Airway Clearance Techniques for COPD Patients

Introduction to Airway Clearance

The American Thoracic Society recommends huffing (forced expiratory technique) as the primary active breathing technique for COPD patients, combined with positive expiratory pressure (PEP) devices when secretions are copious, while avoiding manually assisted cough which can be detrimental 1, 2

Huffing is specifically recommended for COPD patients as it minimizes airway collapse that occurs with vigorous coughing, with a Grade C recommendation (low evidence, small benefit) 1, 2, 3
Huffing consists of one or two forced expirations without glottic closure, starting from mid-lung to low lung volume, followed by relaxed breathing 1
This technique generates lower intrapulmonary pressures than coughing, leading to less airway compression in patients with abnormally compliant central airways 1
Huffing was as effective as directed cough in moving secretions proximally from all lung regions in COPD patients 1

When COPD patients have copious secretions, PEP devices (5-20 cm H₂O) should be added to huffing techniques, as they improve mucus clearance by increasing gas pressure behind secretions through collateral ventilation and preventing airway collapse during expiration 4, 5
In the only outcome study of COPD patients with chronic bronchitis, PEP combined with forced expirations resulted in less cough, less mucus production, fewer exacerbations, and reduced antibiotic use after 5-12 months 4, 5
PEP devices are inexpensive, safe, and can be self-administered 4, 5

Manually assisted cough is contraindicated in COPD and should NOT be used, as it decreases peak expiratory flow by 144 L/min in COPD patients and may be detrimental due to airflow obstruction, with a Grade D recommendation (negative benefit) 2, 3, 6, 7

Oscillatory devices (Flutter, high-frequency chest wall oscillation) have conflicting evidence in COPD and should be considered only as alternatives when standard techniques fail, with a Grade I recommendation (conflicting benefit) 2, 6, 8
Flutter devices in COPD/chronic bronchitis patients showed no difference in sputum volume or FEV₁ compared to postural drainage 8

Long-term outcome data on mortality, quality of life, and hospitalization rates for airway clearance techniques in COPD remain unknown, with most high-quality studies performed in cystic fibrosis patients, not COPD 1, 2, 3, 4, 6