The role of positive expiratory pressure and inspiratory muscle training devices in primary care

A number of devices are available to help patients with chronic respiratory disease to clear troublesome mucus and breathe more easily but our use of them in the UK lags behind other European countries. How do they work, and should we be prescribing them more often?

Do you see patients with chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD)? If so, when was the last time you recommended or even prescribed a device to facilitate expectoration or improve inspiratory muscle tone and strength? Compared with Europe, the UK uses very few of these devices and yet there is evidence of their benefit for people with chronic lung diseases. The aim of these devices is to improve the quality of care for people with chronic respiratory conditions by improving inspiratory muscle strength, facilitating expectoration and improving breathlessness, health status and quality of life.

In this article we will look at why patients might benefit from them and consider some of the devices currently available and how they work.

Many chest conditions, including COPD, bronchiectasis and cystic fibrosis are complicated by breathlessness, mucus hypersecretion, cough and sputum. The impact of these symptoms is recognised in quality of life tools such as the COPD assessment test.¹ Helping to alleviate these symptoms is one of the main goals of managing respiratory disease.

IMPACT OF MUCUS HYPERSECRETION IN COPD

Chronic cough and sputum production are known to be related to decline in FEV1, increase in exacerbations, hospitalisation and premature death in people with COPD.² However, mucus hypersecretion is also seen in the peripheral airways of the lungs of people with COPD who do not suffer from chronic cough and this is associated with increased mortality. The peripheral airways have no cough receptors, which may explain why mucus can accumulate and lead to poor outcomes. This suggests that many people with COPD would benefit from interventions that help to keep the airways clear of mucus, including the use of PEP devices.³

FACILITATING EXPECTORATION

As well as pharmacological treatments to aid expectoration, such as muscarinic antagonists and mucolytics, there are non-pharmacological interventions which can help with chest clearance. The active cycle of breathing technique (ACBT) is a process that involves the patient cycling normal breathing with ‘huffing’ to help loosen and expectorate sputum. The process takes at least 10 minutes and should be carried out until the chest feels clear; it is usually performed once or twice daily, depending on the individual and their diagnosis.⁴ This can make adherence an issue. In contrast, chest clearance devices which aid expectoration can be quicker to use and more user-friendly. These devices, also known as oscillatory positive expiratory pressure (PEP) devices, are indicated in people with COPD, bronchiectasis, cystic fibrosis and other lung conditions where mucus production impairs quality of life. They produce continuous waves of pressure and vibrations, which help to loosen and liquefy sputum allowing it to be expectorated more easily. They have also been shown to improve breathlessness by opening up the airways and reducing air trapping. A reduction in antibiotic use and hospital admissions has also been reported.⁵ They can be used in conjunction with pharmacological interventions and smoking cessation programmes to improve outcomes. The Joint British Thoracic Society/Association of Chartered Physiotherapists in Respiratory Care (BTS/ACPRC) guidelines for the physiotherapy management of lung conditions state that there is evidence for using plain or oscillating PEP devices for patients with stable COPD who need an airway clearance technique to assist in the removal of secretions.⁶

PATHOPHYSIOLOGY

COPD is diagnosed when symptoms of shortness of breath, cough and sputum production are associated with objective evidence of largely irreversible airflow limitation on post-bronchodilator spirometry.⁷ These symptoms, and breathlessness in particular, eventually lead to exercise intolerance and the individual may then avoid physical activity in order to reduce these feelings of breathlessness. The overall effect of this is general physical deconditioning with an increase in breathlessness, which is often disproportional to the level of lung disease. It can also have a significant effect of health related quality of life.⁸ Improving symptoms of breathlessness is an important part of managing COPD, therefore. This can be achieved both pharmacologically and through interventions such as pulmonary rehabilitation,9 including the use of inspiratory muscle training (IMT) devices.

IMPACT OF IMT

Studies have shown that improvements in inspiratory muscle strength and exercise tolerance can be seen in people with COPD who used IMT devices, making them a useful adjunct to standard therapies.¹⁰ In patients with significant COPD, the use of IMT with the Powerbreathe device was associated with an increase in exercise capacity, improved quality of life and decreased breathlessness.¹¹ The same study also demonstrated a reduction in hospital bed days of 29% and GP consultations by 23% compared with placebo. The device has also been tested in people with asthma and the results showed an 86% reduction in hospitalisations/emergency room visits and an average 51% reduction in B2-agonist use following IMT for people with moderate/severe asthma.¹²

This suggests that encouraging the use of IMT devices could be a cost-effective intervention for clinical commissioning groups as well as improving quality of life and health status of patients with asthma and COPD. The Joint BTS/ACPRC guidelines for the physiotherapy management of lung conditions state that there is grade A evidence for considering inspiratory muscle training in the management of COPD to improve respiratory muscle strength and/or endurance.⁶

COMMONLY USED DEVICES

Acapella

The Acapella Choice device is a hand held device that incorporates PEP and oscillatory vibrations as a way of mobilising airways secretions. It has been shown to be as effective as the active cycle of breathing technique in this respect and has been shown to be preferred by patients to the ACBT as it was easier to use.¹³ It can be used in the primary or secondary care setting, or at home. The Acapella also has an adaptor that can be used with a nebuliser. The type of Acapella device and resistance setting that is best suited for the individual will usually be selected by the specialist. A breathing programme can then be commenced – five regular breaths and five slow breaths, for example, with exhalation taking three-to-four times longer than inhalation. At the end of each exhalation a breath hold of 2 to 3 seconds should be made. After five or six cycles, the patient should aim to cough or huff to expectorate secretions. The device is easily disassembled and reassembled for cleaning and disinfection at home, and can be put in the dishwasher. It can be used in any position: sitting, standing or lying prone or supine. The Acapella is available on prescription. More information on the Acapella can be found at http://medicalsupplies.about.com/od/Med-Product-Reviews/fl/Acapella-Vibratory-PEP-Mucous-Clearance-Device.htm

RC-CORNET

The RC-Cornet works on the same principals as the Acapella but the manufacturers state that the RC-Cornet oscillates at lower pressures; this makes it more effective for people with low FEV1 volumes and more severe respiratory disease. Its range of settings, which can be adapted by the patient to suit them individually, is also seen as an advantage as they can be adjusted to treat breathlessness or to improve expectoration.¹⁴ It has four positions: position 0 and 1 help primarily with breathlessness, while positions 3 and 4 are used to loosen and move sputum with a force known as dynamic PEP. It is recommended that people start with position 0 and turn the mouthpiece clockwise to switch to the desired position after 2 minutes. As the patient breathes out through the device, the positive pressure generated creates an oscillatory effect that can be heard and felt. The PEP that is produced by the RC-Cornet is ‘asymmetrical,’ which is thought to increase the amount of sputum production when compared with the symmetrical PEP produced by the Acapella and Flutter devices.¹⁵ The recommended use is for 2-5 minutes three times a day. As with the Acapella, the RC-Cornet can also be used with a nebuliser, enabling the patient to add lung physiotherapy to their nebuliser sessions. The RC-Cornet is available to purchase and approval is pending for it to be available on prescription. The RC- Cornet can also be used by the patient in any position, like the Acapella. More information about the RC-Cornet is available from http://www.cegla-ltd.com/resources.html

Flutter

The Flutter was the first hand-held PEP device to produce an oscillating pressure wave allowing mobilisation and expectoration of sputum. It has been shown to improve lung function and oxygenation, although this study was in patients with cystic fibrosis.¹⁶ Unlike the previously mentioned devices, the Flutter device should be used in the sitting or supine position. The patient should inhale deeply and hold their breath for 2 to 3 seconds before exhaling slowly through the device and huffing to facilitate expectoration of mucus. The power of the vibrations is altered by changing the degree at which the device is held. The Flutter device is available on prescription, and detailed instructions for use are available at http://www.clement-clarke.com/ProductInfo/MucusClearance/FlutterInstructions.aspx.

POWERbreathe

The POWERbreathe Medic device is an IMT device that has been shown to help people, including patients with COPD, improve their inspiratory muscle strength. A recent systematic review also demonstrated that the device can be used for expiratory muscle training (EMT) and that EMT plus IMT improved respiratory muscle strength and could be used as part of a pulmonary rehabilitation programme for people with severe or very severe COPD.¹⁷ POWERbreathe Medic is available on prescription. More information is available at http://www.powerbreathe.com/

CONTRAINDICATIONS TO USING THESE DEVICES

The contraindications to using these devices are not dissimilar to those associated with performing spirometry as the manoeuvres for each are similar. This list would therefore include acute exacerbations of respiratory conditions, pneumothorax, haemoptysis, recent surgery and unstable cardiac disease. In general, although these devices can be bought without prescription, potential users should be seen and taught how to use them effectively, either by someone who knows about them in the practice or by, for example, a physiotherapist who has experience of using the devices.

IN SUMMARY

The common symptoms of respiratory diseases include breathlessness and sputum production. Although national and international guidelines tend to focus on the use of pharmacological options to relieve these symptoms, pulmonary rehabilitation can be a cost effective option in many cases. British guidelines support the use of IMT and PEP devices in respiratory conditions including COPD. While not every patient will want or need one of these devices, consideration should be given to the use of these devices in patients suffering from these symptoms as they have been shown to be a cost effective management option.

REFERENCES

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16. Mcllwaine PM, Wong LT, Peacock D, et al. Long-term comparative trial of positive expiratory pressure versus oscillating positive expiratory pressure (flutter) physiotherapy in the treatment of cystic fibrosis. J Pediatr 2001;138:845–849.

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