Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

POS Flashcards - Box 2 > Hematology > Flashcards

Hematology Flashcards

1
Q

Outline of events for hemostasis

A

No back to cue card

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Draw the coagulation cascade

A

cost $ to add a pic, google coagulation cascade

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What bleeding disorders do PT/INR screen for?

A
  • extrinsic pathway factors: VII

- common pathway factors: V, X, prothrombin/thrombin (II), fibrinogen/fibrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What bleeding disorders does PTT screen for?

A
  • Intrinsic pathway factors: HMWK, prekallikrein, VIII, IX, XI, XII
  • Common pathway factors: II/thrombin, V, X, fibrinogen/fibrin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is thrombin time and when would you expect it to be prolonged?

A
  • time required to clot after the addition of thrombin

- may be prolonged in: DIC, hypofibrinogenemia, dysfibrinogenemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does bleeding time estimate the function of?

A

qualitative platelet function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does a normal INR and an abnormal PTT indicate?

A

deficiency of proximal intrinsic pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does an abnormal INR and a normal PTT indicate?

A

Abnormalities of vitamin K dependent factors such as II, VII, IX, and X (1972)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the mixing test and what does it tell us?

A
  • patient’s plasma mixed with normal plasma
  • test normalizes = deficiency of a factor
  • test does not normalize = inhibitor present
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are some minor factor deficiencies?

A
  • factor XII deficiency
  • defects / deficiency of HMKW kininogen and prekallikrein
  • factor XI deficiency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is factor XI deficiency?

A
  • autosomal recessive
  • causes spontaneous bleeding and then VIII or IW* deficiency

(*thats the what the card reads, but probably should be IX)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the genetics of hemophilia A?

A
  • congenital coagulation disorder resulting from deficiency or abnormality of VIII
  • X-linked with +++ different mutations
  • up to 30% spontaneous mutations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does hemophilia A present clinically?

A
  • onset of bleeding following trauma is usually hours or days after injury since the platelet plug works fine
  • bleeding may then persist
  • usually present with bleeding into deep tissues or joints as opposed to mucosal bleeding seen with platelet abnormalities
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the lab work look like in hemophilia A?

A
  • prolonged PTT
  • normal PT/INR
  • normal bleeding time
  • normal vWF : Ag
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is hemophilia A classified?

A
  • based on functional levels of VIII
  • termed VIII:C
  • VIII:Ag refers to the antigenic and not functional levels of VIII
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What percentage of hemophilia A are severe, moderate, and mild disease?

A
  • spontaneous bleeding = < 1%
  • severe bleeding = < 2%
  • moderate bleeding = 2-5%
  • mild bleeding = 5-30%
  • no clinical significance = >30%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the minimal VIII needed for hemostasis?

A

30%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the treatment for hemophilia A?

A
  • DDAVP IV or IN - causes release of stored VIII + vWF from endothelial cells, increased levels in mild to mod dz in prep for minor sx or following trauma
  • recombinant VII + plasma-based VIII concentrate - for more serious bleeding
  • cryoprecipitate - good enough but not used when specific VIII available
  • recombinant fVIIa* - for patients with FVIII inhibitors

(*as written on card, should it be fVIII though?)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the genetics of hemophilia B?

A

Inherited x-linked deficiency or deficit in IX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does the bloodwork look like in hemophilia B?

A
  • increased PTT
  • decreased IX
  • normal INR/PT
  • normal bleeding time
  • normal platelet count
  • mixing time not resolved (inhibitor of iX present)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the treatment for hemophilia B?

A
  • prothrombin complex concentrate

- pure IX concentrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the goal of treatment for hemophilia B?

A
  • raise the level to 30% to protect against bleeding post detal extraction or to abort a beginning joint hemarthroses
  • raise the level to 50% if major join or IM bleeding is already evident
  • rain the level to 100% in life threatening bleeding or before a major operatoin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What percentage of activity in hemophilia B is needed for hemostasis?

A

> 30%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is Von Willebrand’s disease?

A
  • vWF causes platelet adhesion to collagen, initiating platelet plug formation
  • also forms a complex with VIII (acts as a carrier protein) in the blood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How is vWF produced?

A

by endothelial cells + megakaryocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the 3 types of vWF disease?

A
  • type I
  • type II
  • type III
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is type 1 vWF?

A
  • autosomal dominant quantitative deficiency of normally functioning vWF
  • abnormal bleeding time
  • mild reduction in VIII : C and vWF
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is type II vWF?

A
  • variably inherited qualitative deficits in vWF
  • dx complicated by many subtypes
  • in general, decreased ristocetin assay - measures effectivenss of vWF in agglutinating platelets
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is type III vWF?

A
  • autosomal recessive with complete absence of vWF
  • severe bleeding
  • mucosal bleeding, petechiae, epistaxis, menorrhagia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the treatment of vWF disease?

A
  • DDAVP - 1 hour prior to surgery, 48 hours b/w injections to allow for VIII + vWF to reaccumulate in endothelial cells, + epsilon-aminocaproic acid or TXA to suppress fibrinolysis, useful in type 1, no value in type II/III
  • Humate P - fVIII product which contains high [vWF]
  • Cyroprecipitate - 1 bag/10 kg q8-12h x sev days to prevent excessive bleeding after major operation, useful for type I/II/III
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is alpha2 antiplasmin deficiency?

A

homozygote with bleed as severely as a hemophiliac after surgery or trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are some acquired bleeding disorders?

A
  • hepatic failure
  • renal failure
  • thrombocytopenia
  • thrombocytopathy
  • hypothermia
  • vit K deficiency
  • warfarin treatment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How does liver failure cause bleeding disorders?

A
  • liver = major source of all factors except VIII + vWF
  • DDAVP can be used to shorten bleeding times in cirrhotics except in the presence of plt dysfunction or thrombocytopenia
  • Lg volumes of FFP may be required to maintain normal factor levels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How does renal failure cause bleeding disorders?

A
  • leads to decrease in aggregation + adhesion of plts

- tx with DDAVP, cryoprecipitate, and conjugated estrogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How does thrombocytopenia cause bleeding disorders?

A
  • failure of production
  • splenic sequestration
  • consumption
  • dilution
  • drugs: quinidine, sulfa, oral hypoglycemics, gold, rifampin, mithramycin, heparin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How does thrombocytopathy cause bleeding disorders?

A
  • chemo drugs
  • thiazides
  • alcohol
  • estrogen
  • antibiotics
  • quinidine
  • quinine
  • methyldopa
  • gold
  • heparin
  • ASA
  • NSAIDs
  • dextrin
  • hypothermia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

How does hypothermia cause bleeding disorders?

A
  • increased fibrinolytic activity
  • thrombocytopathy
  • decrease in collagen-induced plt aggregation
  • spontaneous bleeding occurs when temp < 30 - 40 degrees C
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How does vitamin K deficiency cause bleeding disorders?

A
  • necessary for carboxylation of glutamate in factors II, VII, X and IX (1972)
  • necessary for carboxylation of protein C and S
  • rapidly corrected by FFP
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

How does warfarin treatment cause bleeding disorders?

A
  • effect on protein C and S
  • effect on 1972
  • reversed by vit K
40
Q

How does bleeding associated with platelet disorders present clinically?

A
  • mucosal bleeding
  • easily bruised
  • petechiae
  • purpura
  • menorrhagia
41
Q

What are some platelets disorders?

A
  • Idiopathic (autoimmune) thrombocytopenic purpura
  • Glanzmans’s Thrombasthenia
  • Bernard-Soulier Syndrome
  • May-Hegglin Anomaly
  • Chediak-Higashi Syndrome
42
Q

What is ITP?

A
  • most common cause of isolated thrombocytopenia
  • IgG autoantibody
  • plt destroyed in the spleen but the spleen is not usually palpable
  • peripheral blood smear shows decreased plts / lg plts
  • marrow shows plentiful megakaryocytes
43
Q

How is ITP managed?

A
  • steroids
  • spleenectomy (if steroids fail)
  • immunosuppressives
  • platelets
  • plasma exchange
  • danazol
  • IV gamma globulin
44
Q

What is Glanzman’s thrombocytopenia?

A
  • inherited defect of GpIIb/IIIA (plt membrane glycoprotein)
  • characterized by impaired plt binding to vWF, fibrinogen, and fibronectin
  • leads to severe mucosal bleeding
45
Q

What are the lab findings of Glazman’s?

A
  • failure of plts to aggregate with any physiologic agent
  • absences of clot retraction
  • single plts without aggregates on peripheral blood smear
46
Q

What is the treatment of Glanzman’s?

A

Plt transfusions BUT with develop antibodies , so must be slective when to expose patient to a platelet transfusion

47
Q

What is Bernard-Soulier Syndrome?

A
  • inherited absences of surgace glycoprotein GpIb-IX that binds vWF
  • plts don’e adhere + aggregate
  • absolute plt #s decrease
  • plts larger
48
Q

What is the treatment of Bernard-Soulier Syndrome?

A

platelet transfusions

49
Q

What are disorders of amplification of plt activation?

A
  • May result from: decreased ADP in dense granules, inability to generate TXA2, inability of platelets to repond normally to TXA2
  • Plt aggregation test results found in disorders of plt activation amplification: impaired-to-absent aggregation after exposure to collagen, epi, and low [ADP], normal aggregation after exposure to high [ADP]
  • ASA + NSAIDs may produce the same results
50
Q

What is DIC?

A
  • Procoagulant state
  • Activation of both coagulation + fibrinolytic systems > thrombin + plasmin in circulation
  • Thrombin activates fibrin > fibrin monomers form soluble fibrin clot > microvascular thrombosis > entrapment + depletion of plts
  • Simultaneous degradation of these factors by plasmin occurs. Plasmin also degrades V, VIII, IX, XI and activates complement system
  • Result = decreased fibrinogen levels + increased degradation product levels
51
Q

DIC diagram

A

Can’t upload picture :(

52
Q

Put simply, what happens in DIC?

A
  • procoagulant activation
  • fibrinolytic activation
  • inhibitor consumption
  • biochemical evidence of end organ damage or failure
53
Q

What are some things associated with DIC?

A
  • complication of obstetrics
  • infection & sepsis
  • malignancy including leukemia
  • shock from any cause
  • burns
  • crush injuries
  • massive transfusion
  • liver disease
  • hemolysis
  • inflammatory and autoimmune conditions
  • malignancy hyperthermia
54
Q

What does the lab work look like in DIC?

A
  • decreased plt
  • increased PT/INR
  • increased PTT
  • decreased fibrinogen
    • fibrin monomer present
  • high plasma d-dimer and fibrin degradation products
  • low levels multiple clotting factors (V and VIII)
  • fragmented RBCs on smear
  • low thrombin-antithrombin and antithrombin III
  • increased coagulation factor degradation fragments (F1,2,FpA)
  • decreased plasminogen and alpha2-antiplasmin inhibitors
55
Q

What is the treatment for DIC?

A
  • correct underlying illness
  • heparin if treatment of underlying pathology doesn’t ameliorate the condition in a few hours
  • antithrombin III concentrate
  • washed pRBCs
  • platelets
  • cyropreciptate to replace firbrinogen and VIII
  • FFP to replace V, clotting factors, and antithrombin III
  • Epsilon-amniocaproic acid (or TXA) to inhibit fibrinolysis, which releases fragments D & E that interfere with normal clot formation
56
Q

What are procoagulant states?

A
  • HIT
  • antithrombin III deficiency
  • protein C and S deficiencies
  • resistance to activated protein C (factor V Leiden)
  • lupus anticoagulant
57
Q

What is HIT?

A

Heparin induced thrombocytopenia

HIT I

  • non immune
  • normalized with stopping heparin

HIT II

  • immune mediated (IgG)
  • Ab recognizes multimolecular complex of heparin + plt factor 4 resulting in plt aggregation
58
Q

How do you diagnose HIT II?

A
  • suspect in anyone on heparin who develops thrombosis or when plt < 100
  • typically occurs 5-15 days into treatment, sooner if on heparin in past 3 months
  • dx: serotonin release assay
59
Q

What are complications resulting from HT II?

A
  • bleeding
  • intravascular thrombosis (venous and arterial) with unusual thrombotic complications
  • acute plt activation syndromes (fever, flushing)
  • skin necrosis
60
Q

How do you manage HIT?

A
  • D/C heparin and wait for it to wear off

OR

  • protamine reversal if thrombosis has occurred
  • start warfarin under protection of another anticoagulant
61
Q

What are some anticoagulant options for patients with HIT?

A
  • danaproid (25% cross-reactivity)
  • ASA (some but limited utility)
  • Ancord
  • Lepirudin (direct thrombin inhibitor)
  • Argatroban
  • Dextran
62
Q

Can you switch patients who have HIT to LMWH?

A
  • NO!!!

- 90% cross-reactivity

63
Q

What is antithrombin III?

A
  • the most important plasma protease inhibitor

- serine protease inhibitor of thrombin (II), VIIa, IXa, Xa, Xia, and kallilreinin

64
Q

What is antithrombin III deficiency?

A
  • uncommon but significant risk for recurrent, life threatening thrombosis
  • most cases apparent before 50 years
  • can present with arterial thrombosis
  • suspect when patient cannot be adequately anti coagulated with heparin
65
Q

How is antithrombin III deficiency diagnosed?

A

measure levels and activity

66
Q

What are the causes of antithrombin III deficiency?

A
  • nephrotic syndrome (loss of factor)
  • liver disease (site of production)
  • malignancy
  • malnutrition
  • decreased protein production
  • DIC
  • genetic
67
Q

How do you treat a patient with antithrombin III deficiency requiring anticoagulation?

A
  • antithrombin III concentrates or FFP + heparin

- followed by oral anticoagulants as per usual

68
Q

When is protein C activated?

A
  • when thrombin binds to endothelial cell R thrombomodulin

- thrombomodulin brings protein C in proximity to thrombin to be activated

69
Q

What is protein S?

A

activated protein C co-factor

70
Q

What are the actions of activated protein C / protein S / procoagulant tissue factor?

A
  • inactivates Va and VIIIa > decreased thrombin production

- inhibits tPA inhibitor (PAI-I) > increased plasminogen activity and increased fibrinolysis

71
Q

What are the causes of protein C deficiency?

A
  • congenital (homozygosity is incompatible with life)
  • liver failure
  • DIC
  • nephrotic syndrome
  • inflammatory states
72
Q

How do you diagnose protein C and S deficiency?

A
  • measure protein C levels and activity

- measure antigen level for protein S

73
Q

What is the management for protein C and S deficiency?

A
  • you only need to treat after thrombosis
  • heparin > oral anticoagulants for life - start with low dose warfarin to minimize the transient hypercoaguable state that warfarin induces
74
Q

What is resistance to activated C?

A
  • a common polymorphism of factor V that results in resistance of Va to activated protein C
  • present in 1-2% of the population
  • most common cause for thrombosis
  • associated with increased risk venous thrombus
  • indications for long term anticoagulation unknown
75
Q

What is lupus anticoagulant syndrome?

A
  • hypercoagulable state
  • present of antiphospholipid antibodies in associated with episodes of thrombosis, recurrent fetal loss, thrombocytopenia, and livedo reticularis
76
Q

How is lupus anticoagulant syndrome diagnosed?

A
  • suspected when PTT increased
  • antiphospholipid or anticardiolipin antiboidies detected
  • other coagulation tests normal
77
Q

How is lupus anticoagulant syndrome treated?

A
  • anticoagulation during thrombotic events
  • warfarin with goal INR > 3.0
  • heparin or LMWH for recurrent fetal loss throughout pregnancy
78
Q

What are hematologic drugs?

A
  • protamine
  • warfarin
  • heparin
  • LMWH
  • ASA
  • Ancord
  • EPO
  • medicinal leeches
  • thrombolytics
79
Q

What is protamine?

A
  • weak anticoagulant
  • forms a salt with heparin resulting in loss of anticoagulant activity of both drugs
  • used to reverse heparin effects
  • too rapid administration can cause hypotension and anaphylactoid reaction
80
Q

What are the common side effects of protamine?

A
  • hypotension
  • bradycardia
  • pulmonary artery HTN or hypotension
  • decreased oxygen consumption
  • transitory flushing
  • leukopenia
  • thrombocytopenia
81
Q

How does warfarin work?

A
  • interferes with prothrombin (II), VII, IX, X, protein C and protein S
  • in the liver, these factors are carboxylated in a reaction catabolized by the reduced form of vitamin K
  • warfarin prevents the reduction of vitaminK once it has functioned as a cofactor in the carboxylation reaction
82
Q

What are some major complications of warfarin?

A
  • bleeding

- skin necrosis

83
Q

What is the half-life of warfarin?

A
  • 40 hours
84
Q

What is the reversal agent for warfarin?

A
  • vitamin K

- FFP

85
Q

What are some common drugs that decrease warfarin effectiveness?

A

alcohol, azathioprine, barbiturates, carbamazepine, cortisone, corticotropin, cyclophosphamide, dicloxacillin, haldol, phenytoin, prednisone, ranitidine, rifampin, spironolactone, sucralfate, trazodone, vitamin C

86
Q

What are some common drugs that increase warfarin effectiveness?

A

alcohol, allopurinol, 5-ASA, amiodarone, ASA, Azole antifungals, cephalosporins, clarithro/erythro, 5-FU, flagyl, heparin, NSAIDs, neomycin, PPIs, penicillins, prednisone, propanolol, quinolones, ranitidine, thyroxine, TMP/SMX, tylenol, thrombolytics

87
Q

How does heparin work?

A
  • accelerates the reaction between thrombin and anti-thrombin III, accelerating the inhibition of thrombin (II) and other serine proteases (VII, IX, X, XI, and kallikreinin) by antithrombin III
  • directly binds and inhibits coagulation proteases and is important for the selective inhibitor of thrombin, heparin cofactor II
  • decreases platlelet aggregability
88
Q

How does heparin affect PTT and INR?

A
  • prolongs PTT by depleting intrinsic factors

- prolongs INR

89
Q

How long does it take to clear a dose of heparin?

A

6 hours

90
Q

What are the complications of heparin?

A
  • bleeding
  • HIT I and HIT II (measure plt level q2d starting on day 4)
  • alopecia
  • osteoporosis
91
Q

How does LMWH work?

A

inhibits activated factor X (Xa) but has less effect on antithrombin and on coagulation in general than the unfractionated heparin

92
Q

How does ASA work?

A
  • irreversibly blocks cyclooxygenase (prostaglandin synthesis), which catalyzes conversion of AA to endoperoxide compounds
  • at appropriate doses it decreases the formation of prostaglandins and TXA2 but not the leukotrienes
93
Q

How does ancrod work?

A

a thrombin-like enzyme produces anticoagulation by cleaving fibrinogen into fibrinopeptides that don’t from stable microthrombi

94
Q

What is the half life of ancord?

A

3-5 hours

95
Q

How do medicinal leeches work?

A
  • produce hirudin, a powerful and specific thrombin inhibitor
  • action is independent of antithrombin III which means it can reach and inactivate fibrin-bound thrombin in thombi
  • little effect on platelets or bleeding time
96
Q

What are contraindications to thrombolytics?

A
  • eye or CNS surgery within prev 2 weeks
  • intracranial/spinal neoplasia or vascular anomalies
  • stroke in prev 2 months
  • active bleeding
  • severe hypotension
  • allergy to agent
97
Q

What are the contradictions to thrombolytics in the setting of MI?

A

Absolute: active bleeding, aortic dissection, acute pericarditis, cerebral hemorrhage

Relative: GI or GU hemorrhage or stroke in last 6 months, major surgery or trauma in last 2-4 days, severe uncontrolled HTN, bleeding diasthesis or intracranial neoplasm, puncture of noncompressible vessel, significant chest trauma from CPR

POS Flashcards - Box 2 (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions