Hemostasis, Surgical Bleeding, & Transfusions Flashcards Preview

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