Lecture 5-Hematology Flashcards
1
Q
What are the (3) components of Virchow’s triad?—___ state, ___ wall injury, circulatory ___
A
Hypercoaguable state, vascular wall injury, circulatory stasis
2
Q
Heparin affects ___ (bound clotting factors/unbound clotting factors/both)
A
UNBOUND clotting factors only—does not affect bound clotting factors/doesn’t break up existing clots
3
Q
Heparin MOA = accelerates the rate at which ___ neutralizes ___ and ___; heparin binds ___ (reversibly/irreversibly) to ___ and induces a ___ change
A
Accelerates the rate at which antithrombin III (heparin cofactor) neutralizes thrombin (factor 2A) and factor 10A; heparin binds reversibly to antithrombin III and induces a conformational change
4
Q
What system clears heparin from the body?
A
The reticuloendothelial system
5
Q
Does heparin cross the placenta?
A
No
6
Q
What test is often used to monitor heparin use?
A
ACT [activated clotting time]
7
Q
ACT is used to measure heparin’s ___ (intrinsic/extrinsic) pathway activity
A
Intrinsic pathway activity
8
Q
ACT is monitored in procedures with significant heparin use—T/F?
A
True
9
Q
Heparin induced thrombocytopenia (HIT)—it is considered thrombocytopenia if platelets are < ___
A
< 100K
10
Q
If there is a significant drop in platelet count from the patient’s baseline after heparin administration, you should consider the possibility of HIT (even if platelet count is not necessarily < 100K)—T/F?
A
True
11
Q
HIT occurs ___-___ days after initiation of full dose or low dose heparin therapy, including heparin flush solution
A
5-15 days
12
Q
HIT doesn’t occur immediately unless the patient has received heparin previously—T/F?
A
True
13
Q
Type ___ (1 or 2) HIT occurs d/t heparin dependent antiplatelet ___ antibodies
A
Type 2 HIT occurs d/t heparin dependent antiplatelet IgG antibodies
14
Q
Type ___ (1 or 2) HIT occurs d/t a direct, ___ effect on platelets
A
Type 1 HIT occurs d/t a direct, nonimmunogenic effect on platelets
15
Q
How can HIT be reversed?
A
Stopping heparin therapy
16
Q
In a minority of patients with HIT, it may be associated with thrombotic complications (“procoagulant state”), including arterial thrombosis and platelet-fibrin clots—if this occurs, what should you do?
A
Stop heparin and start patient on argatroban to prevent more clots from forming
17
Q
Before diagnosing HIT, you should rule out other causes for thrombocytopenia—what two medications can cause thrombocytopenia? What disease state can cause thrombocytopenia?
A
Depakote and Pepcid can cause thrombocytopenia; sepsis can cause thrombocytopenia
18
Q
HIT testing—___ testing picks up IgG antibodies; has very few false negatives; can get some false positives if it’s not the ___ specific antibody testing
A
ELISA testing picks up IgG antibodies; can get some false positives if it’s not the IgG specific antibody testing
19
Q
HIT testing—___ = gold standard for HIT diagnosis; highly specific with very few false positives
A
Serotonin release assays
20
Q
HIT treatment = stop ___ products; administer ___ anticoagulants (usually will use ___ or ___); add ___ to chart
A
Stop heparin products; administer non-heparin anticoagulants (usually will use argatroban or bivalrudin); add allergy to chart
21
Q
What is the antidote for heparin?
A
Protamine sulfate
Protamine = cation, combines with strong anion heparin to form a stable salt (protamine NEUTRALIZES heparin)
22
Q
Protamine can be used to reverse LMWHs—T/F?
A
False—LMWH are not as susceptible to protamine antagonism
23
Q
If emergency reversal is needed for LMWH, protamine will neutralize about ___% of anti-Xa activity of LMWHs
A
65%
24
Q
Protamine should be administered ___ (fast/slow)
A
SLOW
25
Rapid IV injection of protamine is associated with acute ___-related ___tension, ___cardia, ___ hypertension, transient ___, ___nea, respiratory ___
Acute histamine-related hypotension, bradycardia, pulmonary hypertension, transient flushing, dyspnea, respiratory distress
26
Patients may have a hypersensitivity reaction to protamine sulfate if they are hypersensitive to ___; have had previous ___ reversal; take protamine containing ___; or had previous ___
Hypersensitive to fish (protamine sulfate comes from salmon sperm); have had previous protamine reversal; take protamine containing insulin (NPH); or had previous vasectomy
27
To prevent hypersensitivity reaction to protamine, you can pre-treat patient with ___ and ___
Corticosteroid and antihistamine
28
Heparin rebound is ___ (common/rare) and is usually seen in patients who had ___ (little/massive) amounts of heparin
Heparin rebound is rare and is usually seen in patients who had massive amounts of heparin (i.e.: CPB cases)
29
What is heparin rebound?—a condition where patients ___ after ___ administration
A condition where patients re-anticoagulate after protamine administration
30
Heparin management [hold times prior to OR]—if patient is on IV heparin, stop ___-___ hours prior to procedure; if patient is on subQ heparin, stop ___ hours prior to procedure
If patient is on IV heparin, stop 4-6 hours prior to procedure; if patient is on subQ heparin, stop 12 hours prior to procedure
31
Heparin management [restart times after OR]—restart ___ hours post-op if patient is low risk for bleeding; restart ___-___ hours post-op if patient is high risk for bleeding (i.e.: liver disease, on other blood thinners, type of surgery puts them at risk for post-op bleeding)
Restart 24 hours post-op if patient is low risk for bleeding; restart 48-72 hours post-op if patient is high risk for bleeding (i.e.: liver disease, on other blood thinners, type of surgery puts them at risk for post-op bleeding)
32
Heparin management [catheter placement]—catheter should be placed ___ hour before heparin administration; catheter should be placed ___ hours before heparin administration if patient is going to have cardiac surgery
Catheter should be placed 1 hour before heparin administration; catheter should be placed 24 hours before heparin administration if patient is going to have cardiac surgery
33
Heparin management [catheter removal]—indwelling neuraxial catheters should be removed ___-___ hours after the last heparin dose and after their coagulation status has been evaluated
Should be removed 2-4 hours after the last heparin dose and after their coagulation status has been evaluated
34
LMWH MOA—inhibit factor ___ and ___—they are much more selective to factor ___ inhibition than ___
Inhibit factor Xa and IIa (thrombin)—they are much more selective to factor Xa inhibition than IIa
35
___ levels are the gold standard for monitoring LMWH therapy
Anti-Factor Xa levels
36
APTT and PT/INR are effective at monitoring LMWH therapy—T/F?
False—aPTT and PT/INR are insensitive to LMWH therapy
37
You should decrease the dose of LMWH in patients with chronic ___ insufficiency
Chronic renal insufficiency—because these drugs are renally eliminated
38
This anticoagulant is the most specific inhibitor of Factor Xa—no effect on factor IIa
Fondaparinux (Arixtra)
39
Black box warning for all LMWHs and fondaparinux (arixtra)—use of neuraxial blockade represents significant risk of ___; monitor for signs and symptoms of ___ damage
Use of neuraxial blockade represents significant risk of epidural hematoma; monitor for signs and symptoms of neurologic damage
40
Spinal/epidural hematoma risk for all LMWHs and fondaparinux—needle placement should occur at least ___ hours after last LMWH LOW dose or fondaparinux dose
Needle placement should occur at least 12 hours after last LMWH LOW dose or fondaparinux dose
41
Spinal/epidural hematoma risk for all LMWHs and fondaparinux—needle placement should occur at least ___ hours after last LMWH HIGH dose
24 hours
42
If epidural catheter is inserted, it should be done at least ___ hours prior to any dose of postoperative LMWH (single daily dosing)
4 hours prior to any dose of postoperative LMWH (single daily dosing)
43
Twice daily dosing of LMWH should be delayed until ___ hours post-op
Delayed until 24 hours post-op
44
Catheters should be removed prior to initiating ___ daily dosing
Twice daily dosing
45
Removal of epidural catheter should be done ___-___ hours before any dose of LMWH
2-4 hours before any dose of LMWH
46
Removal of epidural catheter should occur ___ hours after any dose and ___ hours before a subsequent dose
12 hours after any dose and 2 hours before a subsequent dose
47
What are (3) oral Xa inhibitors?
- Rivaroxaban (Xarelto)
- Apixaban (Eliquis)
- Edoxaban (Savaysa)
“Xa” in the name because they are oral Xa inhibitors
48
Hold time for dabigatran (pradaxa) with poor kidney function is ___-___ days; hold time for dabigatran (pradaxa) with normal kidney function is ___-___ days
3-5 days; 1-2 days
49
Xarelto only needs to be held for ___ hours prior to procedure
24 hours prior to procedure
50
For low risk bleeding, Xarelto should be held for ___ day; for high risk bleeding, xarelto should be held for ___ days
1 day; 2 days
51
Hold time for NOACs/DOACs is much ___ (more/less) than hold times for warfarin
Less than hold times for warfarin (5 days for warfarin vs. 1-2 days for NOACs/DOACs)
52
With NOACs, you don’t have to worry about starting the patient on bridge therapy or formation of clots while the medication is being held—T/F?
True, because the hold time is only 1-2 days (depending on low vs. high risk of bleeding)
53
All DOACs currently have available a BB warning for use with neuraxial anesthesia—T/F?
True
54
Dabigatran (pradaxa) should be held ___-___ days prior to neuraxial procedures
4-5 days prior to neuraxial procedures
55
Oral Xa inhibitors should be held ___-___ days prior to neuraxial procedures
3-5 days prior to neuraxial procedures
56
Dabigatran (pradaxa) and oral Xa inhibitors can be restarted ___ hours post-procedure if the patient is a low bleed risk; can be restarted ___-___ hours post-procedure if the patient is a high bleed risk
Can be restarted 24 hours post-procedure if the patient is a low bleed risk; can be restarted 48-72 hours post-procedure if the patient is a high bleed risk
57
Hemodialysis ___ (can/cannot) remove oral Xa inhibitors
Cannot
58
What is one reversal agent for oral factor Xa meds?
Andexanet alpha (andexxa)
59
Andexanet alpha (andexxa) was approved in January 2019 for reversal of Xa inhibitors; approved for what (2) oral Xa inhibitors?
- Xarelto
| - Eliquis
60
Andexanet alpha (andexxa) is approved for reversal of edoxaban (savaysa)—T/F?
False—approved for reversal of xarelto and Eliquis only
61
Black box warning for andexxa—___ events, ___ events, cardiac ___, sudden ___; may also cause ___, ___onia, infusion related ___
Thromboembolic events, ischemic events, cardiac arrest, sudden death; may also cause UTIs, pneumonia, infusion related reactions
62
Argatroban = direct ___ inhibitor (factor ___)
Direct thrombin inhibitor (factor IIa)
63
Argatroban binds to both ___ and ___-bound thrombin
Both circulating and clot-bound thrombin
64
Argatroban has a ___ (lower/higher) risk of bleeding because it breaks up thrombin that is circulating and thrombin that is bound to clots
Higher risk of bleeding
65
Argatroban is used for the prevention/treatment of thrombosis in patients with ___
HIT
66
Argatroban ___ (does/does not) have a reversal agent
Does not have a reversal agent
67
(2) other direct thrombin inhibitors that are hirudin analogs
- Bivalrudin (angiomax)
| - Lepirudin (refludin)
68
Hirudin comes from ___
Leech spit
69
Hirudin analogs bind ___ (reversibly/irreversibly) to both circulating and clot-bound thrombin; they are used as a heparin alternative if patient has ___
Irreversibly to both circulating and clot-bound thrombin; they are used as a heparin alternative if patient has HIT
70
Hirudin analogs ___ (do/do not) have a reversal agent
Do not have a reversal agent
71
Dose of hirudin analogs must be adjusted in ___ impairment
Renal impairment
72
Anti-hirudin antibodies form in ~___% of patients
~40% of patients
73
Anti-hirudin antibodies may be associated with an increased ___ effect of lepirudin; for this reason, ___ would be a safer choice
Anticoagulant effect of lepirudin; for this reason, argatroban would be a safer choice to treat patient with HIT
74
Dabigatran (pradaxa) is an oral direct ___ inhibitor
Oral direct thrombin inhibitor
75
HD will remove ___-___% of circulating dabigatran (unlike oral factor Xa inhibitors, Xarelto and Eliquis)
62-68% of circulating dabigatran
76
Antidote for dabigatran = ___
Idarucizumab (praxbind)
77
Warfarin antidote = ___
Vitamin K1
78
Warfarin antidote Vitamin K1 takes ~___ hours to see effects
~24 hours
79
Vitamin K1 should never be given ___
SubQ
80
Warfarin is pregnancy category ___
X—never give in pregnancy!
81
Warfarin drug interactions—anti___; other ___; ___s; ___; ___; anti___
Antibiotics; other blood thinners; NSAIDs; acetaminophen; supplements; antiepileptics
82
Most NOACs ___ (do/do not) require bridge therapy, as they are held ___-___ hours prior to procedure
do not require bridge therapy, as they are only held 24-48 hours prior to procedure
83
Warfarin management—goal INR is < ___
< 1.5
84
Warfarin should be held ___ days before procedure
5 days before procedure
85
Warfarin needs to be bridged with ___
LMWH (lovenox)
86
Oral anticoagulants like warfarin are falling out of favor—T/F?
True—d/t drug interactions, longer hold times, need for bridge therapy
87
Thrombolytic agents end in -___; what are (5) thrombolytic agents?
-ase
- alteplase
- reteplase
- tenecteplase
- streptokinase
- urokinase
88
Thrombolytic agents MOA—tPA binds to ___ and ___ and converts bound ___ogen to ___; ___ is our natural clot cleaver in the body, promotes the body to break down clots
TPA binds to fibrin and plasminogen and converts bound plasminogen to plasmin; plasmin is our natural clot cleaver in the body, promotes the body to break down clots
89
Thrombolytic agents put the body into a ___ state
“Systemo-lytic” state—activate plasmin to break down fibrin rich clots throughout the entire body; can be very dangerous
90
Is this an absolute or relative contraindication for thrombolytic therapy?—acute ICH
Absolute contraindication
91
Is this an absolute or relative contraindication for thrombolytic therapy?—history of ICH
Absolute contraindication
92
Is this an absolute or relative contraindication for thrombolytic therapy?—severe, uncontrolled HTN
Absolute contraindication—specifically, SBP 185 or greater, DBP 110 or greater
93
Is this an absolute or relative contraindication for thrombolytic therapy?—age > 75 yo
Relative contraindication
94
Is this an absolute or relative contraindication for thrombolytic therapy?—severe stroke or coma
Relative contraindication
95
Is this an absolute or relative contraindication for thrombolytic therapy?—recent major surgery
Relative contraindication
96
Is this an absolute or relative contraindication for thrombolytic therapy?—serious head trauma or stroke in previous 3 months
Absolute contraindication
97
Is this an absolute or relative contraindication for thrombolytic therapy?—arterial puncture of non compressible vessel within 7 days
Relative contraindication
98
Is this an absolute or relative contraindication for thrombolytic therapy?—platelets < 100,000
Absolute contraindication
99
Is this an absolute or relative contraindication for thrombolytic therapy?—systemic anticoagulation
Absolute contraindication
100
Is this an absolute or relative contraindication for thrombolytic therapy?—BG > 400 or < 50
Absolute contraindication
101
Is this an absolute or relative contraindication for thrombolytic therapy?—recent GI bleed within 21 days
Relative contraindication
102
Is this an absolute or relative contraindication for thrombolytic therapy?—seizure with stroke onset
Relative contraindication
103
Is this an absolute or relative contraindication for thrombolytic therapy?—recent MI within 3 months
Relative contraindication
104
Is this an absolute or relative contraindication for thrombolytic therapy?—CNS structural lesions
Relative contraindication
105
Is this an absolute or relative contraindication for thrombolytic therapy?—early radiographic ischemic changes
Absolute contraindication
106
Is this an absolute or relative contraindication for thrombolytic therapy?—active internal bleeding
Absolute contraindication
107
Is this an absolute or relative contraindication for thrombolytic therapy?—dementia
Relative contraindication
108
Is this an absolute or relative contraindication for thrombolytic therapy?—traumatic CPR
Relative contraindication
109
Dextran MOA—expands ___ by pulling in ___; prevents thromboembolism by decreasing blood ___
Expands intravascular volume by pulling in water; prevents thromboembolism by decreasing blood viscosity (dilution prevention)
110
Dextran side effects—allergic reactions d/t dextran-reactive ___ present in most adults; ___ formation may make subsequent ___ of blood difficult
Allergic reactions d/t dextran-reactive IgG antibodies present in most adults; rouleaux formation may make subsequent cross-matching of blood difficult
111
Aminocaproic acid (amicar) is used to treat ___
Excessive bleeding
112
How does amicar work?—inhibits activation of ___ to inhibit ___
Inhibits activation of plasminogen to inhibit fibrinolysis
113
Amicar load has to be given over ___
1 hour
114
Avoid rapid IV infusion of amicar secondary to ___tension, ___cardia, and/or ___mias
Hypotension, bradycardia, and/or arrhythmias
115
Risk of thrombosis with amicar is very ___ (low/high)
Low
116
TXA = ___ (anti/pro) coagulant
Procoagulant
117
TXA prevents bleeding by inhibiting ___/___
Plasminogen/fibrinolysis
118
TXA should be given ___ (slowly/quickly) d/t ___tension, just like what other drug?
Slowly d/t hypotension, just like amicar
119
Rapid administration of TXA can cause ___ d/t neuronal ___ and ___ inhibition of cerebral emboli
Seizures d/t neuronal GABA and glycine inhibition of cerebral emboli
120
What is raplixa?
Topical fibrin sealant
121
What are (3) components of platelet function?
- Adhesion
- Activation
- Aggregation
122
Platelet adhesion—___ factor promotes platelet adhesion to damaged vascular walls
VonWillebrand’s factor
123
What is the most common inherited coagulation defect?
VonWillebrand’s disease
124
Platelet activation—___ binds to receptor on platelet surface to activate platelet; binding results in ___ change; ___ change releases mediators involved in coagulation and healing—___ and ___
Thrombin binds to receptor on platelet surface to activate platelet; binding results in conformational change; conformational change releases mediators involved in coagulation and healing—Thromboxane A2 and ADP
125
Thromboxane A2 and ADP promote platelet ___
Aggregation
126
Aggregation—thromboxane A2 and ADP uncover ___ receptors; ___ attaches to its receptor, allowing platelets to link together
Thromboxane A2 and ADP uncover fibrinogen receptors; fibrinogen attaches to its receptor, allowing platelets to link together
127
What are two types of platelet aggregation inhibitors?
Aspirin and NSAIDs
128
Aspirin needs to be held for ___ days before surgery because it renders COX non-functional
7 days
129
Aspirin renders COX non-functional for the life of the platelet (8-12 days)—T/F?
True—have to wait for the body to make more platelets
130
NSAIDs need to be held for ___-___ hours before surgery
24-48 hours
NSAIDs depress platelet’s thromboxane A2 production but this is only temporary (24-48 hours)
131
(2) other platelet aggregation inhibitors (thienopyridine ADP-receptor antagonists) = ___ and ___
Clopidogrel (plavix) and ticagrelor (brilinta)
132
Ticagrelor (brilinta) ___ (is/is not) reversible
Is reversible
133
MOA of thienopyridine ADP-receptor antagonists—inhibit activation of the platelet ___ complex that is necessary for fibrinogen-platelet binding
Inhibit activation of the platelet glycoprotein (GP IIb/IIIa) complex that is necessary for fibrinogen-platelet binding
134
Thienopyridine ADP-receptor antagonists ___ (reversibly/irreversibly) modify the receptor
Irreversibly modify the receptor
135
Platelets exposed to thienopyridine ADP-receptor antagonists are affected for the remainder of their lifespan—T/F?
True
136
Aspirin and plavix should be held for ___ days before surgery
7 days
137
Brilinta should be held for ___ days before surgery
5 days before surgery (even though it is reversible)
138
Stop plavix ___ days prior to surgery
7 days prior to surgery
139
Ticlodipine (ticlid) is off the market; needed to be held ___-___ days prior to surgery
10-14 days
140
Stop prasugrel (effient) ___ days prior to surgery
7 days prior to surgery
141
Stop ticagrelor (brilinta) ___ days prior to surgery even though it is ___
5 days prior to surgery even though it is reversible
142
Aspirin, plavix, prasugrel need to be held for ___ days before surgery so that new platelets can be made
7 days
143
NSAIDs should be held for ___ days before surgery
2 days
144
Brilinta—even though it is ___, hold for ___ days
Even though it is reversible, hold for 5 days
145
Platelet function testing—VerifyNow P2Y12–measures percentage of platelet ___
Platelet inhibition
146
Platelet function testing—VerifyNow P2Y12–monitor antiplatelet therapy > ___% for clinical effect; determine when it is safe to proceed with surgery or regional anesthesia < ___%
> 80% for clinical effect; safe to proceed with surgery or regional anesthesia < 20%
147
Antiplatelet management—aspirin and NSAIDs ___ (do/don’t) have risk of epidural hematoma, so ___ (do/don’t) have to hold these medications for neuraxial blockade
Don’t have risk of epidural hematoma, so don’t have to hold these medications for neuraxial blockade
148
Antiplatelet management—hold clopidogrel/prasugrel for ___ days before neuraxial blockade is performed
7 days
149
Antiplatelet management—hold ticlodipine for ___ days before performing neuraxial blockade
14 days
Ticlid is off the market*
150
Antiplatelet management—hold brilinta for ___ days before performing neuraxial blockade
5 days
151
Platelet aggregation inhibitor—dipyridamole + aspirin = ___
Aggrenox
152
Have to hold dipyridamole/aspirin (aggrenox) for ___ days because of the aspirin
5 days
153
Vorapaxar (Zontivity)—no one really takes this medication at all, but terminal half-life is ~___ days
~8 days
154
Platelet aggregation inhibitors—prevent platelets from aggregating together by preventing ___ from binding to ___
Preventing fibrinogen from binding to Gp IIb/IIIa
155
(3) platelet aggregation inhibitors:
- Abciximab (repro)
- Eptifibatide (integrilin)
- Tirofiban (aggrastat)
156
Abciximab (repro) should be held ___-___ hours prior to procedure
24-48 hours prior to procedure
157
Eptifibatide (integrilin) should be held ___-___ hours prior to procedure
4-8 hours prior to procedure
158
Tirofiban (aggrastat) should be held ___-___ hours prior to procedure
4-8 hours prior to procedure
159
DDAVP (desmopressin) is a synthetic analog of ___ and is ___
Synthetic analog of ADH (posterior pituitary hormone) and is hemostatic
160
DDAVP increases ___ factor, tissue-type ___ activator, and ___
Increases vonWillebrand factor, tissue-type plasminogen activator, and prostaglandins
161
DDAVP promotes platelet adhesiveness to vascular endothelium—T/F?
True
162
DDAVP may minimize intraoperative blood loss and transfusion requirements in patients undergoing cardiac surgery or spinal fusion surgery—T/F?
True
163
Xigris (drotrecogin alpha) was removed from the market in 2011 because there was found to be no benefit for what patient population?
Sepsis patients
