A recent study examined the accuracy of general practitioners’ overall impression based on the history and physical examination.21 Four hundred consecutive unselected patients with dyspepsia were evaluated by their general practitioners and then underwent endoscopy, upper abdominal ultrasonography, and laboratory tests. The physicians’ overall clinical impressions had a low sensitivity for diagnosing organic diseases or functional dyspepsia but were fairly specific for organic diseases Table 3. Note from the LRs that while suspicion of gallstone disease or malignancy significantly increased the likelihood of these conditions, an absence of suspicion in no way ruled them out (negative LR near 1).
Imaging studies and endoscopy
Definitively diagnosing the cause of a patient’s dyspepsia usually requires either upper endoscopy or an upper gastrointestinal (UGI) series. The former is more expensive, may not be readily available in some communities, and has a slight risk of complications (such as a 0.05% perforation rate22). Endoscopy is generally believed to be more accurate than a UGI series. However, most studies that compared the accuracy of these tests have used endoscopy as the gold standard, which creates a bias in favor of endoscopy. The few studies that have used repeat endoscopy for lesions detected by radiography but not the initial endoscopy have still shown that radiography is less accurate than endoscopy, especially for lesions smaller than 5 mm Table 4.23,24 Another advantage of endoscopy is the ability to biopsy lesions suspicious for malignancy and to perform invasive tests for H pylori infection. A patient who has a gastric ulcer detected by a UGI series should be referred for endoscopic biopsy, since up to 3% of these ulcers can harbor malignancy.9
Other imaging studies are not routinely recommended for evaluation of dyspepsia. In the absence of typical symptoms of biliary colic, abdominal ultrasonography has a very low yield11; even if gallstones are detected in a patient with dyspepsia, this may be incidental, and cholecystectomy may not improve the patient’s symptoms. Gastric-emptying studies may be abnormal in nearly 40% of patients with functional dyspepsia,25 but basing therapy on the results of these studies has not been consistently shown to benefit patients.1
Detecting H pylori
Patients with dyspepsia should be evaluated for the presence of H pylori, because this infection has been found in up to 95% of patients with duodenal ulcer and 80% with a gastric ulcer. It occurs in approximately 30% to 40% of patients without an ulcer.26 Patients with ulcers who are H pylori–positive have a markedly reduced recurrence rate after successful eradication therapy.27,28 Therefore, patients with gastric or duodenal ulcers who are infected with H pylori should be treated with a combination of antibiotics and acid suppressive agents to eradicate the infection. Noninvasive options for diagnosing H pylori include immunoglobulin G (IgG) antibody testing in serum or whole blood, urea breath tests, and stool antigen tests Table 4.
There are at least 40 commercially available IgG serologic tests. The median sensitivity and specificity are 92% and 83%, respectively, but the accuracy varies considerably.29 Whole blood serologic tests can be performed on capillary blood obtained from finger sticks, and are therefore more convenient than serum tests that require venipuncture but are not recommended because they are less sensitive.30,31 Because patients may have persistently positive IgG antibodies for many months after eradication therapy, a serologic test will often give a false-positive result during that period.32
Urea breath tests are able to detect an active H pylori infection. Patients ingest a specific food or drink that contains carbon-labeled urea. Gastric urease activity, which is highly specific for active H pylori infection, converts the carbon-labeled urea to labeled carbon dioxide and ammonia. The patient breathes into a container, and a positive test occurs when the labeled carbon dioxide exceeds a threshold level. Both 13Carbon and 14Carbon are used. The latter exposes patients to a negligible amount of radioactivity, but is simple, rapid, and less expensive than the 13 carbon tests. In comparative studies, the urea breath tests are more accurate than serologic tests.33,34
Stool antigen is involved in the most recently developed noninvasive test. The few studies that have been conducted to date have demonstrated that these tests are highly accurate.35 The stool antigen has recently been recommended by the European Helicobacter Pylori Study Group as the preferred initial noninvasive diagnostic test.36
Approach to the patient
There are a variety of possible approaches to the initial management of patients with dyspepsia. These include (1) prompt endoscopy (or UGI) for all patients, (2) prompt endoscopy (or UGI) for patients at highest risk for organic disease, (3) empiric acid suppression therapy for all patients with testing reserved for patients who remain symptomatic, (4) empiric H pylori eradication therapy for all patients, and (5) noninvasive H pylori testing for all patients, followed by empiric eradication therapy for those with positive results and empiric treatment of functional dyspepsia for those with negative results (a “test and treat” approach).