Peripheral airway clearance techniques
| Peripheral airway clearance technique name | Typical treatment time | Description | Advantages | Disadvantages | Evidence base |
| Conventional physiotherapy (CPT) (postural drainage and percussion) | 5 minutes each lung area | Manual techniques consist of chest percussion and vibrations or shaking. This is performed using a hand, fingers or facemask and is generally well tolerated. Chest vibrations consist of a rapid extrathoracic force at the beginning of expiration, followed by oscillatory compressions until expiration is complete.258 This is believed to increase peak expiratory flow. | Can be performed in patients that cannot cooperate with other techniques. Can be combined with other techniques to enhance airway clearance. Suitable for all ages. Easy to teach. | May not be effective when used in isolation. Care needs to be taken when applying shaking and vibrations not to take the patient to lung closing volumes. | Despite the lack of evidence base, this can be effective in clearing secretions. An ENMC workshop report and review recommended the use of these techniques in patients with NMD.44 |
| Positioning/gravity-assisted postural drainage | 5 min each lung area | The technique involves placing the patient in a position which drains mucus from the periphery of the lungs to the central upper airway. The addition of gravity can assist in the drainage of secretions further. | Any patient can be positioned to use this technique. | The addition of gravity may not be appropriate for all patients especially those who have severe gastro-oesophageal reflux disease. | Despite the lack of evidence, clinically this can be effective in clearing secretions. |
| Breathing exercises— active cycle of breathing technique (ACBT) and autogenic drainage (AD) | 5–10 min | ACBT uses a cycle of techniques to loosen airway secretions by increasing tidal volumes, increasing expiratory airflow and using channels of colateral ventilation. The technique consists of breathing control, thoracic expansion exercises and the forced expiration technique.259 AD consists of breathing at different lung volumes to enable ‘unsticking’, ‘collecting’ and ‘evacuating’ of secretions. The aim is to achieve high expiratory flows by narrowing the airway through an open glottis while forcing expiration after taking a slow deep inspiration with an inspiratory hold.260 | The techniques do not require any equipment. | These techniques are difficult to learn if the patient has cognitive impairment or is unable to participate. Patients with respiratory muscle weakness also find them difficult to perform if they are unable to independently take a deep breath in. | There is no evidence base for these techniques in learning disability and neurodisability. However, may be effective in patients without weakness and who are able to execute the techniques adequately. |
| Positive expiratory pressure (PEP) and oscillatory PEP | 5 to 10 breaths for 5–10 min | PEP involves breathing out against a set resistance through a mouthpiece or mask. It prevents airway collapse, uses collateral channels of ventilation, decreases hyperinflation and increases lung volumes. Oscillatory PEP has the same principles as PEP but with the addition of oscillations to create internal vibrations within the airway. | The equipment is not expensive and can be used in any environment. For the most effective results, there does need to be some cooperation from the patient. | This technique can induce further fatigue in patients who are weak. It can also be ineffective in patients with low expiratory flows. | There is no evidence base for these techniques in learning disability and neurodisability. However, may be effective in patients without weakness and who are able to execute the techniques adequately. |
| Oscillatory devices: high-frequency chest wall oscillation (HFCWO) and intrapulmonary percussive ventilation (IPV) | 10–30 min | HFCWO provides compression of the chest wall at frequencies that are similar to the resonant frequency of the lung, between 5 and 20 Hz,261 via an air pulse generator and then delivers intermittent positive airflow into the jacket. As the jacket expands compressing the chest wall, it produces a transient/oscillatory increase in airflow in the airways vibrating and creating an expiratory air flow bias moving the secretions from the peripheral airways toward the mouth. IPV is delivered via an intermittent positive pressure breathing pneumatic device. IPV delivers air to the lungs at frequencies of 100 to 300 cycles/min at peak pressures from 10 to 40 cmH2O. IPV superimposes high-frequency bursts of gas on top of the patient’s own respiration. This creates a global effect of internal percussion of the lungs, which promotes clearance from the peripheral bronchial tree. The high-frequency airflow pulsates to expand the lungs, vibrate and enlarge the airways. This delivers air to the distal lung units, beyond accumulated secretions. | HFCWO can be used in conjunction with ventilator support. IPV can also provide ventilatory support. Neither device requires cooperation from the patient. The vibration and movement from the secretions with this technique can elicit a spontaneous cough in individuals who have desensitised their cough reflex. | IPV is not available at present within the UK. HFCWO devices currently require individual funding requests in the UK. | IPV and HFCWO have been shown to decrease hospitalisations and requirement of antibiotics for CAP in neurodisability.262–264 |
| Chest wall strapping (CWS) | Unclear | CWS is the restriction of the chest wall through the application of elastic material around the thorax. Strapping via CWS passively lowers the functional residual capacity without using expiratory muscles. This has been demonstrated to be beneficial for lung secretion clearance.265 The principles and physiological effects of CWS are similar to that of autogenic drainage.260 The single most important physiological change consists of the significant increase in maximal expiratory flow. | Simple effective treatment that does not require cooperation of the patient. If the patient is fatigued, can be used in conjunction with ventilatory support. | Requires a skilled therapist to teach the technique and assess whether it needs to be used in conjunction with other techniques. | There is no evidence regarding deflation and strapping to mimic breathing at a low lung volume as in the airway clearance technique, autogenic drainage (deflation). However, physiological arguments and clinical experience advocate for using CWS which induces breathing at low lung volumes, increases lung elastic recoil and increases maximal expiratory flows.266–268 |
| Expiratory flow acceleration (EFA) | 10–30 min | EFA is a technique that increases expiratory flow and enhances natural secretion movement. | A simple treatment that requires no cooperation from the patient, and there are no contraindications in the spontaneously breathing patient. | A device is required to provide this treatment. | EFA has been shown found in an observational study to reduce primary care visits and hospitalisation for CAP in patients with CP.269 |
| Non-invasive ventilation (NIV) and intermittent positive pressure breathing (IPPB) | 10–30 min | NIV and IPPB provide ventilatory support set to provide a greater tidal volume than they can manage independently. Increasing tidal volume increases the expiratory airflow bias and uses collateral channels of ventilation to enhance secretion movement. | It is not necessary for patient cooperation, can off load the work of breathing and prevent oxygen desaturation during treatment. | A device is required to provide this treatment. | NIV is a recognised tool for airway clearance in adults and children with cystic fibrosis.270 It has been recommended for use in patients with NMD.44 271 |
CAP, community-acquired pneumonia; CP, cerebral palsy; ENMC, European Neuromuscular Centre; NMD, neuromuscular disorder.