Disorders of haemostasis - embolism, DIC, shock

Shit

Non thrombus causes of embolism

Bacterial, parasites, fat droplets (fractures), bubbles, bone marrow, cartilage, foreign bodies, tumour fragments (metastases)

What happens in bacterial emboli (bacterial endocarditis)

Bacterial embolus in pulmonary + systemic circulation → embolic metastatic diseases (glomerulonephritis, pneumonia, hepatitis)

Tyzzers disease

Enterocolitis → organisms enter hepatic portal vein

Dirofilaria immitis

Heart worm in RV + pulmonary artery → systemic circulation

What can happen after fractures

Fat embolism

Common site of fibro-cartilaginous embolism

Spinal cord

Term for tumour cell embolus production

Metastasis

Squamous cell carcinoma is what (common in white cats)

Neoplasm of keratinocytes

DIC stands for

Disseminated intravascular coagulation

DIC def

Acute/subacute/chronic thrombo-haemorrhagic disorder occurring as secondary complication in variety of diseases

steps of DIC

Activation of coagulation cascade in whole body → formation of micro thrombi throughout microcirculation → consumption of platelets, fibrin, coagulation factors, activation of fibrinolysis

CS of DIC

Tissue hypoxia, infarction, haemorrhagic disorder (consumption coagulopathy)

Major underlying mechanisms of DIC (causes)

Release of tissue factor, thromboplastic substances into circulation

Widespread injury to endothelial cells → coagulation cascade

Pathogenesis of DIC- causes

Massive tissue destruction, sepsis, endothelial injury

Pathogenesis of DIC- Effects

Fibrinolysis, ischaemic tissue damage, consumption of clotting factors + platelets, bleeding

Pathogenesis of DIC- Commonly associated with

Severe systemic infections (from direct endothelium injury, immune complex deposition), septic shock, neoplasm, extensive trauma/burns, extensive surgery

Pathogenesis of DIC- How does sepsis (gram -) leads to DIC

Bacterial endotoxins → monocytes release tissue factor + pro inflammatory cytokines → endothelial cells increase expression of tissue factor, decrease expression of thrombomodulin → activate clotting cascade, inhibit clotting control

Pathogenesis of DIC- How does sepsis (gram +) leads to DIC

Bacterial lysis → release cell wall components → monocytes produce cytokines + SIRS + DIC

Neutrophils adhere to endothelium → release proteases + O radicals → capillary dmamage → haemorrhage → shock

Viral diseases associated with DIC - pigs

Classical Swine fever

By endothelial alterations → petechia

Viral diseases associated with DIC - Dog

Infectious canine hepatitis

Viral diseases associated with DIC - Rabbit

Rabbit haemorrhagic diease

Hepatocyte necrosis

Viral diseases associated with DIC - Sheep

Blue tongue

Viral diseases associated with DIC - Mink

Aleutian disease

Immune complex deposition in BV wall → complement + coagulation cascade

Viral diseases associated with DIC - Deer

epizootic haemorrhagic disease

Shock - def + causes

Culmination in systemic hypoperfusion due to reduced CO, reduced effective circulating blood vol

Causes of shock

Severe haemorrhage, microbial sepsis, extensive trauma/burns, large infarction, massive pulmonary embolism

Effects of shock

Hypotension → impaired perfusion → cellular hypoxia

Types of shock

Cardiogenic, hypovolaemic, septic, neurogenic, anaphylactic

Types of shock - cardiogenic

Failure of myocardial pump

Types of shock - hypovolaemic

Loss of blood/ plasma

Types of shock - septic

Systemic microbial infection

Types of shock - neurogenic

Depression of vasomotor centre

Types of shock - anaphylactic

Generalised IgE mediated hypersensitivity

Stages of shock

Non progressive, progressive, irreversible

Pathogenesis of septic shock - type of bacteria

Endotoxin (LPS) producing gram -

Pathogenesis of septic shock - With low LPS

Activation of monocytes, endothelial cells, complement → cascade → local acute inflammation + bacterial clearance

Pathogenesis of septic shock - With mod LPS

Cytokine induced effectors (NO + PAF) → fever, acute phase reactants, endothelial injury, DIC

Pathogenesis of septic shock - With high LPS

Systemic vasodilation, reduced cardiac contractility, DIC → MOSF, SIRS

what does MOSF stand for

Multi organ system failure

Pathogenesis of septic shock in gram + bacteria

Cytokine production (monocytes), SIRS, DIC

Neutrophils adhering to endothelium, release of proteases, O radicals → shock