Arterial Blood Gases (ABG\\\'s)
, Arterial Blood Gases (ABG's)
What is an ABG? Answer- 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? Answer- Respiratory
therapists draw for this profile most commonly from the radial, brachial, and femoral
arteries.
What is acidosis? Answer- 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? Answer- H+, CO2, and H2CO3 (carbonic acid)
How are acids produced? Answer- They are produced during metabolic processes.
How are acids excreted from the body? Answer- Some exit via the lungs; others are
buffered and excreted via kidneys.
What is alkalosis? Answer- 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? Answer- HCO3 (bicarbonate)
What is a buffer? Answer- 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"? Answer- Because it forms carbonic acid
when combined with H2O.
What are compensatory mechanisms? Answer- 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. Answer- Lungs and Kidneys
What is partial pressure? Answer- Pressure exerted by a single gas.
What is the goal in the regulation of pH? Answer- To maintain or restore body pH to a
normal level - either through buffers or compensatory mechanisms.
, Arterial Blood Gases (ABG's)
What is an ABG? Answer- 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? Answer- Respiratory
therapists draw for this profile most commonly from the radial, brachial, and femoral
arteries.
What is acidosis? Answer- 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? Answer- H+, CO2, and H2CO3 (carbonic acid)
How are acids produced? Answer- They are produced during metabolic processes.
How are acids excreted from the body? Answer- Some exit via the lungs; others are
buffered and excreted via kidneys.
What is alkalosis? Answer- 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? Answer- HCO3 (bicarbonate)
What is a buffer? Answer- 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"? Answer- Because it forms carbonic acid
when combined with H2O.
What are compensatory mechanisms? Answer- 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. Answer- Lungs and Kidneys
What is partial pressure? Answer- Pressure exerted by a single gas.
What is the goal in the regulation of pH? Answer- To maintain or restore body pH to a
normal level - either through buffers or compensatory mechanisms.
