JOINT BASE ELMENDORF-RICHARDSON, Alaska -- It is 6 a.m. the morning of your scheduled surgery at the hospital on JBER and you wake up starving. The surgical staff has informed you not to eat anything after midnight, but you think a little snack won’t be a problem, right?
Once you arrive for your surgery at 9 a.m. and inform the staff you had a light snack, they tell you your surgery has been cancelled or postponed for at least 8 hours. What’s the big idea? It was only a light snack, it wasn’t a full meal. Well, there is a reason why we would like for you to follow these instructions on not eating anything for at least 8 hours prior to having a surgery.
According to the American Society of Anesthesiologists (ASA), “preoperative fasting is defined as the prescribed period of time before a procedure when patients are not allowed to intake orals liquids or solids”. These guidelines state patients should not eat food eight hours prior to a procedure, but may consume up to 8 ounces of clear liquids two hours prior.
Here at the JBER Hospital, our anesthesia staff advises patients not to eat or drink anything after midnight. We ask you to do this to prevent aspiration during surgery and to allow for fluctuation within the schedule, if needed. Aspiration is the medical term for inhaling food or liquid into the lungs, making it difficult for you to breathe.
These guidelines are more strict than the American Society of Anesthesiologists (ASA) guidelines, however, if patients have eaten, the below chart outlines the absolute restrictions for consuming liquids and light meals prior to having surgery
Clear liquids: 2 hours prior to surgery (Water, fruit juice without pulp carbonated beverages, clear tea, and black coffee)
Breast Milk: 4 hours prior to surgery
Infant Formula: 6 hours prior to surgery
Non-human Milk: 6 hours prior to surgery
Light Meal: 6 hours prior to surgery
Consuming food and liquids outside of the above parameters, increases the risk of aspiration during surgery once you are asleep. When the anesthesia staff puts you to sleep, your body loses the ability to use its’ normal reflexes, such as coughing when something goes down the “wrong pipe”. If you were to vomit or have gastric reflux (when stomach contents flow back into the food pipe), it would be likely that the food in your stomach will end up in your lungs, resulting in pneumonia.
Medications that can assist in preventing stomach acid secretion can be given by the anesthesia staff to decrease the possibility of aspiration. Since these medications are not routinely given, it is still best practice and safest for patients to fast prior to surgery.
Fasting the night before a scheduled surgery is uncomfortable but necessary. You may be starving but you are safer!
More information on Perioperative fasting can be found at the American Society of Anesthesiologists.
Lieutenant Colonel Brian Kraft is a Nurse Anesthetist and Chief of the Anesthesia Department at the JBER Hospital.