Quiz 5: Hematology Flashcards
What are the three elements that are largely responsible for maintaining the circulation as a closed hemodynamic system referred to as hemostasis:
- Coagulation
- fibrinolysis
- Wound healing
What are the three main points that make up Virchow’s Triad:
- Hypercoagulable State
- Vascular Wall injury
- Circulatory Stasis
Virchow’s Triad of hypercoagulable state consist of:
- Malignancy
- Pregnancy and peri-partum period
- Oestrogen Therapy
- Truama or surgery of lower extremity hip abdomen or pelvis
- Inflamation bowel disease
- Nephrotic Syndrome
- Sepsis
- Thrombophilia
Virchow’s Triad of Vascular wall injury consist of:
- Trauma or surgery
- Venepuncture
- Chemical irritation
- Heart valve disease or replacement
- Atherosclerosis
- Indwelling catheters
Virchow’s Triad of circulatory stasis consist of:
- Atrial fibrillation
- Left ventricular dysfunction
- Immobility or paralysis
- Venous insufficiency or varicose veins
- Venous ovstruction from rumour, obesity or pregnancy
(Extrinsic Pathway) Damage outside (extrinsic to) blood vessels triggers the release of _______ from damaged tissue cells.
Thromboplastin (Factor III)
(Extrinsic Pathway) Thromboplastin activates factor ___. Thromboplasten when complexed on the surface of the platelet with ______ (factor IV) and ________ (IIIa) activates factor _ to __.
- VII
- calcium
- thromboplastin
- X
- Xa
(Intrinsic Pathway) Trauma to the blood itself or exposure of the blood to collagen in a traumatized blood vessel wall activates factor __.
XII
(Intrinsic Pathway) XIIa activates factor __ and __ activates factor __.
- XI
- XI
- IX
(Intrinsic Pathway) IXa when complexed on the platelet surface with activated factor __:Ca and Ca++ activates factor _.
- VIII
- X
(Common Pathway) Activated factor X when complexed on the platelet surface with activated factor _ and _______ (factor __) on the platelet surface, converts ________ (Factor II) to _______ (IIa).
- V
- calcium
- IV
- prothrombin
- thrombin
The therapies such as ASA, Plavix, Ticlid, and possible NSAID are TESTED by _____ ______ and the SYSTEM tested is ______ and _________.
- bleeding time
- Platelets
- Capillaries
The therapy such as Warfarin are TESTED by _____ and the system tested is the _______ and ______.
- PT
- Extrinsic
- Common
The therapy such as Haparin are TESTED by APTT and the system tested is the _____ and _____.
- Intrinsic
- Common
The therapy such as Heparin are
TESTED by TT and the SYSTEM
tested is ____________ to ______.
- fibrinogen
- fibrin
How does heparin work on the INTRISIC pathway?
-NEUTRALIZES
thrombin
Factor Xa
What is the source of heparin?
- Porcine intestinal
- Bovine Lung
What is the mechanism of action for heparin:
-Heparin increases the rate of the thrombinantithrombin III reaction serving as a catalytic template to which both the AT III and protease bind.
By how much does Heparin increase thethrombinantithrombin II reaction:
1000
What does Heparin do to the PTT and TT:
Prolongs the time
T/F: Heparin acts both on bound and unbound factors.
FALSE (Heparin acts only on UNBOUND factors)
What is so interesting about the half life of heparin?
-APPROXIMATELY as the dose double the half life of heparin exponentially increases
Does heparin cross the placenta?
NO
What does abnormal LFTs due to heparin toxicity increase?
- transaminases
Heparin toxicity has ________ risk of osteoporosis and spontaneous vertebral fractures.
-infrequent
When will HIT most likely be seen in a patient receiving treatment.
-1 to 2 WEEKS
In heparin toxicity arterial thrombosis with platelet-fibrin clots are referred to as:
White clots(HITTS)
What is the antidote to heparin?
-Protamine
What is the mechanism of action of protamine?
-protamine complexes with strongly acidic and anionic heparin to form a STABLE SALT
How are the complexes formed by heparin and protamine removed?
-Reticuloendothelial system
Are LMWH as susceptible to protamine antagonism?
NO (Protamine will approximately neutralize 65%)
What will occur when protamine is given rapidly?
- Acute histamine related:
- hypotension
- bradycardia
- pulmonary hypertension
- Transient flushing
- Dyspnea
What will hypersensitivity of protamine cause:
- Uticaria
- angioedema
- acute pulmonary hypertension
What type of reaction is it called when protamine causes a lysosomal enzymes from neutrophils with prostaglandins and thromboxane genertation:
-Anaphylactoid reaction
NOT SURE ON THIS ONE:You may be more ypersensitive to protamine if:
- Hypersensitive to fish
- Previous protamine reversal of heparin
- Protamine containing insulin (NPH)
- Prvious vasectomy
What would be the pretreatment of a sensitivity reaction to protamine?
- Corticosteroid
- Antihistamine
What would happen if protamine is given alone or in excess of heparin?
-result in bleeding theoretically because it has anticoagulatn and antiplatelet effects.
What is the mechanism of action for LMWH:
- Inhibition of factor Xa by antithrombin
- (some factor IIa inhibition)
T/F: PTT and PT relatively insensitive with LMWH therapy.
TRUE
What co-morbidity would you want to decrease the dose of LMWH?
-Chronic renal insufficiency
Fondaparinux (Arixtra) mechanism of action is:
-SYNTHETIC indirect specific inhibitor of FACTOR Xa
-MEDIATED
ATIII
Fondaparinux (Arixtra) has no effect on:
- factor IIa
- platelet function
T/F: Fondaparinux (Arixtra) is associated with H.I.T.
FALSE
Argatroban is used for the prevention and treatement of thrombosis in patient with ___ or _____.
- HIT
- HITTS
T/F: Argatroban reversal agent is protamine.
FALSE (Argatroban has no reversal agent)
What are direct thrombin inhibitors use for:
People whom are intolerant of heparin
(Direct Throbin Inhibitors) Hirudin analogs is the plypeptide that is responsible for the anticoagulant properties of the _____ of the medicinal ______.
- saliva
- leeches
(Direct Thrombin Inhibitors) Hirudin analogs bind _____ to the active catalytic and substrate recognition sites of both _______ and ______ Thrombin (Factor __).
- irreversibly
- circulating
- clot bound
- IIa