Acoustic Cough—Reflux Associations in Chronic Cough: Potential Triggers and Mechanisms

Guidelines for the Diagnosis and Management of Gastroesophageal Reflux Disease

“…A recent study of 237 patients with extraesophageal refl ux symptoms that were refractory to PPI, found that the presence of heartburn or abnormal acid exposure on pH monitoring predicted response to escalation of therapy, but the SI, SAP, or impedance variables did not ( 132 ). Th e recent development of ambulatory refl ux-cough monitoring by combining impedance-pH to measure refl ux (acid or nonacid) along with acoustic detection of cough, which eliminates the subjectivity of patient-reported cough, has enabled a more accurate assessment of the relationship between refl ux and cough; a recent study using this approach was able to document refl ux-induced cough as well as cough-induced refl ux ( 133 ). Whether these technical improvements increase the yield of symptom association analysis in patients with cough attributed to refl ux requires further studies.…”

Response of Chronic Cough to Acid-Suppressive Therapy in Patients With Gastroesophageal Reflux Disease

“…The elegant study by Smith et al 6 provides insight into why patients with chronic cough are relatively refractory to GERD therapy. That study combined sound recordings with acoustic analysis and pH-impedance recordings to accurately defi ne the temporal relationship between cough and refl ux events.…”

“…5 Second, approximately one-half of unselected patients with chronic cough show a positive symptom association between cough and refl ux during refl ux monitoring. 6 However, unlike heartburn, which is usually caused by acid refl ux, 7 chronic cough has a diverse range of potential causes. Estimates of the proportion of patients with chronic cough in whom reflux is the underlying cause vary greatly among specialists, ranging from 0% to 41%.…”

New concepts in the management of chronic cough

“…11 Furthermore, in patients with a positive GOR-cough temporal association, Smith et al found that a significant number of cough episodes were unrelated to GOR and therefore it is unlikely that amelioration of GOR will lead to resolution of cough. 12 It is likely that combined oesophageal impedance-cough monitoring recordings will have a role in the investigation of patients with chronic cough in future. Further studies are needed to determine the sensitivity and specificity of oesophageal impedance monitoring for establishing the diagnosis and predicting the response to therapy.…”