Hemostasis, Surgical Bleeding, & Transfusions Flashcards Preview

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Flashcards in Hemostasis, Surgical Bleeding, & Transfusions Deck (86):
1

Define Hemostatic Process

Process involves interaction between blood vessel walls, platelets, & coagulation proteins

2

Initial Hemostasis Activity After Injury

Vasoconstriction
Platelets adhere to site of vascular injury
After adhesion, platelets release ADP causing platelet aggregation
Formation of white thrombus
Formation of permanent thrombus with fibrin

3

Coagulation Pathway

Extrinsic: thromboplastin interacts with VII to covert X to Xa
Intrinsic: factors XII, XI, IX, & VIII to convert X to Xa
Common: X, V, II, & I; factor VIII

4

Deficiency of what factors causes bleeding?

Any EXCEPT XII

5

What can reduce the effectiveness of clotting?

Hypocalcemia

6

Evaluation of a Bleeding Patient

Hx: OTC, ASA, clopidogrel (Plavix), warfarin (Coumadin)
Look for signs of bleeding disorder
Labs: platelets, PT, PTT, bleeding time, thrombin time

7

Signs of a Bleeding Disorder

Splenomegaly
Hepatomegaly
Bleeding after dental procedures
Menses
Minor cuts
Family history of bleeding

8

What does a platelet count verify?

An adequate number of platelets are available in the circulation

9

What is a normal platelet value?

150,000-400,000

10

What are some reasons for low platelets?

Cancer treatment
Meds: lasix, penicillins, sulfonamids, NSAIDs
Autoimmune disorders

11

What does prothrombin time measure?

Ability of the blood to form stable thrombi
Extrinsic & common pathway

12

When is a PT normally ordered?

Monitor warfarin

13

Define INR

Ratio of a patient's PT to a normal (control) sample

14

What does a partial thromboplastin time (PTT) measure?

Adequacy of intrinsic & common pathways

15

When is PTT most commonly used?

Unfractionated heparin therapy

16

Define Bleeding Time

Time from injury to cessation of bleeding

17

What may a prolonged bleeding time indicate?

Thrombocytopenia
Medication (ASA)
Von Willebrand disease

18

What does thrombin time evaluate?

Fibrinogen to fibrin conversion with an external source of thrombin

19

What may a prolonged thrombin time indicate?

Low fibrinogen levels
Abnormal fibrinogen
Fibrin & fibrinogen split products
Heparin
Blood or coagulation disorders
DIC Chronic liver disease

20

Von Willebrand's Disease Pathophysiology

Reduced factor VII activity & von Willebrand activity

21

Main Site of Bleeding for Von Willebrand's Disease

Mucocutaneous

22

Lab Results for Von Willebrand Disease

Prolonged PTT
Normal PT
Abnormal platelet function

23

Treatment of Von Willebrand Disease

Cryoprecipitate infusions
Desmopressin (DDAVP)

24

Pathophysiology of Hemophilia A

Reduced or absent factor VII activity

25

Main Sites of Bleeding for Hemophilia A

Joints
Intramuscular

26

Lab Results of Hemophilia A

Prolonged PTT
Normal PT
Normal platelet function

27

Treatment of Hemophilia A

Purified factor VII products

28

Common People who get Hemophilia A

Males

29

Causes of Acquired Bleeding Disorders

Advanced liver disease
Anticoagulation therapy
Acquired thrombocytopenia
Platelet-inhibiting drugs
Uremia

30

Liver Disease as an Acquired Bleeding Disorder

Inability to synthesize proteins leads to decreased levels of prothrombin & factors V, VII, & X

31

What liver disorders may lead to clotting factor deficiencies?

Obstructive jaundice
Cirrhosis

32

Anticoagulation Therapy

Warfarin (Coumadin)
Heparin

33

MOA of Warfarin (Coumadin)

Depression of clotting factors II, VII, IX, X

34

How can warfarin (Coumadin) be reversed in an emergency?

FFP
Vitamin K

35

MOA of Heparin

Increases speed of antithrombin III binds to & neutralizes factors IXa, Xa, XIa, XIIa, & thrombin

36

Lab Results on Heparin

Prolonged PTT
Prolonged thrombin time

37

How is heparin reversed?

Protamine sulfate

38

3 Mechanisms of Acquired Thrombocytopenia

Decreased platelet production in bone marrow
Increased destruction of platelets in peripheral blood
Splenic pooling in enlarged spleen

39

Examples of Acquired Thrombocytopenia

ITP
DIC
Aplastic anemia
Cirrhosis
Platelets destroyed during surgery
Cell saver

40

Platelet-Inhibiting Drugs

ASA
Clopidogrel (Plavix)
NSAIDs

41

Medication-Associated Bleeding

Anticoagulants: warfarin, heparin
Platelet-inhibiting drugs: clopidogrel, ASA, NSAIDs
OTC meds: dong quai (angelica), garlic, giner, gingko biloba, ginseng, St. Johns wort

42

How is intra-operative bleeding controlled?

Gelfoam
Surgicel
Floseal
Tisseel

43

Reasons for Post-Op Bleeding During Surgery

Poor hemostasis
Residual heparin
Shock
Altered liver function
Malnutrition

44

Classification of Post-Op Bleeding

Primary
Reactive
Secondary

45

Post-Op Bleeding: Primary

Occurs during operation
Monitor with drains post-op

46

Post-Op Bleeding: Reactive

Occurs within 24 hours of operation
Hemorrhage-like reaction

47

Post-Op Bleeding: Secondary

7-10 days post procedure
Erosion of the blood vessels: usually due to infection

48

Define DIC

Intravascular coagulation & thrombosis that is diffuse instead of localized at the site of injury

49

What does DIC result in?

Systemic deposition of platelet-fibrin micro thrombi that causes diffuse tissue injury

50

Etiology of DIC

Release of tissue debris into bloodstream after trauma or obstetric catastrophe
Endothelial damage to vascular wall
Hypotension
Operations with large blood loss
Burns
Sepsis
Transfusion reactions

51

How is DIC diagnosed?

Diminished levels of coagulation factors & platelets

52

Labs for DIC

Prolonged PTT & PT
Hypofibrinogenemia
Thrombocytopenia
Presence of fibrin & fibrinogen products

53

Treatment of DIC

Remove precipitating factors
Cryoprecipitate
Platelet transfusion
FFP

54

5 Types of Blood Transfusions

Whole blood
Packed RBCs
Washed RBCs
Leukoreduced RBCs
Divided or pediatric unit RBCs

55

Factors in Deciding When to Infuse

Reason for anemia
Degree & acuity/chronicity of anemia
Underlying medical condition
Anticipated future transfusions
Hemodynamic instability

56

How much does 1 unit of PRBCs raise the hematocrit & hemoglobin?

Hct: 3%
Hg: 1 g/dL

57

What does FFP not contain?

RBC
Leukocytes
Platelets

58

Indications for FFP

Coagulation factor deficiency with clinical bleeding
Need for invasive procedure

59

Indications for Platelets

Patients with thrombocytopenia due to platelet dysfunction

60

Complications with Blood Transfusions

Metabolic derangements
Immunologic reactions
Infection complications
Volume overload
Pulmonary complications

61

Most Common Metabolic Derangements with Blood Transfusions

Hypocalcemia
Hyper/hypokalemia
Hypothermia

62

When are metabolic derangements usually seen with blood transfusions?

Large volume transfused
Older blood products

63

How does hypocalcemia occur in blood transfusions?

Rapid rate of transfusion

64

Presentation of Hypocalcemia

Muscle tremors
ST prolongation
Delayed T waves
V-fib
Tachycardia

65

When does hyperkalemia occur in blood transfusions?

Units of blood frozen longer than 35 days

66

How does hypokalemia occur in blood transfusions?

After transfusion, potassium is taken up by the red cell

67

How to prevent hypothermia in blood transfusions?

Multiple transfusions
Need to be placed in a warmer

68

Types of Immunologic Reactions with Blood Transfusions

Febrile reaction
Acute & delayed hemolytic reactions
Thrombocytopenia
Anaphylactic shock
Urticaria
Graft vs. host disease
Immune suppression

69

Presentation of Febrile Reaction to Blood Products

Fever/chills
Tachycardia

70

What can you pretreat a blood transfusion with to prevent a febrile reaction?

ASA
Antipyretics
Antihistamines
*Leukocyte reduced RBCs*

71

What are hemolytic reactions generally caused by?

ABO incompatibility

72

Presentation of Hemolytic Reactions

Hot/cold flushing
Chest pain
Low back pain
Fever
Hypotension
Tachycardia
Hematuria
Acute renal failure

73

Treatment of Hemolytic Reactions

Stop transfusion
Recheck blood

74

When does a graft vs. host disease occur?

Immunosuppressed patients receive donor leukocytes

75

Presentation of Graft vs. Host Disease

Delayed reaction
Fever
Rash
Liver dysfunction
Diarrhea

76

Prevention of Graft vs. Host Disease

Leukocyte-reduced RBCs
Irradiated RBCs

77

Infectious Agents in Transfusion of Blood Products

Bacteria: usually platelets
Viruses: Hep B, Hep C, HIV
Parasites

78

Presentation of Bacteria Infection with Blood Transfusion

Fever/chills
Tachycardia
Hypotension

79

When do transfusion-related lung injuries usually occur?

Units transferred that contain plasma

80

What is transfusion-related lung injury characterized by?

Pulmonary edema

81

Treatment of Transfusion-Related Lung Injury

Supportive
Possibly intubation

82

Define Massive Transfusions

10+ PRBCs in 24 hours
Patient's total blood volume in 24 hours
1/2 patients blood volume in 1 hour

83

Complications of Massive Transfusions

Dilutional coagulopathy
Oxygen transport abnormalities
Electrolyte/acid-base derangements
Hypothermia
Disease transmission
ARDS

84

Define Autologous Blood

Collection & re-infusion of a patient's own blood

85

Collection of Autologous Blood

Pre-surgical donation
Intra-operative cell saver

86

Reasons for Autologous Blood

Fully compatible
No risk of transmission
Less dependent on blood bank
Patients with rare blood types