Page 325 - WSAVA2018
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Y. Bruchim1
1Senior Lecturer of Veterinary Medicie,
The Hebrew University of Jerusalem, Jerusalem, Israel
Coagulation disturbances are common in emergency and ICU patients. It may be a sequel of various etiologies including intoxications (rodenticide intoxication),
snake bite, GDV, pancreatitis, severe trauma, sepsis
(e.g septic peritonitis, pyometra, pyothorax) or any etiology associated solely with thrombocytopenia (IMT, Erlichiosis). Although all the aforementioned etiologies carry various coagulation disturbances severity, clinical presentation, treatment, prognosis and outcome, they
all share in common inflammatory process so called systemic inflammatory response syndrome (SIRS). SIRS and sepsis are thought to be intimately associated with coagulation system (Fig 1). The mortality is due to organ failure and increases with the number of organ system involvement and failure. Much of the organ failure is
due to the microvascular and coagulation disturbances leading to enhance thrombosis and disseminated intravascular coagulation (DIC). The coagulation disturbances are dynamic and variable, depending on the etiology and the severity of the primary disease. Cytokine production, vascular damage and the
release of tissue factor all contribute to the stimulation
of coagulation cascade, down regulation of the fibrinolytic system and consumption of the endogenous anticoagulant.
In healthy animals, the normal clot formation and fibrinolysis mechanisms are well balanced, so coagulation and formation of clots occur only on demand. However, during massive trauma, infective, inflammatory/septic state this balance may be disrupted, leading to concurrent excessive clot formation and bleeding (Fig. 1). Thus, DIC may be considered as
an uncontainable burst of thrombin generation and activation, resulting in systemic fibrin formation, followed by plasmin and kinnin activation, with simultaneous suppression of the physiologic anticoagulation mechanisms and delayed fibrin removal as a consequence of impaired fibrinolysis (Fig. 2).1-3 During this excessive intravascular coagulation phase, platelets and coagulation factors are consumed, resulting in thrombocytopenia, thrombocytopathy and depletion and inactivation of coagulation factors.
DIC is categorized into bleeding, organ failure and non- symptomatic types according to the sum of vectors for hyper coagulation and hyperfibrinolysis. There are 3
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types of clinical presentation of DIC; bleeding, massive bleeding and the organ failure hypofibrynolitic type.4
The bleeding, massive bleeding and hypofybrinolytic types
When the dominant feature of haemostatic disorder
is hyperfibrinolysis, bleeding is the primary syndrome, therefore is called the bleeding type. This form of DIC is often seen in patients with major trauma, neoplasia (e.g hemangiosarcome, leukemia, lymphoma) and obstetric disease in women. In the other hand when the hypercoagulation is the more remarkable process along with hypofironolysis, organ failure is the common symptom. This type of DIC is called the organ failure type due to intravascular clott formation and deposition, resulting in organ failure commonly liver, kidney and CNS. This type is common in infectious diseases, particularly sepsis.4
The third type is the massive bleeding type or so called consumptive type, when both coagulation and fibrinolysis are highly activated resulting in whispered clott formation and massive bleeding in the same time, which may result in acute death. This form of DIC is seen in patients with heatstroke, snake bite and severe acute necrotizing pancreatitis or any major trauma.
When both vectors of coagulation are weak (coagulation and fibrinolysis) there are mild to non clinical signs directly related to the coagulation disorders, commonly seen in different neoplastic diseases in which only laboratory coagulation parameters are mildly abnormal, and there is a new chronic coagulative balance, tha can deteriorated to one of the above described clinical state of DIC.4
Sepsis and coagulation
The most common etiology involved in coagulation abnormalities in both human and veterinary medicine ICU is sepsis. Sepsis is one of the oldest and most elusive syndromes in medicine. However, with the advent of modern antibiotics, germ theory did not fully explain the pathogenesis of sepsis: many patients with sepsis died despite successful eradication of the inciting pathogen. In addition it was noticed that other etiologies not infective resemble sepsis in the clinical signs; tachycardia, tachypnea, elevated/decreased white blood cells count, hypoglycemia, with no apparent infectious site (e.g heatstroke, trauma, cancer). Thus, researchers suggested that it was the host, not the germ that drove the pathogenesis of SIRS/sepsis. The incidence of sepsis increase with the use of immunosuppressive drugs, chemotherapy and invasive procedures. It is a leading cause of death in human and in the veterinary medicine with high mortality rate of 30-50%. Common diseases associated with sepsis in the veterinary medicine are pneumonia, pyothorax, peritonitis, pancreatitis, prostatitis and wound infection.

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