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oxicological screening Carbon monoxide

المؤلف:  Sue Jickells , Adam Negrusz (Editors)

المصدر:  Clarkes Analytical Forensic Toxicology

الجزء والصفحة:  233-234

2026-10-18

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oxicological screening

Carbon monoxide

Carbon monoxide is one of the most frequent causes of fatal poisoning in developed countries. Common sources of carbon monoxide are vehicle exhaust fumes, smoke from fires and emissions from improperly maintained and ventilated heating systems. More rarely, expo sure to dichloromethane vapours from paint strippers, degreasing agents and aerosol propel lants can lead to carbon monoxide poisoning because the solvent can be metabolised by mixed-function oxidases to carbon dioxide and carbon monoxide. The affinity of carbon monoxide for haemoglobin is 200–300 times that of oxygen and therefore most of the toxic effects result from diminished oxygen delivery to the tissues. Symptoms progress from headache, nausea, gastrointestinal upset, hyperventilation, hypertension and drowsiness to coma. Chronic poisoning as a result of continuous exposure to small amounts of carbon monoxide leads to nonspecific symptoms, such as headaches, dizziness, fatigue and general malaise, and is often undiagnosed. Elevated carboxyhaemoglobin (COHb) concentrations confirm a diagnosis of carbon monoxide poisoning. When a patient is removed from the contaminated atmosphere the COHb disappears rapidly, particularly if oxygen is administered. Hospital clinical chemistry laboratories are usually equipped with automated differential spectrophotometers (CO-oximeters) that measure simultaneously the absorption of a blood haemolysate at four or more wavelengths to determine total haemoglobin, the percentage saturation of oxyhaemoglobin and COHb, as well as methaemoglobin and sulfhaemoglobin (Widdop 2002). If such an apparatus is not avail able, the spectrophotometric method of Rodkey et al. (1979) can be used.