Base excess — FRCA Primary MCQ

Correct answer: E — Acidosis shifts the oxyhaemoglobin curve right

A negative base excess indicates a metabolic base deficit. Left ventricular coronary perfusion occurs mainly in diastole is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. Ventilation of poorly perfused alveoli increases dead space is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. Right ventricular afterload rises with pulmonary vascular resistance is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. Increased preload increases stroke volume through fibre stretch 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