Regional Anesthesia and Anticoagulants

Question 1

examples of cox 1 inhibitors

Answer 1

NSAIDS, aspirin

Question 2

criteria to consider for neuraxial block when patient takes COX1 inhibitors

Answer 2

coagulation status appears normal, no other blood thinners in use

Question 3

MOA of glycoprotein IIb/IIIa antagonists

Answer 3

inhibits platelet aggregation via surface receptors

Question 4

examples of glycoprotein IIb/IIIa antagonists

Answer 4

tirofiban
eptifibatide
abciximab

Question 5

anesthetic management of patient on glycoprotein IIb/IIIa antagonists that requires neuraxial block

Answer 5

avoid until platelet function has recovered.
contraindicated within 4 weeks of surgery aka do not restart

Question 6

hold tirofiban and eptifibatide how many hours before block placement?

Answer 6

4-8 hours

Question 7

hold abciximab how many hours before block placement?

Answer 7

24-48

Question 8

MOA of thienopyridine derivatives

Answer 8

inhibits platelet aggregation by blocking ADP transferase

Question 9

examples of thienopyridine derivatives

Answer 9

clopidogrel
prasugrel
ticlopidine

Question 10

post op anesthetic management of a patient on thienopyridine derivatives that require block placement

Answer 10

may restart 24h post op

Question 11

how long to hold clopidogrel before a block is placed?

Answer 11

5-7 days

Question 12

how long to hold prasugrel until block is placed?

Answer 12

7-10 days

Question 13

how long to hold ticlodipine until block is placed?

Answer 13

10 days

Question 14

MOA of unfractionated heparin

Answer 14

potentiates antithrombin, inhibits thrombin (factor 2) and factors 9, 10, 11, 12

Question 15

anesthetic management of a patient on unfractionated heparin that requires a neuraxial block

Answer 15

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

Question 16

how long after block placement can you restart heparin or catheter removal

Answer 16

1 hour

Question 17

before block placement, hold low dose heparin (5000 units up to TID) for

Answer 17

4-6 hours

Question 18

before block placement, hold higher dose heparin (less than or equal to 20,000 units daily) for

Answer 18

12 hours

Question 19

before block placement, hold heparin doses > 20,000 units daily in pregnant patients for

Answer 19

24 hours

Question 20

hold heparin SQ for how many hours after last dose or discontinuation of IV infusion for neuraxial catheter removal?

Answer 20

4-6 hours

Question 21

MOA of LMW heparin

Answer 21

irreversibly inhibits 10a

Question 22

examples of LMW heparin include

Answer 22

enoxaparin
dalteparin
tinzaparin

Question 23

anesthetic management of a patient on LMW heparin that requires a neuraxial block includes

Answer 23

coags WNL and no other blood thinners in use
obtain platelet count if on LMWH for >4 days

Question 24

before block or catheter placement, delay LMWH at least ___ hours after prophylactic dose

Answer 24

12 hours

Question 25

before block or catheter placement, delay LMWH at least ______ hours after therapeutic dose

Answer 25

24 hours

Question 26

after block placement, if LMWH is ordered-

Answer 26

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

Question 27

MOA of anti vitamin K drugs

Answer 27

impairs factors 2,7,9,10

Question 28

anesthetic management of a patient on warfarin that requires a neuraxial block

Answer 28

verify normal INR

Question 29

hold warfarin for how long before block placement?

Answer 29

5 days

Question 30

at what level should INR be before neuraxial catheter removal if patient is on warfarin

Answer 30

<1.5

Question 31

examples of PO anti factor 10a agents

Answer 31

apixiban betrixiban edoxaban rivaroxaban

Question 32

how long should you discontinue anti factor 10a agents before catheter placement

Answer 32

at least 72 hours (3 days). if <72h, consider checking 10a

Question 33

how long should you wait to dose anti factor 10a agents before neuraxial catheter removal

Answer 33

6 hours before first postop dose

Question 34

MOA of thrombolytic agents

Answer 34

activates plasminogen

Question 35

examples of thrombolytic agents

Answer 35

TPA streptokinase alteplase urokinase

Question 36

anesthetic management of patient on thrombolytic agent who requires neuraxial anesthesia

Answer 36

absolute contraindication to neuraxial

Question 37

MOA of herbal therapies

Answer 37

inhibits platelet aggregation

Question 38

examples of herbal therapies

Answer 38

garlic ginkgo ginseng

Question 39

anesthesia management of patient on herbal therapies that requires neuraxial block

Answer 39

proceed with neuraxial anesthesia if patient is not on other blood thinning drugs

Question 40

tx for PDPH

Answer 40

bed rest NSAIDS caffeine (cerebral vasoconstriction) epidural blood patch sphenopalantine ganglion block

Question 41

if PDPH doesn't get better after how many epidural blood patches, consider other etiologies

Answer 41

2

Question 42

describe sphenopalatine ganglion block

Answer 42

-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

Question 43

most common culprits for post spinal bacterial meningitis

Answer 43

streptococcus veridians

Question 44

most effective preparation method to prevent post spinal bacterial meningitis

Answer 44

chlorhexidine and alcohol

Question 45

what is the threshold for spinal induced HoTN

Answer 45

<90SBP

Question 46

methods to minimize spinal induced HoTN risk

Answer 46

-vasopressors (neo) -5HT3 antagonist (zofran) that inhibits bezold jarisch reflex -"co loading" of IVF just after block with 15mL/kg IVF -postioning (pelvic tilting)

Question 47

cauda equina syndrome cause s/sx tx

Answer 47

cause: neurotoxicity is result of exposure to high concentrations of LA s/sx: bowel and bladder dysfunction, sensory deficits, weakness, paralysis tx: supportive

Question 48

transient neurological sx's cause factors that increase risk s/sx tx

Answer 48

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

Question 49

what can you do if you encounter resistance when removing epidural catheter?

Answer 49

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

Question 50

why is blood usually in epidural needle and how to fix

Answer 50

placed too laterally (in epidural vein) redirect towards midline

Question 51

risk factors for epidural vein cannulation

Answer 51

multiple insertion attempts pregnancy (epidural vein engorgement) sniffing using a stiff catheter trauma to epidural veins during block placement

Question 52

if spinal does not set up after 15-20 min, you can

Answer 52

repeat injection

Question 53

what should you do if your spinal block is patchy

Answer 53

dont repeat spinal for fear or neuro toxicity. switch to IV or GA

Question 54

what should you do if your block is unilateral

Answer 54

position patient with poorly blocked side down and administer several mL of LA if that doesn't work, consider another technique

Question 55

most common cause of unilateral epidural block

Answer 55

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