Pehl Christian, Boccali Ilona, Hennig Michael, Schepp Wolfgang
Department of Gastroenterology, Hepatology and Gastrointestinal Oncology, Academic Teaching Hospital Bogenhausen, Munich, Germany.
Eur J Gastroenterol Hepatol. 2004 Apr;16(4):375-82. doi: 10.1097/00042737-200404000-00002.
Before pH measurement, manometry is recommended for precise pH probe positioning. We investigated whether the pH probe could be positioned accurately by the pH difference between the oesophagus and the stomach (pH step-up).
Dual-channel 24-h pH-metry with probes positioned 5 cm above either the manometrically determined upper lower oesophageal sphincter margin or the pH step-up was performed in healthy volunteers and reflux patients. To determine the pH step-up, the pH probe was pulled back from the stomach until a sudden rise to pH greater than four occurred. Probe position, reflux episodes and the fraction of the time pH was less than four were compared using the Wilcoxon test for difference and the Hodges-Lehman estimate inclusive confidence interval for equivalence. The pH step-up method was evaluated further during proton pump inhibitor therapy and after drug discontinuation.
The pH probe was positioned 2 cm and 1 cm closer to the stomach by the pH step-up method in the volunteers and reflux patients, respectively. A small increase in upright reflux episodes but not in supine reflux episodes was registered by the probe positioned by pH step-up. No significant differences in the fraction of the time pH was less than four were obtained between the two probes. The Hodges-Lehman calculation proved equivalence for both methods of probe positioning for 24-h pH-metry. During proton pump inhibitor therapy, no pH step-up was detectable in three volunteers and in one patient. On the first day after discontinuing therapy, the pH step-up method yielded clear-cut results again.
The pH probe for diagnostic 24-h pH-metry and, with some limitations, also for 24-h pH-metry for therapy control, can be positioned accurately by the pH step-up method.
在进行pH测量之前，建议进行测压以精确放置pH探头。我们研究了是否可以通过食管和胃之间的pH差异（pH升高）来准确放置pH探头。
在健康志愿者和反流患者中进行双通道24小时pH测量，探头放置在测压确定的食管上下括约肌边缘上方5厘米处或pH升高处。为了确定pH升高，将pH探头从胃中撤回，直到pH突然升至大于4。使用Wilcoxon差异检验和Hodges-Lehman估计包含性置信区间进行等效性比较，比较探头位置、反流发作次数和pH小于4的时间比例。在质子泵抑制剂治疗期间和停药后，进一步评估pH升高方法。
在志愿者和反流患者中，通过pH升高方法，pH探头分别更靠近胃2厘米和1厘米。通过pH升高放置的探头记录到直立反流发作次数略有增加，但仰卧反流发作次数没有增加。两种探头在pH小于4的时间比例上没有显著差异。Hodges-Lehman计算证明两种探头放置方法在24小时pH测量中具有等效性。在质子泵抑制剂治疗期间，三名志愿者和一名患者未检测到pH升高。在停药后的第一天，pH升高方法再次产生明确的结果。
用于诊断性24小时pH测量的pH探头，以及在一定限制下用于治疗控制的24小时pH测量的探头，可以通过pH升高方法准确放置。
