Relationship between venous and arterial carboxyhemoglobin levels in patients with suspected carbon monoxide poisoning.
OBJECTIVE
To test the hypothesis that venous carboxyhemoglobin (V-COHb) levels accurately predict arterial (A-COHb) levels.


METHODS
Prospective comparison of A-COHb and V-COHb levels in patients with suspected carbon monoxide (CO) poisoning.


METHODS
Municipal hospital emergency department with contiguous multiplace hyperbaric chamber staffed 24 hours a day.


METHODS
Unselected convenience sample of 61 adults with suspected CO toxicity.


METHODS
Simultaneous sampling of arterial and venous blood.


RESULTS
Correlation between V-COHb and A-COHb showed an r value of .99 (95%CI, .99 to .99), and an r2 value of .98. Agreement between V-COHb and A-COHb levels was examined by use of a plot of arteriovenous differences against the mean of the two measurements. The mean arteriovenous difference was .15% COHb (95%CI, .13% to .45%), with 95% of the differences ranging from 2.4% COHb to -2.1% COHb.


CONCLUSIONS
Venous COHb levels predict arterial levels with a high degree of accuracy. Patients with suspected CO poisoning can be screened with the use of venous blood, without the need for arterial puncture.
Touger
M
M
Department of Medicine, Bronx Municipal Hospital, Albert Einstein College of Medicine.
Gallagher
E J
EJ
Tyrell
J
J
D000328:Adult; D001158:Arteries; D001800:Blood Specimen Collection / Q000379:methods; D002249:Carbon Monoxide Poisoning / Q000097:blood*; D002263:Carboxyhemoglobin / Q000378:metabolism*; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D014680:Veins
D002263:Carboxyhemoglobin