Hendrix T R
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Dysphagia. 1993;8(2):122-4. doi: 10.1007/BF02266992.
Ambulatory, long term (24-h) intraluminal esophageal pH monitoring is the "gold standard" for detection and quantification of gastroesophageal reflux. Is it, however, the "gold standard" for the diagnosis of gastroesophageal reflux disease (GERD)? The answer depends in part on how GERD is defined. Is it to be defined on the basis of symptoms, inflammatory changes in the esophageal mucosa, extent of the exposure of the esophagus to acid or some combination of these factors? Since the correlation between acid exposure of the esophageal mucosa and either symptoms or histologic changes is poor at best, it seems there must be factors in addition to acid exposure that determine the severity of symptoms and histologic damage. One such is the resistance of the individual patient's mucosa to injury by acid exposure. In view of the above, it is not surprising that no specific value for acid exposure of the esophagus can be equated with the diagnosis of GERD. The addition of the symptom index, the frequency with which symptoms coincide with reflux episodes, has done little to increase the sensitivity and specificity of pH recording in the diagnosis of GERD. Another variable only occasionally considered is the day to day variation in the frequency and duration of acid reflux. Finally, intraesophageal pH recording measures only the intensity of acid exposure but we have no clinical measure of mucosa resistance to acid-induced injury, the other factor contributing to the pathogenesis of GERD.
动态、长期（24小时）食管腔内pH监测是检测和量化胃食管反流的“金标准”。然而，它是否是胃食管反流病（GERD）诊断的“金标准”呢？答案部分取决于GERD如何定义。是基于症状、食管黏膜的炎症变化、食管暴露于酸的程度还是这些因素的某种组合来定义呢？由于食管黏膜酸暴露与症状或组织学变化之间的相关性充其量也很差，似乎除了酸暴露之外，必定还有其他因素决定症状的严重程度和组织学损伤。其中一个因素就是个体患者黏膜对酸暴露损伤的抵抗力。鉴于上述情况，食管酸暴露的特定值不能等同于GERD的诊断也就不足为奇了。增加症状指数，即症状与反流发作同时出现的频率，对提高pH记录在GERD诊断中的敏感性和特异性作用不大。另一个只是偶尔被考虑的变量是酸反流频率和持续时间的每日变化。最后，食管内pH记录仅测量酸暴露的强度，但我们没有临床方法来衡量黏膜对酸诱导损伤的抵抗力，而这是导致GERD发病机制的另一个因素。
