HEMA Flashcards
Normal PT and APTT results in a patient with a poor wound healing may be associated with:
Factor XIII deficiency
Factor XIII deficiency can lead to impaired wound healing and may cause severe bleeding problems. Factor XIII is a fibrin stabilizing factor that changes the fibrinogen bonds in fibrin polymers to stable covalent bonds. Factor XIII is not involved in the process of fibrin formation and, therefore, the PT and APTT are both normal.
Which results are associated with hemophilia A?
Prolonged APTT, normal PT
Hemophilia A is associated with factor VIII deficiency. Factor VIII is a factor in the intrinsic coagulation pathway that is evaluated by the APTT and not the PT test. The PT test evaluates the extrinsic and common pathways.
Primary substrate of thrombin:
Fibrinogen
In which of the following lists the steps of hemostatic response in the correct order?
Injury → primary hemostasis → secondary hemostasis → fibrinolysis
Hereditary hemorrhagic telangiectasia is a disorder of:
Connective tissue
Which defect characterizes Gray’s syndrome?
Alpha granule defect
Gray’s syndrome is a platelet granule defect associated with a decrease in alpha granules resulting in decreased production of alpha granule proteins such as platelet factor 4 and beta thromboglobulin. Alpha granule deficiency results in the appearance of agranular platelets when viewed on a Wright’s stained blood smear.
Normal platelet adhesion depends upon:
Glycoprotein Ib
In the Ivy method of bleeding time, the blood pressure cuff is inflated to:
40 mm. Hg
If an average of 10 platelets are seen per oil immersion field, what is the estimated platelet count?
200 x 10 9th/L
For platelet estimate on a wedge smear:
Factor is 20,000
To evaluate normal platelet numbers in an appropriate area of a blood smear, approximately how many platelets, should be observed per oil immersion field?
8 to 20
Primary PLATELET AGGREGATION disorders:
Glanzmann’s thrombasthenia and essential athrombia
Glanzmann thrombasthenia and essential athrombia are similar, rare, primary aggregation disorders.
In thrombocythemia, the platelets are:
Increased
Immune thrombocytopenic purpura (ITP):
Due to platelet antibodies
The normal range of platelets in the systemic circulation is:
150 – 400 x 10 9th/L
The normal range of platelets in the systemic circulation is:
150 – 400 x 10 9th/L
Approximately ___ of the total number of platelets circulate in the systemic circulation?
Two-thirds
Which order of events should be followed at the conclusion of a laboratory worker’s shift in order to prevent the spread of bloodborne pathogens?
Disinfect area, remove gloves, remove lab coat, wash hands
Which of the following is a proper way to clean up a small blood spill that has dried on a countertop?
Moisten it with a disinfectant and carefully absorb it with a paper towel
If a patient adamantly refuses to have blood drawn, you should:
Notify the patient’s nurse or physician
A blood sample is needed from a patient with IV fluids running in both arms. Which of the following is an acceptable procedure?
Obtain sample from below the IV site with special restrictions.
Most common complication encountered in obtaining a blood specimen:
Ecchymosis (bruise)
Which results would be expected for the PT and APTT in a patient with polycythemia?
Both prolonged
EDTA-induced pseudothrombocytopenia can be identified on blood smear by:
Finding platelets adhering to WBCs
Platelet satellitosis (platelet encircling the peripheral borders of neutrophils) is seen in a rare patient whose blood is anticoagulated with EDTA. This phenomenon is thought to be due to a serum factor which reacts in the presence of EDTA.
EDTA-induced pseudothrombocytopenia can be identified on blood smear by:
Finding platelets adhering to WBCs
Platelet satellitosis (platelet encircling the peripheral borders of neutrophils) is seen in a rare patient whose blood is anticoagulated with EDTA. This phenomenon is thought to be due to a serum factor which reacts in the presence of EDTA.
EDTA is used in concentrations of ___ mg/1 mL of whole blood.
1.5 mg/1 mL of whole blood
EDTA is used in concentrations of 1.5 mg/1 mL of whole blood
Intrinsic factor
XII Hageman Factor
XI Rosenthal
IX Plasma thromboplastin component
VIII Antihemolytic factor
Hageman factor
XII Glass factor
Extrinsic factor
VII: Proconvertin
Serum prothrombin serum accelerator (SPCA)
Common pathway factor
X: Stuart-Prower factor
V: Labile factor
II: Prothrombin
I: Fibrinogen
Prolonged PT
Extrinsic Factor: VII (Stable factor)
Common factor: X, V, II, I, XIII
- X: Stuart
- V: Labile factor
*II: Prothrombin
*I: Fibrinogen
Prolonged APTT
Intrinsic: XII, XI, IX, VIII
*XII: Hageman (Glass)
*XI: Antihemophilic C
*IX: Plasma thromboplastin Component Antihemophilic C - Christmas factor
*VIII: Antihemophilic A
Common factor: X, V, II, I, XIII
* X: Stuart
* V: Labile factor
*II: Prothrombin
*I: Fibrinogen
Normal PT, APTT
Soluble in 5M Urea
Factor XIII
Urea solubility test: Duckerts sensitive
All factors are proteins except
Factor IV: Calcium
Mineral
No coagulation factor has been assigned to
Factor VI
AP, APTT are synthetic function of ________
Liver function test
Factor no activated form
Factor I: fibrinogen
Coagulation nomenclature are assigned according to their:
Pangalan nila in roman eme ay base saan//?
Order of their initial description or discovery
Most concentrated coagulation factor
Factor I: Fibrinogen
Activated factor V
Factor VI- non existent
Antihemophilic Factor A
VIIIC: Antihemophilic factor (AHF)
Antihemophilic Factor B
IX: Plasma thromboplastin COMPONENT
Antihemophilic Factor C
XI: Plasma thromboplastin ANTECEDENT
Glass factor
Contact factor
XII: Hageman
All coagulation factors are produced by the liver except
VIII complex: VIIIC (AHF) and vWF (Primary and larger than VIIC)
In Liver disease, VIII complex is unaffected
a. VIIIC - coagulant VIII:C
b. vWF - produced by megakaryocyte in endocells
vWF disease
Prolonged bleeding time and clotting time
no VIIIC AH-A (secondary: clot)
no vWf (primary: bleed)
Antihemophilic factor A disease (FactorVIII defeciency) prolonged _____
Clotting time
Secondary Coagulation
Coagulation factors prematurely activated by cold temperature:
VII: Stable factor
XI:
Labile factors
V: Proaccelerin — labile factor
VIIIC: Antihemophilic Factor A
Decreases on storage diseases:
(densed, granular)
V: Stable
VIIIC: AHF-A
Fibrinogen level increased in elderly every decade for ___
10mg/dl
a decade is 10years so 1mg/dl per year starting age 65-79
Prolonged APTT and AT when fibrinogen level is
less 100mg/dl
Level of fibrinogen marked decrease in end-stage of liver failure:
<100mg/dl
Prolonged APTT, PT
Fibrinogen normal range
200-400mg/dl
Transfer of blood from syringe to tube
19 gauge, slowly inject
also for adult who has good veins >25ml
PT storage conditions:
18-24C within 24hrs
citrated blood - PPP
PTT storage conditions:
18-24C within 4hrs
PT reagent to activate factor VII
Thromboplastin-calcium chloride
Thromboplastin is a source of phospholipoprotein
Source of thromboplastin
new
old
New: Human tissue, sensitive
Old: Rabbit’s brain or lungs
Prothrombin time: Normal value
12.6-14.6 seconds
Screening for extrinsic factor VII: stable factor PCC (convertin?)
A child ingested rat poison “coumarin-like substabce). what test should be performed to test the effect of poison/ eme
Prothrombin time
APTT: Activated partial thromboplastin time normal value
25-35s
26-38s
Therapeutic range for px receiving heparin therapy: APTT
60-100s
Specimen for platelet aggregometry
PRP: Platelet Rich Plasma
Specimen for clot-based test
PPP: Platelet poor plasma
- PT & APTT
APTT reagent activator
- Kaolin, Celite and Ellagic Acid: Activates XII
AP RGNT:
1. activator
2. phospholipids: substitute for platelets
3. Calcium chloride: start of time on addtn on this for APTT
The only test that is sensitive for factor XIII
Duckert’s test
5M Urea solubitility test
Reagent of 5molar urea
2% acetic acid/ 1% monochloroacetic acid
Result:
Normal: there is clotting ` insoluble
Deficiency: dissolved in 24hrs
Most concentrated coagulated factor
FIbrinogen
200-400mg/dl
<100mg/dl - endstage liver disease prolonged PT,APTT
Primary risk factor for thrombotic disorders
fibrinogen
Hemarthrosis: Joint bleeding deficiency
Factor VIII deficiency
Hemophilia A
Rosenthal syndrome. Most common in Ashkenazi jews. Coag deficiency
Factor XI
Hemophilia c
Royal blood disease
Factor IX
Hemophilia B
Negative bleeding. No bleeding coag deficiency. Increased risk for thrombosis
Factor XII
Most common coagulopathy accounts for most fatal hemorrhage
Acute coagulopathy of trauma shock
(ACOTS)
Congenital bleeding disorders (4)
vWD (most common congenital bleeding)
Factor VIII: Hemophilia A
Factor IX: Hemophilia B
platelet fxn disorders
Initial workup for vWF
CBC: thrombocytopenia
PT: Primary hemostasis
APTT: Intrinsic coag (VIIIC)
Consumed during coagulation process; present in plasma but not in serum
Fibrinogen group
I,V,VIII and XIII
Prothrombin group: Vitamin K, calcium dependent. present in plasma, serum and ads plasma
II, VII, IX, X
Contact phase group factor: stable. present in serum, plasma, ad plasma BaSO4 (barium sulfate)
XI, XII, Prekallikren, HWMK
Major inhibitor of fibrinolysis
Alpha 2 antiplasmin
The Bethesda assay is used for which determination?
Factor VIII inhibitor titer
What clotting factors (cofactors) are inhibited by protein S?
VA and VIIIa
Which of the following is associated with multiple factor deficiencies?
Severe liver disease
Acute disseminated intravascular coagulation is characterized by:
Hypofibrinogenemia
The D-dimer test is a specific test for:
Plasmin degradation of fibrin
Plasma thromboplastin or prothrombinase includes:
Complex of activated factors X and V, platelet factor 3 and calcium ions
Classic hemophilia is a condition in which there may be a:
Prolonged activated partial thromboplastin time
Which one of the following factors typically shows an increase in liver disease?
Factor VIII