The Arterial Blood Gas (ABG) analyzer is an essential tool for evaluating the balance between oxygen supply, carbon dioxide removal, and acid–base status in the body. By analyzing an arterial blood sample, it provides measurements of pH, PaO₂, PaCO₂, bicarbonate (HCO₃⁻), and oxygen saturation. These values help clinicians understand how effectively the lungs are exchanging gases and whether the body’s buffering systems are maintaining acid–base balance.

ABG interpretation is especially important in critically ill patients where rapid changes in respiratory or metabolic function can occur. For example, a low pH may signal acidosis, which could be due to respiratory causes such as hypoventilation or metabolic causes such as renal dysfunction or lactic acidosis. Conversely, an elevated pH may indicate alkalosis from hyperventilation or excessive loss of acids. Evaluating PaO₂ helps determine the severity of hypoxemia, while PaCO₂ indicates whether the lungs are adequately ventilating.

Beyond respiratory conditions, ABG analysis is a vital component in the management of shock, sepsis, diabetic ketoacidosis, and renal failure. It allows clinicians to quickly identify whether interventions like oxygen therapy, intravenous fluids, or ventilator adjustments are effective. In intensive care units, ABG results are often checked repeatedly to track patient progress and guide treatment decisions in real time.