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Flashcards in Heme Deck (76):
1

Mechanism of action of unfractionated heparin

Antithrombin III inhibits thrombin and factor Xa

2

5 contraindications to unfractionated heparin

Hypersensitivity
Active GI bleed
ICH
Bacterial endocarditis
HIT

3

Treatment of major bleeding on heparin

Stop heparin
Protamine 1 mg/100 units given over previous 4 hours, administer slowly as risk of anaphylaxis

4

What is HIT syndrome, diagnosis and treatment

Autoimmune response to heparin, presents as >50% reduction platelets or thrombosis. HIT assay confirms
Treat with direct thrombin inhibitor

5

Mechanism of action of LMWH

Inhibits factor Xa

6

Which patients require monitoring of factor Xa while on LMWH

GFR <50 (cleared by kidneys, needs dose adjustment)
Morbid obesity
Pregnancy

7

Fondaparinux: a) uses b) treatment of major bleeding c) mechanism

A) VTE, hip replacement prophylaxis
B) recombinant factor VIIa
C) inhibits factor X

8

Primary indication for direct thrombin inhibitors (lepirudin, bivalirudin)

Patients with HIT
No antidote exists, care is supportive

9

Which coagulation factors are inhibited by warfarin

II, VII, IX, X

10

90yo on warfarin for mechanical valve, INR is 10 with no active bleeding, how do you reverse

Hold warfarin
Vit k 2.5-5 mg po
Recheck INR

11

Warfarin reversal with any major bleeding

Hold warfarin
Vitamin K 10mg iv slow push (risk anaphylaxis)
FFP or PCC or recombinant factor VIIa

12

4 complications of warfarin

Under anticoagulation
Over anticoagulation (bleed)
Paradoxical thrombosis between 2nd and tenth day
Warfarin induced skin thrombosis

Reduce risk of last two by bridging with heparin

13

Mechanism of action of dabigatran, apixaban and Rivaroxaban

Dabi direct thrombin inhibitor
Rivaroxaban and apixaban factor Xa inhibitor

14

Management of major bleed on DOAC

Stop offending drug
Supportive management
PCC, FFP, antifibrinolytics eg tranexamic acid

15

What is bleeding due to with patients taking aspirin

Platelet dysfunction, not thrombocytopenia

16

Three classes of anti platelets and their mechanism of action

Aspirin: cox 1 inhibitor, prevents thromboxane A2 synthesis
Thienopyridines (clopidogrel): irreversibly inhibits platelet aggregation
Glycoprotein IIA/IIIb inhibitors (abciximab): inhibit platelet activation

17

What additives are in packed RBCs

Anticoagulant preservatives; citrate, phosphate, dextrose, adenine

18

How much volume is in one unit of adult and pediatric pRBCs

350 ml in adult
60 ml in peds

19

What should you do to reduce the risk of febrile nonhemolytic reactions and prevent sensitization in bone marrow eligible patients and reduce risk of CMV and HIV transmission in immunesuppressed

Use leukoreduced PRBCs

20

Indications for transfusion pRBCs

End organ damage related to anemia (ie MI, stroke)
Active or recent bleed with Hb level under 70, 80-100 in known cardiac disease

21

How much does one unit of pRBCs increase hemoglobin

10

22

Mechanism of action of tpa

Activates plasminogen to plasmin, breakdown of fibrinogen and cross linked fibrin

23

Define thrombocytopenia and name four causes

Platelets < 100
Decreased production, increased destruction, splenic sequestration

24

Transfusion threshold for platelets

Life threatening hemorrhage and abnormal platelets
Platelets under 10 (except ITP, TTP, HIT, HUS)
Bleeding under 50
Massive transfusion

25

Seven causes of increased platelet destruction

Immunologic:
ITP
HIT
infection
Leukaemia, lymphoma
Mechanical:
TTP
HUS
DIC
HELLP

26

Four causes of decreased platelet production

Marrow infiltration
Drugs
Toxins
Infections

27

Treatment of ITP

Treat for severe bleeding under 50, platelet under 10 without bleeding
Steroids, IVIG for unresponsive to steroids, recalcitrant may need splenectomy
Platelet transfusion only for life threatening hemorrhage
Avoid NSAIDS and physical activity for two months

28

9 causes of DIC

Infection (most common): GP and GN sepsis, meningiococcemia, Rocky Mountain spotted fever, typhoid fever
Trauma (burns, crush, head injury)
Shock
Pregnancy complications (abruption, amniotic fluid embolus)
Transfusion and drug reaction
Carcinoma (lymphoma, leukaemia, adenocarcinoma)
Liver disease
ARDS
envenomation
Surgical procedures
Heat stroke

29

Laboratory findings in DIC

Coagulation product consumption: prolonged PT and PTT, low platelet, low fibrinogen, increased thrombin time
Active clot formation: elevated dimer
Microangiopathic hemolytic anemia:

30

Treatment of DIC

Treat underlying cause
Replace consumed coagulation factors: FFP and Cryo
Platelet transfusion under 50 of bleeding, 10 if not
If thrombosis predominated give heparin
Purpura fulminans (protein c deficiency) treat with protein c concentrate (see in severe sepsis, bruising then necrotic centre)

31

Function of vWF and treatment of Von willebrand disease

Facilitates adherence or platelets to injured blood vessels
Stabilized factor VIII in plasma
Treatment:
DDAVP (stimulates release of vWF and factor VIII)
vWF concentrate in all cases serious bleeding
Cryo if no vWF available but carries risk infection

32

What should you consider in someone with bleeding disorder but normal platelet, PT, PTT?

Von willebrand disease

33

Which factors are deficient in hemophilia a and b

A= VIII
B= IX

34

Clinical symptoms hemophilia

Easy bruising, hemarthrosis, hematuria, muscle hematoma
excessive bleeding after procedures, severe/delayed bleeding with minor trauma

35

Management of bleeding or trauma in hemophilia A

Factor VIII replacement by site (weight based and dependent on intrinsic factor activity)
DDAVP in mild to moderate bleeding in hemophilia a

36

Treatment of hemophilia B

Factor ix replacement weight based and site based
Use in extreme caution with presence of inhibitors (clotting factor mixing test) as can cause anaphylaxis so use PCC or factor VIIa in these cases

37

9 massive transfusion complications

Hypocalcemia
Hypothermia
Acidosis
Hyperkalemia
TACO
TRALI (supportive) -- see most commonly w FFP and platelets
Fever transfusion reaction
Acute hemolytic transfusion reaction (ABO incompatibility)
Allergic
Delayed transfusion reaction (extravascular hemolysis from small amounts RBC antibodies)
Graft vs host disease (irradiate platelets in immunecompromised)
Infection


38

How much does one unit of platelets elevate platelet level by

30

39

Three situations where you want to avoid platelet transfusion

ITP, TTP, HIT

40

What is in fibrinogen, how is it administered

All clotting factors, fibrinogen
Given as 4-6 units (250 ml volume each)
Indicated in significant hemorrhage secondary to coagulopathy
Needs to be cross matched

41

What is in Cryo and when is it indicated

VIII, XIII, vWF, fibrinogen
Indicated in low fibrinogen state plus hemorrhage
Consider in hemophilia and vW

42

What is in PCC

II, VII, IX, X (vit k dependent)
Give in life threatening hemorrhage
Needs to be given with vit k as is transient
Lower volume and faster than FFP

43

Diagnostic findings in hereditary spherocytosis
Treatment

Hemolytic anemia (extravascular)
Negative Coombs
Positive osmotic fragility test
Spherocytes on smear

Folic acid supplementation, some need splenectomy

44

Precipitants of G6PD
Lab findings
Treatment

Infection, fava beans, drugs (eg post malarial treatment)
Hemolytic anemia, hemoglobinuria, hyperbilirubinemia, Heinz bodies on smear and bite cells
Supportive treatment

45

Difference between warm and Cold autoimmune hemolytic anemia

Warm is IgG antibodies against RBCs antigens. Binds at body temp. Associated w lymphoproliferative disorders
Cold is igm antibodies. Binds at cool temp, assoc w EBV, lymphoma, mycoplasma

46

Two examples of alloimmune hemolytic anemia

Transfusion reaction
Hemolytic disease of the newborn

47

6 causes of microangiopathic hemolytic anemia

DIC
TTP
HUS
pregnancy (HELLP)
Malignant hypertension
Malignancies

48

Hallmarks of TTP-HUS spectrum

Microangiopathic hemolytic anemia
Thrombocytopenia
Plus minus renal and neuro involvement

49

Clinical picture HUS

Children, bloody diarrhea
Renal dysfunction, anemia, thrombocytopenia, microangiopathic anemic
Can see jaundice, fever, purpura

50

Pathophysiology of renal failure and neuro involvement in HUS-TTP

Fibrin deposition and platelet aggregation lead to intravascular hemolysis, microthrombi in renal and CNS vasculature

51

Work up of TTP HUS

CBC hapto ldh smear
Coombs to rule out autoimmune
D-dimer, fibrinogen for DIC, ptt inr
Stool for shiga toxin producing bacteria (e coli, salmonella, shigella)
Creatinine
Urine r and m

52

Classic cause of TTP

Congenital or acquired deficiency in ADAMTS13 protein activity

53

Management HUS

Supportive care
Plasma exchange in severe
No antibiotics

54

Management of TTP

Plasma exchange

55

Four types of thalassemia

Alpha minor: usually mild, asymptomatic
Alpha maj: fetal hydrops and demise
Beta min: asymptonatic, hypochromic, microcytic anemia
Beta maj: severe anemia, splenomegaly, frontal bossing, transfusion dependent (splenectomy can reduce need for this)

56

Pathophysiology of sickle cell

Autosomal recessive disease, structure of b globin chain
One chain is carrier, both is disease
Deoxygenated RBCs take on sickle shape, leads to obstruction of RBCs in microcirculatoin and vaso-occlusive ischemic tissue injury

57

3 most common precipitants sickle cell

Hypoxia
Dehydration
Infection

58

Possible indications of exchange transfusion in sickle cell disease

Acute CNS event
Acute chest syndrome
Cardiopulmonary collapse
Priapism

59

Work up of possible sickle cell pain crisis

CBC, retics (hemolysis or aplastic crisis), smear, urine, chest X-ray, culture

60

Bugs implicated in acute chest syndrome in sickle cell

Staph strep chlamydia and mycoplasma
RSV

61

Treatment acute chest syndrome

Oxygen
Iv hydration
Antibiotics
Analgesia
Exchange transfusion if multiple lobe involvement, severe hypoxia, refractory to antibiotics

62

Age of splenic sequestration crisis in sickle cell

6 mo to 6 years

63

9 possible presentations and complications of sickle cell disease

Stroke
Acute chest syndrome
Acute pain crisis
Osteomyelitis (staph aureus, salmonella)
Osteonecrosis
Cholelithiasis
Priapism
Ulceration
Aplastic anemia

64

Definition of polycythemia

165 women, 185 men

65

Causes polycythemia
Treatment

Primary (myeloproliferative)
Secondary (increased epo eg lung disease, high altitude, expo secreting tumor)
Phlebotomy is treatment

66

Complications polycythemia

Both thrombosis from hyperviscosity and bleeding from platelet dysfunction
Hypervolemia syndrome

67

Pathophysiology of methemoglobinemia

Oxidizing agents cause ferrous iron to change to ferric iron which can't bind O2

68

5 causes of methemoglobinemia

Nitrates
Lidocaine
Benzocaine
Sulfa
Dapsone
Pyridium

69

Clinical presentation methemoglobinemia

MI, seizures, coma, death
Cyanosis
Anxiety, headache, tachycardia
Pulse ox 80-85 no response to oxygen with normal PaO2 on abg
Co-oximetry confirms
Mortality with levels over 40%, symptoms over 20%

Treat with methylene blue 1-2 mg /kg contraindicated in G6PD

70

Causes of neutrophilia

Infection or inflammation (esp w left shift or increase in immature neutrophils)
Stress reaction (exercise, seizures, trauma, ketosis)

71

What is a leukemoid reaction

Nonleukemic leukocytosis> 50
See in sepsis, tb, Hodgkins, metastatic non hem cancers

72

Four types of leukaemia

CML: adult, least common, Philadelphia chromosome, typically asymptomatic. Increased polymorphonuclear neutrophils and myelocytes
Aml: most common adult acute, anemia, thrombocytopenia, variable leukocyte, blasts
CLL: lymphadenopathy, lymphocytosis, neutropenia, anemia, thrombocytopenia
ALL: peds, oancytopenia, blasts.

73

Pathophysiology of multiple myeloma

Single plasma cell clone and immunoglobin proliferation

74

Complications of multiple myeloma

Hypercalcemia, pathological fracture, hyperviscosity syndrome, spinal cord compression syndrome

75

What type of malignancy has the Reed-Sternberg cell or owl eye cells

Hodgkin lymphoma

76

Which type of non Hodgkin lymphoma tends to be curable

Aggressive (eg diffuse large B cell, anaplastic large cell, brukittm peripheral T cell, lymphoblastic)