|
Symbol |
Definition |
Normal range |
|
pH |
Negative logarithm of hydrogen ion concentration |
7.35 to 7.45 |
|
PaCO2 |
Arterial level of carbon dioxide |
35 to 45 mm Hg (4.65-6.00 kPa) |
|
HCO3−curr |
Current plasma bicarbonate level |
21 to 27 mmol/L |
|
HCO3−std |
Standard plasma bicarbonate level |
24 (21-25) mmol/L |
|
BE |
Base excess in blood |
−2.3 to +2.3 mEq/L |
|
PaO2 |
Arterial oxygen level |
75 to 100 mm Hgb (10.00-13.33 kPa) |
|
ctCO2 |
Total plasma content of carbon dioxide |
22 to 28 mmol/L 47.0% to 60.5% (volume) |
|
SaO2 |
Oxygen saturation of hemoglobin in arterial blood |
95% to 98%b |
|
a Blood drawn without contact with air. b When interpreting PaO2 and SaO2, always record the fraction of inspired oxygen (FiO2). The normal ranges given here are for respiration with atmospheric air at sea level (an oxygen concentration of 20.9%, which corresponds to an FiO2 of 0.209). When a healthy individual is breathing 100% oxygen (FiO2 = 1.0), PaO2 may be as high as ~600 mm Hg and SaO2 may reach 100%. | ||