Background Excessive or thick respiratory secretions are common in patients with pulmonary and neurologic diseases and for many patients in the last few days of life. This Fast Fact reviews treatment options for managing distressing secretions.

Pathophysiology Mucus consists of water (~ 95%), glycoproteins, and small amounts of proteoglycans and lipids. The mucus layer of the respiratory tract rests against a periciliary watery layer around cilia, which facilitates upward movement of secretions (1,2). With age, respiratory infections, smoking, or chronic respiratory diseases (e.g., COPD), mucociliary clearance can become ineffective. In patients with progressive neurodegeneration (e.g., Alzheimer’s dementia), their cough can become ineffective. In other illnesses (e.g., allergies, bronchitis, acid reflux) mucus production can become excessive or abnormal. As a result of any of these mucociliary disorders, symptoms such as dyspnea, cough, choking sensations, gagging sensations, and aspiration may occur.

Pharmacologic treatments

• Expectorants: Guaifenesin is thought to act by stimulating gastric mucosa and the gastric nerve to stimulate the cough reflex. It also induces a vagally mediated increase in airway secretion. Supporting evidence is limited to a single study in chronic bronchitis patients (3); subsequent research has challenged guaifenesin’s efficacy (4).
• Drying agents: Anticholinergic agents such as scopolamine or glycopyrrolate may reduce excessive mucus production. Watch for anticholinergic side-effects (dry mouth, urinary retention), or over-drying, which may cause overly thick mucus and mucus plugging (see Fast Fact #109).
• Aerosolized solutions: Nebulized hypertonic saline (3%) has demonstrated effectiveness in cystic fibrosis (CF) patients, but not in COPD. Hypertonic/hypotonic solutions can trigger bronchospasm (1,2). Sodium bicarbonate (2-7.5%) solutions are used in aerosolized forms to elevate the pH of tracheobronchial secretions, which weaken the saccharide structures of the mucus. The effects are additive when used with N-acetylcysteine (3).
• Nebulized N-acetylcysteine (Mucomyst ®) severs disulfide bonds of glycoproteins in mucus and lower its viscosity. Some studies demonstrate effectiveness (1,2,5). It has an unpleasant smell and can trigger bronchospasm; co-administration of a beta-adrenergic agonist should be considered.
• Antibiotics: respiratory infection commonly leads to increased mucus production; antibiotics may be indicated depending on the overall goals of care.
• Bronchodilators: Beta-adrenergic agonists improve mucus clearance by increasing ciliary activity (1).
• Enzymatic agents: In CF, DNA is released by leukocytes, increasing mucus viscosity (1). Recombinant human DNase (dornase alfa or Pulmozyme) cleaves DNA and has been shown to be effective.

Non-pharmacological treatments

• Hydration: Studies of COPD patients have not demonstrated improved mucus production or mucus clearance with added parenteral hydration (1).
• Suctioning: For many patients with a weak cough reflex, gentle suctioning can be very helpful. However, deep suctioning should be avoided as in some, it can be an irritant that triggers even more secretions.
• Postural drainage/Chest Physiotherapy (CPT): CPT loosens secretions and facilitates cough or suctioning (1).
• External oscillation device: This device achieves the same degree of efficacy as CPT. It is a small, lightweight, plastic, pipe-shaped device that is inexpensive (~$50) and easy to use (4).
• Other devices: such as PEP (positive expiratory pressure) masks and external compression vests may also be appropriate for certain patients.

Initial management recommendations

• Assess quantity and quality of secretions.
• Consider providing immediate relief through suctioning, postural drainage, or nebulization first.
• Select agents based on the balance of benefits vs. undesirable effects (examples: guaifenesin may worsen nausea; scopolamine dries/thickens secretions, causes dry mouth, and sedation, which may or may not be desirable).
• Avoid antisecretory agents in patients with thick secretions.

References

1. Aboussouan LS. Role of mucolytic agents in the treatment of COPD. In: Rose BD (ed). UpToDate. Waltham, MA: UpToDate; 2006.
2. Connolly MA. Mucolytics and the critically ill patient: help or hindrance? AACN Clinical Issues. 1995; 6(2):307-15.
3. Manaker S, Tietze KJ, Wittbrodt ET. Pulmonary pharmacotherapy. In: Fishman AP, et al (eds). Fishman’s Pulmonary Diseases and Disorders, Vol 2. 3rd Ed. New York, NY: McGraw-Hill;1998: 2643-60.
4. Eyassu DG, McCoul ED. Guaifenesin: the ubiquitous orphan. Otolaryngology-Head and Neck Surgery 2024; May 28.
5. O’Reagan, AW & Berman JS. Bronchiectasis. In: Crapo JD, et al (eds). Baum’s Textbook of Pulmonary Diseases. 7th Ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2004: 257-78.

Version History: originally edited by David E Weissman MD and published in June 2006; 2nd Edition in April 2009; 3rd Edition in July 2015; 4th Edition done by Adrienne Klement MD in October 2024.
Conflicts of Interest: None to report