ABGs Flashcards
Where do you do take an ABG?
Radial artery
What do you have to tell the machine in addition to the blood?
Oxygen
What does an ABG give you?
pH PaO2 PaCO2 HCO3 Base excess
Potassium
Lactate
Ca
Hb
What’s the normal pH of blood?
7.35-7.45
What is the normal PaO2?
10-14
If someone is on oxygen, what is the normal range?
10 minus the percentage of oxygen they’re on
What exactly is PaO2?
The percentage of oxygen in the blood (can be dissolved, no necessarily in the RBC).
What is the normal range for PaCO2?
4.5-6
What’s the normal HCO3 range?
22-26
What’s the normal base excess?
-2 to +2
What’s the normal Hb level?
120+
What’s the normal lactate level?
Less than 2
What’s the first thing you look for on an ABG?
Is it acidotic or alkalotic (look at pH)
Which value crudely tells you whether the acidosis/alkalosis is METABOLIC?
HCO3
Which value crudely tells you whether the acidosis/alkalosis is RESPIRATORY?
PaCO2
What does CO2 do in water?
Becomes Carbonic acid (H2Co3) which can split into H+ ions an HCO3-
What is partially compensated respiratory acidemia?
When the kidneys
What happens in fully compensated acidemia?
The pH levels seems normal, but either of the PaCO2 level or HCO3 level is higher
If paO2 AND paCO2 are low?
Type 1 respiratory low
If paO2 is low but PaCO2 is normal or high?
Type 2 respiratory failure
What causes type 1 respiratory failure?
PE Pneumonia Pulmonary fibrosis Asthma Pulmonary oedema Pneumothorax
Signs/symptoms of pulmonary oedema
Frothy pink sputum with cough
Better when sitting up
Signs/symptoms of pneumothorax
Gasping and breathless
Reduced chest expansion
Deviated trachea
What is severe atelectasis?
Lobar collapse of lung (collapsing of the alveoli)
Causes of type 2 respiratory failure
Reduced respiratory drive
COPD
Opiod overdose
Why must you be careful with giving oxygen for someone with COPD?
Their brain is so used to being underperfused, that if they get more oxygen, their brain will think they’re getting sufficient oxygen that it will think it won’t need to breathe as much, so their resp drive goes down, so they retain co2, hence they go into type 2 respiratory failure
What are the ways in which to give oxygen?
Nasal canula
Venturi mask
Non rebreathe ask
CPAP/BiPAP
What levels go n the same direction on an ABG if there is compensation?
HCO3 goes down if PaCO2 goes down to compensate, and in the opposite direction if it goes high
What levels go in the same direction on an ABG if there is compensation?
HCO3 goes down if PaCO2 goes down to compensate, and in the opposite direction if it goes high
