A 27 year old female with a known history of asthma presents to the ED with breathlessness and wheeze with no relief from using her salbutamol inhaler. Vital signs are as follows: HR = 136 RR = 25 BP=101/61 mmHg SaO2 = 92%. An ABG is taken and the results reveal the following numbers:
pH = 7.29
PaO2 = 8 kPa
PaCO2 = 6.2kPa
HCO3 = 24 mmol/L
Which type of acid-base abnormality does the ABG show?
Well done, correct.
Answer:
Step 1: The history suggests exacerbation of asthma.
Step 2: PaO2 is low so the patient is hypoxic and the patient is also hypercapnic suggesting type 2 respiratory failure.
Step 3: pH is lower than normal and so the patient is acidotic.
Step 4: PaCO2 is increased.
Step 5: HCO3 is normal.
Putting the information together and using the ROME mnemonic we come to the conclusion that this is a respiratory acidosis with no metabolic compensation.
