Arterial Blood Gas (ABG) Analysis and Classification
ABG analysis is a vital diagnostic process that evaluates a patient’s gas exchange and acid-base status. Typically performed after arterial puncture and specimen collection, ABG interpretation relies on comparing key values—such as partial pressure of oxygen (PaO₂), carbon dioxide (PaCO₂), and blood pH—against calibrated standards within the ABG analyzer. These values are measured using specialized electrodes: the Clark electrode for PaO₂, the Severinghaus electrode for PaCO₂, and the Glass electrode for pH.
Using the Henderson-Hasselbalch equation, clinicians can determine the blood's pH and evaluate its alignment with normal physiological parameters. By analyzing the relationship between PaCO₂ (respiratory component) and bicarbonate (HCO₃⁻, metabolic component), we can classify the patient’s condition into categories such as respiratory acidosis, respiratory alkalosis, metabolic acidosis, or metabolic alkalosis.
ABG classification aids in identifying whether the body is compensating for an abnormality and if the condition is acute or chronic. Some results indicate a need for immediate medical intervention—such as severe acidosis or hypoxemia—while others may suggest a “wait and see” strategy, depending on severity and patient symptoms. However, any abnormal ABG finding warrants increased clinical observation, with overnight monitoring recommended before considering discharge.
This interactive ABG calculator demonstrates how changes in PaCO₂ and HCO₃⁻ affect pH, providing insights into the body’s acid-base balance and helping guide decision-making based on real-time inputs.