Lab Med Blood Disorders & Malignancy Flashcards
What are the 2 broad categories of bleeding disorders?
- Coagulopathy
2. Platelet disorder
Coagulopathies include… (4)
- intrinsic factor defect
- extrinsic factor defect
- combination defect
- hypercoagulable state (inherited or acquired)
Platelet disorders include… (2 categories, 5 disorders)
Thrombocytopenia
- -Drug Induced
- -ITP (immune thrombocytopenic purpura)
- -Heparin-Induced:Immune Mediated
Platelet Dysfxn
- -Acquired
- -Inherited
Coagulopathy vs. Platelet Disorder (amount of bleed after surface cut)
Coag: Normal to slight increased time
Plt: Excessive, prolonged
Coagulopathy vs. Platelet Disorder (onset of bleed after injury)
Coag: Delayed bleed after sx or trauma // Spontaneous bleed into joints or hematoma development
Plt: Immediate bleeding
Coagulopathy vs. Platelet Disorder (clinical presentation)
Coag: Deep & excessive bleeding into joints, muscles, GI tract, and GU
Plt: Superficial & mucosal bleeding (GI, gingival, nasal), Petechiae, ecchymosis
Initial labs for bleeding disorders
-PT/PTT
-CBC
-Platelet count – in CBC
-DIC Panel:
D-dimer
Fibrinogen
Peripheral blood smear
When looking at labs for platelet disorders you should…
- consider if it’s low count or dysfunction
- Focus on PLT count 1st – if low then we have thrombocytopenia
- If PLT disfxn - count could be normal, just not working/or inhibited fxn
When looking at labs for coagulopathy you should…
- Focus on PT and PTT values
- If one or both are elevated there is a coagulation defect.
- Think clotting cascade and coagulation factors involved.
Define thrombocytopenia
LOW PLT count < 90,000 cells/uL
What can cause low plt count?
Most Common is Drug-induced – R/o with medication reconciliation and short discontinuation of causative agent prior to procedure then resume after recovery period. (Clopidogrel, Enoxaparin, etc.)
Would would severely low platelets indicate?
ITP (immune thrombocytopenic purpura)
*exclude DIC after running a negative panel
What would delayed low platelets indicate?
Heparin-induced: Immune-mediated
- usually 4-14 days after initiated heparin treatment.
- Confirmed with LAB order = PF-4 antibodies
What plt count would you see in plt dysfunction that’s acquired?
NORMAL - PLT count 150-400 x 10,000cells/uL
What is on your diff dx for acquired plt dysfunction?
- Severe Liver Dz
- HELLP syndrome(seen in pregnancy with pregnancy-induced HTN)– Hemolysis, elevated liver enzymes, & low plts.
- Cirrhosis, End Stage Liver Dz.
- Severe Renal Dz (ARF/CRF, HUS, ESRD)
- DIC
- Aspirin use
- Multiple myeloma
What plt count would you see in plt dysfunction that’s inherited?
NORMAL - PLT count 150-400 x 10,000cells/uL
What is on your diff dx for inherited plt dysfunction?
- Bernard-Soulier Syndrome
- Glanzmann’s thrombasthenia
- Storage Pool Disease
What is the treatment for both acquired and inherited plt dysfxn?
*give them normal platelets
MEDS: Desmopressin, OCPs (oral contraceptive pills), and FFP (fresh, frozen plasma - used in severe cases when plt infusion doesn’t work) or cryoprecipitate
What 3 steps do you follow to confirm plt disorder?
1 Confirm Platelet Count in citrated blood
#2 Repeat CBC, peripheral blood smear and 1 HR post transfusion platelet count.
*Distinguish between LOW PLT PRODUCTION/pancytopenia/ small plts/or increased plt count following plt transfusion.
*AND INCREASED PLT DESTRUCTION large plts/ no significant increase in plt count post transfusion.
#3 Obtain bone marrow biopsy with cases of severe thrombocytopenia
What do you focus on for coagulation defects?
PT/PTT
What do you expect to see for intrinsic coagulation defects?
Normal PT
Elevated PTT
Dx = heparin use
*could order mixing study
What do you expect to see for extrinsic coagulation defects
Elevated PT
Normal PTT
What do you expect to see for combined coagulation defects
Elevated PT
Elevated PTT
What is a mixing study?
Lab tech mixes equal amounts of the patient’s plasma with normal value plasma and then rerunning the PT and PTT tests on the mix
What is your diff dx if after mixing study, PTT is now normal?
DIAGNOSIS:
- Factor VIII deficiency (Hemophilia A, sort of Von Willebrand)
- Factor IX deficiency (Hemophilia B)
- Factor XI deficiency (Hemophilia C)
- All intrinsic factors
- Order each of these Factor tests to confirm which deficiency.
What is your diff dx if after mixing study, PTT is still elevated?
DIAGNOSIS:
- Factor VIII inhibitor
- Factor IX inhibitor
- Factor XI inhibitor
- Order each of these Factor tests to confirm which inhibitor.
Hemophilia A is deficiency in which factor?
VIII (8)
Hemophilia B is deficiency in which factor?
IX (9)
What will occur in both hemophilia A/B after mixing study?
Both fall under Intrinsic coagulopathy, therefore initially the PTT will be elevated and then normalize after mixing study.
What is your diff dx if PT is elevated? (extrinsic coagulation defect)
-Early DIC
-Liver Disease
-Warfarin use
-Vitamin K deficiency
Confirm with empirical treatment of oral vitamin K to see PTT normalize
How do you confirm early DIC?
Confirm with Panel D-dimer, fibrinogen, blood smear (see handout)
How do you confirm liver disease?
Confirm with elevated LFTs, Hepatitis Panel (to come in GI)
How do you confirm warfarin use?
Confirm with medication reconciliation
How do you confirm vitamin K deficiency?
Confirm with empirical treatment of oral vitamin K to see PTT normalize
What is your diff dx if both PT & PTT are elevated? (combined coagulation defect)
- Heparin use (confirm with medication reconciliation)
- Severe DIC (confirm with DIC panel)
- Severe Liver Disease (confirm with elevated LFTs, Hepatitis Panel)
- Severe Vitamin K deficiency (confirm with empirical treatment of oral vitamin K to see PT normalize. Research probable cause to prevent continued deficit)
What do you order if no previous diff dx is confirmed?
Then order FACTOR LEVELS (all 3) to see which one is low…
- Factor II deficiency
- Factor V deficiency
- Factor X deficiency
- Fibrinogen < 100mg/dl
- VWD - Factor
Hypercoagulation is commonly referred to as…
Thrombophilia
Examples of inherited hypercoagulation (6)
- Most common = Factor V Leiden Deficiency
- Prothrombin 20210 mutation
- Protein C or S Deficiency
- Anti-thrombin III Deficiency
- Homocystinemia
- Fibrinolysis Defects
Examples of acquired hypercoagulation (9)
- Prolonged Rest
- Immobilization
- Smoking
- OCP
- Pregnancy
- Nephrotic Syndrome
- Cancer
- DIC
- Lupus anticoagulant
What is another hypercoagulation?
Antiphospholipid Syndrome - APS
What is APS?
Arterial or venous thrombosis or pregnancy loss and the presence of antiphospholipid antibodies
Primary APS vs. Secondary APS
Primary if alone Secondary if associated with: --SLE --Rheumatic disorders --Or infection --Or medication
Labs for APS
- Antiphospholipid Abs
- Anticardiolipin Abs
- Lupus Anticoagulant
- B2-glycoprotein I Ab
- Plus tests for inherited factors
