Division of Gastroenterology and Hepatology, Digestive Disease Center, Medical University of South Carolina, Charleston, SC 29425, USA.
J Clin Gastroenterol. 2012 Aug;46(7):e55-7. doi: 10.1097/MCG.0b013e318247c319.
We aim to look at the prevalence of multichannel intraluminal impedance-pH (MII-pH) studies, which are difficult to interpret secondary to low distal baseline impedance (DBI), and characterize them by their respective diagnosis and DBI.
Some patients exhibit low DBI because of fluid retention in the esophagus or acute or chronic mucosal changes. Low DBI can make MII-pH difficult to interpret.
We reviewed MII-pH reports from patients studied from January 2002 to December 2009. We conducted a computerized search of the final interpretation for the terms "low," "low baseline," "difficult," and "unable." Reflux reports stating difficult or unable to interpret were analyzed. The associated manometry studies were reviewed to obtain the DBI (mean value at 5 and 10 cm above the lower esophageal sphincter in the pretest esophageal resting state).
Of 2809 MII-pH tracings, 38 (1.4%) were classified as difficult to interpret because of low DBI. The most common underlying manometric diagnosis was ineffective esophageal motility at 36.8%, followed by 28.9% with achalasia, and 10.5% with scleroderma esophagus. An additional 15.8% of patients had increased gastroesophageal reflux on MII-pH. In only 7.9% of patients was no obvious reason for the low DBI identified. Of the 38 patients, 92% had a DBI <1000 Ω, and 58% had a DBI <500 Ω.
These findings indicate that difficulty in interpreting MII-pH due to low baseline is very infrequent, and they suggest that it is unadvisable to perform MII-pH testing on patients with a DBI <500 Ω on prior MII-esophageal manometry. If needed, pH only testing off acid-suppressing therapy may be more advisable in these patients.
我们旨在观察多通道腔内阻抗-pH（MII-pH）研究的患病率，这些研究由于远端基础阻抗（DBI）低而难以解释，并根据各自的诊断和 DBI 对其进行特征描述。
一些患者由于食管内液体潴留或急性或慢性黏膜变化而表现出低 DBI。低 DBI 会使 MII-pH 难以解释。
我们回顾了 2002 年 1 月至 2009 年 12 月期间接受研究的患者的 MII-pH 报告。我们对最终解释进行了计算机搜索，搜索的术语包括“低”、“低基线”、“困难”和“无法”。分析了报告中注明难以或无法解释的反流报告。回顾相关的测压研究以获得 DBI（在食管静息状态下，下食管括约肌上方 5cm 和 10cm 处的平均值）。
在 2809 份 MII-pH 描记图中，有 38 份（1.4%）因 DBI 低而被归类为难以解释。最常见的基础测压诊断是无效食管动力障碍，占 36.8%，其次是贲门失弛缓症，占 28.9%，硬皮病食管占 10.5%。另有 15.8%的患者在 MII-pH 上存在胃食管反流增加。在仅有 7.9%的患者中，未发现明显的低 DBI 原因。在 38 名患者中，92%的患者 DBI<1000 Ω，58%的患者 DBI<500 Ω。
这些发现表明，由于基础线低而导致 MII-pH 解释困难的情况非常罕见，并且表明对于先前 MII 食管测压的 DBI<500 Ω 的患者，不建议进行 MII-pH 测试。如果需要，在这些患者中，可能更适合在停用抑酸治疗后仅进行 pH 测试。
