Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
Measurement of carboxyhaemoglobin (COHb) is used to assess carbon monoxide toxicity in cases of suspected exposure. Carboxyhaemoglobin (COHb) is haemoglobin covalently bound to carbon monoxide. Haemoglobin has an affinity for carbon monoxide >200 times that for oxygen. High levels of COHb result in hypoxia, cyanosis possibly death due to it being unable to transport oxygen. The most common cause of carbon monoxide toxicity is exposure to vehicle exhaust fumes. Significant levels of COHb can also be observed in heavy cigarette smokers.
Specimen container paediatric:
Lithium heparin whole blood or balanced heparin syringe
Specimen container adult:
Lithium heparin whole blood or balanced heparin syringe
Minimum volume paediatric:
0.5 mL blood
Minimum volume adult:
0.5 mL blood
Special requirements:
Must be analysed within 30 minutes of collection
Transport requirements:
Ambient
Interpretation:
Raised levels may indicate exposure to carbon monoxide.
Reference ranges:
Non-smokers: less than 2 %
Heavy smokers: less than 8 %