Hemostasis, Bleeding and Transfusions

Question 1

Coagulation pathway

Answer 1

Extrinsic coagulation pathway:
Begins with thromboplastin
Interacts with factor VII to convert factor X to Xa
Intrinsic coagulation pathway:
Requires factors XII, XI, IX, and VIII to convert factor X to Xa
Common coagulation pathway:
Involves factor X, V, II (prothrombin), and I (fibrinogen)
Factor XIII (fibrin-stabilizing factor)

Bleeding may occur with deficiency of any factors except factor XII

Question 2

Prothrombin Time

Answer 2

Measures ability of the blood to form stable thrombi
Evaluates factors VII, X, and V, prothrombin, and fibrinogen, and both extrinsic and common pathways
Most common use is monitoring Warfarin
PT is reported with international normalized ratio (INR)

Question 3

Partial Thromboplastin Time

Answer 3

Evaluates adequacy of fibrinogen, prothrombin, factors V, VIII, IX, X, XI, XII, and intrinsic/common pathways
Most commonly used to evaluate unfractionated heparin therapy
Normal in patients with factor VII deficiency

Question 4

Hemophilia A

Answer 4

Reduced Factor 8
Joints and intramuscular
Only males
Labs:
Prolonged PTT
Normal PT
Normal platelet function

Question 5

Von Willebrand Disease

Answer 5

Reduced Factor 8 and von Willebrand Activity

Treat with cryoprecipitate infusions and DDAVP

Question 6

DIC

Answer 6

Intravascular coagulation and thrombosis that is diffuse instead of localized at the site of injury
Results in systemic deposition of platelet-fibrin microthrombi that causes diffuse tissue injury
Extensive endothelial damage to vascular wall
Hypotension

Question 7

FFP

Answer 7

FFP is the platelet-poor plasma removed from whole blood
Does not contain RBC, leukocytes, or platelets
Indication for use: Lab evidence of coagulation factor deficiency with clinical bleeding, Need for invasive procedure

Question 8

Metabolic derangements as a complicaiton from blood transfusion

Answer 8

Hypocalcemia
Hyper and Hypokalemia
hypothermia (transfuse fluids through a warmer)

Question 9

Hemolytic reactions

Answer 9

Most caused by ABO-mismatched blood
Present with;
Hot or cold flushing
Chest pain
Low back pain
Fever
hypotension
Stop transfusion and recheck blood