How long should a healthy adult patient be fasted prior to surgery?

• A. 2-4 hours
• B. 0 hours
• C. 6-12 hours
• D. 24 hours

Answer: (C)

Fasting before anesthesia mainly aims to minimize the risk of stomach contents being aspirated into the lungs during induction, while avoiding excessive fasting that can cause dehydration or hypoglycemia. For a healthy adult, the stomach typically empties solid meals within a window of six to twelve hours. This range provides enough time for most solid foods to clear, reducing aspiration risk, without imposing unnecessary fasting that can cause discomfort or metabolic stress. Shortening the fasting period too much leaves solid contents in the stomach, increasing risk, while extending it beyond the window offers little additional protection and can be harmful. So, six to twelve hours is the best general guideline for a healthy adult prior to surgery. (Clear fluids are handled differently and may be allowed closer to induction, depending on policy.)