New insights in the diagnosis of chronic refractory cough

Abstract

Background: Chronic Refractory Cough (CRC) is a common condition that significantly impairs patients' quality of life. Unfortunately, in many situations patients continue to experience CRC in spite of following published guidelines for diagnosis and treatment.

Methods: 99 patients were referred to National Jewish Health (NJH), a specialty respiratory center for evaluation of CRC (cough ≥ 8 weeks duration). Study duration occurred over 18 months. Intake evaluation for all patients included history, physical examination, spirometry and fiberoptic laryngoscopy. Testing to confirm causes of CRC were performed. Specific therapy for each potential cause was provided. A visual analog cough scale measured cough response.

Results: Ten final diagnostic categories were found in the cohort of 99 patients with CRC: Obstructive sleep apnea (apnea/hypoxia index ≥ 5), rhinosinusitis, Tracheobronchomalacia (≥65% collapse of airway with dynamic expiratory imaging), esophageal dysmotility, gastroesophageal reflux, abnormal swallowing with laryngeal penetration, asthma, COPD, bronchiectasis and paradoxical vocal cord movement. In these patients there were 42 incorrect intake diagnoses and 101 new diagnoses established. Patients with CRC have had multiple diagnoses (3.8 ± 1.6) associated with chronic cough. With directed therapy 71/76 (93%) patients had resolution or improvement in cough symptoms.

Conclusions: Among patients referred to a specialty respiratory center with CRC multiple concomitant diagnoses for cough were common. Certain diagnoses such as OSA and TBM have not been reported in cough guidelines but in this study are commonly associated diagnoses. Targeted therapy for each recognized diagnosis improves patient response.

Keywords: Asthma; Bronchiectasis; Chronic cough; Gastroesophageal reflux; Obstructive sleep apnea; Tracheobronchomalacia.