Objective Gastro-oesophageal reflux is considered to be an important contributing factor in chronic unexplained cough. It remains unclear why some reflux episodes in the same patient causes cough while others do not. To understand more about the mechanism by which reflux induces cough, we aimed to identify factors which are important in triggering cough. Design In this multicentre study, 49 patients with reflux-associated chronic cough were analysed using 24-hour pH-impedance-pressure monitoring. The characteristics of reflux episodes that were followed by cough were compared with reflux episodes not associated with cough. Results The majority (72.4%) of the reflux episodes were acidic (pH<4). Compared with reflux episodes that were not followed by cough, reflux episodes that were followed by a cough burst were associated with a higher proximal extent (p=0.0001), a higher volume clearance time (p=0.002) and a higher acid burden in the preceding 15 min window (p=0.019) and higher reflux burden in the preceding 30 min window (p=0.044). No significant difference was found between the two groups when looking at the nadir pH, the pH drop, the acid clearance time or the percentage of reflux episodes which were acidic. Conclusions The presence of a larger volume of refluxate and oesophageal exposure to reflux for a longer period of time seems to play an important role in inducing cough, while the acidity of the refluxate seems to be less relevant. This helps explain the observation that most patients with chronic cough tend not to benefit from acid inhibitory treatment.

中文翻译：

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反流性慢性咳嗽的决定因素

目的胃食管反流被认为是导致慢性不明原因咳嗽的重要因素。目前尚不清楚为什么同一名患者的一些反流发作会引起咳嗽，而另一些则不会。为了更多地了解反流诱发咳嗽的机制，我们旨在确定触发咳嗽的重要因素。设计 在这项多中心研究中，使用 24 小时 pH-阻抗-压力监测对 49 名与反流相关的慢性咳嗽患者进行了分析。将伴随咳嗽的反流发作的特征与与咳嗽无关的反流发作进行比较。结果 大多数 (72.4%) 的反流发作是酸性的 (pH < 4)。与没有咳嗽的反流发作相比，伴随咳嗽爆发的反流发作与较高的近端范围 (p=0.0001)、较长的容积清除时间 (p=0.002) 和前 15 分钟窗口内较高的酸负荷 (p=0.019) 和更高相关前 30 分钟窗口内的回流负担 (p=0.044)。在观察最低 pH 值、pH 值下降、酸清除时间或酸性反流事件百分比时，两组之间没有发现显着差异。结论 大量反流物的存在和食管长时间暴露于反流似乎在诱发咳嗽中起重要作用，而反流物的酸度似乎不太相关。这有助于解释大多数慢性咳嗽患者往往无法从抑酸治疗中获益的观察结果。更高的体积清除时间 (p=0.002) 和更高的酸负荷 (p=0.019) 和更高的回流负荷 (p=0.044) 在前 15 分钟窗口中。在观察最低 pH 值、pH 值下降、酸清除时间或酸性反流事件百分比时，两组之间没有发现显着差异。结论 大量反流物的存在和食管长时间暴露于反流似乎在诱发咳嗽中起重要作用，而反流物的酸度似乎不太相关。这有助于解释大多数慢性咳嗽患者往往无法从抑酸治疗中获益的观察结果。更高的体积清除时间 (p=0.002) 和更高的酸负荷在前 15 分钟窗口 (p=0.019) 和更高的回流负荷在前 30 分钟窗口 (p=0.044)。在观察最低 pH 值、pH 值下降、酸清除时间或酸性反流事件百分比时，两组之间没有发现显着差异。结论 大量反流物的存在和食管长时间暴露于反流似乎在诱发咳嗽中起重要作用，而反流物的酸度似乎不太相关。这有助于解释大多数慢性咳嗽患者往往无法从抑酸治疗中获益的观察结果。019) 和前 30 分钟窗口内更高的回流负荷 (p=0.044)。在观察最低 pH 值、pH 值下降、酸清除时间或酸性反流事件百分比时，两组之间没有发现显着差异。结论 大量反流物的存在和食管长时间暴露于反流似乎在诱发咳嗽中起重要作用，而反流物的酸度似乎不太相关。这有助于解释大多数慢性咳嗽患者往往无法从抑酸治疗中获益的观察结果。019) 和前 30 分钟窗口内更高的回流负荷 (p=0.044)。在观察最低 pH 值、pH 值下降、酸清除时间或酸性反流事件百分比时，两组之间没有发现显着差异。结论 大量反流物的存在和食管长时间暴露于反流似乎在诱发咳嗽中起重要作用，而反流物的酸度似乎不太相关。这有助于解释大多数慢性咳嗽患者往往无法从抑酸治疗中获益的观察结果。结论 大量反流物的存在和食管长时间暴露于反流似乎在诱发咳嗽中起重要作用，而反流物的酸度似乎不太相关。这有助于解释大多数慢性咳嗽患者往往无法从抑酸治疗中获益的观察结果。结论 大量反流物的存在和食管长时间暴露于反流似乎在诱发咳嗽中起重要作用，而反流物的酸度似乎不太相关。这有助于解释大多数慢性咳嗽患者往往无法从抑酸治疗中获益的观察结果。