Chronic cough in patients with sleep-disordered breathing

Abstract

Chronic cough can be the sole presenting symptom for patients with obstructive sleep apnoea. We investigated the prevalence, severity and factors associated with chronic cough in patients with sleep-disordered breathing (SDB).We invited 108 consecutive patients who had been referred for evaluation of SDB to complete a comprehensive questionnaire on respiratory and sleep health, which included the Leicester Cough Questionnaire (cough specific quality of life; LCQ), Epworth Sleepiness Scale (ESS) and the Mayo Clinic gastro-oesophageal questionnaire. Chronic cough was defined as cough for a duration of .2 months.33% of patients with SDB reported a chronic cough. Patients with a chronic cough had impaired cough related-quality of life affecting all health domains (mean¡SEM LCQ score 17.7¡0.7; normal521). Patients with SDB and chronic cough were predominantly females (61% versus 17%; p,0.001) and reported more nocturnal heartburn (28% versus 5%; p50.03) and rhinitis (44% versus 14%; p50.02) compared to those without SDB. There were no significant differences in ESS, respiratory disturbance index, body mass index, or symptoms of breathlessness, wheeze, snoring, dry mouth and choking between those with cough and those without.Chronic cough is prevalent in patients with SDB and is associated with female sex, symptoms of nocturnal heartburn and rhinitis. Further studies are required to investigate the impact of continuous positive airway pressure therapy on cough associated with SDB to explore the mechanism of this association.

Cough in idiopathic pulmonary fibrosis

“…In the general population, chronic cough is more prevalent in OSA and can be improved by treatment with continuous positive airway pressure (CPAP) [50]. A complicating factor is that obstruction of the upper airway in OSA could increase the trans-diaphragmatic pressure difference promoting GORD [51,52]. GORD, on the other hand, may promote OSA, through microaspiration of gastric substances, creating an inflammatory reaction blocking the airway [53].…”

“…1: traction leading to a weaker lower oesophageal sphincter tonus [45]; 2: microaspiration inducing epithelial damage [38,46]; 3: restriction inducing instability of the upper airway [39]; 4: intermitted hypoxaemia promoting profibrotic mechanisms [49]; 5: increased cough reflex sensitivity [22][23][24][25][26][27][28][29][30][31]; 6: pressure causing stretch injury and activation of fibrotic mechanisms [31]; 7: microaspiration causing an inflammatory reaction blocking the airway [53]; 8: obstruction increasing trans-diaphragmatic pressure [51,52]; 9: aspiration directly and acid reflux indirectly stimulate the cough reflex [6,47]; 10: cough increasing trans-diaphragmatic pressure [47]; 11: less central inhibition and inflammation increasing cough reflex sensitivity [54]. sensory nerves.…”

Utility of Continuous Positive Airway Pressure Therapy for Treating Chronic Coughs in Patients with Obstructive Sleep Apnea

“…Although the current diagnostic and treatment guidelines for chronic cough attempt to rule out such conditions, a significant proportion of chronic coughs remain unexplained (3,4). In recently reported cases of chronic cough in which obstructive sleep apnea (OSA) was concomitantly diagnosed, the administration of continuous positive airway pressure (CPAP) therapy resolved the cough symptoms (5)(6)(7)(8)(9). Although the current treatment guidelines for chronic cough do not incorporate tests for OSA, OSA is increasingly being recognized as a cause of chronic cough.…”

Chronic cough and obstructive sleep apnoea: reflux-associated cough hypersensitivity?: Table 1–

“…However, it is difficult to ascribe this benefit solely to CPAP as the majority of these patients had multiple therapeutic interventions for their cough. In a prospective series of 108 patients being evaluated for sleep disordered breathing, co-existent cough was documented in 33% [6]. Our case report evaluates the effect of CPAP on cough in a prospective and systematic manner and looks at a possible mechanism of this association.…”