secondary haemostasis Flashcards
List the 4 cells that are involved in secondary haemostasis
fibroblasts
platelets
endothelial cells
leukocytes
What substances apart from cells are needed in secondary haemostasis
enzyme coagulation factors
fibrinogen
calcium
List the factors that are in the intrinsic pathway
XII- 12
XI- 11
IX- 9
VIII- 8
List the factors on the extrinsic pathway
III- 3
VII- 7
List the factors that are on the common pathway
X- 10
V- 5
II- 2
I - 1
List the clotting factors that are vitamin K dependent
II- 2
VII- 7
IX- 9
X- 10
What tests are used to diagnose secondary haemostasis
Whole blood clotting time
One stage prothrombin time
Activated partial thromboplastin time
Specific factor assays
What pathways does WBCT measure
intrinsic and common pathways
List the pathways that OSPT measure
extrinsic and common
What pathways does APTT measure
Intrinsic and common pathways
Any factors in their respective lines being below what percentage of what it should be will result in increases in OSPT and APTT
30%
What is hyphema
anterior chamber of the eye filled with blood
What is the difference between ecchymoses and petechiae?
Petechiae= pin pricks
Ecchymoses= large areas
What are some disorders of secondary haemostasis
Haemophillia A or B
Vitamin K antagonist (rat bait)
Hepatic disease
What factor deficiency does Haemophilia A result in
Factor VIII- 8
What factor deficiency does Haemophilia B result in
Factor IX- 9
How long does it take for clinical effects to occur in rat bait poisoning
1-3 days
What coagulation test results does haemophilia resut in
APTT increased
Increased WBCT
What coagulation test results does vitamin K antagonist (rat bait) toxicity result in
increased WBCT
increased OSPT
increased APTT
What coagulation test results does hepatic disease result in?
Increased OSPT
increased APTT
What is fibrinogen
the end product of the coagulation cascade
converted by thrombin into fibrin during blood coagulation
fibrin then cross linked by factor XIII to form clot
List 3 things that can result in increased fibrinogen concentrations
DIC
potential bleeding
liver problem
What would result in decreased fibrinogen concentrations?
-Viral and bacterial infections
-Kidney disease
-Traumatic injuries or surgery
-Cancer
-Heart disease
-Canine pregnancy
When is D-dimer concentration in the blood increased?
Thrombosis occuring
Fibrinolysis occuring
What are some examples of pro-thrombotic states in animals?
DIC
feline thromboembolic disease
protein losing nephropathy
hyperadrenocorticism
What is the pathophysiology behind disseminated intravascular coagulation?
-Excessive activation o haemostatic pathways results in high thrombin and microvascular thrombi
-Coagulation factors and platelets are depleted leading to haemorrhage
What are the main triggers for DIC?
-Endothelial damage: electrocution, heat stroke, sepsis
-Platelet activation: mainly viral (FIP)
-Release of tissue procoagulants: trauma, pancreatitis, bacterial infections
What infectious agents are implicated in causing DIC?
-Bacterial sepsis
-Viral disease (FIP)
-Protozoa (Babesia Canis)
-Parasites (A.vasorum)
What neoplasias are implicated in causing DIC?
-Metastatic tumours are overrepresented
-Haemangiosarcomas
-Haematopoietic
-Cholangiocarcinoma
-Pancreatic adenocarcinoma
What inflammatory/necrotic processes are implicated in causing DIC?
IMHA
-Pancreatitis
-Hepatitis
-Vasculitis
-GDV
-Hepatic lipidosis (cats)
What test results can be indicative of DIC?
-Thrombocytopaenia or platelets consistently dropping in normal range
-Hypofibrinogenaemia
-Increased fibrinogen degradation products (D-dimer high)
-Schistocytes
In what rabbit diseases is subacute and acute death caused y DIC?
-RHDV
-RHDV2
