Chronic hypertension brain flow — FRCA Primary MCQ

Correct answer: D — Chronic hypertension shifts cerebral autoregulation right

Chronic hypertension shifts autoregulation toward higher pressures. Renin rises with reduced afferent arteriolar pressure is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. Left ventricular coronary perfusion occurs mainly in diastole is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. Small myelinated fibres block relatively early is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. Hypocapnia causes cerebral vasoconstriction 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