Normal Lab Values for Blood Gases


Measurement Range
Anion gap 12-16 mmol/l
Arterial CO2 4.7 - 6.0 kPa
Mixed venous CO2 5.5 - 6.8 kPa
Arterial oxygen 12.0 - 14.5 kPa
Mixed venous oxygen 4.0- 6.0 kPa
H^+ ion activity 36 - 44 nmol/l
Arterial pH 7.35 - 7.45 pH units
Bicarbonate arterial- whole blood 19-24 mmol/l
Bicarbonate venous - plasma 22 - 28 mmol/l
Bicarbonate cord blood 14 - 22 mmol/l
Base excess +/- 2 mmol/l
Carboxyhaemoglobin (non- smoker) <2%
Carboxyhaemoglobin (smoker) 3-15%
Carboxyhaemoglobin (toxic at) >15%
Carboxyhaemoglobin (coma at) >50%