ARTERIAL BLOOD GAS ANALYSIS: Part 2: Interpretation of acid-base balance

ARTERIAL BLOOD GAS ANALYSIS: Part 2: Interpretation of acid-base balance Suthat Rungruanghiranya   M.D.(Hon)* Department of Internal Medicine,Faculty of Medicine, Srinakharinwirot University The arterial blood gas (ABG) analysis is one of the most commonly used clinical test in assessing a patient's oxygenation, ventilation, as well as acid-base status. However, ABG analysis appears to be a complicated and confusing matter to many physicians . Very often, this procedure was performed incorrectly, compromising its clinical usefulness and accuracy. To maximize its yield, one must understand its technical details, including the techniques, sample collection, handling, and common pitfalls. More important, to correctly interpret the ABG analysis, a practical, stepwise approach is required. That stepwise approach should begin with the assessment of oxygenation, ventilation, and acid-base disturbances. This article will focus only on the interpretation of acid-base balance. Once one utilizes this test with care and knowledge, I believe it will soon a simple and straightforward test for everyone. Vajira Med J 2004 ; 48 : 117 - 123