Jason S. Krahnke

Clinical issues of mucus accumulation in COPD

Airway mucus is part of the lung’s native immune function that traps particulates and microorganisms, enabling their clearance from the lung by ciliary transport and cough. Mucus hypersecretion and chronic productive cough are the features of the chronic bronchitis and chronic obstructive pulmonary disease (COPD). Overproduction and hypersecretion by goblet cells and the decreased elimination of mucus are the primary mechanisms responsible for excessive mucus in chronic bronchitis. Mucus accumulation in COPD patients affects several important outcomes such as lung function, health-related quality of life, COPD exacerbations, hospitalizations, and mortality. Nonpharmacologic options for the treatment of mucus accumulation in COPD are smoking cessation and physical measures used to promote mucus clearance. Pharmacologic therapies include expectorants, mucolytics, methylxanthines, beta-adrenergic receptor agonists, anticholinergics, glucocorticoids, phosphodiesterase-4 inhibitors, antioxidants, and antibiotics.

Home non-invasive ventilation use following acute hypercapnic respiratory failure in COPD

RATIONALE Patients with COPD and hypercapnic respiratory failure have a worse prognosis and experience a faster deterioration in their pulmonary function. The benefit of home NPPV following an acute exacerbation of COPD with hypercapnic respiratory failure is not well understood. OBJECTIVES To evaluate the effect of home NPPV use in patients following a hospitalization for AECOPD with acute hypercapnic respiratory failure on event-free survival after an index admission. METHODS We conducted a retrospective, single-center, chart review on patients hospitalized in 2011 with a diagnosis of AECOPD, hypercapnia, and used NPPV during hospitalization. 166 patients were included and were divided into two groups: patients who used NPPV post discharge and patients who did not. RESULTS Patients in the NPPV post discharge group demonstrated superior event-free survival compared to the no-NPPV post discharge group (y2 = 23.8, p < 0.0001). The NPPV post discharge group had a statistically significant reduction in hospital readmissions (40% versus 75%, p < 0.0001) through 180 days from the index admission. CONCLUSIONS Patients who used NPPV following an admission for AECOPD with hypercapnic respiratory failure had lower readmission rates and improved event-free survival after 180 days from an index admission compared to patients who did not use NPPV post discharge.

The Effect of Chronic Sputum Production on Respiratory Symptoms in Severe COPD

Background: Chronic sputum production is a significant but variable complaint in COPD; its effect on symptom burden has not been comprehensively described. We sought to characterize the daily burden of chronic sputum production in severe COPD and the phenotype of those with chronic sputum symptoms. Methods: We studied 50 outpatients with severe COPD who used an electronic diary to document peak expiratory flow (PEF) and respiratory symptoms daily for up to 2 years. A sputum index was derived based on complaints of sputum quantity, color, and consistency, and patients were divided into groups based on average daily sputum index (Low, Medium, High). The presence and severity of respiratory symptoms were scored by a novel method using daily changes in symptoms and PEF from baseline and were categorized into mild, moderate, and severe. Percent emphysema was measured using quantitative CT. Results: In the 14,500 observation days, severe symptom days were greater in the Medium and High groups (379/6089, 1609/4091, and 2624/4317 observation days in Low, Medium, and High, p < 0.0001). The same trend was found even when sputum complaints were removed from the symptom severity score. Observed/predicted PEF ratio was lower in the High group (0.56 ± 0.24, 0.55 ± 0.19, and 0.42 ± 0.12 in each group, p < 0.05 for High compared to Medium and Low). Percent emphysema inversely correlated with average sputum index and quantity (r = −0.449 and r = −0.584, respectively, p < 0.05). Conclusions: Increased sputum production in severe COPD is frequently encountered daily and is associated with more respiratory symptoms, worse airflow obstruction, and less emphysema.

Azithromycin and COPD Exacerbations in the Presence or Absence of Symptoms or Active Treatment for Gastroesophageal Reflux

Introduction: Gastroesophageal reflux disease (GERD) is common in chronic obstructive pulmonary disease (COPD) and is associated with COPD exacerbations. Since macrolides have prokinetic effects and consequently may decrease GERD, we hypothesized that azithromycin may decrease exacerbations by decreasing GERD. Methods: We conducted a retrospective review of data collected in a prospective, randomized, controlled trial of azithromycin for preventing COPD exacerbations. Participants were classified as having GERD on the basis of having a history of GERD or having a history or being treated for GERD. Results: We analyzed 1116 participants, 478 (43%) and 568 (51%) had GERD on the basis of history and history or treatment respectively. Individuals with GERD developed exacerbations sooner and more frequently, and were more likely to be hospitalized than those without GERD but the difference only reached significance when GERD was defined by history or treatment (P = 0.02, 0.02, and 0.03, respectively). Azithromycin reduced exacerbations regardless of the presence of GERD, but had a greater effect in those without GERD. Conclusions: GERD is associated with more frequent and severe COPD exacerbations. Azithromycin reduces COPD exacerbations regardless of the presence or absence of GERD but does so to a greater degree in individuals without GERD.