After finishing a big meal, you feel it – that scorched feeling in your chest. pH testing has uses in the management of GERD other than just diagnosing GERD. For example, the test can help determine why GERD symptoms do not respond to treatment. Perhaps 10 to 20 percent of patients will not have their symptoms substantially improved by treatment for GERD. This lack of response to treatment could be caused by ineffective treatment. This means that the medication is not adequately suppressing the production of acid by the stomach and is not reducing acid reflux. Alternatively, the lack of response can be explained by an incorrect diagnosis of GERD. In both of these situations, the pH test can be very useful. If testing reveals substantial reflux of acid while medication is continued, then the treatment is ineffective and will need to be changed. If testing reveals good acid suppression with minimal reflux of acid, the diagnosis of GERD is likely to be wrong and other causes for the symptoms need to be sought.
Barrett’s esophagus can be recognized visually at the time of an endoscopy and confirmed by microscopic examination of the lining cells. Then, patients with Barrett’s esophagus can undergo periodic surveillance endoscopies with biopsies although there is not agreement as to which patients require surveillance. The purpose of surveillance is to detect progression from pre- cancer to more cancerous changes so that cancer -preventing treatment can be started. It also is believed that patients with Barrett’s on the main page esophagus should receive maximum treatment for GERD to prevent further damage to the esophagus. Procedures are being studied that remove the abnormal lining cells. Several endoscopic, non-surgical techniques can be used to remove the cells. These techniques are attractive because they do not require surgery; however, there are associated with complications, and the long-term effectiveness of the treatments has not yet been determined. Surgical removal of the esophagus is always an option.
The advantage of the capsule over standard pH testing is that there is no discomfort from a catheter that passes through the throat and nose. Moreover, with the capsule, patients look normal (they don’t have a catheter protruding from their noses) and are more likely to go about their daily activities, for example, go to work, without feeling self-conscious. Because the capsule records for a longer period than the catheter (48 versus 24 hours), more data on acid reflux and symptoms are obtained. Nevertheless, it is not clear whether obtaining additional information is important.
It appears that the diaphragm that surrounds the LES is important in preventing reflux. That is, in individuals without hiatal hernias, the diaphragm surrounding the esophagus is continuously contracted, but then relaxes with swallows, just like the LES. Note that the effects of the LES and diaphragm occur at the same location in patients without hiatal hernias. Therefore, the barrier to reflux is equal to the sum of the pressures generated by the LES and the diaphragm. When the LES moves into the chest with a hiatal hernia, the diaphragm and the LES continue to exert their pressures and barrier effect. However, they now do so at different locations. Consequently, the pressures are no longer additive. Instead, a single, high-pressure barrier to reflux is replaced by two barriers of lower pressure, and reflux thus occurs more easily. So, decreasing the pressure barrier is one way that a hiatal hernia can contribute to reflux.
The acid perfusion test, however, is used only rarely. A better test for correlating pain and acid reflux is a 24-hour esophageal pH or pH capsule study during which patients note when they are having pain. It then can be determined from the pH recording if there was an episode of acid reflux at the time of the pain. This is the preferable way of deciding if acid reflux is causing a patient’s pain. It does not work well, however, for patients who have infrequent pain, for example every two to three days, which may be missed by a one or two day pH study. In these cases, an acid perfusion test may be reasonable.