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

Table 1 Diagnostic value of laboratory investigation for chronic cough due to gastroesophageal reflux

Diagnostic tests	Indications	Advantages	Drawbacks
Barium radiographs	Not recommended for diagnosis of GERC unless evaluating for dysphagia	High specificity	Extremely low sensitivity
Upper gastrointestinal endoscopy	Not recommended for diagnosis of GERC. Only useful for the detection of erosive esophagitis but not for non-erosive reflux disease	High specificity	Low sensitivity
Ambulatory 24-h esophageal pH monitoring	Able to detect acid reflux but not non-acid (weakly acidic and alkaline) reflux	Relatively high sensitivity	Modest specificity
Multi-channel intraluminal impedance-pH monitoring	Able to detect both acid and non-acid reflux	High sensitivity	Modest specificity

GERC: Gastroesophageal reflux-induced chronic cough.

Table 2 Evaluation of therapeutic options for refractory chronic cough due to gastroesophageal reflux

Therapeutic options	Evaluations
Pharmacologically
Optimization of PPIs therapy
Switch to another PPI	Useful for some refractory cough due to acid reflux
Doubling the current dose of PPI	Useful for refractory cough due to severe acid reflux
Add-on therapy
Histamine H2 receptor antagonists	Useful for refractory cough due to severe acid reflux and night-time reflux
TLESRs inhibitors (baclofen)	Useful for refractory cough due to acid or non-acid reflux resistant to PPI therapy
Gabapentin	Useful for refractory cough due to acid or non-acid reflux resistant to PPI and baclofen therapy
Surgically
Laparoscopic fundoplication	A treatment option for long-term therapy of refractory cough due to acid or non-acid reflux
Endoscopic therapy or transoral incisionless fundoplication	Not recommended for refractory cough due to reflux on the basis of lack of long-term efficacy
Radiofrequency augmentation	Not recommended for refractory cough due to reflux on the basis of lack of long-term efficacy

PPI: Proton pump inhibitor. TLESRs: transient lower esophageal sphincter relaxations.