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Anticoagulant Rodenticide Toxicity (view source)
Revision as of 12:32, 23 August 2010
, 12:32, 23 August 2010→Laboratory Tests
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Line 65:
===Laboratory Tests===
===Laboratory Tests===
+
+Coagulation screening tests are unlikely to reveal abnormalities
+until at least 36 to 72 hours post-exposure. The
+prothrombin time (PT) generally becomes prolonged
+first (by 36 to 48 hours), since F-VII, a component of the
+tissue factor-mediated coagulation pathway, has the
+shortest half-life (about six hours) and is therefore the
+first factor to become depleted. The partial thromboplastin
+time (PTT) and activated clotting time (ACT) are
+usually prolonged by 48 to 72 hours post-exposure. The
+thrombin clotting time (TCT), platelet count and buccal
+mucosal bleeding time (BMBT) (an assessment of
+platelet function) are usually normal (see table below).
+The so-called 'proteins induced by vitamin K antagonism'
+(PIVKA) are acarboxylated proteins formed as a
+result of anticoagulant rodenticide toxicity. While not
+normally detected in the circulation, these increase in the
+plasma of poisoned animals and can be detected using
+the PIVKA test which is available through some veterinary
+diagnostic laboratories. PIVKA are usually cleared
+within 12 hours of administration of vitamin K. Samples
+for coagulation testing should be collected before initiating
+vitamin K therapy.
+Other possible confirmatory tests include quantitation
+of vitamin K epoxide concentrations and determination
+of the specific anticoagulant in the blood, liver and/or
+stomach contents.
+
===Pathology===
===Pathology===