Hematology Flashcards

(79 cards)

0
Q

Heparin and warfarin MOA

A

Heparin: increases Antithrombin III levels, affects intrinsic pathway and decreases fibrinogen levels
Warfarin: inhibits vitamin K activated factors- 10, 9, 7, 2 and Protein C and S

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1
Q

What lab value measures heparin vs. warfarin?

A

Heparin: PTT
Warfarin: PT

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2
Q

Intrinsic pathway

A

XII -> XI -> IX -> VIII -> X

Factor X is where intrinsic and extrinsic collide

X -> V -> II -> XIII -> Fibrin to crosslinked fibrin
Factor II also converts fibrinogen to fibrin

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3
Q

Extrinsic pathway

A

III helps convert VII -> VIIa -> X

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4
Q

Antidote for heparin and warfarin

A

Heparin: protamine sulfate
Warfarin: Vitamin K, fresh frozen plasma

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5
Q

Enoxaparin MOA

A

Inhibits Factor X

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6
Q

Platelet dysfunction vs coagulation dysfunction manifestation

A

Platelet dysfunction: petechiae

Coagulation dysfunction: hemarthroses

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7
Q

Hemophilia: inheritance and types

A
X linked recessive
A: Factor VIII dysfunction
B: Factor IX dysfunction
C: Factor XI dysfunction
Factor VII deficiency: PT elevation only
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8
Q

Mixing study

A

Mix patient’s blood with normal blood. If the PTT corrects, it’s likely dysfunctional factors that are causing the disease. If it doesn’t, there’s an antibody present

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9
Q

Hemophilia characterization

A

Mild: >5% normal levels of factors
Moderate: 1-3% normal levels of factors
Severe: <1% normal levels of factors

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10
Q

Cryoprecipitate

A

Mainly factor VIII and fibrinogen
Small concentrations of factor XIII, vWF, and fibronectin
It is a more concentrated source of factor VIII and fibrinogen than FFP
Good for treatment of Hemophilia A (Factor VIII deficiency)

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11
Q

Mild hemophilia tx

A

DDAVP

-vasopressin is an ADH analog which increases the amount of factor VIII in the blood

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12
Q

von Willebrands disease inheritance

A

Autosomal dominant disease with low levels of vWF and Factor VIII (carried by vWF)

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13
Q

Diagnosis of von Willebrands disease

A

PT is normal. PTT and bleeding time may increase 2/2 decreased Factor VIII levels
Ristocetin cofactor assay: measures the capacity of vWF to aggregate platelets

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14
Q

Bernard Soulier syndrome

A

Deficiency of GpIb (a receptor on platelets which binds to vWF)

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15
Q

Glanzmann’s thrombasthenia

A

GP IIb/IIIa deficiency (GP IIb/IIIa is a receptor on platelets which binds to fibrinogen. The fibrinogen binds to two different receptors on different platelets, allowing platelets to aggregate)

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16
Q

Clopidogrel mechanism of action

A

Irreversibly blocks the ADP receptor

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17
Q

Most common thrombophilias

A

Thrombophilia = hypercoaguable state

Most common = Factor V Leiden

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18
Q

Sickle cell disease

A

Hereditary disease of RBCs, causing them to sickle
Sludging and occlusion of arterial vasculature can lead to stroke
-due to malformed RBCs

Tx: Exchange transfusion
-DO NOT USE FIBRINOLYTICS OR ANTI-COAGS

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19
Q

Antiphospholipid syndrome

A

Hypercoaguable state
VDRL +
Causes thrombocytopenia and prolonged PTT
Tx: LMWH or Coumadin

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20
Q

Lepirudin MOA

A

Direct thrombin inhibitor

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21
Q

Danaparoid (MOA)

A

Direct thrombin inhibitor

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22
Q

DIC vs TTP vs ITP MOA

A

DIC: deposition of fibrin in small vessels leads to thrombosis and depletion of clotting factors and platelets. Platelet microthrombi block off small blood vessels
TTP: Platelet microthrombi block off small blood vessels
ITP: IgG antibodies against patient’s platelets are formed and destroy platelets. NO MICROTHROMBI PRESENT

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23
Q

DIC associated disorders

A

Sepsis, acidosis, drug reactions, massive trauma, ARDS, intravascular hemolysis
OB complications
Neoplasms, APML

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24
DIC vs liver disease
DIC: Factor VIII is depleted also, while in liver disease factor VIII is normal (because Factor VIII is made by endothelial cells)
25
DIC Tx
Reverse underlying cause, RBC and platelet transfusion
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Microangiopathic hemolytic anemia
Caused by DIC, TTP, and HUS Basically, small microthrombi of platelets deposit in small blood vessels and RBCs shear when they go through them Causes hemolysis and fragmented RBCs (schistocytes)
27
5 common symptoms of TTP
``` TTP = idiopathic activation of platelets leading to microthrombi and microangiopathic hemolytic anemia. TTP definition is MAHA + end-organ ischemia 5 common si/sx: -thrombocytopenia -MAHA -neuro changes (delirium, sz, stroke) -impaired renal function -fever ```
28
TTP vs HUS
HUS occurs after an E Coli infection Both = MAHA + end-organ damage HUS has much worse renal failure
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Treatment of TTP
Steroids to decrease microthrombus formation Plasmapharesis DO NOT REPLACE PLATELETS
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ITP
IgG antibodies against patient's platelets causes thrombocytopenia BM production of platelets increases (increased megakaryocytes in the BM) Sx: mild, no systemic sx; some bruising, petechiae, hematuria, hematemesis, melena
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ITP associated with what diseases:
lymphoma, leukemia, SLE, HIV, HCV
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Most common pediatric cause of renal failure
HUS
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Treatment of ITP
Most cases remit (in childhood) Symptomatic bleeding: corticosteroids, high dose IVIG, and splenectomy -PLATELET TRANSFUSION IS NOT HELPFUL
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Differential diagnosis for thrombocytopenia
``` HIT SHOC: HIT/HUS ITP TTP/Treatment (ie meds) Splenomegaly Hereditary (ie Wiskott Aldrich syndrome) Other causes ie malignancy Chemotherapy ```
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What are bands on a differential?
Bands = precursor to neutophils, eosinophils, basophils
36
Retic > 2.5
Hemolysis or hemorrhage
37
What type of anemia is pyridoxine deficiency?
Can cause sideroblastic anemia if INH is given without pyridoxine (microcytic or normocytic)
38
Physical exam findings of Fe deficiency anemia
Glossitis, angular cheilitis, and koilonychia (spoon nails)
39
Fe deficiency vs ACD labs
Fe deficiency: - Serum Fe: decreased - Ferritin: decreased - Transferrin/TIBC: increased - serum transferrin receptor: increased ACD: - Serum Fe: decreased - TIBC/transferrin: decreased - ferritin: increased - serum transferrin receptor: normal
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Acquired sideroblastic anemia
Defective heme synthesis 2/2 pyridoxine dependent impairment ie INH Dimorphic RBCs: both hypochromic and monochromic Tx: B6 Labs: normal Fe, decreased TIBC
41
Cobalamin
B12
42
What cells produce intrinsic factor?
Parietal cells in the GI tract
43
Folate stores length vs. B12
Folate: 4 months B12: years
44
B12 deficiency: sx other than anemia
Neuro sx: deymyelinating disorder causing motor, sensory, autonomic, and/or neuropsychiatric dysfunction -aka subacute combined degeneration of the cord
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What infection can cause B12 deficiency?
Diphyllobothrium latum: tapeworm
46
Schilling test
Ingestion of radiolabeled cobalamin: - First give pt unlabeled B12 IM to saturate all B12 receptors in the liver - Then give an oral challenge of radiolabeled B12. If everything is normal, the B12 will be absorbed in the GI tract, but the liver is unable to use it so it should pass through into the urine. Radiolabeled B12 in the urine = positive test, meaning that pt has nutritional B12 deficiency - No radiolabeled B12 in the urine means pt may have pernicious anemia, bacterial overgrowth, or pancreatic enzyme deficiency; give B12 with IF and check urine, with antibiotics and check urine, and with pancreatic enzymes and check urine
47
Diagnosis of B12 and folate deficiency
B12: elevated MMA and homocysteine, increased LDH Folate: normal MMA, elevated homocysteine, normal LDH
48
G6PD deficiency
X-linked recessive hemolytic anemia | Increased sensitivity to oxidative stress
49
Paroxysmal nocturnal hemoglobinuria
Hemolytic anemia Increased blood cell sensitivity to complement activation Patients are prone to thrombotic events
50
Hereditary spherocytosis | -what is it, how to diagnose, what to supplement these patients with
Abnormality of the RBC membrane, leading to spherocytes on smear which lack areas of central pallor Dx: with a osmotic fragility test (these RBCs are more fragile) Supplement with folate
51
Autoimmune RBC destruction
2/2 EBC, mycoplasma, CLL, rheumatoid disease, or medications
52
How does hemolytic anemia present differently than anemia?
Jaundice, low haptoglobin, elevated indirect bilirubin, elevated LDH Urine is dark with hemoglobinuria Increased excretion of urinary and fecal urobilinogen Elevated retic count
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G6PD stressors
Infection, quinidine, nitrofurantoin, fava beans, antimalarials, dapsone, sulfonamides, metabolic acidosis
54
Coombs test
Direct: Pt's RBCs are washed to remove any unbound antibodies and mixed with antihuman antibodies (aka Coombs reagent); the antihuman antibodies bind the pt's anti-RBC antibodies on multiple RBCs and cause agglutination = + test Indirect: Patient's serum is collected (which contains anti-RBC antibodies) and mixed with donor RBCs; The donor RBCs will bind to the pt's antibodies; Antihuman antibodies are added (Coombs reagent) and these will agglutinate the mixture already the big difference is where the RBCs are from
55
Causes of aplastic anemia
Fanconi's anemia (congenital), Parvovirus B19, HIV, toxins (drugs, cleaning solvents), and radiation
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Aplastic anemia: hx/PE, Dx, Tx
Hx/PE: -pancytopenia: pallor, weakness, tendency to infection, petechiae, bruising, bleeding Dx: BM biopsy shows hypocellularity and space occupied by fat Tx: blood transfusion + stem cell transplant - immunosuppresion with cyclosporine A and antithymocyte globulin - infections are major cause of mortality
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Fanconi's anemia
Hereditary aplastic anemia | PE: cafe au lait spots, short stature, radial/thumb hypoplasia/aplasia
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Sickle Cell Disease | -genetics and affected protein
Genetics: autosomal recessive disorder | Affected protein: B chain of hemoglobin
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Symptoms of sickle cell disease
Dactylitis, cholelithiasis, increased cardiac output (cardiomegaly and murmur), delayed growth, splenic infarction (predisposes to pneumococcal sepsis), acute chest syndrome (pneumonia and pulmonary infarct), pain crises (triggers: cold temp, dehydration, infection)
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Osteomyelitis in sickle cell disease
Most common: S aureus Very prone to Salmonella also Increased risk of AVN of the hipt
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Target cells
sickle cell disease
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Treatment of sickle cell disease
Hydroxyurea, which stimulates fetal hemoglobin production
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Treatment of vaso-occlusive reactions in sickle cell disease
Pain management, aggressive hydration, incentive spirometry, and keeping sickle cell variant < 40% -this will keep VOD from progressing to acute chest syndrome
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Alpha vs beta thalassemia
Alpha: affects one or more of 4 alpha-globin chains Beta: affects one or both of 2 beta-globin chains
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Types of thalassemia
B-thal major: absent both B-globin genes; severe microcytic anemia and need chronic transfusions or marrow transplant B-thal minor: 1 of 2 B-globin genes; asymptomatic, but cells are microcytic and hypochromic Hydrops fetalis: 0/4 alpha-chains; patients die in utero Hemoglobin H disease: 1/4 alpha chains present; severe hypochromic, microctyic anemia; chronic hemolysis, splenomegaly, jaundice, and cholelithiasis; elevated reticulocyte count a-thal trait: 2/4 alpha chains; low MCV, but asymptomatic Silent carrier: 3/4 alpha chains present; no signs or symptoms of dz
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Fe chelator
Deferoxamine
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Hyperviscosity syndrome
2/2 erythrocytosis | Easy bruising/bleeding, blurred vision, pruritis after a warm bath, hsm, CHF, neuro abnormalities
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Causes of primary erythrocytosis
Polycythemia vera, hypoxia (smoking, high altitudes, restrictive lung dz, fetal hypoxia), tumors (EPO producing tumor)
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PCV pathophysiology
Clonal proliferation of a pluripoitent marrow stem cell 2/2 JAK2 mutation; all marrow lines increase, RBCs more than others Low EPO levels
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Polycythemia vera treatment
Cytoreductive drugs: hydroxyurea, interferon | -ASA also because PCV is prothrombotic
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Types of blood transfusion reactions
Nonhemolytic febrile reaction Minor allergic reaction Hemolytic transfusion reaction
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Nonhemolytic febrile reaction
Cytokine formation during storage of blood Fevers, chills, rigors, malaise 1-6 hours after transfusion Stop transfusion and give acetaminophen
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Minor allergic reaction to blood transfusion
Antibody formation against donor proteins, after receiving plasma containing product p/w prominent urticaria Tx: antihistamines; if the reaction is severe, may need to stop and give epinephrine
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Hemolytic transfusion reaction
Antibody formation against donor erythrocytes, results from ABO incompatibility or from minor Ag mismatch p/w fevers, chills, nausea, flushing, burning at IV site, tachycardia, hypotension shortly after transfusion; can cause hemoglobinuria which can lead to ATN and renal failure Tx: stop transfusion immediately; give IVF and maintain UO
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Leukocyte alkaline phosphatase
Increased in leukemoid reactions | Decreased in hematologic malignancies
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Porphyria
Congenital abnormality of heme production which leads to accumulation of porphyrins Photodermatitis Neruopsychiatric complaints Visceral complaints: usually colicky abdominal pain and seizures PE: tachycardia, skin erythema and blisters, areflexia, and nonspecific abdominal exam Erythropoietic porphyria: hemolytic anemia
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Porphyria triggers
EtOH, OCPs, barbiturates
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Pink urine
porphyria