Perf Tech Test 7 Flashcards
Pig Mucosal Heparin
LMWH, less protamine to neutralize, but more bleeding post op cuz Xa is not reversed by protamine, lower potency
Cow Lung Heparin
HMWH, more potent, more protamine to neutralize, cheaper, more likely to develop HIT
United States Pharmacopoeia (USP) Units
1 USP unit= amount of heparin that maintains fluidity of 1 mL citrated sheep plasma for 1 hour after recalcification
British Pharmacopoeia (BP) Units
sulfated ox blood activated by thromboplastin
European Pharmacopoeia (EU) Units
decalcified sheep plasma in the presence of kaolin and cephalin incubated for 2 minutes therefore constituting an aPTT for sheep plasma
International Standard
mean of pharmacopial methods (cuz mass and potency varies)
Dosing Protocols 4
1) initial dosing- loading and in prime
2) Empiric dosing- loading dose, then give every 30 minutes (don’t check ACT)
3) Heparin-dose response curve-Bull- personalized slope of how patient reacts
4) Heparin concentration- based on how much in blood
USE with HepCon (ceiling 4.0u/ml)
ACT values
< 180 life threatening
180-300 questionable
>480 recommended
>600 unwise
Heparin Resistance
> 600 u/kg and ACT <300
HIT
Heparin Induced Thrombocytopenia
Type 1- little hit- mild reduced platelet count - will normalize even with added heparin
Type 2- HITT (and thrombosis)- immune mediated, body makes antibodies which cause platelet clots
HIT Antibody Tests
we need to test for antibodies and if active!
4T Test
thrombocytopenia, timing, thrombosis, and oTher causes of thrombocytopenia
Heparin Alternatives
- LMWH- lower affinity to platelets
- Direct Thrombin Inhibitors
1) hirudin- leeches, ecarin clot time (ECT), RENAL clearance
2) Bivalirudin/Angiomax- cleaves thrombin and itself (so no reversal), don’t let circuit sit still!, ECT/aPTT constantly!
3) Argatroban- bleed and clot at same time, LIVER clearance
RES
Reticuloendothelial System- now Mono-nuclear Phagocyte System
monocytes (intravascular)
macrophages (extra) they eat stuff (how protamine cleared)
Protamine Calculations
1) fixed dose- based on heparin given
2) Hep ACT Dose Response Curve
3) Hep concetration-takes time and estimating plasma volume
4) Protamine Titration- in OR good
