P20 Mucolytics for acute exacerbations of chronic obstructive pulmonary disease: A systematic review and meta-analysis

• Published in: Thorax Vol. 77; no. Suppl 1; p. A91
• Main Authors: Papadopoulou, E, Hansel, J, Lazar, Z, Kostikas, K, Tryfon, S, Vestbo, J, Mathioudakis, AG
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd and British Thoracic Society 11.11.2022; BMJ Publishing Group LTD
• Subjects: Chronic obstructive pulmonary disease; Deciphering ‘The Da Vinci Code’ – Biomarkers in airways disease; Meta-analysis; Success; Systematic review; Viscosity
• ISSN: 0040-6376; 1468-3296
• DOI: 10.1136/thorax-2022-BTSabstracts.156

BackgroundHypersecretion of mucous with increased viscosity represents a prevalent, burdensome treatable trait in acute exacerbations of chronic obstructive pulmonary disease (COPD) and has been associated with unfavourable outcomes and disease progression. Mucolytics could facilitate sputum clearance by regulating mucous viscoelastic properties. Therefore, they could potentially improve both the symptoms and outcomes of COPD exacerbations. We conducted a meta-analysis of randomised controlled trials (RCTs) to assess the safety and clinical efficacy of mucolytics for COPD exacerbations.MethodsBased on a preregistered protocol and following standard methods recommended by Cochrane and GRADE, we conducted a systematic review and meta-analysis of RCTs evaluating the addition of mucolytics to standard care for patients with moderate or severe COPD exacerbations. Primary outcomes were treatment success and overall symptom scores, while we also assessed cough, ease of expectoration and the outcomes prioritised in the European Respiratory Society (ERS) COPD Exacerbations Core Outcome Set.ResultsWe identified 21 eligible RCTs involving 1,411 patients with a moderate or severe COPD exacerbation. All RCTs were at high risk of methodological bias. The most commonly administered mucolytic was N-acetylcysteine (9 RCTs), followed by ambroxol (n=5) and erdosteine (n=4), bromhexine (n=2) and hypertonic saline (n=1). Moderate-certainty evidence suggests mucolytics improve the treatment success rate (RR 1.37, 95% confidence intervals [1.08, 1.73], I2= 63%) and overall symptom scores post-intervention (SMD 0.91 [1.11, 0.70], I2= 0%) compared to control. Respondents’ analysis suggests with low certainty that mucolytics improve cough (RR 1.93 [1.15, 3.23], I2= 29%), and ease of expectoration (RR 2.94 [1.68, 5.12], I2= 0%), but not breathlessness. Mucolytics were also associated with a modest beneficial impact on the partial pressure of oxygen in arterial blood (MD 3.21 [1.51, 4.92], I2= 38%) and oxygen saturation (MD 0.96 [0.27, 1.66], I2= 0%).ConclusionsOverall, we found moderate-certainty evidence that mucolytics improve symptoms and treatment success rate in COPD exacerbations. These benefits may be potentiated in patients exerting sputum hypersecretion with increased viscosity; however, we were not able to assess this subgroup in the absence of adequate data.