Right heart failure — FRCA Primary MCQ

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

Pulmonary vasoconstriction increases RV afterload and can precipitate RV failure. Renin rises with reduced afferent arteriolar pressure 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. Citrate binds ionised calcium is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. Hypothermia shifts the oxyhaemoglobin curve left 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