Case 1.
A 22-year-old shop assistant was found unconscious and on a table beside her was an empty
box from barbiturates. On admission she was comatose and cyanotic.
Arterial gases by breathing ambient air:
PaO2 40 mmHg, PaCO2 80 mm Hg
1. Could you estimate from these values, what is the cause of her hypoxemia? Is it just one
cause?
2. You calculated the alveolo-capillary gradient? What is its value in this patient?
3. What about the pH? As an ABR failure at her you would expect?
Case 2.
A 42-year-old truck driver started to suffocate while eating olives. At admission to the
emergency department he had intensified breathing sounds over the right lung and lung X-ray
showed atelectasis of the right lung.
Arterial gases by breathing ambient air:
PaO2 41 mm Hg, PaCO2 32 mm Hg and pH 7.47
1. What is the cause of the patient's hypoxemia? It's just one cause? Calculate the alveolocapillary gradient of this patient.
2. Explain his pH.
Case 3.
A 63-year-old man, heavy smoker, complains of trouble breathing. His arterial gases by
breathing ambient air are PaO2 50 mmHg, PaCO2 39 mm Hg
1. What is the cause of the patient's hypoxemia? Is it just one cause?
2. Is the patient hypoventilating?
3. Calculate the alveolo-capillary gradient of this patient.
4. Could you estimate his pH?
Case 4.
A 56-year-old lady had an accident two weeks before and her ankle was treated by not
walking cast. To move around the apartment she has got the crutches. She is experiencing
shortness of breath while trying to walk for two days now. Auscultation and X-ray of the
lungs were normal. She was sent for hypoxemia for further examination, which revealed
pulmonary embolism. Arterial gases by breathing ambient air:
PaO2 82 mm Hg, PaCO2 30 mm Hg and pH 7.48
1. What was the cause of her hypoxemia? Is it just one cause?
2. Calculate the alveolo-capillary gradient.
3. What could you say about the patient’s ventilation?
4. Has she changed ABB?