ABG algorithm Flashcards
1
Q
Step 1 of acidosis
pH is low => acidosis
What is the PCO2
A
Normal or low
- metabolic acidosis
- if low => partial compensation
High
- respiratory acidosis
- move onto step 2
2
Q
Step 2 of acidosis
Is the sum of PCO2 and PO2 greater than 18kPa
A
No
-lung problem with inadequate alveolar ventilation
Yes
- respiratory depression
- too much O2 for CO2 retainer
3
Q
Step 1 of alkalosis
pH is high => alkalosis
What is the PCO2
A
Normal or high
- metabolic alkalosis
- if high => partial compensation
Low
-respiratory alkalosis
move onto step 2
4
Q
Step 2 of alkalosis
Is the PO2 low
A
No
-other driver for ventilation (anxiety, pain)
Yes
-gas exchange problem driving increased ventilation (asthma, fibrosis, altitude)
5
Q
What if the pH is normal but the PO2, PCO2 and HCO3 values are not
A
Full compensation is occuring
If CO2 retention is chronic, HCO3 will also be high
