1. Platelet bleeding is nuisance bleeding- immediate bleed, petechiae, nosebleeds, menorrhagia, rarely requires transfusions, rarely life threatening
2. Clotting factor bleed is delayed bleed (i.e. at dentist, initially you don't bleed but you do later)
3. Bleeding time (platelet function)
- BP cuff on arm, blow it above venous pressure
- Cut a few mm on volar surface of arm, every 15 seconds dab blood with filter paper. Stop the clock when the filter paper stops absorbing blood. Normal = 2-8 minutes.
- Won't run if platelet <50K; even with PFA-100, you expect worse function with lower counts
4. ITP
- Larger platelets, sort of like retics
- Can have low platelets, but normal clinical appearance
- Typically low numbers imply poor function, but these people may have normal function and thus be fine with procedures, so its good to run PFA-100/bleed time
5. Causes of platelet dysfunction (congenital)
- vWF - platelet dysfunction AND low factor VIII (20-30% of function) but not low enough to have clinically significant hemophilia-like picture (hemophiliacs have 0-1% of factor VIII function)
- Can treat vWF with intranasal DDAVP - useful in young women with very heavy periods because of vWF
- Others (rare): glanzmann's, storage pool disease.
6. Causes of platelet dysfunction (acquired) 
- Uremia (although this is plus minus)
- Aspirin (pepto-bismol is a salicylate, sominex has a salicylate, many cough/cold medicines, alka-seltzer is aspirin with antacid). Effect of aspirin lasts as long as the platelet (most platelets have a 9-10 day lifespan, but given different ages of platelets in your blood, real effect is probably around 5 days.
- Drugs: NSAIDs, guaifenasin, 3rd generation penicilins: ticaricillin, piperacillin, 3rd generation cephalosporins
- Myeloproliferative disorders (p. vera, essential thrombocythemia)- lots of platelets that don't work
- Myeloma- abnl protiens made by myeloma coats platelets and affects function
7. Isolated prolonged PTT
- Deficiency: 8, 9, 11, 12-- Factor 12 def are not associated with bleeding, 11 is (rare) and 8 and 9 are.
- Inhibitor - iatrogenic (drawing blood above a heparin drip, backflow from a citrated/heparainated tube into your syringe that gets pushed into another tube) vs true (see below)
- Differentiate between the two: mixing study. If you mix pt's plasma with normal, if it works then you know its a deficiency; if it doesn't, there's a deficiency.
8. Inhibitor: 
- lupus anticoagulant (not associated with bleeding)
- acquired factor inhibitors-- acquired factor 8 inhibitors as a sequelae of drugs or viral illnesses, has high mortality rate. Tx with immunosuppressants (steroids, rituximab, cyclophosphamide to block generation of inhibiting antibody) and give activated recombinant factor 7 to stop the bleeding.
9. Isolated prolonged INR
- likely vit K deficiency from antibiotics or decreased nutrition
- Transfuse FFP - as close to surgery as you can as the factors begin degrading immediately.
- Factor VII - half life around 6 hours
- In someone on warfarin, all drugs interact with it so any new drugs means you have to monitor the INR again
- Generally all antibiotics will prolong INR just because of gut flora effects
- Be careful of rapid correction with vitamin K if you overshoot the INR; if someone has an INR of 5-6, 2.5 mg of vit K PO will bring someone down to a safer level, at which point you can readjust the warfarin. But if someone is slightly high, don't go crazy with the vitamin K because if you overcorrect they may clot off whatever you were trying to keep from clotting off with the warfarin in the first place.
10. Vitamin K
- NOT IM don't give people with coagulopathy IM injection; they may get site hematomas that lead to neuropathy etc
- IV, SubQ, PO
- Takes around 24 hrs to work