Answers:
Question 1:
A 45-year-old man presents with vomiting and numbness on his fingers . He has CML and he is on chemotherapy. His blood biochemistry showed the following:
Na = 130 mmol/L
K = 6.8 mmol/L
PH = 7.30, that is mild acidaemia.
HCO3 = 16.6 mmol/L. So, we have metabolic acidosis.
Next, we need to calculate the anion gap and the compensation for this patient.
50-year-old man with history of type II diabetes and colorectal cancer. He is on Metformin and other anti-diabetic medications. He has been started on new chemotherapeutic medication. He has nausea and poor oral intake. He presented with hypoglycemia. Sugar level was corrected on arrival, his venous blood gases showed the following:
PH = 7.30
pCO2 = 34.4 mmHg
Question 1:
PH = 7.13, that is moderate acidaemia.
HCO3 = 9.4 mmol/L, Accordingly, it is metabolic acidosis.
Next, we need to calculate the respiratory compensation and the anion gap.
39-year-old lady with history of gestational diabetes x2. This patient stopped eating due to mood disturbances. Her venous blood gases showed the following:
PH = 7.17
pCO2 = 26 mmHg
Question 1:
PH = 7.31 That is mild acidosis
PCO2 = 61, that is high (>40). So, we have respiratory acidosis. Next we need to look at HCO3 to determine if it is acute or chronic respiratory acidosis.
65 year old lady with history of COPD presented with shortness of breath. He chest auscultation revealed bilateral wheezes.
Her arterial blood gas on 40% O2 showed the following:
PH = 7.31
PCO2 = 61 mmHg
40-year-old man was brought to ED with low GCS after an ingestion of unknown substance. His arterial blood gases (after intubation) showed the following:
PH = 7.12
pCO2 = 31 mmHg
Answers:
PH = 7.56, that is moderate alkalaemia
We have low pCO2 (34 mmHg) and high HCO3 (30 mmol/L), both these values can lead to alkalosis. Most likely combined alkalosis. However, it will be easier to calculate the compensation with metabolic part (Then we don’t need to think acute vs chronic) and ultimately we will end up with the same results.