Pulmonary hypertension — FRCA Primary MCQ

Correct answer: D — Right ventricular afterload rises with pulmonary vascular resistance

Hypoxia and hypercapnia increase pulmonary vascular resistance and right ventricular afterload. Ventilation of poorly perfused alveoli increases dead space is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. Perfusion of non-ventilated alveoli creates shunt is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. Acidosis shifts the oxyhaemoglobin curve right is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. Reduced haemoglobin lowers arterial oxygen content is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. In Primary FRCA physiology, the correct answer is usually the variable that best explains the observed change in the anaesthetised patient.

Reference: West's Respiratory Physiology; Ganong Review of Medical Physiology; Primary FRCA textbooks