The question always comes up about what to eat before surgery. Usually, patients are told to be "NPO" (nothing by mouth) after midnight. This means no food or drink after midnight. It is recommended that you fast at least 8 hours prior to surgery. NPO after midnight doesn't mean you should stuff yourself with cheesecake at 11:58 PM. Eat a normal meal in the evening and even a snack before you go to sleep- just as long as you go to sleep before midnight. Does this mean if your surgery is scheduled for 2 PM that you can eat breakfast at 6 AM? Not really. What happens frequently is that surgery begins sooner than scheduled and even if your surgery is at 2 PM, you should still fast after midnight. Your surgery may always be moved up !

The reasons for these precautions are for your own safety and to help your anesthesiologist protect your lungs. How does not eating protect your lungs? Well, anesthesiologists try to do everything possible to prevent aspiration. Aspiration is not something you "aspire" to but rather what happens when acid/food/liquid etc. in your stomach, gets regurgitated into your lungs. This can have a grave consequence, and the less food and acid in your stomach, the less chance you will aspirate. Because of this, the recommendation is NPO after midnight.

But why should someone aspirate you may ask? Well, general anesthesia for surgery causes you to lose all your reflexes including the cough and gag reflexes which protect your airway and lungs. While you are anesthetized or sedated, it is easier for anything in the stomach to be regurgitated into the lungs.

Some people are more likely to have food in their stomach despite being NPO for a long time. Patients with diabetes and reflux fall into this group and may be given an antacid or some IV medication to speed up the rate at which the stomach empties.

There are some exceptions to the NPO after midnight rule involving children and babies. Newborns need to eat every 2-4 hours and therefore keeping them NPO for 8 hours before surgery can really dehydrate them, not to mention the screams the parents would hear if we suggested this. Newborns can have formula up to 4 hours before surgery. They can even have clear liquids e.g. water, apple juice or Pedialyte, up to 2 hours before surgery. Breast milk is considered by some to be similar to formula and mothers may nurse their infants up to 4 hours before the surgery. For small children, the clear liquid limit is 4 hours prior to the anesthesia. The longer they can last however, the better. In any case, always check with the surgical and anesthesia teams prior to any surgery.