Arterial carbon dioxide tension, or partial pressure
PACO2
Alveolar carbon dioxide tension, or partial pressure
PvO2
Oxygen tension of mixed venous blood
P(A-a)O2
Alveolar-arterial oxygen tension difference. The term formerly used (A-a DO2) is discouraged.
P(a/A)O2
Alveolar-arterial tension ratio; PaO2:PAO2 The term oxygen exchange index describes this ratio.
C(a-v)O2
Arteriovenous oxygen content difference
SaO2
Oxygen saturation of the hemoglobin of arterial blood
SpO2
Oxygen saturation as measured by pulse oximetry
CaO2
Oxygen content of arterial blood
pH
Symbol relating the hydrogen ion concentration or activity of a solution to that of a standard solution; approximately equal to the negative logarithm of the hydrogen ion concentration. pH is an indicator of the relative acidity or alkalinity of a solution