Pauwels Ans, Blondeau Kathleen, Dupont Lieven, Sifrim Daniel
Centre for Gastroenterological Research KU Leuven, Gasthuisberg University Hospital, KU Leuven, Leuven, Belgium.
Pulm Pharmacol Ther. 2009 Apr;22(2):135-8. doi: 10.1016/j.pupt.2008.11.007. Epub 2008 Nov 27.
Gastroesophageal reflux (GER) is one of the three most common causes of chronic unexplained cough. Diagnosing GER-related cough is challenging since many patients do not have esophagitis or an increased esophageal acid exposure during 24 h esophageal pH-metry. A significant time association between acid reflux and cough can be demonstrated in a subgroup of patients, even if the total esophageal acid exposure is normal. Establishing an exact time relationship between reflux and cough requires objective measurements of both cough and reflux episodes. A variety of techniques for cough assessment are available, including sound recordings and continuous measurement of gastroesophageal pressures. The Symptom Association Probability (SAP) has been suggested as the most reliable algorithm to establish the non-chance association between GER and cough. Although the relationship between acid reflux and cough is generally accepted, the response rate of patients with chronic unexplained cough to proton pump inhibitor treatment (PPI) is poorer compared to that in patients with typical GERD symptoms. Combined impedance-pH recordings, a new technique for the measurement of all types of reflux, have recently shown that not only acid but also weakly acidic GER may be associated with cough. Moreover, measurements in patients "on" PPI therapy demonstrated that weakly acidic reflux may persist during PPI treatment and may be associated with cough. Aspiration of gastric contents into the lungs and a vagally mediated reflex arc, originating from the distal esophagus, have been proposed as pathophysiological mechanisms in GER-related cough. More recently, reflux induced bronchial hypersensitivity has been proposed as a third underlying mechanism. Treatment of GER-related cough remains challenging. So far, long term PPI treatments produce unsatisfactory results. In patients not responding to PPI, weakly acidic GER might still be the cause of cough. In these patients other therapeutic strategies i.e. abolishing all types of GER might need to be considered. Antireflux surgery has been performed successfully in a group of patients with GER-related cough. However, controlled, prospective outcome studies are necessary to confirm the role of antireflux treatments in the management of GER-related cough.
胃食管反流(GER)是慢性不明原因咳嗽的三大常见病因之一。诊断与GER相关的咳嗽具有挑战性,因为许多患者在24小时食管pH监测期间没有食管炎或食管酸暴露增加。即使食管总酸暴露正常,在一部分患者中也可证明酸反流与咳嗽之间存在显著的时间关联。要确定反流与咳嗽之间的确切时间关系,需要对咳嗽和反流发作进行客观测量。有多种咳嗽评估技术可供使用,包括声音记录和胃食管压力的连续测量。症状关联概率(SAP)被认为是建立GER与咳嗽之间非偶然关联的最可靠算法。尽管酸反流与咳嗽之间的关系已被普遍接受,但与典型GERD症状患者相比,慢性不明原因咳嗽患者对质子泵抑制剂治疗(PPI)的反应率较差。联合阻抗-pH记录是一种测量所有类型反流的新技术,最近显示不仅酸反流,而且弱酸性GER也可能与咳嗽有关。此外,对接受PPI治疗的患者的测量表明,弱酸性反流在PPI治疗期间可能持续存在,并可能与咳嗽有关。胃内容物吸入肺部以及源自食管远端的迷走神经介导的反射弧已被提出作为GER相关咳嗽的病理生理机制。最近,反流诱导的支气管高敏反应被提出作为第三种潜在机制。GER相关咳嗽的治疗仍然具有挑战性。到目前为止,长期PPI治疗产生的结果并不理想。在对PPI无反应的患者中,弱酸性GER仍可能是咳嗽的原因。在这些患者中,可能需要考虑其他治疗策略,即消除所有类型的GER。抗反流手术已在一组GER相关咳嗽患者中成功实施。然而,需要进行对照的前瞻性结局研究来证实抗反流治疗在GER相关咳嗽管理中的作用。