how to fix
placed too laterally (in epidural vein)
redirect towards midline
risk factors for epidural vein cannulation
multiple insertion attempts
pregnancy (epidural vein engorgement)
sniffing
using a stiff catheter
trauma to epidural veins during block placement
if spinal does not set up after 15-20 min, you can
repeat injection
what should you do if your spinal block is patchy
dont repeat spinal for fear or neuro toxicity. switch to IV or GA
what should you do if your block is unilateral
position patient with poorly blocked side down and administer several mL of LA
if that doesn’t work, consider another technique
most common cause of unilateral epidural block
catheter was inserted too far and tip has exited epidural space into intervertebral foramen
-pull catheter back 1-2cm, place patient in lateral decub, administer several mL of dilute concentration LA
-if this doesn’t work, replace catheter
