Transcript Arterial Blood Gas Analysis

ARTERIAL BLOOD GAS
ANALYSIS
Nur 211
Gail L Lupica PhD, RN, CNE
ABGS
What does an arterial blood gas give us
information about?
What does an arterial blood gas give us
information about?
1.
Acid-Base balance
2.
Oxygenation status
What are the components and the normal
parameters?
• Ph 7.35 – 7.45
• PaO2 80 – 100mmHg
• PaCo2 35 – 45mmHg
• HCO3- 23 – 28mEq/L
• SaO2 90 – 100%
Acid-Base Balance
For starters:
• What is an acid? A H+ ion donor
• What is a base? A H+ ion receiver
• The balance between acids and bases in
the body provides the homeostatic
environment where body cells can
function best. Even slight imbalances
can affect body functions. Conditions
such as infection, organ dysfunction,
trauma, or medications can affect acidbase balance.
In order to assess acid-base balance
according to the ABG results, we
need to look at three of the five
components of the ABG.
1. Ph
2. PaCo2
3. HCO3-
WHAT DOES EACH
COMPONENT MEAN?
Let’s look
1.
Ph:
7.35 – 7.45
• H+ ion concentration in the blood
• <7.35= acidic
• >7.45= alkalemic
• Must look at PaCo2 and HCo3- to determine this.
PaC02
35-45 mmHg
• Represents alveolar ventilation
• It’s a potential ACID in the body.
• Consider it an acid!
Example
ph
7.30
pC02 50 mmHg
What is this?
WHAT ARE SOME
CAUSES OF ALVEOLAR
HYPOVENTILATION?
Example
ph
7.48
paC02 30mmHg
What is this?
What are some causes of alveolar
hyperventilation?
What if??????
ph
7.28
paC02 30 mmHg
What’s going on here?
COMPENSATION
HC0322-28mEq/L
The metabolic component.
Regulated by the renal system.
HC03- is a BASE….. The higher it is the more alkalemic
(basic) the arterial blood is.
Example
Ph 7.52
HC03- 32
What is this?
What could cause a metabolic alkalosis?
Example
Ph
7.32
HC03- 17
What is this?
What could cause a metabolic acidosis?
What type of patient did we study that falls into this
category?
What about this?
Ph 7.22
C02 26
HC03- 14
Uncompensated Metabolic Acidosis
OXYGENATION
Where do we look to judge a patient’s oxygenation status
on the ABG?
What do we look at when we don’t have an ABG?
Pa02
80-100 mmHg
< 80 indicates hypoxemia
< 60 indicates severe hypoxemia
Pa02
• What would happen to the ph if the cells were so deprived
of oxygen they had to switch over to anaerobic
metabolism? (Hint: What is the byproduct of anaerobic
metabolism?)
02 saturation
90-100%
The amount of 02 bound to Hg in relation to how much it
can hold
Question
• Does 02 saturation always positively correlate with Pa02?
Is it equally correlated?
Lots of Practice
• Now we are ready to interpret our
page of ABGs!