Department of Surgery, Keck School of Medicine, University of Southern California, 1510 San Pablo Street, Suite 514, Los Angeles, CA 90033, USA.
J Gastrointest Surg. 2010 Nov;14(11):1653-9. doi: 10.1007/s11605-010-1327-3. Epub 2010 Sep 11.
Cervical esophageal pH monitoring using a pH threshold of <4 in the diagnosis of laryngopharyngeal reflux (LPR) is disappointing. We hypothesized that failure to maintain adequate alkalization instead of acidification of the cervical esophagus may be a better indicator of cervical esophageal exposure to gastric juice. The aim of this study was to define normal values for the percent time the cervical esophagus is exposed to a pH ≥7 and to use the inability to maintain this as an indicator for diagnosis of LPR.
Fifty-nine asymptomatic volunteers had a complete foregut evaluation including pH monitoring of the cervical esophagus. Cervical esophageal exposure to a pH <4 was calculated, and the records were reanalyzed using the threshold pH ≥7. The sensitivity of these two pH thresholds was compared in a group of 51 patients with LPR symptoms that were completely relieved after an antireflux operation.
Compared to normal subjects, patients with LPR were less able to maintain an alkaline pH in the cervical esophagus, as expressed by a lower median percent time pH ≥ 7 (10.4 vs. 38.2, p < 0.0001). In normal subjects, the fifth percentile value for percent time pH ≥ 7 in the cervical esophagus was 19.6%. In 84% of the LPR patients (43/51), the percent time pH ≥ 7 were below the threshold of 19.6%. In contrast, 69% (35/51) had an abnormal test when the pH records were analyzed using the percent time pH < 4. Of the 16 patients with a false negative test using pH < 4, 11 (69%) were identified as having an abnormal study when the threshold of pH ≥ 7 was used.
Normal subjects should have a pH ≥7 in cervical esophagus for at least 19.6% of the monitored period. Failure to maintain this alkaline environment is a more sensitive indicator in the diagnosis of the LPR and identifies two thirds of the patients with a false negative test using pH <4.
使用 pH 值<4 作为诊断喉咽反流（LPR）的标准，对颈段食管 pH 监测的效果并不理想。我们假设，未能维持颈段食管充分碱化而不是酸化可能是胃食管反流物暴露于颈段食管的更好指标。本研究旨在确定颈段食管 pH 值≥7 的时间百分比的正常值，并将无法维持这一值作为 LPR 诊断的指标。
59 名无症状志愿者接受了完整的上消化道评估，包括颈段食管 pH 监测。计算颈段食管 pH 值<4 的暴露时间，并使用 pH 值≥7 作为新的阈值重新分析记录。将这两个 pH 阈值的敏感性与 51 例 LPR 症状患者进行比较，这些患者在抗反流手术后症状完全缓解。
与正常受试者相比，LPR 患者在颈段食管维持碱性 pH 值的能力较差，表现为 pH 值≥7 的中位时间百分比较低（10.4% vs. 38.2%，p<0.0001）。在正常受试者中，颈段食管 pH 值≥7 的第 5 百分位数为 19.6%。在 84%（43/51）的 LPR 患者中，pH 值≥7 的时间百分比低于 19.6%的阈值。相比之下，当使用 pH 值<4 作为分析标准时，69%（35/51）的患者检测结果异常。在使用 pH 值<4 作为分析标准时出现假阴性检测的 16 例患者中，有 11 例（69%）患者在使用 pH 值≥7 的阈值时被诊断为异常。
正常受试者应至少有 19.6%的监测时间颈段食管 pH 值≥7。未能维持这种碱性环境是 LPR 诊断中更敏感的指标，它可以识别出使用 pH 值<4 作为分析标准时出现假阴性检测的三分之二的患者。
