If you have been advised to undergo any kind of surgery, you will in most cases be told not to eat for at least 8-12 hours prior to the procedure. Depending on the type of surgery, you may be allowed to consume a small amount of water. While fasting may seem like an unnecessary bother to you, it’s extremely important and can affect the outcome of the surgery. The consumption of food prior to surgery can increase the risk of various complications, which is why patients are instructed against the consumption of any food or fluid prior to surgery. Some of the reasons for this requirement are as follows:
Decrease the possibility of getting infections
Abrupt intake of food increases the risk of getting stomach and intestinal infection in those patients who undergo gastrointestinal surgery. This may occur because the food contents in the stomach and intestine interfere with the ongoing surgical procedure and thus complicates it, resulting in gut infection.
Reduces the risk during anesthesia
When physicians inject anesthesia, the person’s bodily reflexes temporarily stop and the body attains a ‘sleep mode’. In that condition, swallowing becomes unfeasible. Moreover, the body also loses its gasopharyngeal reflex (protective reflex to stop the backflow of food from the stomach to the throat) under the influence of anesthesia. In that state, the risk of backflow of food substances (from the stomach to the esophagus) becomes considerably high. Additionally, while inhaling, the food content that is regurgitated may also spill into your lungs (due to the loss of protective gag reflex) via the air passage. These food substances may effectively block the flow of air to the lungs leading to complications like pulmonary aspiration. This situation may even put some patients at a risk of pneumonia. An empty stomach significantly decreases the risk of pulmonary aspiration and thus pneumonia.
Reduces the risk of acidity
In some patients who suffer from problems like GERD (Gastroesophageal reflux disorder) or gastric paresis (paralysis of the stomach; mostly occurs in diabetic patients), the rule of keeping an overnight fast should strictly be followed prior to the surgery. A heavy meal before surgery may cause acidity in these patients which leads to vomiting as well. Such patients are usually advised to follow a fast for a longer period for their own safety.
Although in recent years the fasting guidelines have been modified, most of patients are still advised to follow an overnight fasting procedure. However, it is always reasonable to talk to your doctor about your fasting requirements. In some cases, doctors may even advise patients to maintain a fast for more than 12 hours. The duration depends on the health status of the patient and the type of surgery.