Leah Noaeill
The patient’s chart says it all: bronchiectasis, daily productive cough, multiple exacerbations this year, and yet another admission for pneumonia. For bedside RTs and clinicians building daily care plans, the question is not whether airway clearance matters — it’s what combination of therapies will actually help this patient.
Chronic lung disease, neuromuscular weakness, and postoperative changes each affect lung volume, mucus properties, and cough strength in different ways. As new technologies emerge, clinicians are left to sort through marketing claims and historical habits to answer a basic question: How does this therapy fit into airway clearance, and how does it compare to the other options available?
Although the goal is simple — to move mucus out of the lungs — the way we get there can be complex. Over the past several decades, airway clearance approaches have evolved from manual chest physiotherapy to a wide range of patient-directed techniques and system-based therapies. With so many options, clinicians need a practical way to evaluate whether a patient’s current regimen is complete or whether critical steps are being missed.
One way to organize these options is to think of airway clearance as a three-step process. Each step addresses a distinct physiologic objective, and skipping a step can limit the effectiveness of the therapies that follow.
Prepare: Recruit Volume and Open Airways
Before mucus can be mobilized effectively, the lungs need to be open. Patients with chronic lung disease, atelectasis, or postoperative changes often have collapsed or poorly ventilated regions where mucus accumulates but airflow cannot reach. If a mobilization therapy is applied to a lung that has not been adequately expanded, oscillation or percussion may not reach the distal airways where secretions are trapped.
The Prepare phase uses lung expansion, sustained positive pressure, or deep-breathing techniques to recruit collapsed alveoli, improve ventilation distribution, and open airways ahead of mucus-mobilizing therapies.
Techniques that address the Prepare phase include: positive expiratory pressure (PEP), oscillating lung expansion (OLE) systems, lung expansion maneuvers within the active cycle of breathing technique (ACBT), and incentive spirometry in cooperative patients.
Clinical implication: When a patient is adherent to a mobilization therapy but still retaining secretions, the Prepare phase is the first place to look. Is the lung adequately expanded before oscillation or percussion is applied?
Mobilize: Move Mucus from Distal to Central Airways
Once airways are open and ventilation is distributed, the goal shifts to moving mucus from the peripheral airways toward the central airways where it can be cleared. Mucus mobilization relies on creating shear forces at the airway wall through oscillation, vibration, or percussion.
Different therapies generate these forces through different mechanisms. External approaches, such as high-frequency chest wall oscillation (HFCWO), transmit energy through the chest wall. Internal approaches, such as intrapulmonary percussive ventilation (IPV) and OLE systems, deliver high-frequency oscillations directly to the airway via a mouthpiece, mask, or tracheostomy interface. Patient-directed techniques, such as the forced expiration technique within ACBT and oscillatory PEP devices, use the patient’s own breathing to help generate expiratory flow bias.
Each approach has practical tradeoffs in session time, patient tolerance, care setting, caregiver requirements, and whether a pressurized gas source is needed. The comparison table in this article maps these differences across common therapies.
Clinical implication: Mobilization is the phase clinicians most commonly address — but mobilization alone does not complete airway clearance. Mucus that is loosened but not evacuated can migrate back to distal airways.
Evacuate: Clear Secretions from the Upper Airways
The final step is removing mobilized secretions from the central and upper airways. For patients with adequate cough strength, a spontaneous or huff cough is sufficient. For patients with neuromuscular weakness or an ineffective cough — common in conditions such as ALS, muscular dystrophy, spinal cord injury, and post-extubation — mechanical insufflation–exsufflation (MIE) or suctioning may be required.
This phase is often assumed rather than assessed. A care plan that includes mobilization without a plan for evacuation may move mucus centrally without clearing it, leading to mucus plugging or reaccumulation in dependent airways.
Clinical implication: Evacuation should be explicitly addressed in the care plan. For patients with marginal cough strength, assess whether assisted cough techniques or MIE should be added.
Identifying Gaps: Is Your Protocol Covering All Three Phases?
The framework above is not only a way to categorize therapies — it is a practical tool for evaluating whether a patient’s current airway clearance regimen is complete.
Clinicians can audit an existing care plan by asking three questions:
CLINICAL EXAMPLE
Consider a patient with non-CF bronchiectasis who has been prescribed HFCWO vest therapy at home. The patient is adherent — using the vest twice daily for 20-minute sessions — but continues to experience frequent exacerbations, persistent daily sputum production, and two hospitalizations in the past year. The patient also performs nebulized bronchodilator and hypertonic saline treatments separately from vest sessions, bringing total daily therapy time to over 60 minutes.
Using the framework, the clinician would observe that the current regimen addresses Mobilize (vest) and Evacuate (the patient has adequate cough strength) but does not include a dedicated Prepare phase. The lungs may not be optimally expanded before oscillation begins, potentially limiting mucus transit from distal airways. Additionally, the separation of nebulized therapy from airway clearance adds to the daily therapy burden — a well-documented driver of poor long-term adherence in bronchiectasis.
The framework would prompt the clinician to consider whether adding or substituting a therapy that addresses the Prepare phase — or one that integrates Prepare, Mobilize, and aerosol delivery — could improve both clinical outcomes and therapy sustainability.
Conclusion: Key Takeaways for Therapy Selection
Airway clearance is rarely a single-step intervention. Most patients benefit from a combination of therapies — or an integrated approach — that addresses all three phases:
By mapping therapies onto this Prepare → Mobilize → Evacuate framework, clinicians can identify gaps in a patient’s current airway clearance regimen and build protocols that match each patient’s diagnosis, care setting, and ability to participate.
When a patient is adherent to therapy but still symptomatic, the answer may not be more of the same — it may be that a phase is missing. The framework gives clinicians a structured way to ask that question and a practical path to answering it.
Originally published in Spring 2026 edition of Respiratory Therapy – The Journal of Pulmonary Technique
Leah Noaeill, MBA, is Vice President of Marketing & Clinical Affairs at ABM Respiratory Care. She leads clinical education, marketing, and product management for airway-clearance systems and respiratory solutions used in hospital and home care settings.