The anion gap (AG) is a calculated parameter derived from measured plasma electrolyte concentrations that is most frequently used to elucidate acid-base disturbances in the critically ill. It is defined as the difference between measured anions and cations in blood plasma and is calculated by subtracting the sum of...

When collecting blood for blood gas analysis, it is important to remove air bubbles from syringes to avoid erroneous results, especially for pO₂, with a number of factors affecting the potential magnitude of the interference to pO₂ by air bubbles.  In this study, we calculate the expected theoretical changes in pO₂...

Arterial blood gases (ABG), a clinical test that involves measurement of the pH of arterial blood and the amount of oxygen and carbon dioxide dissolved in arterial blood, is routinely used in the diagnosis and monitoring of predominantly critically/acutely ill patients being cared for in hospital emergency rooms and...

Unless suffering some unrelated acute/critical illness, diabetic patients are only usually submitted for arterial blood gas analysis if they are suspected of suffering diabetic ketoacidosis, the potentially life-threatening acute complication of diabetes that is almost invariably associated with severe hyperglycemia....

By measurement of the partial pressure of oxygen in arterial blood (pO₂(a)) and oxygen saturation in arterial blood (sO₂(a)), blood gas analysis provides the means for monitoring supplemental oxygen therapy. Oxygen is prescribed in many medical emergencies in which tissue oxygenation is threatened because of...

Arterial blood gas (ABG) analysis generates a number of parameters (listed in BOX 5) that together allow assessment of pulmonary gas exchange, blood oxygenation and acid-base balance. These physiological functions of the blood, respiratory and renal systems are disturbed in a range of respiratory and non-respiratory...

The clinical value of any patient test result depends on the quality of the reference interval used for its comparison (interpretation), so that good laboratory medicine practice demands continuous review of reference intervals. There is a paucity of published study aimed at validating the health-associated reference...

Plasma bicarbonate concentration, a parameter generated during arterial blood gas analysis, is essential to the assessment of patient acid-base status. Blood gas analyzers do not have the capacity to directly measure bicarbonate; instead, it is calculated from measured pH and pCO₂(a), using the Henderson-Hasselbalch...

Although arterial blood remains the gold standard sample for blood gas analysis, it is, compared with peripheral venous blood, a more difficult sample to obtain, and its collection is more painful and hazardous for the patient. These considerations have fuelled a growing interest in study aimed at establishing if...

Metabolic alkalosis is a disturbance of acid-base balance, with many possible causes, characterized by primary increase in blood bicarbonate (HCO₃) and pH. Hypoventilation is the normal compensatory respiratory response to metabolic alkalosis. This results in increased pCO₂ and, if the metabolic alkalosis is...