Antifibrinolytics, Protamine, and DDAVP Flashcards
antifibrinolytics MOA
prevent the lysis of fibrin, promotes clot formation, interfere with formation of plasmin
two types of antifbrinolytics
lysine analogs ( tranexamic acid, Amicar) serine protease inhibitor (aprotinin)
Amicar PEARLS
inhibits the proteolytic enzyme plasmin in trauma, CPB, and spinal fusions
bolus: 5-15 mg
infusion: 1-2g/hr
TXA PEARLS
inhibits fibrinolysis by competitively binding to the lysine receptor sites on plasminogen preventing plasmin from binding to and degrading fibrin
for non cerebral trauma, spine fusion, craniosynostosis, ortho cases, cardiac cases, obstetrics
TXA dosing
10-15 mg/kg IV up to 1 gram, infusion 1-5 mg/kg/hr
TXA contraindications and precautions
active intravascular clotting (PE, DVT), anaphylaxis, subarachnoid hemorrhage
UTI, hypotension, color vision defect, seizures, impaired renal function
Protamine MOA
positively charged alkaline protamine combines with the negatively charged acidic heparin to form a stable complex void of anticoagulant activity
protamine dose
1-1.5 mg for every 100 units of heparin
guided by last ACT and estimated amount of total heparin administered within the last 2 hours
protamine adverse responses
hypotension (rapid IV push), pulmonary HTN, allergic reaction
what is the concern with allergic reaction with protamine?
limited options for treatment of true allergy
patients at risk for true protamine allergy
prior reaction, allergy to vertebrae fish (salmon), exposure to NPH insulin, allergy to any drug
DDAVP MOA
causes release of endogenous store of factor VIII and von willebrand
DDAVP dose
0.3 mcg/kg IV infusion over 15-30 mins
platelet adhesion increases within 30 minutes
DDAVP contraindications
hypersensitivity, moderate to severe renal impairment, hyponatremia (overuse can lead to water retention and dilutional hyponatremia and convulsions)
