Arterial blood gas analysis

Arterial blood gas analysis is a medical test that measures the amounts of certain gases (such as oxygen and carbon dioxide) in arterial blood. It is used to assess the adequacy of ventilation and oxygenation, and the acid-base status of patients.

Procedure

The procedure involves puncturing an artery, usually the radial artery, with a thin needle and syringe and drawing a small volume of blood. The blood is then analyzed in a laboratory. The results provide information about the patient's respiratory and metabolic status.

Indications

Arterial blood gas analysis is indicated in patients with acute respiratory distress, unexplained tachypnea, severe trauma, and suspected metabolic acidosis or alkalosis. It is also used to monitor patients on mechanical ventilation and to assess the effectiveness of therapeutic interventions.

Interpretation

Interpretation of arterial blood gas results involves the assessment of four main components: the partial pressure of oxygen (PaO2), the partial pressure of carbon dioxide (PaCO2), the bicarbonate level (HCO3-), and the arterial blood pH.

The PaO2 and PaCO2 values provide information about the adequacy of ventilation. The HCO3- level and arterial blood pH provide information about the patient's metabolic status.

Complications

Complications of arterial blood gas analysis are rare but can include hematoma, arterial spasm, and infection. In rare cases, damage to the artery can occur.

See also

• Blood gas test
• Acid-base imbalance
• Respiratory failure