hemo exam 7 Flashcards
acquired vascular 1* hemostasis defects
vasculitis, collagen deficiency, extensive vascular injury
vasculitis is
no vasoconstriction, usually symptom of something
what happens with collagen deficiency
no collagen to trigger 1*
what happens with vascular injury
burn or road rash, vessels damaged, impede vasoconstriction
inherited 1* hemostasis defects
von Willebrands disease
what happens with von Willebrand’s disease?
its not being produced by the endothelium and factor VIII
most common inherited bleeding disorder of dogs
von Willebrand’s disease
1* hemostasis platelet plug hemostasis defects are caused by either
number(thrombocytopenia) or function
1 bleeding disorder of dogs
thrombocytopenia
causes of thrombocytopenia
increase destruction, increased consumption, decreased production
reasons for increased destruction of platelets
ITP
reasons for increase consumption of platelets
DIC
reasons for decreased production of platelets
bone marrow reasons
platelets plug function issues include
thrombopathia, thrombocytopathy
what happens during platelet plug function defects
there’s no adhesion, aggregation, secretion
what causes function defects in the platelet plug
drugs, DIC, uremia (platelets cannot stick)
hereditary causes of function defects in the platelet plug
vWB dz, basset hound thrombopathy, epistaxis in simmental, Chediak-Hagashi, thromblasthenic thrombopathia
how does vWB dz effect function of platelet plug
platelets fail to adhere to subendothelial collagen
clinical signs of 1* hemostasis defects
petechia, ecchymosis, bleeding from the MM, bleeding out after venipuncture
acquired secondary hemostasis defects causes
Vit-K deficiency,Liver disease/failure, DIC,
example of what can cause vit-k deficiency
warfrin poisoning
DIC can be caused by
2* heat stroke, viremia, endotoxemia, massive necrosis, trauma, septicemia, IV hemolysis, consumption of hemolysis factors and hemorrahage
hereditary causes of 2* hemostasis defects
hemophilias, vWB dz
with vWB disease lack
von Willebrand factor and factor 8
clinical signs of 2* hemostasis defects
hematoma, bleeding into muscle, joints, and body cavity, delayed bleeding after venapuncture*
causes of acquired fibrinolysis defects
liver failure, DIC
how does liver failure cause fibrinolysis defects
can’t clear FDPS
DIC mechanism
2, excessive activation, consumption, excessive FDPs, organ failure, signs or both 1 and 2*
thromboembolic disorder
clot forms then travels and lodges somewhere else
causes of thromboembolic disorder
roughened endothelium, protein C deficiency, Nephrotic syndrome
causes of roughened endothelium
cardiomyopathy, HWD dogs, IVC in AIHA
how does protein c deficiency cause thrombolytic disorder
down regulated firbrinolysis( activated PC hydrolyzes plasminogen activator inhibitor)
how does nephrotic syndrome cause thrombolytic disorder
loss of antithrombin III
In house tests for bleeding disorders (4)
platelet estimate, platelet count, BMBT, ACT
platelet estimate evaluates
1* hemostasis, platelet number
platelet count evaluates
1* hemostasis, platelet number
BMBT stands for
buccal mucosal bleeding time
BMBT method
dab filter paper every 10 seconds until bleeding stops
Normal BMBT in cats and dogs
1-3
BMBT evaluates
1* hemostasis interaction of platelets and the vascular system
best test for platelet dysfunction
BMBT
ACT stands for
activated clotting time
ACT method
fill DET tube, mix set timer, check every 5-10 minutes for clots, stop timer when clot forms
normal ACT time dogs
60-90 sec
normal ACT time cats
<65 seconds
ACT evaluates
2* hemostasis, intrinsic and common pathways
best in house screening test for all 2* defects
ACT
PTT stands for
partial thromboplastin time
PTT evaluates
2* hemostasis intrinsic and common pathway
PT stands for
prothrombin time
PT evaluates
2* hemostasis extrinsic and common pathway
best test for Warfrin toxicity
PT
How does PTT test for warfrin toxicity
isolation of vit K dependent factor 7
VWF test evaluates
1* and 2* hemostasis VWF and VIII
TT stands for
thrombrin time
TT detects
decrease in fibrinogen and thrombin inhibition by FDP’s
FDP test evaluates
decreases in fibrinogen thrombin inhibition by FDP
D-Dimers is a type of
FDP
D-Dimer test for
very specificFDP that shows up after fibrinolysis
order of tubes
RT, LT, BT
steps to venpuncture for coag studies
blood draw before TX, atraumatic, multiple vacutainer
why atraumatic venipuncture
to avoid introduction of tissue thromboplastin
why make blood films immediately to evaluate 1* hemostasis
because platelets aggregate and dissolve in old samples
platelet count must be done within
4 hours
tubes for evaluating 1* hemostasis
LTT, BTT
BTT full for what test
VWD factor assay
tubes for 2* hemostasis test
DET, BTT, RTT
DET for evaluation of
intrinsic and common
BTT for evaluation of
intrinsic, extrinsic, common
RTT for evaluation of
liver function
BTT test has to be run within
6 hours
symptoms of marrow failure (4)
non-regenerative anemia, unexplained leukopenia, unexplained thrombocytopenia, abnormal/ immature cells in peripheral blood
indications for bone marrow sampling
marrow failure, tumor
types of bone marrow samplings
bone marrow aspirate bone marrow core biopsy
bone marrow aspirates provides
cytology sample
bone marrow core biopsy provides
cytology and histology sample
syringe used for bone marrow sampling
12cc
anticoag used for bone marrow sampling
EDTA
preservative for histology
10% neutral buffered fromalin
needles for bone marrow cytology
rosenthal, illinois sternal iliac
needle used for bone marrow core biopsy
jamshidi
sites for collect bone marrow sample
proximal humerus, proximal femur, crest and wing of ilium, sternum and dorsal ends of ribs
