Nasi Ary, Frare Rita de Cássia, Brandão Jeovana F, Falcão Angela M, Muchelsohn Nelson H, Sifrim Daniel
Laboratório de Investigação Funcional do Esôfago do Serviço de Cirurgia do Esôfago do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo.
Arq Gastroenterol. 2008 Oct-Dec;45(4):261-7. doi: 10.1590/s0004-28032008000400002.
By internationally accepted standardization, the esophageal pH-meter distal sensor is positioned 5 cm above the superior border of the lower esophageal sphincter, identified by esophageal manometry. However, several authors suggest alternative positioning techniques that leave out the manometry; among such techniques, the pH step-up is the one to be pointed out. This subject is controversial; some publications state that the step-up technique is not reliable while some others consider it reliable.
Considering the existent controversy and the small number of prospective works with suitable sample and methodology, we have idealized the present study, that aims the evaluation of the suitability of the pH-meter distal sensor positioning based on the step-up technique, by analyzing the presence, the type and the degree of the error of positioning that such technique provides and the influence of the position adopted by the patient during the procedure.
One thousand and thirty one patients conducted to the esophageal pH-meter procedure were studied in a prospective way. During the clinical interview, the demographic data and the presented clinical complaints were registered. All the patients were submitted to both esophageal manometry in order to localize the lower esophageal sphincter and the pH step-up technique, that consists of the introduction of the pH-meter sensor in the gastric chamber and in the sensor's gradual traction until the pH steps up to levels over 4. The step-up point was identified by two distinct ways, characterizing two study groups: with the sitting patient (group I - 450 patients) and with the patient in supine position (group II - 581 patients). After the step-up point identification, the pH-meter distal sensor was placed in the standard position (based on the sphincter manometric placement). It was registered where the pH sensor would be positioned if the step-up technique were adopted. To evaluate the positioning suitability, the error was considered to be represented by the difference (in centimeters) between the suitable placement (manometry) and the one that would be adopted in case the step-up technique were adopted. The positioning error was considered rough if it were larger than 2 cm. The most frequent type of error was also analyzed (if above or below the standard position).
It was observed that if the step-up technique were adopted, there would be error in the sensor positioning in 945 patients (91.6%). In terms of error degree, there would be a rough error in 597 (63.2%) cases. Concerning the type of error, the sensor would be positioned below the standard place in 857 (90.7%) patients. As to the interference of the position adopted by the patient during the step-up technique, it was observed that there was no significant difference among the groups of study in any of the analyzed parameters.
按照国际公认的标准化方法，食管pH监测仪的远端传感器应放置在食管测压法确定的下食管括约肌上缘上方5厘米处。然而，一些作者提出了无需测压的替代定位技术；其中，pH值上升法值得一提。这个问题存在争议；一些出版物称上升法不可靠，而另一些则认为它可靠。
鉴于现有争议以及采用合适样本和方法的前瞻性研究数量较少，我们开展了本研究，旨在通过分析上升法所提供的定位误差的存在情况、类型和程度，以及患者在操作过程中所采取的体位的影响，来评估基于上升法的pH监测仪远端传感器定位的适用性。
对1031例行食管pH监测的患者进行前瞻性研究。在临床问诊过程中，记录人口统计学数据和所呈现的临床症状。所有患者均接受食管测压以定位下食管括约肌，并接受pH值上升法，该方法包括将pH监测仪传感器插入胃腔，并逐渐牵拉传感器直至pH值升至4以上。通过两种不同方式确定上升点，从而形成两个研究组：患者坐位（I组 - 450例患者）和患者仰卧位（II组 - 581例患者）。确定上升点后，将pH监测仪远端传感器置于标准位置（基于括约肌测压定位）。记录若采用上升法pH传感器将放置的位置。为评估定位适用性，误差被认为由合适放置位置（测压法）与若采用上升法将采用的位置之间的差值（以厘米为单位）表示。若定位误差大于2厘米，则认为是粗略误差。还分析了最常见的误差类型（高于或低于标准位置）。
观察到若采用上升法，945例患者（91.6%）的传感器定位会出现误差。在误差程度方面，597例（63.2%）病例会出现粗略误差。关于误差类型，857例（90.7%）患者的传感器将放置在标准位置下方。至于患者在上升法操作过程中所采取的体位的干扰，在任何分析参数中，各研究组之间均未观察到显著差异。
