Iron deficiency anemia RBC lab values
Microcytic, hypochromic anemia with an elevated RDW
Anemia of chronic disease or thalassemia RDW
Problems with protoporphyrin that prevents Fe release from the mitochondria. Most common acquired = alcohol.
When do you see a high RDW?
Folate/B12 deficiency anemias, iron-deficiency anemia or recent hemorrhage.
Platelet count in an acute bacterial infection?
High. Thrombocytosis is apart of the acute phase response to a bacterial infection.
Causes of bleeding from platelet dysfunction with normal PT, APTT.
vWF deficiency and uremia from kidney disease.
How do you diagnose a platelet dysfunction.
Make a nick under the forearm and measure how long it takes to stop bleeding.
Deficiency in GpIIb-IIIa that prevents cross-linking of fibrinogen between platelets
Deficiency in GpIb that prevents binding of vWF to platelet
Bleeding disorders that present with normal PT, aPTT and platelets.
Steroid use, scurvy, alpha-2 antiplasmin deficiency
Differential for elevated PT, normal aPTT and normal platelets
Vitamin K deficiency (nutritional deficiency or Coumadin/Warfarin), acquired factor VII deficiency, liver disease.
What happens to the PT and aPTT in early liver disease?
You may only see an elevation in PT because factor VII has a shorter half life.
Differential for normal PT, elevated aPTT, normal platelets.
Hemophilia A/B, factor XI deficiency, heparin (activates ATIII), late liver disease, lupus anticoagulant (presents w/o bleeding).
What is lupus anticoagulant? Why does it extend the aPTT?
Anti-phospholipid antibody that binds to proteins associated with phospholipids. This antibody blocks the phospholipid that is added to activate the aPTT. Their clotting is normal.
Differential for elevated PT, elevated aPTT and normal platelets.
End-stage liver disease, vitamin K and inherited deficiencies in V, X, I or II.
Differential for elevated PT, aPTT and decreased platelets.
End-stage liver disease or DIC.
What often accounts for elevated PT and aPTT in post-surgical patients?
Vitamin K deficiency
What will happen to a patient’s aPTT when you do the correction study if they have Lupus?
It will not correct because the anti-phospholipid antibody will not be corrected by simply adding more factors.
aPTT test corrects when patients have lupus anticoagulant