Measurement of carboxyhemoglobin and total hemoglobin by five specialized spectrophotometers (CO-oximeters) in comparison with reference methods.
We measured total hemoglobin (CtHb) and carboxyhemoglobin (COHb) in 100 patients' blood samples by using five specialized spectrophotometers (CO-oximeters)--IL 482 CO-Oximeter, Corning 2500 CO-oximeter, Radiometer OSM 3 Hemoximeter, Corning 270 CO-oximeter, and the AVL 912 CO-Oxylite--and compared the results with those obtained with the manual cyanmethemoglobin method and a gas-chromatographic (GC) method, respectively. For the CtHb measurements, the differences between the cyanmethemoglobin method and the CO-oximeters were not clinically important for any model. For the blood COHb measurements, the direction of the bias relative to GC was dependent on COHb concentration. In general, the CO-oximeters underestimated COHb concentration for COHb > 2.5% of total hemoglobin but overestimated COHb concentration for COHb < or = 2.5%. We conclude that all five CO-oximeters compared favorably with the reference methods for CtHb and for high concentrations of COHb. However, the inaccuracy of CO-oximeters for low-concentration (< or = 2.5%) COHb measurements may make these instruments unsuitable for some applications.
Mahoney
J J
JJ
Department of Pulmonary Physiology, Stanford University Hospital, CA 94305.
Vreman
H J
HJ
Stevenson
D K
DK
Van Kessel
A L
AL
D002263:Carboxyhemoglobin / Q000032:analysis*; D002849:Chromatography, Gas; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D008706:Methemoglobin / Q000031:analogs & derivatives / Q000032:analysis; D010092:Oximetry / Q000295:instrumentation; D011786:Quality Control; D013053:Spectrophotometry / Q000295:instrumentation* / Q000379:methods
D006454:Hemoglobins; C007169:cyanomethemoglobin; D008706:Methemoglobin; D002263:Carboxyhemoglobin