Chewing gum before surgery is a common concern for patients preparing for a procedure requiring anesthesia. Rules surrounding oral intake before an operation are strictly enforced for patient safety. These protocols protect the airway and lungs when protective reflexes are suspended by anesthetic medications. The instruction against chewing gum relates directly to how the body prepares for digestion and the risks associated with having contents in the stomach during general anesthesia.
Understanding Pre-Surgical Fasting Guidelines
The standard medical directive for restricting oral intake before surgery is known as “Nil per os,” often abbreviated as NPO, which is Latin for “nothing by mouth.” These guidelines are established protocols set by anesthesiologists and surgical teams to minimize the volume and acidity of contents in the stomach. The duration of the fast varies based on the type of substance consumed.
For healthy adults undergoing elective procedures, the standard recommendation is to fast from solid food and non-clear liquids, such as milk, for six to eight hours prior to the procedure. However, the fasting period for clear liquids, such as water or plain black coffee, is often much shorter, typically two hours before the administration of anesthesia. These timelines are based on how quickly different substances clear the stomach, ensuring the organ is as empty as possible when the procedure begins.
How Chewing Gum Affects Stomach Contents
The act of chewing, even without swallowing, signals the body to prepare for food. This process, known as the cephalic phase of digestion, triggers physiological responses. Chewing stimulates the salivary glands to produce saliva, which is swallowed and adds liquid volume to the stomach.
The motion of chewing also stimulates the vagus nerve, signaling the stomach to begin the digestive process. This prompts the release of gastric acid and other digestive juices. While studies suggest chewing gum may not significantly alter the acidity of stomach contents, it consistently increases the volume of liquid present. This increased fluid volume poses a safety concern during the induction of general anesthesia.
The Risk: Aspiration During Anesthesia
The primary danger pre-surgical fasting seeks to prevent is pulmonary aspiration, a severe complication occurring when stomach contents enter the lungs. General anesthesia relaxes the body’s muscles and suppresses protective reflexes. This includes relaxing the lower esophageal sphincter, the muscle ring that normally acts as a one-way valve between the esophagus and the stomach.
When this sphincter relaxes, material in the stomach can easily reflux into the esophagus and the back of the throat. If this material is inhaled into the trachea and lungs, it causes aspiration pneumonitis. The severity of this lung injury relates directly to the volume and high acidity of the stomach contents. Aspiration pneumonitis can lead to respiratory distress, infection, and can be life-threatening.
What To Do If You Have Chewed Gum
If you have inadvertently chewed gum before surgery, the immediate step is to inform a member of your surgical team, such as the pre-operative nurse or the anesthesiologist. Honesty about oral intake is necessary for the safety assessment before the procedure. The surgical team needs this information to make an informed decision regarding your care.
The anesthesiologist assesses the situation by considering factors like the type of gum, how long it was chewed, and your overall health status. Depending on the circumstances, the team may determine that the slight increase in gastric volume does not warrant a delay, particularly for healthy individuals. However, in some cases, the surgery may need to be postponed for a few hours to allow the stomach to empty completely before anesthesia is administered.