Equine Med- Hemolymphatic 2

wilsbach's version from 2016-04-10 15:49

Platelet disorders/ clotting

Question Answer
what is primary hemostasis? Interaction between vessel wall and platelets → Hemostatic plug
explain how primary hemostasis happens/ what things play a role in thisInitial injury → Subendothelial collagen exposed → Platelets adhere.... vWF, membrane glycoproteins, Adenosine diphosphate, catecholamines, serotonin, Thromboxane A2 <--these all play a role in the cascade for 1* hemostasis
explain how 2* hemostasis happens/ what things play a role in thisStabilizes hemostatic plug. Mediated by coagulation factors.
which coag factor isnt produced in the liver?VIII
what are the vitamin K dependant clotting factors?II, VII, IX, X....and protein C
what electrolyte is needed for coagulation?Ca++
what is the intrinsic path started? Extrinsic?Intrinsic: initiated by contact of Factor XII with collagen. Extrinsic: requires tissue factor activation
3 tests you can use to test primary hemostasis? (what exactly is it looking at?)(1) Platelet enumeration (count platelets) (2) bleeding time ( vascular integrity) (3)clot retraction (platelet number and function)
4 tests you can use to test secondary hemostasis (what is measured with it?)(1) ACT (tests intrinsic and common paths: XII XI IX VIII X V II and fibrinogen) (2) PTT: same as activated clotting but more sensitive. (3) PT: Extrinsic and common pathways: III (tissue factor), VII, X, V, II and fibrinogen (4) TT: terminal common pathway: fibrinogen quality and quanitity
which test tests the fibrinogen quantity and quality?TT
common pathway factors?X, V, II and fibrinogen
extrinsic pathway factors?III (tissue factor), VII
intrinsic pathway factorsXII XI IX VIII
It's important to keep an eye on coag tests with horses, if they are endotoxic or are having a systemic inflammatory response, their coag state can be ...hypercoagulable (pre-DIC basically)
what are FDP's and what do they tell us? What would it mean if you see an inc in these?fibrin degradation products- they tell is if there is fibrinolysis. You will see an inc of these in DIC, severe inflammation, hemorrhagic disorders, excess intravascular fibrin deposition
what is antithrombin? What are situations where you'd see an inc or dec of this?Antithrombin is an inhibitor of coagulation. DECrEASE: DIC, PLE, PLN, production failure (liver). INCREASE: hepatic disease and inflammatory reactions
Primary hemostatic disorders are a problem with _________, and what clinical signs do you see?Prob with platelets. You will see PETECHIATION (busted BVs which havent been plugged up), especially on the mucous membranes. You will also see prolonged bleeding times (a 1* hemostasis test-- i think this is aka BMBT) when they are at less than 40,000 platelets
Secondary hemostatic disorders are a problem with _________, and what clinical signs do you see?prob with coag factors. You will see CSs like Hematomas (esp at venipuncture sites) (platelets are there so there is a wad of blood at the site, it wants to be a proper clot but cant so just adds MORE platelets and blood...hence hematoma), also see localized bleeding
explain primary cause versus secondary cause of immune mediated thrombocytopeniaPrimary is when there are antiplatelet antibodies. Secondary can happen because of infectious, neoplasia, drug reaction, toxic causes which make confused Abs which attack the platelets.
In immune mediated thrombocytopenia, what are platelet levels, OSPT, APTT, and FDPs like?everything is normal except platelet levels are low
how do you diagnose immune mediated thrombocytopenia?flow cytometry
how do you treat IMTP? What if they're bleeding actively?(1) treat underlying issue if you can find it (2) IMMUNOSUPPRESSION: dexamethasone (0.1mg/kg IV or IM, taper once at 100,000 cells), or azothioprine. (3) if bleeding: Platelet rich plasma or transfuse
what is the thing horses are more likely to eat than warfarin which works the same way?mouldy sweet clover
how does moldy sweet clover/warfarin work? So how do you tx it then?Blocks Vitamin K dependant clotting factors (2,7,9,10, protein C)-- so provide vitamin K and plasma to tx
Hemophilia A-- WHO gets this? how? what factor is this disorder about?Inherited (inbreeding, autosomal recessive), it is a deficiency in factor 8 and is in MALES ONLY!! (factor 8 is intrinsic)
3 inherited 2* hemostasis clotting disorders?Hemophilia A, vWF deficiency, Prekallikrein deficiency
what is Prekallikrein deficiency? Who gets this?secondary clotting disorder which happens in belgians and minis
DIC is a primary and secondary clotting problem. What is happening in DIC, and what are the clinical signs?It is a Systemic thrombo-hemorrhagic disorder which can be triggered due to many diseases. CSs: Petechial or ecchymotic hemorrhages, Bleeding (venipuncture sites, epistaxis), Microthrombi (renal, thrombophlebitis, laminitis)
what will platelet be like with DIC?thrombocytopenia
how many abnormal coag tests might tell you it is DIC? (in what way might the tests be abnormal)3 out of 6. PT prolonged, APTT prolonged, TT prolonged, FDPs - increased, Fibrinogen - decreased (used up), Antithrombin - decreased
4 things you can try to use to tx DIC?(1) NSAIDS-flunixin meglumine (2) heparin- This is controversial!! consider Unfractionated vs low molecular weight heparin ($$$) (3) aspirin (4) whole blood or plasma
Snake envenomation causes what kinda problems?Local tissue damage, coagulopathies (1* and 2*) & cardiopulmonary effects-- LOOK OUT FOR UPPER AIRWAY OBSTRUCTION. Coag dysfunction can appear as Bleeding from venipuncture and nares, Thrombocytopenia, Prolonged PT/APTT. Can also see acute hemolytic anemia. And Cardiac arrhythmias/colic/laminitis
How do you go about tx snake envenomation? (what do you do FIRST? what drugs can you consider? How should the horse be positioned?)#1 IS ESTABLISH THE AIRWAY (swelling is not your friend), provide fluids/ fresh whole blood. You can consider antivenin but its super expensive but not research in horses and also prolly dont know what kinda snake bit them. Can give NSAIDs, furosemide, (antimicrobials?), tetanus toxoid.... KEEP HEAD ELEVATED
what type of neoplasia can you find in the mediastinum of older horses, and what are the usual clinical signs you will see?THYMIC/MEDIASTINAL LYMPHOSARCOMA. It is generally associated with RESPIRATORY signs: pleural effusion, ventral edema, Regional lymphadenopathy, choke, Laryngeal hemiplegia