Gastric emptying opioids — FRCA Primary MCQ

Correct answer: D — ADH inserts aquaporin-2 channels in collecting ducts

Opioids reduce gastrointestinal motility through mu receptor effects. Left ventricular coronary perfusion occurs mainly in diastole is less appropriate because it would fit a different clinical clue or a separate anaesthetic problem. High oxygen consumption and low FRC shorten safe apnoea time 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. Raised PaCO2 lowers alveolar oxygen tension 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