About Carbon Dioxide
The CO2 (bicarbonate) value on a basic metabolic panel is a surrogate for blood bicarbonate, reflecting the body's primary chemical buffer against acidosis. Low CO2 (metabolic acidosis) is associated with advanced kidney disease, diabetic ketoacidosis, lactic acidosis, or diarrhoea; high CO2 (metabolic alkalosis) is typically caused by prolonged vomiting, diuretic use, or mineralocorticoid excess. In people with chronic kidney disease, a low bicarbonate independently accelerates kidney function loss and is now actively treated.