Who Benefits

Conditions where airway clearance is used

Airway clearance is most commonly used in conditions where excess mucus production or impaired clearance leads to airway obstruction, infection, or lung damage.^[1]

Primary indications

Bronchiectasis: Damaged, widened airways that trap mucus. Airway clearance is a core part of daily management and is recommended by ERS, BTS, and ATS guidelines.^[1]
Cystic fibrosis (CF): Thick, sticky mucus throughout the airways. Twice-daily airway clearance is standard of care, typically started in infancy.^[2]
COPD with chronic mucus hypersecretion: Chronic bronchitis phenotype with persistent sputum production. Airway clearance may reduce exacerbation frequency.
Neuromuscular disease: Conditions like ALS, muscular dystrophy, or spinal cord injury where cough strength is impaired and secretions cannot be cleared effectively.

Other situations

Acute pneumonia or lung abscess: When mucus plugging or retained secretions complicate recovery.
Post-surgical: After thoracic or abdominal surgery, when pain limits cough effectiveness and atelectasis risk is high.
Ventilator weaning and ICU recovery: When secretion management is critical for liberation from mechanical ventilation.
Primary ciliary dyskinesia: Inherited impairment of mucociliary clearance.
Allergic bronchopulmonary aspergillosis (ABPA): Thick mucus plugging associated with fungal sensitization.

Manual Techniques

Breathing-based airway clearance

These techniques use controlled breathing patterns to move mucus from the small airways toward the larger airways where it can be coughed or huffed out. They require no equipment and can be performed independently once taught.^[1,2]

Huff cough (forced expiration technique)

A huff is a forced exhalation with an open glottis — like fogging a mirror or breathing onto eyeglasses.
More effective than a standard cough for clearing mucus from the medium and smaller airways because it creates less airway collapse than a forceful cough.
Technique: Take a medium breath in, then exhale forcefully through an open mouth making a "huff" sound. Repeat 2–3 times, then rest with gentle breathing.
Can be performed at different lung volumes — a huff from mid-lung volume clears peripheral mucus; a huff from high lung volume clears central mucus.
Used as part of ACBT (below) and as a standalone technique after device-based therapies.

Active cycle of breathing technique (ACBT)

ACBT is the most commonly used manual airway clearance technique worldwide.^[1]
It combines three phases in a repeating cycle:
1. Breathing control: Relaxed, gentle tidal breathing for 20–30 seconds. Allows airways to recover between efforts.
2. Thoracic expansion exercises: 3–4 deep breaths, sometimes with a 3-second breath hold at full inspiration. Opens airways and gets air behind mucus.
3. Forced expiration technique (huff): 1–2 huffs followed by breathing control. Moves mucus centrally.
The cycle is repeated for 10–30 minutes or until mucus production decreases.
Can be performed sitting upright or in postural drainage positions.
No equipment required. Can be taught by a physiotherapist or respiratory therapist.

Autogenic drainage

A self-performed technique that uses controlled breathing at different lung volumes to move mucus from the periphery to the central airways.
Three phases: breathing at low lung volume (unstick mucus), mid-lung volume (collect mucus), then high lung volume (evacuate mucus).
Requires more training than ACBT but can be very effective once mastered.
No equipment needed. Particularly popular in European practice for cystic fibrosis.

Postural drainage and percussion (chest physiotherapy)

Uses gravity-assisted positioning to drain mucus from specific lung segments. The patient lies in different positions (head-down, side-lying, sitting) depending on which lung areas need drainage.
Often combined with manual percussion (rhythmic clapping on the chest wall with cupped hands) or vibration by a caregiver or therapist.
One of the oldest airway clearance techniques. Still used when other techniques are not feasible (e.g., infants, cognitively impaired patients).
Head-down positioning is contraindicated in patients with significant reflux, increased intracranial pressure, or hemodynamic instability.

Devices

Device-based airway clearance

Devices can supplement or replace manual techniques. They are particularly useful for patients who prefer independent clearance, have difficulty performing manual techniques, or benefit from the oscillation component.^[1,2]

Oscillating PEP devices

These handheld devices combine positive expiratory pressure (PEP) with airway vibration/oscillation during exhalation. The oscillations help loosen mucus from airway walls while the positive pressure splints airways open and moves air behind secretions.^[1]

Aerobika: Flow-based oscillating PEP. Works in any position. Widely used and well-studied.
Acapella: Available in low-flow and high-flow versions. Generates oscillations through a counterweighted plug and magnet.
Flutter (VRP1): Steel ball in a cone creates oscillations during exhalation. Position-dependent — must be held at the correct angle.

Technique: Inhale to about three-quarters of a full breath, seal lips around the mouthpiece, and exhale slowly and steadily for 3–4 seconds. Repeat for 10–20 breaths, then perform 2–3 huffs. Complete 2–4 cycles per session.

High-frequency chest wall oscillation (HFCWO)

An inflatable vest connected to an air pulse generator rapidly oscillates the chest wall at various frequencies. Creates small, rapid airflow changes that loosen mucus and move it toward the central airways.

Sessions typically last 20–30 minutes, alternating 5 minutes of oscillation with huff coughs or coughing breaks.
Often used at multiple frequency settings (e.g., 8–12 Hz then 13–17 Hz) during a session.
Does not require specific body positioning or hand coordination.
Well established in cystic fibrosis care. Also used in bronchiectasis, neuromuscular disease, and COPD.^[2]
Common systems include the SmartVest, The Vest (Hill-Rom), AffloVest (wearable/portable), and InCourage.
Requires a prescription. Often covered by insurance for eligible conditions.

Non-oscillating PEP

PEP therapy uses a mask or mouthpiece with a one-way valve and resistor to create back-pressure during exhalation.
The positive pressure gets air behind mucus through collateral channels (pores of Kohn, canals of Lambert), helping move secretions from small to large airways.
Typically 10–20 breaths through the device, then remove and perform 2–3 huffs. Repeat for 10–20 minutes.
Devices include the TheraPEP and PEP mask systems.

Mechanical insufflation-exsufflation (cough assist)

A device that delivers a deep breath (insufflation) followed by a rapid negative pressure (exsufflation), simulating a cough.
Primarily used in neuromuscular disease when cough strength is impaired (peak cough flow < 270 L/min).
Common in ALS, muscular dystrophy, spinal cord injury, and post-extubation patients.
The device is applied via a face mask or tracheostomy adapter.
Typical settings: +30 to +40 cmH₂O for insufflation, –30 to –40 cmH₂O for exsufflation.

Medications

Adjunct medications for airway clearance

Certain medications can be used before or during airway clearance sessions to thin mucus, open airways, or reduce inflammation, making clearance more effective.^[1,3]

Mucolytics and hydrators

Hypertonic saline (3–7%): Inhaled via nebulizer before or during airway clearance. Draws water into the airway, hydrating and thinning mucus. Well-studied in bronchiectasis and CF. May cause bronchospasm — pretreat with a bronchodilator.^[1,3]
Dornase alfa (Pulmozyme): An enzyme that breaks down DNA in thick purulent mucus. FDA-approved for CF. Not recommended for non-CF bronchiectasis (shown to be ineffective and potentially harmful).^[3]
Normal saline (0.9%): Nebulized to help with mucus hydration in milder cases. Less effective than hypertonic saline but better tolerated.
N-acetylcysteine (NAC): Available orally and as a nebulized solution. Theoretical mucolytic benefit; evidence is mixed. Nebulized NAC can cause bronchospasm and an unpleasant taste.

Bronchodilators and other agents

Short-acting bronchodilators (albuterol): Used before airway clearance to open airways and improve mucus mobilization. Particularly important before hypertonic saline to prevent bronchospasm.^[1]
Guaifenesin: An oral expectorant. Increases airway water content to thin secretions. Available OTC. Evidence for clinical benefit is limited, but it is safe and widely used.
Inhaled corticosteroids: Not directly for clearance, but treating underlying airway inflammation can reduce mucus overproduction.
Long-term macrolide antibiotics: Azithromycin three times weekly reduces exacerbations in bronchiectasis, partly through anti-inflammatory and anti-biofilm effects.^[3]

Practical tips for effective clearance

Timing: Perform airway clearance at consistent times — typically morning and evening. Morning sessions clear overnight secretion buildup.
Pre-treatment sequence: Bronchodilator first (if prescribed), then hypertonic saline (if used), then airway clearance technique, then maintenance inhalers.
Stay hydrated: Adequate oral fluid intake throughout the day helps keep mucus thin and easier to clear.
Avoid clearance right after eating: Wait at least 1 hour after meals, especially if postural drainage positions are used.
Track your sputum: Note color, volume, and consistency. Increasing purulence (green/yellow) or volume may signal an exacerbation.
Clean devices regularly: Follow manufacturer instructions for cleaning PEP and oscillating devices. Most should be washed daily in warm soapy water and air-dried.
Work with your team: A respiratory therapist or physiotherapist can help select the right technique, adjust your approach, and ensure you are performing it correctly.

Trusted resources

References

Polverino E, Dimakou K, Traversi L, et al. European Respiratory Society statement on airway clearance techniques in adults with bronchiectasis. Eur Respir J. 2023;62(1):2202053. doi:10.1183/13993003.02053-2022
Flume PA, Robinson KA, O'Sullivan BP, et al. Cystic fibrosis pulmonary guidelines: airway clearance therapies. Respir Care. 2009;54(4):522-537. doi:10.4187/002013209790983250
Hill AT, Sullivan AL, Chalmers JD, et al. British Thoracic Society guideline for bronchiectasis in adults. Thorax. 2019;74(Suppl 1):1-69. doi:10.1136/thoraxjnl-2018-212463

Airway Clearance