Arterial Blood Gases (ABG's) actual exam practice update most tested exam questions

Arterial Blood Gases (ABG's) actual exam practice update most tested exam questions What is an ABG? - a measurement of the partial pressure of O2, CO2, pH, and HCO3 in arterial blood Who normally draws this bloodwork? Where is it drawn from? - Respiratory therapists draw for this profile most commonly from the radial, brachial, and femoral arteries. What is acidosis? - It is characterized by an abundance of H+ ions in the arterial blood, with a pH of less than 7.35. What are the acids? - H+, CO2, and H2CO3 (carbonic acid) How are acids produced? - They are produced during metabolic processes. How are acids excreted from the body? - Some exit via the lungs; others are buffered and excreted via kidneys. What is alkalosis? - It is characterized by a decrease of H+ ions in the arterial blood, with a pH of more than 7.45. What are the bases? - HCO3 (bicarbonate) What is a buffer? - A chemical substance that reduces changes in systemic pH by either releasing or binding H+ ions. It is considered to be a moment by moment regulation. Why is CO2 considered a "potential acid"? - Because it forms carbonic acid when combined with H2O. What are compensatory mechanisms? - Mechanisms that try to prevent large changes in pH and/or attempt to correct alterations in acid-base balance; compensatory mechanisms ALWAYS alter the pH towards a normal level. Give 2 examples of compensatory mechanisms. - Lungs and Kidneys What is partial pressure? - Pressure exerted by a single gas.