Hematologic Emergencies Flashcards
Only procoagulant not synthesized in the liver
Von Willebrands Factor (vWF)
Extrinsic Pathway
Tissue Factor - III
VII
Triggered by Tissue Damage
Measure via PT
Intrinsic Pathway
XII
XI
IX
VIII
Measure with PTT
Common Pathway
X
V
II (prothrombin)
I (fibrinogen)
X is activated by both Extrinsic and Intrinsic pathways to cause fibrin clot formation
Only factor deficiency that doesn’t cause coagulopathy
Factor XII
Platelet Count
Normal is 150,000-400,000
If abnormal get smear
Low platelets may be caused by: Lasix, NSAIDs, sulfonamides, PCN, Autoimmune disease
Prothrombin Time
Used to monitor Warfarin (INR)
Normal uncoagulated INR: 0.8-1.2
Evaluates VII (extrinsic), X, V, prothrombin, fibrinogen
Partial Thromboplastin Time (PTT)
Monitor unfractionated Heparin therapy - also Warfarin
Not effective monitor for LMWH
Evaluates fibrinogen, prothrombin, V, VIII, IX, X, XI, XII (intrinsic and common pathway)
Thrombin Time
Fibrinogen to fibrin conversion with abundant thrombin time
Prolonged: low/abnormal fibrinogen, low split products, Heparin
Used to check for DIC and chronic liver disease
Von Willebrand Disease
Most common congenital bleeding disorder
Reduced VIII and vWF activity
vWF binds to factor VIII to prevent degradation
Mucocutaneous bleed
Prolonged PTT and abnormal platelet function
PT normal
Treat with Cryoprecipitate infusion or Desmopressin (DDAVP)
Hemophilia
Reduced/absent factor VIII/IX activity
Males only
Joint or intramuscular bleed - swollen and painful
Bleeding from tissues, urinary, CNS - Internal bleed is biggest risk
No petechiae or ecchymosis
Prolonged PTT, normal PT and platelet function
Tx: Purified factor VIII/IX products
Liver Disease Acquired Bleeding Disorder
Most common - no protein synthesis
Results in low prothrombin, V, VII, X
Obstructive jaundice and cirrhosis may also cause these
-Will respond well to Vitamin K
Warfarin
Effects II, VII, IX, X
Reverse with FFP or Vitamin K in a hurry
Heparin
Increases antithrombin III
Neutralizes IXa, Xa, XIIa and thrombin
Prolonged PTT and thrombin time
Often given during vascular surgery
Reverse with protamine sulfate
Vitamin K-Dependent Factors
VII
X
Prothrombin (II)
Coagulation Termination
Antithrombin (antithrombin III): neutralizes thrombin; heparin-like prevention of thrombus formation on endothelium
Tissue factor pathway inhibitor
Clotting-initiated inhibitory process - Protein C pathway
Protein C and S
Plasma proteins
C: acts as anticoagulant protein - inactivates factors V and VIII
S: breaks down fibrin into degradation products which act as anticoagulants
Signs of Anemia/Bleeding
Palpitations
Dizziness
Orthostatic HOTN
Exertional Intolerance
Tinnitus
Secondary Hemostasis Disorders
Coagulation factor issues
Intrinsic: Hemophilia A&B, vWF
Extrinsic: Vitamin K deficiency
3 Stages of Hemostasis
- Vasospasm
- Neutrophils migrate to site
- Platelets migrate to site, make sticky by vWf
Vitamin K Deficiency
Common in Alcoholics, liver disease, malabsorption, poor diet, long-term abx use
PT/PTT prolonged, PT more so
Decreased factors II, VII, IX, X and Proteins C&S
Treat: Vitamin K supplementation - doesn’t work with liver disease (liver doesn’t respond)
Idiopathic Thrombocytopenia Purpura (ITP)
Antibodies bind to platelets and cause them to be cleared by spleen - no splenomegaly
Kids - often after viral infection; adults - transfusion, IVDA, Graves
Bruising, petechiae, purpura, epistaxis, retinal hemorrhage
Tx w/ platelets <50k or if bleeding - prednisone
Secondary ITP Causes
Drugs: Sulfa, Thiazide, Cimetidien, Heparin
SLE
AI disease
Hepatitis
HIV
Thrombotic Thrombocytopenic Purpura (TTP)
Abnormal activation of platelets nd endothelial cells with clot formation in microvascular and peripheral destruction of platelets and rbcs
Pentad: hemolytic anemia, thrombocytopenia, renal, neurologic, fever
Commonly in young females - pregnancy, drugs, infections, estrogen use
Treatment: plasma exchange; never transfuse w/ platelets, only makes it worse
Hemolytic Uremic Syndrome (HUS)
Lacks the neurologic and fever of TTP
Diarrhea - e.coli/Shigella; often in kids
Renal failure, hemolytic anemia, thrombocytopenia
TTP/HUS from DIC
Coags are normal with TTP/HUS
Disseminated Intravascular Coagulation (DIC)
Both bleeding and thrombosis - bleeding MC
Digital ischemia/gangrene, renal necrosis, CNS and respiratory failure with shock and widespread bleeding
PT, PTT prolonged; positive D-dimer; low coagulation inhibitors (C) and coagulation factors as well as fibrinogen levels
Tx: correct cause, hemodynamic support with transfusions
Anemia Murmur
Systolic murmur
Heart is having to work harder to pump - causes rapid flow with higher cardiac output and circulatory overload
Not a true murmur, just increased volume coming through
Heart has to work harder due to lack of oxygen
Factor V Leiden Deficiency
MC clotting deficiency
Causes strokes, PE, pathologic clotting (DVT)
Factor V resistant to breakdown by activated protein C
