title: Validity of CO-oximetric determination of carboxyhaemoglobin in putrefying blood and body cavity fluid.
abstract: Most commercial CO-oximeters pose warning flags in their measured carboxyhaemoglobin (COHb) levels when total haemoglobin (tHb) concentrations in the samples are below a certain threshold, typically about 3-4gdl. The warning flags acknowledge the fact that the haemoglobin levels are outside the ranges these instruments are designed (or validated) for. By using a parallel GC method and special sample treatment methods prior to CO-oximetric measurements, this study demonstrates that CO-oximeters could actually produce valid COHb results for samples with tHb as low as 1g/dl, and that the warning flags have no bearing to the accuracy and precision of the measurements. This study also indicates that warning flags due to high methaemoglobin (MetHb) and sulphaemoglobin (SHb), and often turbidity did not affect the validity of the CO-oximetric measurements.
authors.affiliation: Forensic Science Division, Government Laboratory, 7/F, Ho Man Tin Government Offices, 88 Chung Hau Street, Homantin, Kowloon, Hong Kong SAR, China.
authors.forename: Chau-wing
authors.initials: CW
authors.lastname: Lee
authors.forename: Jimmy C N
authors.initials: JC
authors.lastname: Tam
authors.forename: Lok-Keung
authors.initials: LK
authors.lastname: Kung
authors.forename: Lai-kam
authors.initials: LK
authors.lastname: Yim
mesh_terms: D001826:Body Fluids; D002249:Carbon Monoxide Poisoning / Q000097:blood* / Q000175:diagnosis; D002263:Carboxyhemoglobin / Q000032:analysis*; D005554:Forensic Medicine / Q000379:methods; D006801:Humans; D010092:Oximetry / Q000592:standards*
chemical_list: D002263:Carboxyhemoglobin