Chapter 13 Pulmonary rehabilitation in chronic respiratory disease
INTRODUCTION
In the early 1980s there was scepticism regarding the value of physical training, due partly to one study that demonstrated negative results after an exercise training programme in patients with chronic obstructive pulmonary disease (COPD) (Belman & Kendregan 1981). These negative results may in part be explained by inadequate intensity of training. Fortunately, scientific advances have led to widespread recognition of the value of exercise in COPD. There is now a strong body of evidence showing that exercise training by itself or as part of a pulmonary rehabilitation programme results in improvements in disease-related problems of dyspnoea, reduced exercise intolerance, muscle weakness and poor health-related quality of life (Lacasse et al 2002). Despite the strong evidence supporting the benefits of physical training, survey data suggest that less than 2% of appropriate patients receive pulmonary rehabilitation (British Lung Foundation 2002). It is hoped that this chapter, publications, reviews and the impending National Service Framework for COPD will help to redress the balance and improve delivery of pulmonary rehabilitation to all patients with COPD.
Pulmonary rehabilitation is defined as:
Pulmonary rehabilitation programmes are delivered ideally by a multidisciplinary team whose structure varies according to patient population, programme budget, availability of team members and resources (Nici et al 2006). For many years, physiotherapists have been an important part of this multidisciplinary approach and have played an important role in the management of patients with respiratory disease. Effective positioning, mobilization, functional exercises, relaxed breathing and techniques to aid the removal of secretions are recognized physiotherapeutic treatment interventions for these patients. Physiotherapists have also traditionally been active in the education of patients with respiratory disease. The aim now must be to promote healthy attitudes and recognition of the benefits of exercise.
RATIONALE FOR REHABILITATION IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE
COPD is a major cause of morbidity and mortality worldwide, and individuals with COPD constitute the largest proportion of patients referred for pulmonary rehabilitation. One of the major limiting symptoms reported by patients with COPD is dyspnoea: the distressing and fearful sensation of breathlessness. Patients with COPD report significant limitations during daily life and reductions in exercise tolerance. One study has shown high levels of disability in patients with COPD, with 50% of patients studied requiring assistance with household chores (Garrod et al 2000a). Almost all the patients investigated reported some degree of breathlessness during washing and dressing. Other studies have shown that most patients with severe COPD are breathless even when performing simple activities of daily living (ADL) or walking around at home (Bestall et al 1999, Restrick et al 1993). Reduced tolerance to exercise is also a feature of COPD, and may be attributable to the illness itself (e.g. ventilatory limitation), cardiac dysfunction, gas exchange limitations, pre-existing levels of cardiovascular fitness and muscle dysfunction. In fact, while dyspnoea remains a striking and important symptom of COPD, weakness in the peripheral muscles (and possibly respiratory muscles) contributes strongly to exercise inefficiency (Gosselink et al 1996, Koppers et al 2006, Lotters et al 2002). It is increasingly apparent that muscle weakness and muscle fatigue play an important part in the disability evidenced in COPD patients. Fat-free mass in particular has been identified as an important predictor of muscle mass and associated with peak oxygen uptake during exercise (Gosker et al 2003). Peripheral muscle dysfunction in COPD is characterized by reduced muscle strength, reduced muscle endurance, impaired muscle oxidative capacity, and a shift toward a glycolytic fibre-type distribution; that is, a decrease in type I (slow oxidative) fibres and an increase in type IIb (fast glycolytic) fibres (Allaire et al 2004, Gosker et al 2002, Gosselink et al 2000, Janaudis-Ferreira et al 2006, Mador et al 2003, Maltais et al 1999 , Whittom et al 1998). Janaudis-Ferreira and co-workers compared quadriceps muscle strength and endurance in 42 patients with COPD with 53 age-matched healthy controls and showed significantly reduced muscle strength in the COPD group (Janaudis-Ferreira et al 2006). In addition, endurance was lower in the COPD group compared with their healthy age-matched controls. This supports earlier observations that leg fatigue is experienced at lower work intensities in COPD patients compared with healthy subjects (Killian et al 1992). The quadriceps muscle may therefore be significantly weaker and more prone to fatigue in patients with COPD compared with healthy subjects.
Patients with COPD are exposed to a number of factors that may contribute to peripheral muscle dysfunction. An extremely sedentary lifestyle is observed in this population (Pitta et al 2005a, Sandland et al 2005). Donaldson and co-workers showed that time spent outdoors declines markedly over time and deteriorates acutely during exacerbations (Donaldson et al 2005). Pitta and co-workers showed that patients with COPD are severely inactive not only during hospitalization for an acute exacerbation but also after discharge (Pitta et al 2006a). While it is clear that physical inactivity is an important factor, other factors such as the use of corticosteroids, malnutrition, disequilibrium in protein balance, chronic hypoxia and hypercapnia, oxidative stress, muscle apoptosis and genotype profile contribute to muscle impairment (American Thoracic Society/European Respiratory Society (ATS/ERS) 1999, Troosters et al 2005). There is now much interest in the place of inflammation in COPD and the part it plays in the development of muscle dysfunction. It has been shown that systemic inflammation is associated with loss of fat-free mass and muscle weakness both in stable patients and in patients during an acute exacerbation (Schols et al 1996, Spruit et al 2003). Importantly, data have shown relationships between inflammatory markers such as C-reactive protein (CRP), interleukin 6 (IL-6) and tumour necrosis factor alpha (TNFa) and health status, muscle weakness and exercise tolerance (Broekhuizen et al 2006, de Torres et al 2006, Garrod et al 2005a, Yende et al 2006). The mechanisms and contribution of inflammation to disability, reduced exercise tolerance and response to training are not yet clear (Spruit et al 2005), although it has been suggested that the intensity of systemic inflammation is linked to the severity of airflow obstruction (Gan et al 2004, Takabatake et al 2000). Furthermore, inactivity, oxidative stress, lactic acidosis and inflammatory cytokines may work congruently to disrupt the local anabolic/catabolic mechanisms (Debigare et al 2001). The current body of evidence demonstrates that peripheral muscle dysfunction in COPD is multifactorial, and factors mentioned above may act in combination. Owing to this multidimensional character, determining the severity of the disease based only on pulmonary function measurements has been questioned and a multidimensional index has been used to characterize COPD patients. Besides pulmonary function, this index includes also body composition, level of dyspnoea and functional exercise capacity (6 minute walking test — 6MWT) (Celli et al 2004). These developments in our understanding of the causes of myopathy in COPD reinforce the fact that strategies aimed at maximizing functional performance and peripheral muscle strength are of utmost importance in the pathophysiology of COPD.
The aims of pulmonary rehabilitation are to:
EXERCISE PRESCRIPTION
Exercise training is considered the cornerstone of a pulmonary rehabilitation programme (Lacasse et al 1997). Reconditioning of patients with respiratory disease reflects the same principles as those applied in healthy subjects, although programmes should be adapted to the individual limitations of the patient and take into consideration ventilatory, cardiovascular and muscular abnormalities (Troosters et al 2005). Based on solid evidence, it is now widely accepted that exercise training is beneficial to patients with chronic respiratory disease. It is also known that the training effects depend on different factors including duration and frequency of the training programme, training intensity and training modality. The extent of the benefits obtained will depend on the management of these factors.
Duration and frequency of the training programme
There is as yet no consensus as to the optimal duration of an exercise training programme for patients with COPD. Evidence suggests that longer programmes yield larger and more endurable training effects (Lacasse et al 2002). Twenty sessions of pulmonary rehabilitation have been shown to produce better results than 10 sessions in outcomes such as exercise tolerance and health-related quality of life (Rossi et al 2005). Furthermore, various studies have demonstrated that exercise programmes lasting at least 7 weeks (7–12 weeks) result in greater benefits than programmes of shorter duration (Bendstrup et al 1997, Carrieri-Kohlman et al 2005, Green et al 2001, Lake et al 1990). It has therefore been suggested that programmes of at least 8 weeks are advisable to result in substantial positive effects (Fabbri & Hurd 2003, Troosters et al 2005). A meta-analysis has shown strong trends for improved results in functional exercise capacity from longer programmes with close supervision (Lacasse et al 2002). Programmes of 6 months or longer also seem to result in better long-term effects (Berry et al 2003, Guell et al 2000, Salman et al 2003, Troosters et al 2000).
Ideal training frequency is also a topic that has been much debated but there is as yet insufficient evidence to identify the optimal frequency. The scarce evidence available suggests that patients should exercise at least three times per week, and that regular supervision is fundamental (Puente-Maestu et al 2000, Ringbaek et al 2000, Wadell et al 2005). However, many programmes with twice-weekly supervision and encouragement of ‘home exercise’ have shown good results (Lacasse 2006). One intensive programme with 20 sessions condensed into 3–4 weeks showed positive results (Fuchs-Climent et al 1999), suggesting that frequency may be as important as duration of the programme.
Training intensity
Determining training intensity
A further element of exercise prescription concerns the intensity of exercise. A number of early studies of pulmonary rehabilitation had methodological flaws concerning the description of exercise intensity. Before considering appropriate levels of intensity, it is necessary to revisit relevant assessment tools. Two common methods of prescribing intensity are used: symptom-limited exercise prescription and physiological testing derived from maximal oxygen consumption (or related measures). In the first method patients are instructed to exercise to a prescribed symptom level, for example ‘moderately or somewhat short of breath’ (scores of 4–6) on the Borg breathlessness score (Borg 1982, Horo-witz et al 1996). Although this provides an effective training stimulus for most patients, problems may occur when patients demonstrate very high levels of dysp-noea, thus limiting the intensity of training. Dyspnoea is very much a subjective perception, meaning that fear and anxiety at the start of a programme may heighten scores. If this method is used, it may be necessary to reassess dyspnoea levels halfway through the programme and set a higher training target if appropriate. Calculating the exercise intensity from maximum oxygen consumption (VO2max) is probably more reliable and is easily performed using cycle ergometry or derived from an associated measure such as the shuttle walk test (Dyer et al 2002). However, for patients with COPD, a true VO2max may be unattainable due to ventilatory limitations. An effective compromise is to determine the initial exercise prescription at 70–80% of the derived VO2max and then to use breathlessness scores to monitor the training and adjust accordingly (Mahler et al 2003).
Power output has also been used as an option to determine training intensity, and an intensity of 60–80% of the maximal workload has been frequently used with positive results. However, the peak work rate obtained during the maximal incremental exercise test is determined by the work rate increment used in the test and this must be taken into consideration (Debigare et al 2000). Another option to determine training intensity is using a percentage of the maximal heart rate. Caution is necessary because this may result in inadequate training stimulus (Brolin et al 2003, Pitta et al 2004, Zacarias et al 2000). This inadequacy may occur because maximal exercise capacity is often not affected by the cardiocirculatory system in COPD patients, and heart rate is also influenced by various medications commonly prescribed to COPD patients.
Ideal training intensity
Casaburi and colleagues (1991) demonstrated greater physiological and cardiovascular benefits in patients who exercise at higher intensities when compared with patients exercising for a longer duration but at a lower intensity. The same research group, in another study, targeted patients with more severe COPD and obtained similar results (Casaburi et al 1997). Puente-Maestu and colleagues have also shown that supervised higher- intensity training programmes were more effective than lower-intensity self-monitored training (Puente-Maestu et al 2000). Others studies have also highlighted the positive effects of high-intensity exercise training (Gimenez et al 2000, Punzal et al 1991). These studies recommend training intensities of 60–80% of peak work rate or maximal oxygen consumption in order to achieve the greatest effects, although the rate of work increment during the maximal incremental test is an important factor in determining whether a patient is able to achieve a training target of 80% of peak work rate (Debigare et al 2000, Maltais et al 1997, Neder et al 2000). Low-intensity training has also been shown to result in significant improvements in symptoms and quality of life (Normandin et al 2002) and even in exercise tolerance (Clark et al 1996, Roomi et al 1996). Wedzicha and colleagues stratified a group of COPD patients according to their degree of dyspnoea and instructed them to exercise until moderately to severely shortness of breath (Wedzicha et al 1998). They reported that the improvement in exercise performance and health status following an exercise programme depends on the initial degree of dyspnoea. Therefore, a cautionary note concerns the relative severity of the patients.
Findings from a systematic review highlight the fact that in very severe patients, there is a lack of evidence to indicate that high-intensity exercise is the ideal mode of training. (Puhan et al 2005). Applicability of high-intensity training in these most severe and symptomatic COPD patients requires further study in order to determine the ideal training intensity and to achieve better results. In summary, the most recent consensus statement by the American Thoracic Society and European Respiratory Society states that:
In cases where high-intensity exercise is advocated for the more symptomatic patients with severe COPD, interval training may prove to be more comfortable (Vogiatzis et al 2005).
Training modality
A variety of training modalities has been employed in the management of patients with COPD, all with generally good results. The British Thoracic Guidelines recommend including functional exercises (Morgan et al 2001). Most programmes use continuous (or endurance) exercise training, incorporating an element of walking and/or cycling for 20–30 minutes per session. An alternative approach is interval training, where the 20- or 30-minute exercise session is divided into short bouts of high-intensity exercise for 30 seconds to 2–3 minutes, interspersed with equal periods of rest. One study compared interval training with continuous training in COPD patients and showed a different pattern of physiological response (Coppoolse et al 1999). Continuous training resulted in an improvement in maximal oxygen consumption, reduction in minute ventilation and a more pronounced decrease in lactic acid production, whereas interval training resulted in improvement in peak workload and a decrease in leg pain. This difference in training response may be a reflection of specific training effects in either oxidative or glycolytic muscle metabolic pathways. Vogiatzis and colleagues (2005) compared high-intensity interval training (bouts of 30 seconds at 125% maximal cycle ergometry and 30 seconds rest for 45 minutes) with equivalent constant load (at 75% of maximum for 30 minutes constantly) 3 times per week for 10 weeks. Both groups showed significant training effects; however, during the training sessions, symptoms of dyspnoea and leg discomfort were significantly lower for the high-intensity interval group. These data suggest that in order to minimize discomfort associated with exercise training (and hence aid long-term adherence) patients may be advised to exercise in short, high-intensity bursts of activity. Furthermore, interval training may allow more severe patients to achieve higher work rates and to exercise for longer with fewer symptoms, due to less dynamic hyperinflation and a higher stable ventilation (Sabapathy et al 2004, Vogiatzis et al 2004). When using interval training, it is important that the total exercise time is not reduced but kept to 20–30 minutes.
The relative benefits of generalized training programmes have been compared with individualized training programmes (Sewell et al 2005). General exercises consisted of three strength training activities for the lower limbs (step-ups, sit to standing and stationary cycling), thoracic exercises and upper limb activities (wall pushes, arm circling and shrugging). Individualized exercises were based on patient goals identified using the Canadian Occupational Performance Measure (2005). After the 7-week programme, there were no differences in any outcome measure between the 59 patients randomized to general training and the 64 randomized to individualized training. The sample size was large in this study with adequate power suggesting that targeting exercise specifically to patient-identified goals is unnecessary assuming that adequate attention is made to ensure that both upper and lower limb exercises are included at an appropriate intensity.
As data have become available from studies investigating the relative merits of different training regimens in pulmonary rehabilitation, it may be concluded that the most important aspect of exercise is that strengthening exercises are routinely incorporated into programmes. Strength training has the potential to increase muscle mass and muscle force, both of which are common therapeutic aims in COPD patients. Training is generally performed with 2 to 4 sets of 6 to 12 repetitions, at intensities ranging from 50% to 85% of the one repetition maximum (O’Shea et al 2004). A systematic review evaluating a number of comparative study designs concluded that strength training resulted in greater improvements in health-related quality of life than endurance training, although the benefits of strength over endurance are equivocal when considering the relative change in exercise tolerance (Puhan et al 2005). Interestingly, a randomized controlled trial reported no difference in change in muscle strength, distance walked or health-related quality of life between those who performed a strength training regimen compared with endurance training (Spruit et al 2002). In addition, Probst and colleagues showed that a major advantage of strength training is that the cardiopulmonary stress during this kind of exercise is lower than during whole-body endurance exercise and results in fewer symptoms (Probst et al 2006). As muscle weakness contributes to reductions in maximal walking test but not to endurance walking, there is probably a place for both types of training (Steiner et al 2005). Guidelines for pulmonary rehabilitation in COPD patients currently recommend a combination of endurance and strength training as it has multiple beneficial effects and is well tolerated (Nici et al 2006).
Although the focus of most studies of exercise training in COPD patients has been the lower limbs, it has been shown that upper limbs are also affected (Franssen et al 2005, Gosselink et al 2000) and that upper limb activity influences dynamic hyperinflation and pulmonary mechanics (Dourado et al 2006, Gigliotti et al 2005, McKeough et al 2003). Due to the fact that improvement is specific to the muscles trained, the inclusion of exercise for the upper limbs in a programme is justified, particularly exercises that reflect activities of daily living. Examples of such exercises include arm cycle ergometer, multigyms, free weights and elastic bands.
When training the upper limbs, it is important to consider the principles of positioning during exercise. Exercise endurance is less during unsupported upper limb compared with supported upper limb work (Astrand et al 1968), especially when the arms are elevated above the head such as in ‘reaching’ or ‘arching the arms’. Stabilization of the accessory muscles occurs only during movements where the shoulder girdle is fixed. These principles can be utilized during training. Unsupported upper limb work may achieve greater desensitization of dyspnoea, while strength training will be performed best with the upper limbs supported in order to minimize dyspnoea and maximize the number of repetitions possible. Guidelines for exercise prescription in pulmonary rehabilitation for patients with COPD are outlined in Box 13.1.
PHYSIOLOGICAL TRAINING RESPONSES
Physiological training effects differ according to the training regimen. The first aspect of training that occurs is a learning effect or improved neuromuscular coordination. This is not associated with physiologi-cal training effects per se, but may result in improved gait efficiency and increased stride length after a programme involving repeated walks (McGavin et al 1977).
Improved mechanical efficiency
Mechanical efficiency is reduced in patients with chronic respiratory disease when compared with a healthy elderly population (Baarends et al 1997, Richardson et al 2004). The explanation for this seems to be linked to the elevated number of less efficient type II fibres (Richardson et al 2004) and the increased oxygen cost of breathing observed in COPD (Baarends et al 1997). Arm efficiency seems to be relatively preserved in comparison to the lower limbs (Franssen et al 2002).
Much of the improvement in exercise tolerance following pulmonary rehabilitation is likely to be a result of improvements in mechanical efficiency (O’Donnell 1994). Measures that may suggest an improvement in efficiency include stride length and gait coordination. McGavin and co-workers (1977) showed improvements in exercise tolerance after a 12-week home programme of low-intensity exercise. They reported a modest increase of approximately 8% in walking distance which was probably attributable to improvements in mechanical efficiency rather than cardiovascular changes per se. Similarly a group of patients housebound because of dyspnoea, showed some improvement in exercise tolerance after an 8-week home-based programme although this was not significant when compared with a control group (Wedzicha et al 1998). Another programme of home exercise, continued over a period of 1 year showed larger changes, suggesting that when exercise intensity is low a longer period of time may be needed to achieve true physiological training effects (Sinclair & Ingram 1980). Improvements in efficiency of the skeletal muscles after exercise training may lead to reduced alveolar ventilation during exercise, therefore reducing dynamic hyperinflation and reducing exertional dysp-noea (Nici et al 2006).
Cardiovascular adaptations
Cardiovascular adaptations that might be expected in a normal subject after training include a reduction in the heart rate after training for a given level of work, reductions in minute ventilation, a lowering of the onset of lactic acidosis and a lower maximum oxygen uptake (VO2max) for a given work rate. Numerous studies show evidence of these changes in patients with COPD, with both moderate and severe obstruction (Casaburi et al 1991, Griffiths et al 2000, Ries et al 1995).
Muscle changes
Studies have shown that the peripheral muscles in COPD respond to training in a similar manner to muscles in healthy individuals (Casaburi et al 1991). This suggests that the contractile mechanism of the peripheral muscles in patients with COPD remains intact and muscle strength can be improved with an appropriate training programme (Bernard et al 1999, Maltais et al 1997, Simpson et al 1992). Recently Vogiatzis and colleagues performed muscle biopsies of COPD patients before and after pulmonary rehabilitation (Vogiatzis et al 2005) and demonstrated that training, both interval and continuous, achieved physiological changes in muscle fibres of COPD patients. The improved oxidative capacity of muscles, evident by changes in cross-sectional area of both type I and type II fibres and by a shift from type II b fibres (glycolytic) to type IIa (oxidative) fibres, supports previous observations that showed delayed onset of lactic acidosis with training. The result of this is an improvement in oxygen uptake and the ability to maintain aerobic muscle metabolism for a prolonged period (Casaburi et al 1991).
In addition, there is evidence that type I fibres increase in size and number and that the concentration of mitochondrial enzymes is greater after training (Maltais et al 1996). Strength training is predominantly associated with an increase in size of muscle cells and number of myofibrils. Most importantly, muscle capillaries and myoglobin levels within a trained muscle are higher after training, thus improving the transport of oxygen to exercising muscles. In summary, adequate exercise training leads to improvements in the capacity to generate and to sustain contraction. However, it is important to remember that peripheral muscles of patients with COPD are responsive to training but factors other than deconditioning also contribute to dysfunction, namely nutritional status, hypoxia and hyper capnia, inflammatory mediators and circulating hormones.
PRACTICAL ASPECTS OF TRAINING
Location
There are arguments in favour of rehabilitation in a number of settings, from the hospital inpatient setting to the outpatient, home or community setting. Hospital inpatient programmes (Goldstein et al 1994) are better suited to patients with severe deconditioning and/or limited transportation resources. These programmes may offer a multidisciplinary approach and intensive training, but are costly and may lack insurance coverage in some countries. Outpatient programmes seem to be the most cost-effective in producing optimal effects especially in moderate to severe patients, as a multidisciplinary approach, adequate equipment and careful supervision are possible at more reasonable costs (Nici et al 2006). Most studies involving rehabilitation programmes that resulted in significantly positive effects were developed in hospital-based outpatient settings (Fig. 13.1) (Lacasse et al 2002, Nici et al 2006). The advantage of home-based programmes relates to improved adherence and prolonged benefits with an additional focus on functional and meaningful activities (Strijbos et al 1996). The disadvantages relate to the lack of peer group support (Wedzicha et al 1998), the potentially limited space for mobilization and the limited availability of a multidisciplinary team, exercise equipment and proper supervision. Individual supervision is required and patients may need input for a longer period of time when compared with outpatient programmes (Sinclair & Ingram 1980). The pros and cons of pulmonary rehabilitation at home are reviewed (Garrod 1998) and summarized in Table 13.1.
Table 13.1 The pros and cons of pulmonary rehabilitation at home
| Pros | Cons |
|---|---|
(Adapted from Garrod 1998)
Other avenues are being explored, from community care settings (Cambach et al 1997) to primary care interventions in local surgeries and sports centres, but further trials will be needed to evaluate the role of rehabilitation in primary care. Recent advances in ‘exercise on prescription’ schemes run in conjunction with local sports facilities and general practitioner surgeries point towards greater community involvement and better use of private sector resources. In recognition of patient wishes and significant underresourcing of pulmonary rehabilitation, future developments will need to make greater use of community facilities (Garrod & Backley 2006). Physiotherapists are ideally placed to lead the way with referrals, support and training of local members.
Timing
Perhaps of more importance than where pulmonary rehabilitation should take place, is the issue of when rehabilitation is initiated. Pitta and co-workers showed that physical activity is markedly reduced not only during hospitalization for an acute COPD exacerbation, but also continued to be low after discharge (Pitta et al 2006a). In this study, the amount of time spent being active was related to the degree of muscle weakness. A study by Man et al (2004) has shown positive benefits of a training programme delivered within 10 days of discharge from hospital. In this randomized controlled trial a large clinical and statistically significant difference was seen in change in exercise tolerance after rehabilitation, compared with usual care only. No adverse events were reported and the drop out rate was similar in each group. Although the trial was small there were trends towards a reduction in hospital admissions and a significant difference in emergency room visits was observed. These are important findings, since they highlight two factors: firstly that rehabilitation early after discharge is safe and secondly that with usual care alone, exercise tolerance at 3 months following discharge does not improve (and in fact shows a small decline), suggesting that patients may deteriorate over time rather than improve without rehabilitation. A study involving pulmonary rehabilitation and neuromuscular electrostimulation initiated immediately after a hospital admission for acute exacerbation has also highlighted the benefits of early initiation of rehabilitation after exacerbation (Vivodtzev et al 2006). A higher level of physical activity has also been shown to be associated with a 46% reduction in readmission in COPD (Garcia-Aymerich et al 2003), further emphasizing the clinical importance of early rehabilitation. Preliminary data from Probst et al (2005) have shown that an exercise protocol based on strength training can be safely applied even during hospitalization, resulting in improvement in muscle force and counteracting the deleterious effects of immobilization.
Whether rehabilitation programmes should be repeated for individuals is an important clinical question. At the moment data suggest there is little value in repeating a programme 1 year after attendance (Foglio et al 2001), although there has been some suggestion that the number of hospitalizations may be reduced as a result of repeat rehabilitation. Another trial also showed that in severe and disabled COPD patients, a more frequently repeated inpatient programme resulted in only modest additional benefits over 1 year (Romagnoli et al 2006). These benefits were mostly linked to self-reported symptoms and health-related quality of life. The issue is made more complex when consideration is given to the fact that patients often request additional sessions, while many more known people with COPD do not have the opportunity to attend even one course of rehabilitation.
Equipment
As mentioned previously, functional exercise programmes are of the utmost importance to the success of pulmonary rehabilitation. Simple exercises aid clarity, and practical measures to include exercise in daily life may aid long-term adherence. Moreover, for older patients with COPD exercise must be seen as ‘appropriate’; for patients with less severe disease, swimming, bike riding, golfing, bowling and walking are all appropriate forms of exercise. The type of equipment will depend primarily on the type of training to be performed and local financial resources. Equipment requirements may be as simple as a mat for floor exercises, dumbbells or hand weights and space to perform aerobic training. Where endurance training is the main objective, equipment such as cycle ergometry (Fig. 13.2A) and a treadmill may be helpful. However, walking practice, devices to simulate stair climbing (Fig. 13.2B), or actual stairs have high functional applicability. In order to achieve long-term benefits, patients must be able to continue exercising effectively after the programme has ended. For strength training a multigym may be ideal but simple hand and ankle weights will also be sufficient. It is important to note the necessity of training both the upper and lower limbs (Lake et al 1990, Sivori et al 1998) and the use of breathing control throughout exercise (see Other adjuncts to rehabilitation later in this chapter).
Changing attitudes towards exercise and dyspnoea
Fear and anxiety influence the breathing pattern. For many patients, the thought of exercise exacerbates dysp-noea. The underlying philosophy of pulmonary rehabilitation is that exercise is beneficial. During the programme the therapist attempts to help the patient to replace negative thought processes with positive ones. Teaching patients to perceive breathlessness as a positive effect of ‘good’ exercise rather than a negative effect of their health may enhance the training effect (Atkins et al 1984). This philosophy must, of course, extend to relatives and demands the education and involvement of the families of those with respiratory disease.
Supplemental oxygen during exercise training
The use of supplemental oxygen during training remains a complex question, one that in many cases is further complicated by the issue of available resources. It is widely accepted that oxygen supplementation leads to significant acute improvement in exercise tolerance in hypoxaemic patients (O’Donnell et al 2001), even in patients without appreciable exercise desaturation (Somfay et al 2001). Despite this, studies in which oxygen was provided during an exercise training programme have not been able to show additional benefits directly linked to oxygen supplementation. An early study by Zack & Palange (1985) showed an improvement in exercise tolerance after a 12-week outpatient training programme in which all patients trained with supplemental oxygen. However, there was no control group and it is not known whether additional benefits resulted from the use of supplemental oxygen. One randomized study investigated the role of oxygen in patients with severe COPD and exercise desaturation (Garrod et al 2000a). This showed an improvement in dyspnoea after rehabilitation that was greater in the patients who trained with oxygen compared with those who did not. However, as in an earlier study (Rooyackers et al 1997), there was no difference in the changes in exercise tolerance between the two groups. This suggests that although additional oxygen may augment desensitization to dyspnoea, it does little to enhance changes in exercise tolerance. Further data from 2001 showed similar results and concluded there were minimal benefits of oxygen as a training adjunct (Wadell et al 2001).
Hoo (2003) has undertaken a comprehensive review of this issue. Emtner and colleagues (2003) performed a randomized evaluation of the effects of oxygen on training in 29 non-hypoxaemic COPD patients. Breathing oxygen significantly increased endurance time compared with the air-trained group. Furthermore the rate of improvement was greater in the oxygen-trained patients. These data support previous observations that supplemental oxygen has a greater effect on sub-maximal exercise, improving endurance rather than intensity and reinforcing the likelihood that oxygen benefits are accrued largely through reductions in dynamic hyperinflation rather than correction of hypoxia per se (Somfay et al 2001). At the present time it is prudent to advise that patients who are on long-term oxygen therapy (LTOT) should exercise with supplemental oxygen. In addition, training with oxygen both for hypoxaemic and non-hypoxaemic patients may allow them to exercise at higher intensity and with less dyspnoea, although it is still unknown whether this translates into significant clinical benefits following a training programme.
Safety issues in rehabilitation
Many elderly people perceive exercise at ‘their age’ to be dangerous (O’Brien et al 1995). Issues of safety are obviously compounded in older people with respiratory disease and considerable reassurance may be required concerning safety. The issues of safety are somewhat unknown in the field of pulmonary rehabilitation. Although full exercise testing with ECG heart monitoring is recommended as routine for patients with COPD (American Thoracic Society 1999), a maximal incremental cycle ergometry test is unrealistic for many patients with severe disease. Even unloaded cycling can be exhausting for these patients, while adding incremental loads may cause distressing dyspnoea, ultimately preventing further exercise and disheartening the patient.
Most programmes exclude patients with unstable angina. For most patients, a field walking test with pulse oximetry (Fig. 13.3) and heart rate monitoring will identify oxygen needs and enable prescription of exercise intensity. In the hospital setting, resuscitation equipment and oxygen should be readily available and the personnel involved trained in the use of this equipment. However, a more pragmatic approach is required in the community setting where patients may be exercising at home or in local centres. There is evidence that patients with COPD demonstrate arterial desaturation during routine activities. The long-term effects of temporary falls in arterial saturation are unknown and warrant further investigation (Schenkel et al 1996). Patients with COPD often demonstrate ventilatory limitation or report fatigue before there is significant cardiovascular stress. However, this will not be the same for all groups of patients with respiratory disease and further research is required in this area. Anecdotally the only complications of exercise in these patients have been related to minor musculoskeletal injuries.
