Platelets and Coagulation Flashcards
(47 cards)
Describe the platelet number in general terms?
Formula for platelet # estimation.
Average # platelets in 10 fields x 20,000= #/uL
What two dog breeds usually have lower platelets numbers?
greyhounds
Cavalier King Charles spaniels
Describes the levels of platelets for mild, moderate, severe thrombocytopenia?
- Mild® 80,000-100,000/uL (marrow dz or consumption)
- Moderate® 40,000-80,000/uL (marrow dz/consumption)
- severe® <20,000-30,000/uL (marrow dz or destruction)
What is the main clinical sign of thrombocytopenia?
subcuntaneous/mucosal bleeding
What are the main classification of the causes of thrombocytopenia?
- peripheral
a. increased destruction
b. increased consumption
c. abnormal distribution - Bone marrow problem: decreased production
If an equine has thrombocytopenia and a bone marrow aspirate was taken, what is the likely diagnosis?
neoplasia
What does the picture show? What is it an appropriate response to?
Megakaryocytic hyperplasia-appropiate response to thrombocytopenia
What hematology abnormality does bracken fern posioning in cattle cause?
thrombocytopenia- disrupt production in the bone marrow
What infection causes cyclic thrombocytopenia and is known to infect platelets?
Anaplasma platys
A patient comes in 3-10days after being vaccinated with a modifed-live vaccine for surgery. What hematology index will be low? Should we pocede with surgery?
thrombocytopenia- wait more than 2 weeks to do surery
What is the inclusion?
A dog presents with thrombocytosis and the blood film below. What is the likely cause?
neoplasia (tumor in platelet)- may be primary thrombocytosis from neoplastic disease
What are the secondary causes of thrombocytosis?
- Iron-deficiency anemia; blood loss iron deficiency anemia
- Hypercortisolemia
- Inflammation® typically chronic
- Vinca alkaloids
- Post-splenectomy
- Rebound:
- after severe acute hemorrhage;
- ending myelosuppression
- resolution of immune-mediated thrombocytopenia
What happens to platelets levels after a splenectomy?
increase (thrombocytosis)
If there is an platelet type bleeding but the platelet level is normal and coagulation is normal, what is the best test to perform?
BMBT
What are the minimum platelets levels for most species and horses?
most species 7-10 platelets/100x hpf
horses 4-10 platelets/100x
What are the acquire causes of thrombopathia?
- fibrin degradation products inhibit platelet function (DIC)
- Drugs
- NSAIDs (aspirin, acetaminophen, phenylbutazone)
- anesthetics
- Bronchodilators
- Calcium channel blockers
- Renal failure
- Hyperglobulinemia
- Plasma cell neoplasia (multiple myeloma)
- Chronic ehrlichiosis
- immune-mediated thrombocytopenia
What are the congenital causes of a thrombopathia?
- von Willegrand’s disease
- rare intrinsic platelet defects
What are the vitamin K dependent coagulation factors?
2 (thrombin), 7, 9, 10
What are two ways vitamin K can become deficient?
rodenticide toxicity
maldigestion
What is the vitamin K factor with the shortest half-life?
factor 7
What event in the coagulation cascade leads to the formation of a stable fibrin clot?
thrombin burst
What factor is activated to form cross-linked monomers of fibrin in the clot?
Factor 13
