Biochemical Tests - Analytical Toxicology

BIOCHEMICAL TESTS

·              Blood Glucose: Apart from insulin and other anti-diabetic drugs, hypoglycaemia is a feature of poisoning with ethanol, iron salts, paracetamol, and salicy-lates. Hyperglycaemia may be seen less commonly in salicylates, while it is more common in salbutamol and theophylline overdose.

·      Electrolytes, Blood Gases and pH: The value of theseparameters in various kinds of poisoning have been discussed.

·      Plasma Enzymes: Shock, coma, and convulsions areoften associated with non-specific increase in plasma or serum activities of enzymes such as lactate dehy-drogenase, aspartate aminotransferase, and alanine aminotransferase. In severe cases, there may be evidenceof rhabdomyolysis and disseminated intravascular coagu-lation manifested by high serum aldolase or creatine kinase, together with myoglobinuria. High serum or plasma potassium, uric acid, and phosphate concentra-tions usually indicate the onset of acute renal failure. The plasma activities of hepatic enzymes are enhanced in poisoning due to carbon tetrachloride, copper salts, and paracetamol. Chronic alcoholism is often associated with increased gamma glutamyl transferase activity. Depressed plasma cholinesterase activity is a useful indicator of exposure to organophosphate or carbamate pesticide.