ABG Flashcards
Pa02 represents ( ) and PCO2 represents ( )
oxygenation
ventilation
normal HCO3 and PC02 values
24, 40
PaCO2 is inversely related to
alveolar ventilation
What determines PaCO2 the most***
respiratory rate, 2nd is tidal volume
Bicarb gets absorbed in
H+ ions can be absorbed/secreted in the
PCT
DCT via aldosterone
Metabolic acidosis
- loss of HCO3or addition of [H+] (HCO3<22)
Diarrhea/lower GI tract loss
Metabolic alkalosis
- loss of [H+] or addition of HCO3 (HCO3>28)
Vomiting/upper GI loss-lose HCl
Every time there is acidosis there is….
hyperkalemia….H ions are replaced with K ions because the cell is taking in H+ to neutralize it but a K+ has to be excreted to be even
Every time there is alkalosis…
hypokalemia
Respiratory acidosis
- increase in pCO2 (PaCO2>45)
Respiratory alkalosis
- decrease in pCO2 (PaCO2<35)
you can have two of the four primary acid base disturbances at the same time except for…
respiratory acidosis and alkalosis
Chronic respiratory acidosis characteristics
pH is low, PC02 is higher and bicarb is higher
Chronic respiratory alkalosis characteristics
-pH high, PCO2 and bicarb are low
3 main signs of respiratory acidosis
- hypoxia
- hyperkalemia
- dysrhytmias
in acute respiratory acidosis, if PCO2 goes up from 40 to 50, how much will bicarb of 24 go up?
1 to 25
in chronic respiratory acidosis (>24 hours), bicarb will increase by
4 units for every 10 mm/hg increase in PCO2 because kidney has more time to help
chronic hypercapnea may cause
Sleep disturbances Loss of memory Daytime Somnolence Personality changes Impairment of coordination Motor disturbances such as tremor, myoclonic jerks, and asterixis
main causes of respiratory acidosis
- brain (acute)
- lungs (chronic)
- chest wall problems (chronic)
in respiratory alkalosis, if you decrease pCO2 from 40 to 30, becoming alkalotic, bicarb will go down by…
2
If this continues bicarb will go down by 5
main sign of respiratory alkalosis
hypokalemia
Upper GI loss causes
Lower GI loss cause
metabolic alkalosis hypokalemia
metabolic acidosis also with hypokalemia
sepsis is a state of
metabolic acidosis from lactic acid
metabolic acidosis causes
hyperkalemia