Hemostasis, Surgical Bleeding, & Transfusions Flashcards Preview

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

Define Hemostatic Process

A

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

2
Q

Initial Hemostasis Activity After Injury

A

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
Q

Coagulation Pathway

A

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
Q

Deficiency of what factors causes bleeding?

A

Any EXCEPT XII

5
Q

What can reduce the effectiveness of clotting?

A

Hypocalcemia

6
Q

Evaluation of a Bleeding Patient

A

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

7
Q

Signs of a Bleeding Disorder

A
Splenomegaly
Hepatomegaly
Bleeding after dental procedures
Menses
Minor cuts
Family history of bleeding
8
Q

What does a platelet count verify?

A

An adequate number of platelets are available in the circulation

9
Q

What is a normal platelet value?

A

150,000-400,000

10
Q

What are some reasons for low platelets?

A

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

11
Q

What does prothrombin time measure?

A

Ability of the blood to form stable thrombi

Extrinsic & common pathway

12
Q

When is a PT normally ordered?

A

Monitor warfarin

13
Q

Define INR

A

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

14
Q

What does a partial thromboplastin time (PTT) measure?

A

Adequacy of intrinsic & common pathways

15
Q

When is PTT most commonly used?

A

Unfractionated heparin therapy

16
Q

Define Bleeding Time

A

Time from injury to cessation of bleeding

17
Q

What may a prolonged bleeding time indicate?

A

Thrombocytopenia
Medication (ASA)
Von Willebrand disease

18
Q

What does thrombin time evaluate?

A

Fibrinogen to fibrin conversion with an external source of thrombin

19
Q

What may a prolonged thrombin time indicate?

A
Low fibrinogen levels
Abnormal fibrinogen
Fibrin & fibrinogen split products
Heparin
Blood or coagulation disorders
DIC Chronic liver disease
20
Q

Von Willebrand’s Disease Pathophysiology

A

Reduced factor VII activity & von Willebrand activity

21
Q

Main Site of Bleeding for Von Willebrand’s Disease

A

Mucocutaneous

22
Q

Lab Results for Von Willebrand Disease

A

Prolonged PTT
Normal PT
Abnormal platelet function

23
Q

Treatment of Von Willebrand Disease

A

Cryoprecipitate infusions

Desmopressin (DDAVP)

24
Q

Pathophysiology of Hemophilia A

A

Reduced or absent factor VII activity

25
Q

Main Sites of Bleeding for Hemophilia A

A

Joints

Intramuscular

26
Q

Lab Results of Hemophilia A

A

Prolonged PTT
Normal PT
Normal platelet function

27
Q

Treatment of Hemophilia A

A

Purified factor VII products

28
Q

Common People who get Hemophilia A

A

Males

29
Q

Causes of Acquired Bleeding Disorders

A
Advanced liver disease
Anticoagulation therapy
Acquired thrombocytopenia
Platelet-inhibiting drugs
Uremia
30
Q

Liver Disease as an Acquired Bleeding Disorder

A

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

31
Q

What liver disorders may lead to clotting factor deficiencies?

A

Obstructive jaundice

Cirrhosis

32
Q

Anticoagulation Therapy

A

Warfarin (Coumadin)

Heparin

33
Q

MOA of Warfarin (Coumadin)

A

Depression of clotting factors II, VII, IX, X

34
Q

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

A

FFP

Vitamin K

35
Q

MOA of Heparin

A

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

36
Q

Lab Results on Heparin

A

Prolonged PTT

Prolonged thrombin time

37
Q

How is heparin reversed?

A

Protamine sulfate

38
Q

3 Mechanisms of Acquired Thrombocytopenia

A

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

39
Q

Examples of Acquired Thrombocytopenia

A
ITP
DIC
Aplastic anemia
Cirrhosis
Platelets destroyed during surgery
Cell saver
40
Q

Platelet-Inhibiting Drugs

A

ASA
Clopidogrel (Plavix)
NSAIDs

41
Q

Medication-Associated Bleeding

A

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

42
Q

How is intra-operative bleeding controlled?

A

Gelfoam
Surgicel
Floseal
Tisseel

43
Q

Reasons for Post-Op Bleeding During Surgery

A
Poor hemostasis
Residual heparin
Shock
Altered liver function
Malnutrition
44
Q

Classification of Post-Op Bleeding

A

Primary
Reactive
Secondary

45
Q

Post-Op Bleeding: Primary

A

Occurs during operation

Monitor with drains post-op

46
Q

Post-Op Bleeding: Reactive

A

Occurs within 24 hours of operation

Hemorrhage-like reaction

47
Q

Post-Op Bleeding: Secondary

A

7-10 days post procedure

Erosion of the blood vessels: usually due to infection

48
Q

Define DIC

A

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

49
Q

What does DIC result in?

A

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

50
Q

Etiology of DIC

A
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
Q

How is DIC diagnosed?

A

Diminished levels of coagulation factors & platelets

52
Q

Labs for DIC

A

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

53
Q

Treatment of DIC

A

Remove precipitating factors
Cryoprecipitate
Platelet transfusion
FFP

54
Q

5 Types of Blood Transfusions

A
Whole blood
Packed RBCs
Washed RBCs
Leukoreduced RBCs
Divided or pediatric unit RBCs
55
Q

Factors in Deciding When to Infuse

A
Reason for anemia
Degree & acuity/chronicity of anemia
Underlying medical condition
Anticipated future transfusions
Hemodynamic instability
56
Q

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

A

Hct: 3%
Hg: 1 g/dL

57
Q

What does FFP not contain?

A

RBC
Leukocytes
Platelets

58
Q

Indications for FFP

A

Coagulation factor deficiency with clinical bleeding

Need for invasive procedure

59
Q

Indications for Platelets

A

Patients with thrombocytopenia due to platelet dysfunction

60
Q

Complications with Blood Transfusions

A
Metabolic derangements
Immunologic reactions
Infection complications
Volume overload
Pulmonary complications
61
Q

Most Common Metabolic Derangements with Blood Transfusions

A

Hypocalcemia
Hyper/hypokalemia
Hypothermia

62
Q

When are metabolic derangements usually seen with blood transfusions?

A

Large volume transfused

Older blood products

63
Q

How does hypocalcemia occur in blood transfusions?

A

Rapid rate of transfusion

64
Q

Presentation of Hypocalcemia

A
Muscle tremors
ST prolongation
Delayed T waves
V-fib
Tachycardia
65
Q

When does hyperkalemia occur in blood transfusions?

A

Units of blood frozen longer than 35 days

66
Q

How does hypokalemia occur in blood transfusions?

A

After transfusion, potassium is taken up by the red cell

67
Q

How to prevent hypothermia in blood transfusions?

A

Multiple transfusions

Need to be placed in a warmer

68
Q

Types of Immunologic Reactions with Blood Transfusions

A
Febrile reaction
Acute & delayed hemolytic reactions
Thrombocytopenia
Anaphylactic shock
Urticaria
Graft vs. host disease
Immune suppression
69
Q

Presentation of Febrile Reaction to Blood Products

A

Fever/chills

Tachycardia

70
Q

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

A

ASA
Antipyretics
Antihistamines
Leukocyte reduced RBCs

71
Q

What are hemolytic reactions generally caused by?

A

ABO incompatibility

72
Q

Presentation of Hemolytic Reactions

A
Hot/cold flushing
Chest pain
Low back pain
Fever
Hypotension
Tachycardia
Hematuria
Acute renal failure
73
Q

Treatment of Hemolytic Reactions

A

Stop transfusion

Recheck blood

74
Q

When does a graft vs. host disease occur?

A

Immunosuppressed patients receive donor leukocytes

75
Q

Presentation of Graft vs. Host Disease

A
Delayed reaction
Fever
Rash
Liver dysfunction
Diarrhea
76
Q

Prevention of Graft vs. Host Disease

A

Leukocyte-reduced RBCs

Irradiated RBCs

77
Q

Infectious Agents in Transfusion of Blood Products

A

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

78
Q

Presentation of Bacteria Infection with Blood Transfusion

A

Fever/chills
Tachycardia
Hypotension

79
Q

When do transfusion-related lung injuries usually occur?

A

Units transferred that contain plasma

80
Q

What is transfusion-related lung injury characterized by?

A

Pulmonary edema

81
Q

Treatment of Transfusion-Related Lung Injury

A

Supportive

Possibly intubation

82
Q

Define Massive Transfusions

A

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

83
Q

Complications of Massive Transfusions

A
Dilutional coagulopathy
Oxygen transport abnormalities
Electrolyte/acid-base derangements
Hypothermia
Disease transmission
ARDS
84
Q

Define Autologous Blood

A

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

85
Q

Collection of Autologous Blood

A

Pre-surgical donation

Intra-operative cell saver

86
Q

Reasons for Autologous Blood

A

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