Arterial blood gas analysis is designed to measure the levels of oxygen and carbon dioxide in the blood, as well as the acid-base (pH) balance. Arterial blood gas analysis can assist healthcare professionals to evaluate respiration, circulation and metabolic processes in deteriorating patients. Arterial blood gas analysis is usually undertaken by a trained healthcare professional where patients are acutely unwell or deteriorating. REFLECTIVE ACTIVITY: 'How to' articles can help to update your practice and ensure it remains evidence based. Apply this article to your practice. Reflect on and write a short account of.