Procoagulants/Blood Products Flashcards
1
Q
What is the onset of Direct-Acting Non-Vit K Oral Anticoagulants?
A
Rapid onset of action; therapeutic anticoagulation occurs within hours of administration
2
Q
What needs to be monitored with Direct-Acting Non-Vit K Oral Anticoagulants?
A
Don’t need routine monitoring
3
Q
When is PCCs recommended?
A
- PCCs recommended for immediate INR reversal along w/vitamin-K administration
- PCCs also used for managing bleeding in patients receiving Xa inhibitors (apixaban, edoxaban, & rivaroxaban)
4
Q
What can FFP be used for Management of Direct-Acting Non-Vit K Oral Anticoagulants?
A
- FFP can be used
- carries transfusion-related risk & risk of volume overload
5
Q
What is the MOA of Platelet Inhibitors: Aspirin?
A
Irreversibly acetylates cyclooxygenase & prevents formation of thromboxane A2
6
Q
How long do the effects of Platelet Inhibitors: Aspirin last?
A
Effects on platelets irreversible & last for life of the platelet: 7-10 days
7
Q
Aspirin reduces incidence of ___________
A
occlusive arterial vascular events
8
Q
Review cell membrane destruction.
A
9
Q
What is the drugs in the class of Platelet Inhibitors: Thienopyridines?
A
clopidogrel (Plavix), prasugrel (Effient), & ticagrelor
10
Q
What do Platelet Inhibitors: Thienopyridines (clopidogrel, prasugrel, & ticagrelor)?
A
These drugs irreversibly bind/antagonize platelet receptors which block adenosine diphosphate (ADP) binding which inhibits ADP-mediated platelet activation & aggregation
11
Q
What are drugs involved in the Platelet Glycoprotein IIb/IIIa Antagonists?
A
abciximab (ReoPro), tirofiban (Aggrastat), eptifibatide (Integrilin)
12
Q
What is the MOA of Platelet Glycoprotein IIb/IIIa Antagonists?
A
Drugs: abciximab (ReoPro), tirofiban (Aggrastat), eptifibatide (Integrilin)
- Block fibrinogen binding to platelet GP IIb/IIIa receptors that are a common pathway of platelet aggregation & inhibit platelet aggregation
13
Q
What effect do Platelet Glycoprotein IIb/IIIa Antagonists have on platelet response?
A
Drugs: abciximab (ReoPro), tirofiban (Aggrastat), eptifibatide (Integrilin)
- Inhibit platelet function which inhibits platelet response to vascular injury & clot formation
- prevent thrombus formation initiated by platelets in acute coronary syndrome (unstable angina, myocardial infarction)
- angioplasty failure
- stent thrombosis
14
Q
What is the Perioperative management of patients on platelet inhibitors?
A
(coming to the OR; having procedures requiring anesthesia) requires careful coordinated care between cardiology, surgeon, & anesthesia
15
Q
What is the MOA of Thrombolytic Drugs?
A
These drugs act as plasminogen activators to convert endogenous plasminogen to plasmin which causes fibrinolysis (clot lysis)
16
Q
What does Thrombolytic Drugs administration restore?
A
circulation through occluded artery or vein (usu coronary artery)
17
Q
What is a risk with Thrombolytic Drugs?
A
Risk of bleeding (particularly intracranial hemorrhage) & hemorrhagic complications
18
Q
What are Antifibrinolytic agents?
A
are procoagulants, promote hemostasis
19
Q
What is the use for Antifibrinolytic Agents?
A
- used to treat bleeding perioperatively
- reduce need for transfusion (cardiac & orthopedic surgery, trauma)
20
Q
What are examples of Antifibrinolytic Agents?
A
Synthetic lysine analog antifibrinolytic agents: aminocaproic acid (Amicar) & tranexamic acid (TXA)
21
Q
What is the MOA of Antifibrinolytic Agents?
A
Antifibrinolytic Agents: Lysine Analogs
- These agents competitively inhibit activation of plasminogen to plasmin (enzyme that degrades fibrin clots) & fibrinogen
22
Q
What can TXA cause?
A
TXA inhibits plasmin at high doses; risk of seizures
23
Q
What is not a property of Antifibrinolytic Agents: Lysine Analogs?
A
- These agents are not prothrombotic
- they are clot stabilizers
- prevent compensatory responses of inflammatory injury & clot lysis
24
Q
What does Antifibrinolytic Agents: Aprotinin?
A
Inhibits plasmin
25
What is the use for Antifibrinolytic Agents: Aprotinin?
Used in cardiac surgery to reduce bleeding & transfusion requirement
26
What is the properties of Antifibrinolytic Agents: Aprotinin?
Demonstrated a procoagulant state; resulted in declined use
27
What is Protamine formed from?
Commercially produced from the sperm of salmon
28
What is a potential allergic reaction from Protamine?
considered that persons who have an allergy to fish could be at risk of protamine reactions
29
What can protamine reverse?
Only agent to reverse unfractionated heparin (acid-base interaction)
30
What does Protamine not reverse?
Does not reverse low molecular weight heparin
31
What can excessive Protamine cause?
Excess should be avoided (common) as too much can contribute to coagulopathy
32
What can occur with Protamine?
Patients can have heparin rebound 2-3 hrs after initial dose (ACT not always a sensitive indicator)
33
What are adverse reactions of Protamine?
anaphylaxis, acute pulmonary vasoconstriction, right heart failure, hypotension
34
Which patients are increased risk for adverse reactions?
Patients at increased risk for adverse reactions: exposure to NPH insulin, vasectomy, prior protamine exposure, multiple allergies
35
What are the administration components of Protamine?
* Give test dose of 10 mg
* Administer slow IV
36
What is the MOA of Desmopressin (DDAVP)?
analog of arginine vasopressin, stimulates the release of vWF from endothelial cells
37
What does vWF mediate?
vWF mediates platelet adherence to vascular subendothelium
38
When is Desmopressin (DDAVP) often used?
Often used in cardiac surgery
39
What does Desmopressin (DDAVP) shorten?
Shortens bleeding time of patients with mild hemophilia A or von Willebrand disease
40
What is the administeration of Desmopressin (DDAVP)?
slowly to prevent hypotension
41
Where is Fibrinogen synthesized?
Synthesized in the liver, critical component of clot formation
42
What is Fibrinogen a substrate?
thrombin, factor XIIIa, plasmin
43
What forms the cross-linking of fibrin polymers?
* Thrombin cleaves fibrinogen to form fibrin that creates a network to trap red cells and begin a clot
* cross-linking of fibrin polymers induced by factor XIIIa
44
What is an important binding site of Fibrinogen?
Acts a binding site for GpIlb/IIIa receptors on platelet surfaces; responsible for platelet aggregation
45
What causes decreased Fibrinogen level?
* During major hemorrhage, hemodilution after blood loss & subsequent volume replacement leads to reduced fibrinogen levels (hypofibrinogenemia)
* impairs fibrin polymerization & reduces clot stability
46
What are fibrogen levels usually replaced with?
Replaced usually with cryoprecipitate or fibrinogen concentrates
47
How much does cryoprecipitate increase Fibrinogen level?
Cryoprecipitate: 1 unit/10kg increases fibrinogen by 50-70mg/dL
48
What are the normal levels of Fibrinogen?
Normal level is 200-400 mg/dl
49
What is cruical for bleeding patients?
Bleeding patient (surgical, trauma): crucial to measure & replenish fibrinogen
50
When is Recombinant Activated Factor VIIa used for?
Used in patients w/ hemophilia A or B; increasing off-label use for life-threatening emergencies and cardiac surgery
51
What does •Recombinant Activated Factor VIIa produce?
Produces prohemostatic effect by complexing with TF at site of vascular injury to produce thrombin
52
What is true about Recombinant Activated Factor VIIa?
Expensive and concerns with procoagulant state in causing MI, thrombotic events
53
What is the Factor XIII important in?
Important in final step and stabilization of clot
54
When can Recombinant Activated Factor VIIa levels be reduced?
Levels may be reduced after cardiac bypass
55
What are the Prothrombin Complex Concentrates (PCC’s) are concentrations of?
coagulation factors II, VII, IX, X
56
What is the use of Prothrombin Complex Concentrates (PCC’s)?
Prevention and control bleeding for hemophilia B & warfarin reversal
57
What does warfarin inhibit?
Warfarin inhibits vitamin-K dependent cofactors (II, VII, IV, X) in addition to protein C and protein S
58
Where does Warfarin act?
Warfarin acts across both the extrinsic and intrinsic pathways to prevent thrombus formation.
59
When are Prothrombin Complex Concentrates (PCC’s) recommended?
PCCs recommended for life-threatening bleeding & increased INR when urgent reversal is required
60
What is the off label use for Prothrombin Complex Concentrates (PCC’s)?
Off-label use for managing other bleeding in patients receiving non-vitamin K oral anticoagulant direct factor Xa inhibitors (i.e., rivaroxaban & abixaban)
61
What does critical bleeding perioperatively requires?
**volume replacement therapy**
* Crystalloid, colloid, & RBCs
62
What do Crystalloid, colloid, & RBCs not provide?
These products don’t provide coagulation factors or platelets
63
What can administering Crystalloid, colloid, & RBCs exacerbate?
coagulopathy
64
Severe bleeding requires use of \_\_\_\_\_\_\_\_\_
massive transfusion protocol
65
What is the goal of management in major bleeding in surgical & trauma patients?
* restore circulating levels of hemostatic factors
* Monitoring: thromboelastography
66
\_\_\_\_\_\_\_ & _____ must be monitored & abnormality corrected during blood product transfusion
Temperature & pH
67
What is important about Decision to transfuse?
weigh risks of transfusion against the need for improved oxygen-carrying capacity
68
What is the ASA Task Force on Perioperative Blood Transfusion & Adjuvant Therapies recommendations?
* Transfusion of RBCs should usually be administered when the Hgb is low (\<6 g/dL in a young, healthy patient), esp. when anemia is acute
* RBCs are usually unnecessary when Hbg \> 10g/dL
69
Determining whether to transfuse RBC for Hbg 6-10 g/dL should be based on?
* ongoing indication of organ ischemia
* potential or actual ongoing bleeding
* the patient’s intravascular volume status
* patient’s risk factors for complications of inadequate oxygenation (low cardiopulm reserve, high O2 consumption)
70
How long are RBC's stored?
42 days after donation
71
What can RBC's stored \>14-21 days cause?
those stored \>14-21 days may lead to adverse effects (RBC storage lesions) due to degradation and metabolic changes & depletion of ATP and 2, 3 diphosphoglycerate (2,3 DPG)
72
What are the effects of 1 unit of RBC’s increases?
Hct ~ 3% & Hbg by 1g/dL
73
When is Fresh Frozen Plasma used?
* Used w/surgical patients to:
* replace coagulation factors during massive transfusion
* tx or prevent future bleeding during surgery & invasive procedures
* reverse warfarin therapy
* tx coagulation factor abnormalities where specific concentrates are not available
74
What does Fresh Frozen Plasma contain?
Contains factors II, VII, IX, & X, protein C, protein S, antithrombin, & fibrinogen
75
What is true about FFP after thawing?
FFP should be transfused within 24 hours; if not used after thawing, can be relabeled as “thawed plasma” & stored (1-6 degrees C) for additional 4 days
76
How is Fresh Frozen Plasma administered?
Must be transfused using 170 micron filter, must be ABO compatible
77
What is the average volume of Fresh Frozen Plasma?
Average volume is 200-250 mL
78
What are the uses of Fresh Frozen Plasma?
* Used to treat coagulopathies with PT/PTT \> 1.5 normal
* Used to reverse effects of warfarin
* the lowest INR obtainable w/FFP is approx.1.5 (the INR of plasma/FFP)
79
What can overuse of Fresh Frozen Plasma lead to?
Overuse in surgery can result in fluid overload and TRALI
80
When is FFP recommended?
Recommended to start FFP administration early in transfusion protocols along with RBC’s for massive hemorrhage
81
Most common cause of bleeding after surgery is \_\_\_\_\_\_\_
platelet dysfunction
82
What is the lifespan of platelets?
Life span of a donated platelet only 4-5 days
83
What is the range of platelets?
Normal range: 150,000 – 400,000
84
What is the transfusion components of platelet?
Platelets used in transfusion either pooled random-donor or single-donor apheresis; can be stored up to 5 days
85
How much does 1 unit of platelets increase your levels?
1 unit (250mL) increases platelet count by 30,000 – 60,000
86
When is platelet transfusion usually indicated?
for platelet count \< 50,000 in presence of hemorrhage/surgery
87
When are platelets incidated prophylactically?
Indicated prophylactically for patients with platelets counts \< 10,000-20,000 due to risk of spontaneous hemorrhage
88
Cryoprecipitate is a a _________ blood product
multidonor
89
What factors are contained in Cryoprecipitate?
Contains factors VIII, XIII, & fibrinogen
90
What does Cryoprecipitate replenish?
Replenishes fibrinogen levels during coagulopathies
91
What is not contained in Cryoprecipitate?
Does not contain factor V and should not be sole replacement for DIC
92
When should fibrinogen levels be elevated?
in bleeding patients, esp following multiple transfusions
93
What are the guidelines for Cryoprecipitate?
* With fibrinolysis
* Use when fibrinogen levels less than 80-100 mg/dL
* Adjunct for massive transfusion
* Congenital fibrinogen deficiencies
94
What do fluid solutions contain?
Fluid solutions containing ion salts & other low molecular weight substances
95
What are Crystalloids characterized by?
Crystalloids categorized based on tonicity or osmotic pressure of the solution
96
What can large amounts of NS cause?
Administering large volumes of NS can result in hyperchloremic metabolic acidosis
97
What is the components of “Balanced” or “physiologic” crystalloid?
solutions contain composition close to extracellular fluid (LR or Plasma-Lyte)
98
What can administration of of lg volumes of balanced salt solution result?
can result in hyperlactatemia, metabolic alkalosis, & hypotonicity
99
Review common crystalloid solutions.
100
What is the current ASA guidelines of Crystalloids?
Current ASA guidelines recommend moderately liberal approach w/overall positive fluid balance of 1-2L at end of surgery, minimized preop fasting times, close hemodynamic monitoring to guide volume resuscitation
101
What is the advantage of balanced of Crystalloids?
Balanced crystalloid solutions (LR, Plasma-Lyte) may offer advantage of less adverse kidney events than NS
102
What are the solution components of colloids?
are solutions that are macromolecules (plant or animal polysaccharides or polypeptides)
103
\_\_\_\_\_\_\_\_ remain in plasma compartment longer than _______ solutions
Colloids; crystalloid
104
What are the components of Semisynthetic colloid solutions?
are metabolized & excreted, have a shorter duration of effect than human albumin solutions
105
What is albumin?
* produced from human blood & suspended in saline
* studies have found no significant clinical difference in ICU patients treated with albumin or saline
106
What is an example of Semisynthetic colloids?
hydroxyethyl starch (HES)
107
What is the FDA black box warning for Semisynthetic colloids: hydroxyethyl starch (HES)?
* Do not use in critically ill adult patients incl those w/sepsis, those admitted to the ICU
* avoid use in patients w/renal dysfunction
* avoid use in patients undergoing CPB d/t excess bleeding; DC at first sign of coagulopathy
108
What are commonly used for in the OR as biomarkers?
Imaging Dyes
109
What are common OR Imaging Dyes?
* Indocyanine Green
* Methylene Blue
* Indigo Carmine
110
What effect does Indocyanine Green have on SPO2?
artificially lower SpO2 readings (transient) - (based on Beer-Lambert law)
111
What effect does methylene blue have on SPO2?
artificially lower SpO2 readings (transient
112
When is Methylene Blue commonly used?
Commonly given in cardiac surgery; important to remind surgeon and perfusionist that the blood will be very dark
113
When should caution be used with Methylene blue?
Caution with patients taking SSRIs (serotonin syndrome) and methemoglobinemia (concern with higher doses)
114
What imaging dyes turn urine blue?
* Methylene Blue
* Indigo Carmine
115
What effect does Indigo Carmine have on SPO2?
artificially lower SpO2 readings (transient
116
What are the CV effects of Indigo Carmine?
* CV effects are **transient alpha-receptor stimulation**, namely
* increased total peripheral resistance
* diastolic and systolic blood pressure
* and central venous pressure with concomitant decreased cardiac output
* stroke volume and heart rate
117
What have been reported with Indigo Carmine?
Have been hypersensitivity reports
