Limiting Factors of Exercise Performance 1 Year After Lung Transplantation

Exercise testing in pediatric lung transplant candidates with cystic fibrosis

Exercise testing is considered an important prognostic tool for the selection of pediatric lung transplant candidates with end-stage CF lung disease. To better understand the current practice as it pertains to exercise testing, a self-administered questionnaire was distributed to 25 pediatric lung transplant centers within the IPLTC across Australia, Europe, and North America. All centers perform standardized exercise tests. Fifteen centers perform one single-field test (6MWT/12MWT), while seven perform a six-min walk plus an additional test: SWT (N = 1), 3MST (N = 1), and CPET (N = 5). Frequency of testing is markedly different among centers. Two centers conduct exercise testing once, all others at multiple time points. Equipment availability and cost were no limitations, but lack of time (20%) and personnel (16%), and paucity of prognostic evidence (16%) and reference values (12%) were stated. Exercise testing is considered important and extensively used in the evaluation of pediatric lung transplant candidates with CF; methods of exercise test and the frequency of testing vary widely. We propose a prospective multicenter study to evaluate the efficacy of exercise testing and its prognostic value using a standardized protocol.

Effect of inpatient rehabilitation on quality of life and exercise capacity in long-term lung transplant survivors: a prospective, randomized study

BACKGROUND

The purpose of this study was to examine the effect of an inpatient rehabilitation program on health-related quality of life (HRQOL) and exercise capacity (EC) in long-term (>1 year after lung transplantation) survivors (LTSs) in comparison to a control group (CG).

METHODS

Sixty LTSs, 4.5 ± 3.2 years after lung transplantation (LTx), were randomly assigned to two equally sized groups that were stratified for gender and underlying disease. Thirty LTSs (age 49 ± 13 years, 13 male and 17 females, 19 double LTxs, 7 BOS Stage ≥ 1) attended an inpatient rehabilitation program (intervention group, IG) for 23 ± 5 days. The CG (age 50 ± 12 years, 13 males and 17 females, 20 double LTxs, 2 BOS Stage ≥ 1) received medical standard therapy (physiotherapy). Patients were evaluated by cardiopulmonary exercise testing, 6-minute walk test (6MWT), SF-36, SGRQ and the Quality of Life Profile for Chronic Diseases questionnaire before and after (18 ± 3 days) the program.

RESULTS

The groups were statistically indistinguishable in terms of clinical data. Each treatment group significantly improved their sub-maximal EC (6MWT: IG, 493 ± 90 m vs 538 ± 90 m, p < 0.001; CG, 490 ± 88 m vs 514 ± 89 m, p < 0.001) and maximal EC (VO(2peak): IG, 17.0 vs 18.5 ml/min/kg, p = 0.039; CG, 18.0 vs 19.5 ml/min/kg, p = 0.005), without reaching statistical significance between the groups. In both study groups, patients HRQOL tended to improve. Significant correlations were found between EC parameters and HRQOL scales.

CONCLUSIONS

Our data suggest that structured physical training may improve exercise tolerance in LTS. Our study results did not demonstrate a significant benefit of an inpatient over an outpatient exercise program.

Determinants of overweight and obesity in lung transplant recipients

BACKGROUND

Obesity-related diseases have been shown to affect post-lung transplantation survival. An estimated 30% of lung transplant recipients develop overweight.

OBJECTIVE

The aim of this study was to examine the possible determinants of large increases in weight after lung transplantation. The contribution of physical activity, food intake, and resting energy expenditure was examined in lung transplant recipients.

METHODS

In this cross-sectional study 21 overweight lung transplant recipients (11 men, mean age 57 ± 7 years; BMI 30 ± 3) and 21 normal-weight lung transplant recipients (11 men, mean age 56 ± 5 years; BMI 22 ± 3) were matched for disease, gender, age, prescribed medication, and time since lung transplantation. Physical activity was measured by a pedometer and a questionnaire; resting energy expenditure was measured by the ventilated-hood technique, and daily food intake by a dietician. Additionally, fat-free mass, lower-body strength, and fatigue were measured.

RESULTS

The overweight lung transplant recipients had a significantly lower number of steps per day (4,686 ± 3,266 vs. 7,524 ± 3,448 steps/day, p = 0.01) and a lower fat-free mass (64 ± 9 vs. 75 ± 6%, p < 0.05) compared to normal-weight recipients. Obese subjects had a lower percentage of predicted resting energy expenditure level compared to normal-weight recipients (90 ± 14 vs. 100 ± 14% predicted, p = 0.04).

CONCLUSION

Our data suggest that overweight in lung transplant recipients is associated with a lower fat-free mass and lower levels of physical activity and resting energy expenditure compared to normal-weight recipients.

Exercise training after lung transplantation: a systematic review

BACKGROUND

Lung transplant recipients experience persistent impairments in exercise capacity and skeletal muscle function despite a vast improvement in lung function after transplantation. Exercise training may be beneficial in improving exercise capacity in lung transplant recipients. A systematic review was undertaken to examine the evidence for exercise training on functional outcomes in lung transplant recipients.

METHODS

Studies were identified by searching electronic databases and scanning reference lists. Only randomized controlled trials, controlled trials, and prospective cohorts were included in the review. Seven studies met the inclusion criteria. Study quality was assessed using the Physiotherapy Evidence Database, Jadad, and Downs scales.

RESULTS

The overall quality of studies was fair to moderate in assessing the effect of exercise training on maximal and functional exercise capacity, skeletal muscle function, and lumbar bone mineral density. Every study reported significant improvements in these outcomes. Some studies lacked randomization and/or a control group, so it was not possible to separate the effects of training with the natural recovery process after lung transplantation.

CONCLUSION

Some evidence was found to support that a period of structured exercise training could improve maximal and functional exercise capacity, skeletal muscle strength, and lumbar bone mineral density in lung transplant recipients. Further studies are needed to determine the potential for exercise training to optimize these functional outcomes and to develop optimal guidelines for exercise prescription in the lung transplant population.

[Long-term outcome of lung transplantation]

Lung transplantation (LTx) nowadays is an established therapeutic option for various end-stage lung diseases in despite of an optimal medical therapy in selected patients affected with various pathologies such as emphysema/chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF) and various forms of bronchiectasis, pulmonary fibrosis and pulmonary hypertension. Progress and refinement over the last two decades in both surgical techniques and medical management including especially the introduction of cyclosporine A, have been impressive. Patient survival improved significantly over time. According to the most recent data of the International Registry of Lung Transplantation (ISHLT), actuarial survival is 79%, 63%, 52% and 29% at 1, 3, 5 and 10 years respectively, with a current overall survival half-life of 5.3 years, and more than 7 years for those who survived 1 year or more. However, survival depends on different parameters such as the underlying disease, data relative to the donor, the recipient and/or the transplant procedure. Major limitation of long-term survival is still chronic allograft dysfunction, which is histologically represented by an obliterative bronchiolitis and functionally by the bronchiolitis obliterans syndrome (BOS). In uncomplicated cases near-normalization of pulmonary function is the rule, with more than 80% of survivors at 1, 3, 5 and 10 years reporting no activity limitations. Functional results after single LTx remain lower than those of the bilateral LTx, and depend on the potential worsening of the underlying disease and complications arising on the native lung. Exercise performance usually is approximately 50% of predicted, suggesting extrapulmonary causes such as side effects of immunosuppressive drugs. Quality of life improves significantly in all domains including employment status.

Review series: Rehabilitation in non COPD: Mechanisms of exercise limitation and pulmonary rehabilitation for patients with pulmonary fibrosis/restrictive lung disease

The standard of care in the treatment of chronic lung disease includes pulmonary rehabilitation (PR). While evidence of the effectiveness of PR in chronic obstructive lung disease (COPD) is robust, that for pulmonary fibrosis and other non-fibrotic restrictive lung diseases is less extensive. However, PR has been shown to improve functional exercise capacity and health-related quality of life in non-COPD patients, primarily those with interstitial lung diseases. This review examines mechanisms of exercise limitation in non-COPD patients and discusses how they might affect both the application of and outcome measures of PR. We also review the assessment of exercise performance, dyspnea, and quality of life as well as special protocols, safety considerations, and special techniques in PR as applied to patients with pulmonary fibrosis or restrictive lung disease. At present, there are no evidence-based guidelines for PR in non-COPD patients whereas PR is firmly recommended in COPD management. More research is needed to strengthen the evidence for the use of PR in non-COPD patients. Meanwhile, the available data, summarized in this review, support the inclusion of PR in the management of all patients with chronic lung disease including pulmonary fibrosis and restrictive lung disease.

Exercise training before and after lung transplantation

The benefits of exercise training in individuals with chronic lung diseases such as chronic obstructive pulmonary disease, cystic fibrosis, and interstitial lung disease have been well documented. Although there is limited research available, it appears that exercise is safe and beneficial for people with severe end-stage chronic lung disease who are awaiting lung transplantation in addition to recipients of lung transplants. Evidence-based guidelines for exercise training in the pre- and post-lung transplantation phases have not yet been developed. However, by considering exercise guidelines for people with chronic lung disease and in older adults in light of the physiological changes that can occur either pre- or post-lung transplantation, a safe and appropriate exercise training program can be developed. Depending on the individual's exercise capacity and goals, the training program may include aerobic and resistance exercise, and flexibility and balance training. In the pre-transplant and acute post-transplant phases, the intensity of exercise is dictated primarily by symptom limitation and adequate rest, which is required between exercise bouts to allow for recovery. In the post-transplant phase, it is possible for lung transplant recipients to increase their exercise capacity and even participate in sports. Further research needs to be conducted to determine the optimal training guidelines and the long-term benefits of exercise, both in lung transplant candidates and recipients.

Cross-sectional assessment of daily physical activity in chronic obstructive pulmonary disease lung transplant patients

BACKGROUND

Information about daily physical activity of chronic obstructive pulmonary disease (COPD) lung transplant patients is relevant for evaluation of the functional recovery of physical capacity after lung transplantation. The objective of this study was to cross-sectionally assess daily physical activity, pulmonary function, physical fitness, fear of physical activity and motivation to exercise in COPD patients who were lung transplant candidates and lung transplant recipients.

METHODS

Fifteen COPD lung transplant candidates (5 men and 10 women, mean age 53 years, forced expiratory volume in 1 second [FEV(1)] 20% predicted) and 47 recipients (18 men and 29 women, mean age 55 years, FEV(1) 93% predicted, 39 bilateral and 8 unilateral transplants) were enrolled in this observational study. Daily physical activity was measured using a pedometer (Digiwalker SW-200) and the Short QUestionnaire to ASsess Health-enhancing physical activity (SQUASH). Physical fitness was measured by the sit-to-stand test and the arm curl test. Fear of physical activity and motivation to exercise were measured by the Tampa Scale for Kinesiophobia-Dutch version Questionnaire and the Exercise Self-Regulation Questionnaire.

RESULTS

Mean (+/-SD) number of steps per day in lung transplant recipients was higher compared with transplant candidates: 6,642 (+/-2,886) and 1,407 (+/-1,166), respectively (p < 0.05). Number of steps per day correlated significantly with FEV(1) (r = 0.32, p = 0.03) and lower body strength (r = 0.45, p = 0.002) in lung transplant recipients. There was no significant difference in daily physical activity, physical fitness, fear and motivation between bi- and unilateral transplant recipients.

CONCLUSION

Our data suggest that lung transplantation improves daily physical activity, lower body strength and FEV(1).

Physical activity in daily life 1 year after lung transplantation

BACKGROUND

Reduced physical fitness has been reported to occur after lung transplantation. Pre- and post-transplant factors, including an inactive lifestyle, have been proposed as possible causes. However, daily physical activity has not been objectively assessed so far in lung recipients. The purpose of this study was to objectively measure daily physical activity in lung recipients.

METHODS

Twenty-two clinically stable patients with single (n = 7) and bilateral lung grafts (n = 15) underwent measurements of physical activity with activity monitors at least 12 months after surgery. Results were compared with findings from 22 healthy, age- and gender-matched control subjects.

RESULTS

Substantial and statistically significant differences in daily activity were observed. Steps, standing time and moderate-intensity activity of lung recipients were reduced by 42%, 29% and 66%, respectively, relative to controls. Daily sedentary time was increased by 30%. Daily steps correlated with self-reported physical functioning (r = 0.81), 6-minute walk distance (r = 0.68), quadriceps force (r = 0.66) and maximum workload (r = 0.63).

CONCLUSIONS

This study has shown for the first time that daily activity is substantially reduced after lung transplantation and related to measures of physical fitness and health-related quality of life. Future studies need to examine whether physical activity can be modified to improve functional recovery after lung transplantation.

Long-term health-related quality of life and walking capacity of lung recipients with and without bronchiolitis obliterans syndrome

BACKGROUND

Outcome after lung transplantation (LTx) is affected by the onset of bronchiolitis obliterans syndrome (BOS) and lung function decline. Reduced health-related quality of life (HRQL) and physical mobility have been shown in patients developing BOS, but the impact on the capacity to walk is unknown. We aimed to compare the long-term HRQL and 6-minute walk test (6MWT) between lung recipients affected or not by BOS Grade > or =2.

METHODS

Fifty-eight patients were prospectively followed for 5.6 +/- 2.9 years after LTx. Assessments included the St George's Respiratory Questionnaire (SGRQ) and the 6MWT, which were performed yearly. Moreover, clinical complications were recorded to estimate the proportion of the follow-up time lived without clinical intercurrences after transplant. Analyses were performed using adjusted linear regression and repeated-measures analysis of variance.

RESULTS

BOS was a significant predictor of lower SGRQ scores (p < 0.01) and reduced time free of clinical complications (p = 0.001), but not of 6MWT distance (p = 0.12). At 7 years post-transplant, results were: 69.0 +/- 21.8% vs 86.9 +/- 5.6%, p < 0.05 (SGRQ); 58.5 +/- 21.6% vs 88.7 +/- 11.4%, p < 0.01 (proportion of time lived without clinical complications); and 82.2 +/- 10.9% vs 91.9 +/- 14.2%, p = 0.27 (percent of predicted 6MWT), respectively, for patients with BOS and without BOS.

CONCLUSIONS

Despite significantly less time lived without clinical complications and progressive decline of self-reported health status, the capacity to walk of patients affected by BOS remained relatively stable over time. These findings may indicate that the development of moderate to severe BOS does not prevent lung recipients from walking independently and pursuing an autonomous life.

Skeletal muscle force and functional exercise tolerance before and after lung transplantation: a cohort study

We investigated the impact of lung transplantation and outpatient pulmonary rehabilitation after lung transplantation on skeletal muscle function and exercise tolerance. Skeletal muscle force (Quadriceps force, QF), exercise tolerance (six minute walking distance, 6MWD) and lung function were assessed in 36 patients before and after lung transplantation. Seventeen male and 19 female patients (age 57 +/- 4) showed skeletal muscle weakness before the transplantation. A further 32 +/- 21% reduction was seen 1.2 (interquartile range 0.9 to 2.0) months after LTX. The number of days on the intensive care unit was significantly related to the observed deterioration in muscle force after LTX. At this time point 6MWD was comparable to pre-LTX. Rehabilitation started 37 (IQR 29 to 61) days after LTX. 6MWD and QF improved significantly (140 +/- 91 m, and 35 +/- 48%, respectively; p < 0.05) with rehabilitation. QF remained below pre-LTX values. The evolution of the 6MWD with the transplantation and the subsequent rehabilitation was less in female compared to male subjects. We conclude that muscle strength deteriorates after lung transplantation, particularly in patients with long ICU stay. Outpatient pulmonary rehabilitation is feasible after lung transplantation and leads to recovery of skeletal muscle function. In female patients this recovery is significantly less compared to male recipients.