Expel common myths about gastroparesis

Updated definition of gastroparesis came out in January.

Gastroparesis treatment is in transition. “A lot of the things I was taught 10 years ago are no longer true,” said Ellen Stein, MD, ACP Member, a gastroenterologist and assistant professor of medicine at Johns Hopkins University in Baltimore. Dr. Stein described recent changes in practice, and a number of common myths about gastroparesis, during a session at Hospital Medicine 2013, held in National Harbor, Md., this May.

An updated definition of gastroparesis was provided by the American College of Gastroenterology (ACG) in January. The ACG guideline says diagnosis should be based on “symptoms of gastroparesis, absence of gastric outlet obstruction or ulceration, and presence of delay in gastric emptying.” The last of these should be documented before a therapy is selected.

The definitive method for documenting delay is four-hour gastric emptying scintigraphy (GES), which can be a problem to coordinate before discharge from a brief hospitalization, Dr. Stein noted. “I'm sure you find it very hard to get that GES done in the four hours before they go to discharge, and it may be better to do once their symptoms settle down for a few days,” she said.

But a little saved time can actually lead to a lot of wasted time, if patients go home and then return to the emergency department repeatedly because they're still sick. Gastroparesis patients may not show how sick they are after a PO challenge because their stomachs do not empty for more than three or four hours, Dr. Stein explained. Sometimes, this means that the patients appear stable for discharge at two hours, but when they go home, they have symptom recurrence and need to return to the emergency room. “Waiting a little longer to be sure symptoms responded to medical therapy may help for a better transition for more severe cases,” she said.

There are also some confounders to consider with the GES test. If a patient has hyperglycemia, that can be the cause of gastric emptying delay, so blood glucose should be checked and treated to below 200 mg/dL before testing. Smoking is not permitted before testing, either.

Medications such as narcotics, anticholinergics, glucagon-like peptides and amylin analogues can affect gastric emptying. “We do try to stop these medications in as many patients as possible,” said Dr. Stein, noting that it's not always feasible to stop a medicine before testing, for example, in a patient reliant on narcotics.

Patients who have recently suffered a viral illness can appear to have gastroparesis based on the four-hour test, but the condition may later resolve on its own. A recent illness is one of many history issues that should be investigated in suspected gastroparesis cases, or even in patients who have been previously diagnosed with the condition and now have new symptoms.

Get a really good history, and don't hesitate to contact a gastroenterologist for assistance, Dr. Stein advised.

“You really have to do the work-up for nausea and vomiting. You can't just assume it's gastroparesis,” she said. “If she has a uterus, check a pregnancy test.” Even in patients with a known diagnosis of gastroparesis, flare-like symptoms can actually be caused by more usual suspects, like appendicitis or kidney stones.

And remember that not all gastroparesis patients will be thin; actually many are overweight. “If you really had gastroparesis, you'd be thin” is one of the more damaging myths about the disease, Dr. Stein said. Obese patients can have it and can even require nutritional support if they've recently lost 10% or more of their body weight. People can also have gastroparesis without diabetes. The most common causes, however, are idiopathic, post-surgical and diabetes.

Nutrition is an important concern for these patients, who may believe that they should subsist on soda and crackers. “You really need the dietician to go over things with them,” said Dr. Stein. “If they can't tolerate solid food, my favorite thing to recommend is buy a blender. It can keep them out of the hospital.” Patients may be disappointed, she noted, because they expect to go back to eating junk food as soon as they leave the hospital. Instead, when they can tolerate solid food, they should opt for four to six low-fat, low-fiber meals per day.

Patients should be relieved, however, that one of the other top myths is “There is nothing that can be done for gastroparesis.” Controlling blood sugar and eliminating offending medications can resolve symptoms, as can medical, endoscopic (gastro-jejunal feeding) or surgical (gastric pacers) therapy, Dr. Stein said.

Among the medical options, metoclopramide is still a first-line therapy despite concerns about tardive dyskinesia (which patients should be warned to watch for); domperidone is showing promise as an investigational drug (although it affects the QT interval and requires electrocardiograms); and erythromycin works well (IV for inpatients, oral for outpatients) but may lose effectiveness due to tachyphylaxis in long-term treatment. Antiemetics and tricyclic antidepressants help with control of nausea and vomiting, but not gastric emptying.

The treatability of gastroparesis is an important lesson for both patients and physicians. Dr. Stein has seen many patients who have been repeatedly treated and discharged at hospitals. “Their biggest complaint is, ‘The doctors never do anything for me,’” she said.

Hospitalists can help even by just addressing gastroparesis patients' pain, since the absence of pain as a symptom is another common myth. Actually, 46% to 90% of gastroparesis patients have pain, according to study data. “Establish trust with your patients and acknowledge their pain and suffering,” Dr. Stein advised.