Strict pre-surgical fasting often unnecessary

By Robert Davis
USA Today

There's little reason for most patients going in for elective surgery to forgo a morning coffee — but many are still told to do without. Advertiser library photo A fast rundown Listed below are foods and liquids and the minimum fasting period before surgery for each: • Light meal (for example, toast and clear liquids): 6 hours • Regular or heavy meal (may include fried or fatty food, meat): 8 hours • Clear liquids (water, clear tea, black coffee, carbonated beverages, fruit juice without pulp): 2 hours • Breast milk: 4 hours • Other milk, including infant formula: 6 hours Source: American Society of Anesthesiologists. Recommendations are for healthy patients of all ages undergoing elective surgery (including women in labor).

Through the years, doctors have told patients to take no food or liquid after midnight if they're scheduled for surgery the next morning. The doctors worried that if patients vomit under anesthesia, the contents could enter their lungs.

Updated standards allow patients to have a light breakfast before going to the hospital and water or coffee in the waiting room.

But a new study finds that the medical community has been slow to make this customer-friendly change.

"Fasting leads to hypoglycemia, dehydration, dizziness, headache, hunger, thirst and irritability," says Jeannette Crenshaw, a nurse at Presbyterian Hospital of Dallas and an author of a study in the current American Journal of Nursing.

Also, some studies suggest that fasting before surgery leads to stomach upset later.

So anesthesiologists revised their recommendations in 1999 to allow healthy people undergoing elective surgery — fixing a bum knee or putting tubes in a kid's ears — to eat and drink a little before their operation. But Crenshaw's study, "Preoperative Fasting: Old Habits Die Hard," found "inappropriate preoperative fasting," with patients forgoing solids and liquids for about 13 hours. Also of concern: Many surgical patients mistakenly skipped doses of daily medication the day of surgery.

The fasting order, known as NPO, stands for "nil per os" or "non per os," Latin for nothing by mouth. The NPO order was essential in the late 1940s because patients sometimes would vomit before or after surgery, when anesthesia made them unable to protect their airways. Too often, patients would get gastric contents in their lungs, causing serious damage and sometimes death. But today's techniques are improved and pulmonary aspiration in elective surgical patients is rare, so in the mid-1990s many hospitals revised their policies.

"In children, it really caught on," says Mark Warner, head of anesthesiology at the Mayo Clinic. He headed the task force that published the new policies in 1999. But for adult surgical patients, the change has come more slowly.

"We are a little more strict than the guidelines," says Clark Scovel, an anesthesiologist who heads the preoperative evaluation center at Vanderbilt University Medical Center. "We're trying to weigh the risk of aspiration, which is potentially life-threatening, with the inconvenience of being NPO."

Crenshaw suggests other reasons. "The biggie," she says, "is if we liberalize fasting, there's a fear that it will cause delays in surgery." If every patient in the surgical waiting room is fasting, a doctor can easily move a patient on the schedule.

But a Chicago study found little impact on surgical schedules when patients were allowed to eat a little before surgery.

"These directions should be based on research, not tradition," Crenshaw says. "Inappropriate fasting instructions lead to needless discomfort. There's no reason why most patients can't have their morning coffee."