<Tr> <Td> Arterial oxygen partial pressure (P O) </Td> <Td> 11--13 kPa or 75--100 mmHg </Td> <Td> A low PaO indicates that the patient is not oxygenating properly, and is hypoxemic . (Note that a low PaO is not required for the patient to have hypoxia .) At a P O of less than 60 mm Hg, supplemental oxygen should be administered . </Td> </Tr> <Tr> <Td> Arterial carbon dioxide partial pressure (P CO) </Td> <Td> 4.7--6.0 kPa or 35--45 mmHg </Td> <Td> The carbon dioxide partial pressure (Pa CO) is an indicator of CO production and elimination: for a constant metabolic rate, the Pa CO is determined entirely by its elimination through ventilation . A high Pa CO (respiratory acidosis, alternatively hypercapnia) indicates underventilation (or, more rarely, a hypermetabolic disorder), a low Pa CO (respiratory alkalosis, alternatively hypocapnia) hyper - or overventilation . </Td> </Tr> <Tr> <Td> HCO </Td> <Td> 22--26 mEq / L </Td> <Td> The HCO ion indicates whether a metabolic problem is present (such as ketoacidosis). A low HCO indicates metabolic acidosis, a high HCO indicates metabolic alkalosis . As this value when given with blood gas results is often calculated by the analyzer, correlation should be checked with total CO levels as directly measured (see below). </Td> </Tr> <Tr> <Td> SBC </Td> <Td> 21 to 27 mmol / L </Td> <Td> the bicarbonate concentration in the blood at a CO of 5.33 kPa, full oxygen saturation and 37 Celsius . </Td> </Tr>

Ratio of oxygen to carbon dioxide in blood