How to diagnose GERC more effectively: reflections on post-reflux swallow-induced peristaltic wave index and mean nocturnal baseline impedance

INTRODUCTION

Post-reflux swallow-induced peristaltic wave index (PSPWI) and mean nocturnal baseline impedance (MNBI) are novel parameters reflect esophageal clearance capacity and mucosal integrity. They hold potential in aiding the recognition of gastroesophageal reflux-induced chronic cough (GERC). Our study aims to investigate their diagnostic value in GERC.

METHODS

This study included patients suspected GERC. General information and relevant laboratory examinations were collected, and final diagnosis were determined following guidelines for chronic cough. The parameters of multichannel intraluminal impedance-pH monitoring (MII-pH) in patients were analyzed and compared to explore their diagnostic value in GERC.

RESULTS

A total of 186 patients were enrolled in this study. The diagnostic value of PSPWI for GERC was significant, with the area under the working curve (AUC) of 0.757 and a cutoff value of 39.4%, which was not statistically different from that of acid exposure time (AET) (p > 0.05). The combined diagnostic value of AET > 4.4% and PSPWI < 39.4% was superior to using AET > 4.4% alone (p < 0.05). Additionally, MNBI and distal MNBI also contributed to the diagnosis of GERC, with AUC values of 0.639 and 0.624, respectively. AET > 4.4% or PSPWI < 39.4% is associated with a 44% reduction in missed diagnoses of non-acid GERC compared to AET > 6.0% or symptom association probability (SAP) ≥ 95%, and may be more favorable for identifying GERC.

CONCLUSION

The diagnostic value of PSPWI for GERC is comparable to that of AET. Combining PSPWI < 39.4% or AET > 4.4% can improve the diagnostic efficiency by reducing the risk of missed diagnoses in cases where non-acid reflux is predominant. Distal MNBI and MNBI can serve as secondary reference indices in the diagnosis of GERC.

Gabapentin versus baclofen for treatment of refractory gastroesophageal reflux-induced chronic cough

Refractory gastroesophageal reflux-induced chronic cough (GERC) is a special type of gastroesophageal reflux disease (GERD) with predominant cough resistant to pragmatic standard anti-reflux therapy including antisecretory agents alone or in combination with promotility agents but with a favorable response to intensified anti-reflux treatment. The condition is not rare and is difficult to treat. Neuromodulators such as baclofen and gabapentin are considered potential therapeutic options for refractory GERC. Limited data indicate that gabapentin and baclofen could attenuate the cough symptom in patients with refractory GERC by blockade of gastroesophageal reflux or by direct antitussive effects. However, no study has compared the efficacy of these two drugs in treatment of refractory GERC. In an open-labeled randomized clinical study, we demonstrated that, as add-on therapy, gabapentin and baclofen had a similar prevalence of therapeutic success for suspected refractory GERC but gabapentin may be more preferable because of its fewer central side effects. The efficacy of baclofen and gabapentin was suboptimal, so further studies are needed to select the patients with refractory GERC suitable for precise treatment using these two neuromodulators.

Novel Surgical Treatments for Gastroesophageal Reflux Disease: Systematic Review of Magnetic Sphincter Augmentation and Electric Stimulation Therapy

Electric stimulation therapy (EST) and magnetic sphincter augmentation (MSA) represent novel methods for the surgical treatment of gastroesophageal reflux disease (GERD). The aim of this review was to assess the effectiveness and safety of EST and magnetic sphincter augmentation device (MSAD) comapred to laparoscopic fundoplication (LF) and proton pump inhibitor therapy (in case of EST). We performed a systematic literature search without restrictions on publication dates in five electronic databases (MEDLINE, EMBASE, the Cochrane library, PubMed, and Centre for Reviews and Dissemination), complemented by hand search, search in trial registries, and documentation provided by the manufacturers. No study passed inclusion criteria for analyzing EST effectiveness. Concerning safety, lead erosion through the esophagus and trocar perforation of the small bowel occurred in 2.4% of patients (in one study). Only the registry study fulfilled inclusion criteria for effectiveness analysis of MSAD. The crucial outcome of GERD-health-related quality of life (HRQL) score improved from 20 to 3 points in MSAD patients, and from 23 to 3.5 points in LF patients. However, the LF patients were in a more severe stage of the disease. The results yield indefinite conclusions about the use of both MSAD and EST. Clinical effectiveness and safety of both MSAD and EST are not sufficiently proven and are yet to be supported by high quality evidence from randomized controlled trials.

Proton pump inhibitor-refractory gastroesophageal reflux disease: challenges and solutions

A significant percentage of patients with gastroesophageal reflux disease (GERD) will not respond to proton pump inhibitor (PPI) therapy. The causes of PPI-refractory GERD are numerous and diverse, and include adherence, persistent acid, functional disorders, nonacid reflux, and PPI bioavailability. The evaluation should start with a symptom assessment and may progress to imaging, endoscopy, and monitoring of esophageal pH, impedance, and bilirubin. There are a variety of pharmacologic and procedural interventions that should be selected based on the underlying mechanism of PPI failure. Pharmacologic treatments can include antacids, prokinetics, alginates, bile acid binders, reflux inhibitors, and antidepressants. Procedural options include laparoscopic fundoplication and LINX as well as endoscopic procedures, such as transoral incisionless fundoplication and Stretta. Several alternative and complementary treatments of possible benefit also exist.

Diagnosis and treatment of patients with nonacid gastroesophageal reflux-induced chronic cough

Gastroesophageal reflux (GER) is one of the most common causes of chronic cough, and chronic cough due to GER represents a subtype of GER-related diseases. Gastroesophageal reflux-induced chronic cough (GERC) can be divided into two subgroups based on the pH of the GER. Nonacid GERC is less common than acid GERC, and its diagnosis and treatment strategy have not been standardized. However, nonacid GERC usually presents with its unique set of characteristics and features upon diagnosis and treatment in the clinic. Although the underlying molecular mechanism of nonacid GERC is not fully understood, it is considered to be associated with reflux theory, reflex theory and airway hypersensitivity. Multi-channel intraluminal impedance combined with pH monitoring is a promising new technique that can detect both acid and nonacid reflux, and our findings as well as those of others have shown its usefulness in diagnosing nonacid GERC. Development of new diagnostic techniques has led to an increased rate of nonacid GERC diagnosis. We summarize our experience in the diagnosis and treatment of nonacid GERC and provide a guide for future therapeutic approaches.

Refractory chronic cough due to gastroesophageal reflux: Definition, mechanism and management

Refractory chronic cough due to gastroesophageal reflux is a troublesome condition unresponsive to the standard medical anti-reflux therapy. Its underlying mechanisms may include incomplete acid suppression, non-acid reflux, transient lower esophageal sphincter relaxations and esophageal hypersensitivity. The diagnosis of this disorder depends on both the findings of multi-channel intraluminal impedance-pH monitoring and the subsequent intensified anti-reflux therapy. The strategies of pharmacological treatment for refractory chronic cough due to reflux include the optimization of proton pump inhibitors and add-on therapies with histamine H₂ receptor antagonists, baclofen and gabapentin. However, the further study is needed to satisfy its management.

Comparison of clinical characteristics of chronic cough due to non-acid and acid gastroesophageal reflux

BACKGROUND AND OBJECTIVE

Little is known about non-acid gastroesophageal reflux-induced chronic cough (GERC). The purpose of the study is to explore the clinical characteristics of non-acid GERC.

METHODS

Clinical symptoms, cough symptom score, capsaicin cough sensitivity, gastroesophageal reflux diagnostic questionnaire (GerdQ) score, findings of multichannel intraluminal impedance-pH monitoring (MII-pH) and response to pharmacological anti-reflux therapy were retrospectively reviewed in 38 patients with non-acid GERC and compared with those of 49 patients with acid GERC.

RESULTS

Non-acid GERC had the similar cough character, cough symptom score, and capsaicin cough sensitivity to acid GERC. However, non-acid GERC had less frequent regurgitation (15.8% vs 57.1%, χ(2)  = 13.346, P = 0.000) and heartburn (7.9% vs 32.7%, χ(2)  = 7.686, P  = 0.006), and lower GerdQ score (7.4 ± 1.4 vs 10.6 ± 2.1, t = -6.700, P = 0.003) than acid GERC. Moreover, MII-pH revealed more weakly acidic reflux episodes, gas reflux episodes and a higher symptom association probability (SAP) for non-acid reflux but lower DeMeester score, acidic reflux episodes and SAP for acid reflux in non-acid GERC than in acid GERC. Non-acid GERC usually responded to the standard anti-reflux therapy but with delayed cough resolution or attenuation when compared with acid GERC. Fewer patients with non-acid GERC needed an augmented acid suppressive therapy or treatment with baclofen.

CONCLUSIONS

There are some differences in the clinical manifestations between non-acid and acid GERC, but MII-pH is essential to diagnose non-acid GERC.

Therapeutic efficacy of baclofen in refractory gastroesophageal reflux-induced chronic cough

AIM: To evaluate the efficacy and safety of baclofen for treatment of refractory gastroesophageal reflux-induced chronic cough (GERC) unresponsive to standard anti-reflux therapy.

METHODS: Sixteen patients with refractory GERC were given an 8-wk course of baclofen 20 mg three times a day as an add-on therapy to omeprazole. Changes in the cough symptom score, cough threshold to capsaicin, reflux symptom score and possible adverse effects were determined after treatment. The variables of multi-channel intraluminal impedance combined with pH monitoring were compared between responders and non-responders to baclofen.

RESULTS: Twelve of 16 patients completed treatment. Cough disappeared or improved in 56.3% (9/16) of patients, including 6 patients with acid reflux-induced cough (66.7%) and 3 patients with non-acid reflux-induced cough (33.3%). With baclofen treatment, the cough symptom score began to decrease at week 2, was clearly decreased at week 6 and reached a minimum at week 8. At the end of therapy, the lowest concentration of capsaicin required for induction of ≥ 2 and ≥ 5 coughs increased from 0.98 (1.46) to 1.95 (6.82) μmol/L (Z = -2.281, P = 0.024) and from 1.95 (7.31) to 7.8 (13.65) μmol/L (Z = -2.433, P = 0.014), respectively, and the reflux symptom score decreased from 8.0 ± 1.6 to 6.8 ± 0.8 (t = 2.454, P = 0.023). The number of acid reflux episodes was significantly lower in responders than in non-responders. The main adverse effects were somnolence, dizziness and fatigue.

CONCLUSION: Baclofen is a useful, but suboptimal treatment option for refractory GERC.

The Challenge of Protocols for Reflux Disease

Objectives. Gastroesophageal reflux disease (GERD) and laryngopharyngeal reflux (LPR) are very common and controversial diseases. The authors have previously reviewed clinical practice guidelines (CPGs) on reflux disease, and these major consensus statements differ on what constitutes ideal management. The aim is to critically review existing protocols for reflux based on CPG recommendations and to present a refined protocol that may be further used to develop a critical pathway for reflux in ambulatory medical practice.

Study Design. Literature review with discussion.

Methods. A PubMed search was used to identify current clinical protocols or algorithms for reflux disease, and the principal elements of each were compared.

Results. Of the 828 articles identified in the search, 11 met the search criteria. Together with 4 articles previously identified, 15 were analyzed. All protocols discuss the important role of empiric therapy, although with differences in use. Only 5 protocols (33%) were based on systematic review such as CPGs. Eight protocols (53%) used alarm symptoms to prompt a workup. For these patients, upper endoscopy was by far the most common diagnostic method. The use of other modalities varies significantly between protocols. The authors propose a standard protocol based on patient risk factors that employs CPG recommendations and may be used for critical pathway outcomes measures.

Conclusion. There are major differences between existing protocols for reflux disease in the literature, reflecting many clinical controversies. Outcomes of different protocols have not been extensively studied. The authors propose a new protocol that is a synthesis of those reviewed and based on risk stratification.