Setting and content
The principles of pulmonary rehabilitation apply regardless of location; consequently, it has been shown to be effective across the various settings studied so far, although few clinical trials offer direct comparisons between different settings.
Inpatient pulmonary rehabilitation may consist of a planned programme to which a patient is admitted directly, or care provided during an admission for an acute exacerbation. This clinical setting is better suited to patients with severe disease and/or a lack of home management support, or difficulties in transport to outpatient settings. Inpatient rehabilitation can provide similar benefits to those seen in outpatient settings. Potential disadvantages include the higher cost and, in some countries, lack of health insurance coverage.
Outpatient pulmonary rehabilitation is the most common setting employed, and can be based in the hospital or the community. Potential advantages include cost-effectiveness, a safe clinical environment and availability of trained staff. The majority of studies describing the benefits of pulmonary rehabilitation are derived from hospital-based outpatient programmes.
Home-based rehabilitation is the most convenient method for the patient. This method may prolong the benefits of rehabilitation, although in severely disabled patients, it might not be as effective. The potential disadvantages of home-based rehabilitation include the lack of opportunity for group support, limited presence of a multidisciplinary team, variable availability of exercise equipment, lack of safe facilities and the cost of visits by healthcare professionals.
Rehabilitation in the intensive care unit
Early mobilisation of critically ill patients is a relatively new management approach that is advocated as a method of addressing acute respiratory failure and reducing the disability associated with intensive care unit-acquired weakness. It has been shown that early physiotherapy benefits patients receiving intensive care. This therapeutic approach has been reported in clinical trials and is recommended by the ERS and the European Society of Intensive Care Medicine (ESICM) Task Force on Physiotherapy for Critically Ill Patients.
Availability and personnel
As outlined by the recent ERS COPD audit performed in 13 countries, 50% of European respiratory units have access to a pulmonary rehabilitation programme for patients with COPD after hospital admission but only 30% of eligible patients receive pulmonary rehabilitation. 35% of hospitals implement hospital-based pulmonary rehabilitation, 16% implement home-based rehabilitation and 30% implement both.
The effectiveness of pulmonary rehabilitation is more likely to be related to the structure and components of the programme and the quality of the team than to the setting in which it occurs. Pulmonary rehabilitation should be delivered by a multidisciplinary team that includes at least a physiotherapist, an occupational therapist, a psychologist and a dietician, although the exact structure will vary depending on patient population, programme budget and local reimbursement rules. The reported median availability of such personnel in Europe is two per respiratory unit, with wide variations between countries. Overall, 60% of patients admitted to a respiratory unit are seen by a chest physiotherapist.
The improvements attributable to individual elements of a programme are difficult to assess due to the multidisciplinary nature of pulmonary rehabilitation and to the wide range of therapeutic modalities used (table 2).
Physical aerobic training, particularly of the lower extremities, is mandatory. Any patient capable of undergoing training will benefit from a programme that includes leg exercise. Most rehabilitation programmes include endurance training. In patients unable to tolerate high-intensity exercise, an alternative is interval training, which consists of 2–3 minutes of high-intensity training alternating with equal periods of rest. The optimal exercise intensity, modality, level of supervision, duration and maintenance programme remain to be determined. Although high-intensity training is often prescribed, lower-intensity physical training up to the tolerance level of the individual patient can still produce benefits; in fact, greater emphasis on individual prescription of the appropriate amount of exercise is recommended.
Although different exercise training programmes have been safely used in various respiratory diseases, they should not be considered in COPD patients until optimal medical control of the disease has been achieved. The varying severity and complexity of different COPD phenotypes suggest that different options should be used for training respiratory and/or peripheral muscles; thus, although it is not possible to generalise, modalities such as interval training, supported exercise and neuromuscular electrical stimulation have been proposed, in order to include the most disabled individuals.
|Component||Evidence for expected positive results|
|Supplemental oxygen during exercise||++|
|Breathing low-density gas mixtures||+|
|Mechanically assisted ventilation||+|
|Nutritional supplementation and advice||++|
|‘Breathing retraining’ techniques||-|
|Respiratory muscle training||++|
|Neuromuscular electrical stimulation||++|
Table 2 – Components of pulmonary rehabilitation. +++: based on randomised clinical trials and meta-analyses; ++: encouraging results but further evidence is needed; +: indirect evidence; -: no improvement.
Recent studies have shown that, following acute COPD exacerbations requiring hospital admission, pulmonary rehabilitation is associated with clinically meaningful improvement in exercise tolerance. Deterioration in performance after the event may be prevented by peripheral muscle training during acute care.
Adjunctive strategies to exercise
The effects of oxygen supplementation during exercise training are still being debated, although peripheral muscle function has been shown to deteriorate in COPD patients with long-term hypoxaemia. The results of oxygen supplementation during exercise training in patients with or without exercise hypoxaemia, in order to allow them to reach a higher exercise intensity, are also the subject of debate. The use of low-density gas mixtures to improve exercise performance in moderate-to-severe COPD patients is still under investigation.
There is experimental evidence that mechanically assisted ventilation may reduce breathlessness and increase exercise tolerance in COPD patients (allowing them to reach a higher exercise intensity), possibly by ‘unloading’ respiratory muscles and reducing ‘air trapping’ in the lungs – although the exact underlying pathophysiological mechanism remains unclear. In selected patients with severe chronic respiratory disease and suboptimal response to exercise, assisted ventilation may be considered as adjunctive therapy as it may allow for greater training intensity by unloading the respiratory muscles. However, delivering assisted ventilation during exercise is costly, very difficult and labour-intensive, and therefore should only be used in those who will particularly benefit from this therapy. Further studies are needed to further define its role in routine pulmonary rehabilitation.
Supportive strategies, including nutritional supplementation and advice, and/or pharmacological agents (e.g. testosterone or anabolic drugs), can help improve functional outcome, especially in patients suffering from weight loss and muscle wasting. The contribution of education alone remains unclear.
A physiotherapy technique that was previously used as part of rehabilitation encouraged patients to coordinate the breathing process; this technique now receives less emphasis. The term ‘breathing retraining’ generally refers to such techniques, including pursed-lip and diaphragmatic breathing. Pursed-lip breathing is often used subconsciously by COPD patients to enhance exercise tolerance in the face of severe breathlessness and increased ventilatory demand. Pursed-lip breathing results in slower and deeper breaths with a shift in respiratory muscle recruitment from the diaphragm to the accessory muscles of breathing, leading to decreased breathlessness and improved oxygenation on exercise. Physiological studies of diaphragmatic breathing have failed to show any benefits.
Respiratory muscle training increases the strength and endurance of the respiratory muscles. However, the beneficial effect of respiratory muscle training on the exercise capacity and ADL of COPD patients is still an issue of debate. A recent meta-analysis showed that inspiratory muscle training improves muscle strength and endurance, functional exercise capacity, dyspnoea and HRQoL in COPD patients. Inspiratory muscle endurance training has been shown to be less effective than respiratory muscle strength training. Most guidelines still do not recommend this as a method of training.
Neuromuscular electrical stimulation is a possible therapy method for patients with severe chronic respiratory disease who are bed-bound or suffering from extreme skeletal muscle weakness.