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balance between thrombosis and hemorrhage). Most cats with DIC do not show evidence of spontaneous bleeding and the clinical signs are often those associated with the primary disease.3
Diagnosis
Diagnosis is complex and should be based on several and continuous blood coagulation parameter and clinical signs. The definition and diagnostic criteria of DIC in veterinary medicine are somewhat controversial; however it is generally agreed that DIC is suspected when an underlying clinical condition known to precipitate DIC occurs, clinical signs of bleedings tendencies (e.g hematochesia, melena, epistaxis ecc.) with at least one abnormality from the 4 following coagulation groups; 1. Thrombocytopenia < 150,000, 2. Coagulation parameters; prolonged prothrombin time (PT), activated partial thromboplastin times; aPTT and activated cloting time (ACT), 3. Inhibitor consumption; decreased protein C, protein S or antithrombin activities; PCA, PSA and ATA, respectively), and increased fibrinolysis; hypofibrinogenemia, increased D-dimer
and fibrinogen degradation products concentrations (FDPs).3(Table 2)
Table 2: Laboratory screening tests for DIC in dogs and cats
interactions between coagulation factors, platelets, fibrin, fibrinolysis and time. Different thromboelastographic patterns have been identified in a variety of
haemostatic disorders, including coagulation factors deficiency, thrombocytopenia, increased fibrolysis and hypercoagulability.9 In septic human patients TEG has been utilized to identify the hypercoagulable state that precedes the clinically recognizable phase of DIC. 10
In veterinary medicine, TEG has been evaluated in a number of studies in dogs and cats.11-13
Treatment
Treatment should be instituted immediately once a diagnosis of DIC has been established or when a high index of suspicion is present. Removing or eliminating the precipitating cause constitutes the cornerstone and the main therapeutic goal for patients with DIC. The wide variety of underlying disorders makes the therapeutic approach to DIC particularly difficult.14
The treatment aims for DIC in dogs and cats include the following:
1. Impeding, possibly stopping, intravascular coagulation and hemorrhage
2. Maintaining good parenchyma organ perfusion 3. Preventing secondary complications
4. Use of anticoagulant- heparin
5. Use of antifibrinolytic agents- Transhaxemic acid
Replacement therapy is the mainstay for the treatment of DIC 14. A dual approach is used to halt intravascular coagulation:
Blood component therapy:
Administration of fresh or fresh-frozen plasma (FP or FFP, respectively) (at least 30-50 ml/kg /day given initially at 10 ml/kg/hr and then at 2ml/kg/hr). This is done to replace the consumed coagulation factors. Alternatively, fresh whole blood can be administered as a source for the coagulation factors, inhibitors as well as platelets. FP/ FFP administration is aimed at halting the consumption
of platelets, coagulation factors and inhibitors (e.g. AT, a2-macroglobulin) in order to arrest the ongoing hemorrhagic and coagulation processes.
Heparin - unfractionated and low molecular weight heparin:
Administration of heparin, only during the peracute hypercoagulable phase, when PT and aPTT are shortened and AT III activity is at least 80%. Heparin can also be administered following FP/FFP administration and only when the laboratory coagulation tests were normalized.
The literature lacks controlled studies on the use of heparin in DIC. Clinical reports and retrospective studies
Legend Table 2: Laboratory results should always
be interpreted with caution, in light of the history and clinical signs, since an abnormality in any single test is not specific for the diagnosis of DIC. These tests are
not very sensitive markers of DIC, and may yield normal results in the early hypercoagulable stages of DIC. Serial monitoring of laboratory tests to assess the trends in individual DIC-suspected patients is useful.
* Depends on the underlying disease.
Thromboelastography (TEG)
This technique characterizes the coagulation function by recording a tracing that represents blood clot creation and breakdown. The tracing is a sum of the
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