What is the treatment approach for an adult presenting with a wet cough?

Treatment of Wet Cough in Adults

For an adult with wet (productive) cough, the primary goal is to enhance mucus clearance rather than suppress the cough reflex, as clearance of secretions is beneficial and cough suppression may be relatively contraindicated. 1, 2

Initial Assessment and Red Flags

Before initiating treatment, determine if immediate medical evaluation is needed. Seek medical attention if the patient:

• Coughs up blood 1, 3
• Experiences breathlessness 1, 3
• Has prolonged fever and feeling unwell 1
• Has pre-existing conditions (COPD, heart disease, diabetes, asthma) 1
• Has been recently hospitalized 1
• Has symptoms persisting beyond 3 weeks 1, 3

First-Line Non-Pharmacological Approaches

Chest physiotherapy is the cornerstone of wet cough management and should be initiated as first-line therapy to increase mucus clearance, particularly in patients with bronchiectasis or other conditions causing moist cough. 3

Specific techniques include:

• Huffing technique should be taught as an adjunct to other sputum clearance methods, especially in patients with COPD 3
• Positive expiratory pressure (PEP) techniques are recommended over conventional chest physiotherapy as they are approximately as effective, inexpensive, safe, and can be self-administered 3
• Autogenic drainage should be taught as an adjunct to postural drainage, as it can be performed without assistance and in one position 3

Pharmacological Mucoactive Agents

For patients requiring pharmacological support:

• Guaifenesin helps loosen phlegm and thin bronchial secretions to make coughs more productive 4
• Hypertonic saline solution is recommended on a short-term basis to increase cough clearance in patients with bronchitis 3
• Erdosteine may be used on a short-term basis to increase cough clearance in patients with bronchitis 3

Acetylcysteine requires special caution: After administration, an increased volume of liquified bronchial secretions may occur, and when cough is inadequate, the airway must be maintained open by mechanical suction if necessary. 5 Asthmatics should be watched carefully as bronchospasm may occur. 5

Device-Based Therapies

For patients who cannot perform manual techniques effectively:

• Devices designed to oscillate gas in the airway, either directly or by compressing the chest wall, can be considered as alternatives to chest physiotherapy 3
• For patients with neuromuscular disease and impaired cough, mechanical cough assist devices are recommended to prevent respiratory complications 3

Critical Contraindications

Avoid antitussive agents (cough suppressants) in productive cough as suppression may be relatively contraindicated when cough clearance is important. 1, 2 This includes avoiding:

• Dextromethorphan 2
• Codeine 2
• Benzonatate 6

In persons with airflow obstruction caused by COPD, manually assisted cough may be detrimental and should not be used. 3

Addressing Underlying Causes

A systematic approach to diagnosis and treatment remains the most effective way to manage chronic cough. 1 Most cases of troublesome cough reflect the presence of an aggravant in a susceptible individual. 1

Key underlying causes to address:

• Smoking cessation should be strongly encouraged as smoking is one of the commonest causes of persistent cough and cessation is accompanied by significant remission in cough symptoms 1, 3
• ACE inhibitors: No patient with a troublesome cough should continue on ACE inhibitors 1
• Gastroesophageal reflux disease (GORD): Failure to consider GORD as a cause for cough is a common reason for treatment failure, and reflux-associated cough may occur in the absence of gastrointestinal symptoms. Intensive acid suppression with proton pump inhibitors and alginates should be undertaken for a minimum of 3 months. 1
• Rhinosinusitis: In the presence of prominent upper airway symptoms, a trial of topical corticosteroid is recommended 1
• Asthma/eosinophilic airway inflammation: Cough is unlikely to be due to eosinophilic airway inflammation if there is no response to a two-week oral steroid trial 1

When to Refer

For chronic wet cough persisting beyond three weeks, referral to a specialist cough clinic should be considered, as treatment success is considerably higher for patients managed in specialist cough clinics than in general respiratory clinics. 1, 3 A combination of selected diagnostic testing and empirical trials of treatment is likely to be most cost effective. 1

Common Pitfalls to Avoid

• Do not use antitussives for productive cough where clearance of secretions is beneficial 2
• Do not prescribe recombinant DNase to increase cough clearance, as it is not recommended despite improving spirometry in cystic fibrosis 3
• Avoid inappropriate prescribing of antibiotics unless there is clear evidence of bacterial infection with appropriate risk factors 1