Carboxyhemoglobin in Cardiac Surgery Patients and Its Association with Risk Factors and Biomarkers of Hemolysis
Akinori Maeda, Dinesh Pandey, Ryota Inokuchi, Sofia Spano, Anis Chaba, Atthaphong Phongphithakchai, Glenn Eastwood, Hossein Jahanabadi, Hung VO, Siven Seevanayagam, Andrew Motley, Rinaldo Bellomo- Anesthesiology and Pain Medicine
BACKGROUND:
Cardiac surgery with cardiopulmonary bypass (CPB) is associated with hemolysis. Yet, there is no easily available and frequently measured marker to monitor this hemolysis. However, carboxyhemoglobin (CO-Hb), formed by the binding of carbon monoxide (a product of heme breakdown) to hemoglobin, may reflect such hemolysis. We hypothesized that CO-Hb might increase after cardiac surgery and show associations with operative risk factors and indirect markers for hemolysis.
METHODS:
We conducted a retrospective descriptive cohort study of data from on-pump cardiac surgery patients. We analyzed temporal changes in CO-Hb levels and applied a generalized linear model to assess patient characteristics associated with peak CO-Hb levels. Additionally, we examined their relationship with red blood cell (RBC) transfusion and bilirubin levels.
RESULTS:
We studied 38,487 CO-Hb measurements in 1735 patients. CO-Hb levels increased significantly after cardiac surgery, reaching a peak CO-Hb level 2.1 times higher than baseline (
CONCLUSIONS:
CO-Hb may represent a readily obtainable and frequently measured biomarker that has a moderate association with known biomarkers of and risk factors for hemolysis in on-pump cardiac surgery patients. These findings have potential clinical implications and warrant further investigation.