Increased muscle efficiency and sustained benefits in an outpatient community hospital-based pulmonary rehabilitation program

Exercise training in chronic obstructive pulmonary disease

Exercise limitation is a common and disturbing manifestation of COPD. The exercise intolerance is often caused by multiple interrelated anatomic and physiologic disturbances. Importantly, exercise tolerance can be improved despite the presence of fixed structural abnormalities in the lung. Exercise training, undertaken alone or in the context of comprehensive PR, improves exercise endurance and, to a lesser degree, the maximal tolerated workload of patients with COPD. Pulmonary rehabilitation also improves dyspnea and QOL. Exercise training and PR should be considered for all patients lacking contraindications who experience exercise intolerance despite optimal medical therapy. Lower-extremity training should be included routinely in the exercise prescription. The choice of type and intensity of training should be based primarily on the patient's individual baseline functional status, symptoms, needs, and long-term goals. When tolerated, high-intensity (continuous or interval) training may lead to greater improvements in aerobic fitness than low-intensity training but is not absolutely necessary to achieve gains in exercise endurance. Upper-extremity training should be undertaken when possible. Ventilatory muscle training should be considered for patients who continue to experience exercise limitation and breathlessness despite medical therapy and general exercise reconditioning. Exercise tolerance may improve following exercise training because of gains in aerobic fitness or peripheral muscle strength; enhanced mechanical skill and efficiency of exercise; improvements in respiratory muscle function, breathing pattern, or lung hyperinflation; as well as reduction in anxiety, fear, and dyspnea associated with exercise. Gains made in exercise tolerance can last up to 2 years following a limited duration (6-12 week) rehabilitation program.

Exercise training and chronic obstructive pulmonary disease: past and future research directions

Chronic obstructive pulmonary disease (COPD) is a major cause of death and disability in the United States. It is characterized by symptoms of breathlessness that result in sedentary lifestyle, physical deconditioning, and reduced quality of life. Previous research has shown that exercise training in patients with COPD will improve physical function and may help improve the quality of life. Unfortunately, the majority of these previous studies have not been pursued with adequate scientific rigor and the conclusions regarding the efficacy of exercise as an adjunct in the treatment of COPD are equivocal. The purpose of this article is to review the previous research that has focused on the effects of exercise training on individuals with COPD, to examine the problems with this previous research, and to emphasize the need and identify topics for further outcome-based research.

Disease management of COPD with pulmonary rehabilitation

Pulmonary rehabilitation is a set of tools and disciplines that attends to the multiple needs of the COPD patient. It extends beyond standard care by addressing the disabling features of chronic and progressive lung disease. It centers on self-management, exercise, functional training, psychosocial skills, and contributes to the optimization of medical management. Exercise enables other components by building strength, endurance, confidence, and reducing dyspnea. Patients who have undergone rehabilitation often enjoy a reduced need for health-care utilization. On the downside, rehabilitation is a one-time intervention, the benefits of which dissolve over time. The patient's physician is rarely a participant in the program; thus, the physician is at a disadvantage in being able to support a long-term response. Rehabilitation is available to a small percentage of a large patient population who could benefit. Optimal disease management would entail redesigning standard medical care to integrate rehabilitative elements into a system of patient self-management and regular exercise. It should emphasize physician involvement in self-management, which is essential in developing and maintaining an effective exacerbation protocol. Pulmonary rehabilitation should take its place in the mainstream of disease management through its integrative and reconciliative role in the multidisciplinary continuum of services, as defined by the National Institutes of Health, Pulmonary Rehabilitation Research, Workshop of 1994.

The cost/benefits of outpatient-based pulmonary rehabilitation

OBJECTIVE

To evaluate the outcomes of an inexpensive outpatient pulmonary rehabilitation program for stable patients with chronic obstructive pulmonary disease (COPD).

DESIGN

Before-and-after trial.

SETTING

Private, ambulatory setting with carryover to the home.

PATIENTS

Forty-six stable COPD patients, from 45 to 80 years of age.

INTERVENTIONS

A pulmonary rehabilitation program consisting of education, training, group therapy, and an individualized regimen of home-based extremity and inspiratory muscle exercise with weekly ambulatory sessions over a 10-week period.

MAIN OUTCOME MEASURES

Symptom-limited oxygen consumption (SLVO2), distance walked in 12 minutes (12 MW), dyspnea, endurance, forced expiratory volumes, minute ventilation (MV), changes in heart rate and blood pressure, and inspiratory muscle work tolerance (IMWT).

RESULTS

There were significant increases (p < .05) in SLVO2, 12 MW, inspiratory muscle and bicycle work capacity, and forced vital capacity (FVC). The sensation of dyspnea significantly decreased during the performance of activities of daily living (ADL) (p < .05). There was no significant change in forced expiratory volume in 1 second (FEV1). The cost of the 10 outpatient sessions was $650.

CONCLUSIONS

An inexpensive outpatient/home-based pulmonary rehabilitation program provided largely by a specifically trained therapist under physician supervision can significantly improve parameters associated with quality of life for patients with COPD.

Results of 150 consecutive bilateral lung volume reduction procedures in patients with severe emphysema

Between January 1993 and February 1996, we performed 150 bilateral lung volume reduction procedures for patients with severe emphysema. Patients were selected on the basis of severe dyspnea, increased lung capacity, and a pattern of emphysema that included regions of severe destruction, hyperinflation, and poor perfusion. Twenty percent to 30% of the volume of each lung was excised with the use of a linear stapler and bovine pericardial strips attached to buttress the staple line. Patients were between 36 and 77 years old, with an average 1-second forced expiratory volume of 25% of predicted, total lung capacity of 142% of predicted, and residual volume of 283% of predicted. Ninety-three percent of patients required supplemental oxygen, continuously or with exertion. All patients but one were extubated at the end of the procedure. The 90-day mortality was 4%. Hospital stay progressively decreased with experience, and for the last 50 patients the median hospital stay was 7 days. Prolonged air leakage was the major complication. Results at 6 months show a 51% increase in the 1-second forced expiratory volume and a 28% reduction in the residual volume. The Pao2 increased by an average of 8 mm Hg, and 70% of the patients who had previously required continuous supplemental oxygen no longer had this requirement. The improvements in measured pulmonary function were paralleled by a significant reduction in dyspnea and an improvement in the quality of life. Reevaluation at 1 year and 2 years after operation showed the benefit to be well maintained. We conclude that lung volume reduction offers benefits not achievable by any means other than lung transplantation for highly selected patients with severe emphysema.

Short-stay comprehensive inpatient pulmonary rehabilitation for advanced chronic obstructive pulmonary disease

OBJECTIVE

To evaluate the effectiveness of short-term, comprehensive inpatient pulmonary rehabilitation in severe chronic obstructive pulmonary disease (COPD).

DESIGN

Retrospective analysis of several outcome measures.

SETTING

Inpatient pulmonary rehabilitation unit.

PARTICIPANTS

Thirty-eight consecutive adult patients with advanced COPD referred to our inpatient pulmonary rehabilitation program between January 1 and December 31, 1994. All but one were referred from acute care hospitals. The mean forced expiratory volume in 1 second (FEV1) was .69L; 79% required supplemental oxygen.

MAIN OUTCOME MEASURES

(1) Discharge status; (2) timed walk, with measurements of distance and exertional dyspnea; and (3) functional status.

RESULTS

All patients were able to be discharged home after a mean length of stay of 9.9 days. The 12-minute walk distance increased by 66%, from 416 +/- 282 feet to 690 +/- 337 feet (p < .001). Dyspnea during the walk testing also improved: the resting score decreased from 2.87 to .97, the 6-minute score from 7.84 to 3.05, and postwalk score from 8.53 to 3.51 (all p < .001). All patients showed improvement in the Pulmonary Function Status Scale (PFSS), with the functional activities subsection increasing by 39%, the dyspnea score by 65%, and psychosocial score by 35% (all p < .001).

CONCLUSION

Short-term improvement in multiple areas can be accomplished with comprehensive pulmonary rehabilitation of short duration. This is particularly relevant to the current health care environment that dictates shorter in-hospital lengths of stay.

Feasibility and effects of a home-care rehabilitation program in patients with chronic obstructive pulmonary disease

PURPOSE

Pulmonary rehabilitation programs often show beneficial effects in patients with chronic obstructive pulmonary disease (COPD). These programs are usually hospital-based. This study assesses the feasibility and application of a 12-week Home-Care Rehabilitation Program (HCRP), carried out by general practitioners, physiotherapists, and home-care nurses.

METHODS

Effects of the HCRP are assessed in 15 COPD patients with moderate to severe airflow limitation (inspiratory vital capacity [IVC]: mean, 75.4 [SD, 13.7] percent predicted, mean FEV1: 45.5 [6.9] percent predicted) and are compared with a stratified and randomized control group (n = 15).

RESULTS

All participating disciplines judged the program to be useful and feasible. Patient compliance with the rehabilitation exercises was high. No major problems concerning the rehabilitation program were reported. After the HCRP, 4-minute walking distance improved significantly from 274 m [61] to 301 m [72] and maximal work load (W max), as measured during an incremental cycle test, increased from 75.3 W [24] to 85.3 W [28]. At equal work levels (W submax) during the cycle test both Borg dyspnea and leg effort scores decreased significantly after the HCRP (6.7 [1.3] versus 4.9 [1.7] and 4.2 [2.0] versus 1.7 [2.5], respectively). Changes in walking distance, dyspnea, and leg effort scores at W submax were significantly different between the two groups. IVC and FEV1 did not change significantly. In the control group, no significant changes in any parameter were observed.

CONCLUSION

It was possible to design and perform successfully a home-care rehabilitation program, providing both objective and subjective improvements in a group of patients with COPD. A home-care rehabilitation program appears to be a valuable component in the management of COPD patients with a moderate to severe airflow limitation.

Cardiovascular, pulmonary, and cancer rehabilitation. 2. Pulmonary rehabilitation

This self-directed learning module highlights both pulmonary and nonpulmonary aspects in the rehabilitation of patients with pulmonary disease and the assessment and physical therapeutic options in the pulmonary management of patients with neurological disorders. It is part of the chapter on cardiovascular, pulmonary, and cancer rehabilitation in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. New advances covered in this section include the use of physical medicine modalities for respiratory muscle rest and technological advances in the management of airway secretions in both pulmonary and neurological disorders. For the former, these approaches can decrease symptoms and the frequency of hospitalization and increase exercise tolerance and quality of life. The use of physical medicine modalities will be discussed as inspiratory and expiratory muscle aids. These methods, when used as alternatives to tracheal intubation and long-term tracheostomy in patients with neurological disorders, improve quality of life, minimize cost, enhance survival, and facilitate community care.

Pulmonary rehabilitation improves exercise capacity in older elderly patients with COPD

Pulmonary rehabilitation has been shown to improve exercise capacity in patients with COPD. It has been suggested that this improvement applies to all age groups; however, to our knowledge, the effects of pulmonary rehabilitation on older elderly patients (> or = 75 years of age) have not been studied. We compared changes in 12-min walking distance (12MD) and self-assessment scores in 47 older elderly patients with moderate to severe COPD who completed inpatient or outpatient pulmonary rehabilitation with those achieved by 87 younger patients who participated in the same programs from 1987 to 1992. There were 28 older elderly individuals (mean +/- SEM, 78 +/- 1 years) in the outpatient group and 56 younger patients (64 +/- 1 years). There were no differences between older and younger outpatients with respect to FEV1, FEV1/FVC, maximum inspiratory pressure (PImax), baseline 12MD, or baseline self-assessment score. After outpatient pulmonary rehabilitation, 12MD and self-assessment scores improved significantly in both groups. Inpatients included 19 older elderly individuals (81 +/- 1 years) who were also similar to the 31 younger inpatients (64 +/- 1 years) in FEV1, FEV1/FVC, PImax, and baseline self-assessment score, but they tended to be more limited in terms of baseline 12MD (p = 0.09). After inpatient pulmonary rehabilitation, significant improvements in 12MD and self-assessment were seen in both groups. We conclude that comprehensive outpatient and inpatient pulmonary rehabilitation programs are as beneficial in older elderly patients with COPD as they are in younger patients with similar lung function abnormalities. Patients 75 years of age or older should be considered for comprehensive pulmonary rehabilitation.

Comparison of gas exchange, lactate, and lactic acidosis thresholds in patients with chronic obstructive pulmonary disease

During an incremental exercise test, three consequences of the onset of anaerobic metabolism can be observed: rise in blood lactate (lactate threshold, LT); fall in standard bicarbonate (lactic acidosis threshold, LAT); nonlinear increase in CO2 output (V-slope gas exchange threshold, GET). We compared these thresholds in 31 patients with COPD. We found that the GET and LAT overestimated the LT. A better relationship was found between LAT and GET, even though GET was significantly higher than LAT (by 124 ml/min; p < 0.0001). However, since the bias is appreciably greater at lower LAT values (likely because VCO2 kinetics are slower than VO2 kinetics), we separated the studies into two groups: (A) tests where LAT occurred within the first 2 min of the increasing work rate period, and (B) tests where LAT occurred after 2 min. For Group A, there was a substantial bias between LAT and GET (323 ml/min, p < 0.0001), whereas the bias was much smaller (only 5.4%, though statistically significant) for Group B (57 ml/min, p < 0.01). We conclude that when lactic acidosis occurs after the first 2 min of incremental exercise, the GET closely approximates the point at which blood bicarbonate begins to fall.

Exercise in patients with chronic obstructive pulmonary disease

Sporadic visits to the local doctor followed sometimes by changes in oral and inhaled bronchodilators and occasionally by the addition of steroids frequently does little to significantly improve symptoms and function in the disabled patient with COPD. As in other chronic diseases, the management of these patients is facilitated by a team approach in conjunction with general rehabilitation principles. The rationale and practical implementation of such a programme has recently been outlined by the American Association of Cardiopulmonary Rehabilitation. These are multifaceted programmes but a key component, as outlined above, is exercise training. In this brief review the various approaches available have been described. Controversy still reigns regarding the optimal modes of training and there are important differences among the several approaches. Two main groups can be delineated. One emphasises the detailed definition of the impaired physiology with therapeutic measures targeted to specific defects. There is good documentation that, conversely, unstructured programmes that use treadmill and free range walking and cycling also improve endurance for walking. Upper extremity training is of additional benefit. Programmes with as little as three sessions per week of 1-2 hours of low intensity activity have achieved success so we know that simple programmes can be helpful. Moreover, without the necessity for complex testing and training methods these programmes can be implemented with relatively low costs. Future investigations to examine the relationship between improved exercise capacity for walking and arm exercise on the one hand, and the ease of performance of activities of daily living on the other, will help to reinforce the effectiveness of exercise programmes.

Supported arm exercise vs unsupported arm exercise in the rehabilitation of patients with severe chronic airflow obstruction

OBJECTIVE

Compare unsupported (UAEx) vs supported (SAEx) arm exercise in training of patients with severe chronic airflow obstruction (CAO).

DESIGN

Randomized trial of UAEx vs SAEx training added to a 10-week outpatient program of lower extremity (LE) exercise training, respiratory muscle training, breathing retraining, psychological support, and teaching.

SETTING

The Lahey Clinic Medical Center, a tertiary referral center.

PATIENTS

Forty patients with CAO entered the rehabilitation program with 32 completing training and testing.

INTERVENTIONS

All underwent progressive bicycle ergometer and treadmill training and respiratory muscle training using a threshold inspiratory pressure trainer. Patients were randomized to progressive SAEx training (arm cycle ergometer, n = 17) or UAEx training (raising weighted dowel, n = 18).

MAIN OUTCOME MEASURES AND RESULTS

There was no significant difference in disease severity or exercise capacity between the two groups. Twelve-min walk test, bicycle ergometer power output, and respiratory muscle function improved with no significant difference in improvement between the two groups. Both groups showed similar improvements in arm ergometer testing while those trained with UAEx showed greater improvement in dowel testing (UAEx > SAEx, p = 0.002). In 17 patients VO2isotime (time at which patient performed pre-training and post-training tests) was measured during dowel testing. Only those trained with UAEx showed decreases in VO2isotime (UAEx trained, p = 0.02; SAEx, p = 0.18). VO2 during the last minute of a 2-min period of simple arm elevation was also measured in 17 patients. Only those trained with UAEx showed decreases in VO2 (UAEx, p = 0.02; SAEx, p = 0.20).

CONCLUSION

We confirm that a pulmonary rehabilitation program incorporating exercise training improves LE and respiratory muscle function. Arm exercise training improved arm activity with greater increases in unsupported arm activity seen in those trained with unsupported arm training. Metabolic cost of UAEx decreased only in those trained with UAEx. As UAEx is typical of activities of daily living in patients with CAO, the changes seen with UAEx training may be of greater clinical significance. Arm training should be incorporated in exercise training and a simple program of UAEx appears the optimal format.

The long-term benefits of outpatient pulmonary rehabilitation on exercise endurance and quality of life

Although it is generally accepted that outpatient pulmonary rehabilitation (OPR) improves exercise performance and quality of life (QOL), it is not well established whether these gains are sustained over time. To evaluate this, we attempted to contact the 71 patients who had completed our 6-week OPR program for follow-up 12-min walking distance (12 MD) and QOL measurements. Fifty-one patients (71.8 percent) returned for follow-up testing 11.0 +/- 6.1 months following OPR. Of these, 19 had participated in a structured post-OPR exercise maintenance (EM) program, while 32 had not (non-EM). The 12 MD increased from 2,300 +/- 611 ft at baseline to 2,789 +/- 622 ft post-OPR, while the QOL (higher is better) increased from 81.2 +/- 21.4 to 104.7 +/- 22.2 over this period (both, p < 0.0001). Although the 12 MD decreased by 10.6 +/- 15.8 percent to 2,539 +/- 803 ft at follow-up (p < 0.001), it remained 10.3 +/- 23.4 percent greater than baseline (p < 0.001). Similarly, despite decreasing by 7.6 +/- 13.6 percent to 96.4 +/- 23.3 (p < 0.005), the follow-up QOL remained 22.8 +/- 35.0 percent greater than baseline (p < 0.005). The post-OPR to follow-up declines in 12 MD and QOL were not significantly different between EM and non-EM patients. Thus, only a portion of the initial improvement in exercise endurance and QOL is lost at follow-up months later. Post-OPR EM did not appear to provide measurable long-term advantages.

Ventilatory and metabolic changes as a result of exercise training in COPD patients

Patients with COPD feel better and are able to sustain a given level of activity longer after a program of exercise training, but the underlying physiologic mechanisms have not been completely elucidated. Since the physical performance of patients with COPD is limited mainly by pathophysiologic derangements of the ventilatory system, the exercise performance can be ameliorated by increasing the level of ventilation that they can sustain or by reducing the ventilatory requirement for a given level of activity. Almost all studies have yielded negative results in patients with COPD in terms of exercise training having the ability to improve VEmax. The only way to reduce the ventilatory requirement is to reduce CO2 output. Lower levels of lactate result in less nonmetabolic CO2 produced by bicarbonate buffering and this is the likely mechanism responsible for a lower ventilatory requirement for work rates above the pretraining anaerobic threshold. We specifically wished to determine whether a program of intensity, frequency, and duration known capable of producing a physiologic training effect in healthy subjects would do so in patients with COPD. Further, we sought to determine whether exercise training at a work rate associated with lactic acidosis is more effective in inducing a training effect in patients with COPD than a work rate not associated with lactic acidosis. Nineteen patients with COPD were selected and performed an incremental test as well as 2 square wave tests at a low and a high work rate. Identical tests were performed after an 8-week program of cycle ergometer training either for 45 min/day at a high work rate or for a proportionally longer time at a low work rate. For the high work rate training group, identical work rates engendered less lactate (4.5 vs 7.2 mEq/L) and less VE (48 vs 55 L/min) after training; the low work rate training group had significantly less lactate and VE decrease (p less than 0.01). Further, in the first group, there was an increase in exercise tolerance averaging 71% in the high constant work rate test. There was a good correlation (r = 0.73, p less than 0.005) between the decrease in blood lactate and the decrease in ventilation. The major findings of this study are that patients with COPD who experience lactic acidosis during exercise can achieve physiologic training responses from a program of endurance training and that training work rates engendering high levels of blood lactate are more effective than work rates eliciting low lactate levels.

Benefits of a multidisciplinary pulmonary rehabilitation program. Improvements are independent of lung function

We evaluated the conditions of 33 patients who completed an outpatient pulmonary rehabilitation program to determine what types of improvements occurred, and whether these changes were related to the baseline degree of ventilatory impairment, to determine whether rehabilitation was beneficial to patients, regardless of the degree of underlying lung dysfunction. Endurance measurements, including sustained submaximal performance on a cycle ergometer and the 12-minute walk distance (1,349 +/- 625 feet to 1,700 +/- 670 feet) increased significantly (p less than 0.01), as did multiple educational and subjective parameters. Maximal exercise performance on a graded cycle test improved very little, with a decline in the ventilatory equivalent for oxygen consumption (VE/VO2) being the only significant change (48.2 +/- 28.3 L/ml to 36.6 +/- 8.7 L/ml). Of the observed changes, only one endurance measurement, the sustained submaximal exercise performance, correlated with FEV1 (r = 0.5, p less than 0.01), but only if it was expressed as an absolute number (liters) and not as percent predicted. Lung function did not correlate with changes in the 12-minute walk distance, in maximal exercise performance on the cycle ergometer or with changes in educational and subjective parameters. We conclude that because the magnitude of change in both physiologic and psychologic parameters was not directly related to lung function, the benefits of rehabilitation can extend to all patients with chronic lung disease, regardless of the severity of preexisting pulmonary dysfunction.