Hemodynamic responses to exercise after lung transplantation

Respiratory Muscle and Lung Function in Lung Allograft Recipients: Association with Exercise Intolerance

BACKGROUND

In lung transplant recipients (LTRs), restrictive ventilation disorder may be present due to respiratory muscle dysfunction that may reduce exercise capacity. This might be mediated by pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6).

OBJECTIVE

We investigated lung respiratory muscle function as well as circulating pro-inflammatory cytokines and exercise capacity in LTRs.

METHODS

Fifteen LTRs (6 female, age 56 ± 14 years, 63 ± 45 months post-transplantation) and 15 healthy controls matched for age, sex, and body mass index underwent spirometry, measurement of mouth occlusion pressures, diaphragm ultrasound, and recording of twitch transdiaphragmatic (twPdi) and gastric pressures (twPgas) following magnetic stimulation of the phrenic nerves and the lower thoracic nerve roots. Exercise capacity was quantified using the 6-min walking distance (6MWD). Plasma IL-6 and TNF-α were measured using enzyme-linked immunosorbent assays.

RESULTS

Compared with controls, patients had lower values for forced vital capacity (FVC; 81 ± 30 vs.109 ± 18% predicted, p = 0.01), maximum expiratory pressure (100 ± 21 vs.127 ± 17 cm H2O, p = 0.04), diaphragm thickening ratio (2.2 ± 0.4 vs. 3.0 ± 1.1, p = 0.01), and twPdi (10.4 ± 3.5 vs. 17.6 ± 6.7 cm H2O, p = 0.01). In LTRs, elevation of TNF-α was related to lung function (13 ± 3 vs. 11 ± 2 pg/mL in patients with FVC ≤80 vs. >80% predicted; p < 0.05), and lung function (forced expiratory volume after 1 s) was closely associated with diaphragm thickening ratio (r = 0.81; p < 0.01) and 6MWD (r = 0.63; p = 0.02).

CONCLUSION

There is marked restrictive ventilation disorder and respiratory muscle weakness in LTRs, especially inspiratory muscle weakness with diaphragm dysfunction. Lung function impairment relates to elevated levels of circulating TNF-α and diaphragm dysfunction and is associated with exercise intolerance.

Predicting 6-minute walking distance in recipients of lung transplantation: longitudinal study of 108 patients

BACKGROUND

Exercise capacity, muscle function, and physical activity levels remain reduced in recipients of lung transplantation. Factors associated with this deficiency in functional exercise capacity have not been studied longitudinally.

OBJECTIVE

The study aims were to analyze the longitudinal change in 6-minute walking distance and to identify factors contributing to this change.

DESIGN

This was a longitudinal historical cohort study.

METHODS

Data from patients who received a lung transplantation between March 2003 and March 2013 were analyzed for the change in 6-minute walking distance and contributing factors at screening, discharge, and 6 and 12 months after transplantation. Linear mixed-model and logistic regression analyses were performed with data on characteristics of patients, diagnosis, waiting list time, length of hospital stay, rejection, lung function, and peripheral muscle strength.

RESULTS

Data from 108 recipients were included. Factors predicting 6-minute walking distance were measurement moment, diagnosis, sex, quadriceps muscle and grip strength, forced expiratory volume in 1 second (percentage of predicted), and length of hospital stay. After transplantation, 6-minute walking distance increased considerably. This initial increase was not continued between 6 and 12 months. At 12 months after lung transplantation, 58.3% of recipients did not reach the cutoff point of 82% of the predicted 6-minute walking distance. Logistic regression demonstrated that discharge values for forced expiratory volume in 1 second and quadriceps or grip strength were predictive for reaching this criterion.

LIMITATIONS

Study limitations included lack of knowledge on the course of disease during the waiting list period, type and frequency of physical therapy after transplantation, and number of missing data points.

CONCLUSIONS

Peripheral muscle strength predicted 6-minute walking distance; this finding suggests that quadriceps strength training should be included in physical training to increase functional exercise capacity. Attention should be paid to further increasing 6-minute walking distance between 6 and 12 months after transplantation.

Rehabilitation in Patients before and after Lung Transplantation

Lung transplantation is an established treatment for patients with end-stage lung disease. It has been observed that despite near-normal lung function, exercise intolerance and reductions in quality of life (QOL) often persist up to years after transplantation. Several modifiable pre- and posttransplant factors are known to contribute to these persisting impairments. Physiological changes associated with severe and chronic lung disease, limb muscle dysfunction, inactivity/deconditioning, and nutritional depletion can affect exercise capacity and physical functioning in candidates for lung transplantation. After transplantation, extended hospital and intensive care unit stay, prolonged sedentary time, persisting inactivity, immunosuppressant medications and episodes of organ rejection may all impact lung recipients' recovery. Available evidence will be reviewed and content will be proposed (both evidence and experience based) for rehabilitation interventions prior to transplantation, during hospitalization after transplantation, and in both the immediate (≤12 months after hospital discharge) and long-term (>12 months after hospital discharge) posttransplant phase. Outpatient rehabilitation programs including supervised exercise training have been shown to be effective in improving limb muscle dysfunction, exercise capacity, and QOL both before and after transplantation if offered appropriately. Unmet research needs included the absence of sufficiently powered randomized controlled trials measuring the effects of rehabilitation interventions on crucial long-term outcomes such as sustained improvements in QOL, participation in daily activity, survival, incidence of morbidities and cost-effectiveness. Remotely monitored (telehealth) home-based exercise or pedometer-based walking interventions might be interesting alternatives to supervised outpatient rehabilitation interventions in the long-term posttransplant phase and warrant further investigation.

Exercise limitation following transplantation

Organ transplantation is one of the medical miracles or the 20th century. It has the capacity to substantially improve exercise performance and quality of life in patients who are severely limited with chronic organ failure. We focus on the most commonly performed solid-organ transplants and describe peak exercise performance following recovery from transplantation. Across all of the common transplants, evaluated significant reduction in VO2peak is seen (typically renal and liver 65%-80% with heart and/or lung 50%-60% of predicted). Those with the lowest VO2peak pretransplant have the lowest VO2peak posttransplant. Overall very few patients have a VO2peak in the normal range. Investigation of the cause of the reduction of VO2peak has identified many factors pre- and posttransplant that may contribute. These include organ-specific factors in the otherwise well-functioning allograft (e.g., chronotropic incompetence in heart transplantation) as well as allograft dysfunction itself (e.g., chronic lung allograft dysfunction). However, looking across all transplants, a pattern emerges. A low muscle mass with qualitative change in large exercising skeletal muscle groups is seen pretransplant. Many factor posttransplant aggravate these changes or prevent them recovering, especially calcineurin antagonist drugs which are key immunosuppressing agents. This results in the reduction of VO2peak despite restoration of near normal function of the initially failing organ system. As such organ transplantation has provided an experiment of nature that has focused our attention on an important confounder of chronic organ failure-skeletal muscle dysfunction.

The influence of clinical course after lung transplantation on rehabilitation success

Pulmonary rehabilitation (PR) is a cornerstone of treatment following lung transplantation (LTx). The aim of this study was to observe the influence of a prolonged postsurgical clinical course on success of a 3-week inpatient PR. LTx recipients were divided according to their clinical course defined by their individual length of stay (LOS) in the transplant center (cohort 1: LOS >; cohort 2: ≤42 days). Peak work rate (PWR), maximum oxygen uptake (VO(2max) ), 6-min walk distance (6-MWD), vital capacity (VC), forced expiratory volume in one second (FEV1), physical activity of daily life (ADL), and health-related quality of life (HRQoL) measured using Short Form 36 questionnaire (SF36) were assessed at beginning and completion of PR. A total of 138 patients were included (LOS >42 days: 30; LOS ≤42 days: 108). At completion, physical functioning (VC, FEV1, PWR, VO(2max) , 6-MWD, ADL), and HRQoL (all SF36 domains) improved in each cohort (P < 0.05). No differences were found in between both cohorts in VC, FEV1, and ADL (n.s.), but in PWR, 6-MWD, and the SF36 domain 'physical functioning' (P < 0.05). A 3-week inpatient PR improves physical functioning despite prolonged hospitalization. HRQoL is close to normal. (ClinicalTrials.gov. identifier: NCT00759538).

Effects of exercise in renal transplant recipients

Even after a successful renal transplantation, the renal transplant recipients (RTRs) keeps on suffering the consequences of the uremic sickness. Cardiovascular risk, work capacity, and quality of life do not improve according to expectations since biological and psychological problems are not completely solved by pharmacological treatment. Furthermore, post-transplant treatment, per se, induces additional problems (i.e., side effects of drugs). It becomes, indeed, very important to insert “non-pharmacological” therapies able to reverse this trend. Exercise may represent an important contribution in the solution of this problem. In fact, many studies have demonstrated, in the last two decades, that physical training is able both, to improve graft function, work capacity and quality of life, and to reduce cardiovascular risk. In conclusion, if the analysis of the available data suggests that an appropriate dose of physical training represent a useful, safe and non-pharmacologic contribution to RTR treatment, it becomes a kidney transplantologist responsibility to introduce exercise in the current therapy of RTRs.

Lung transplantation and lung volume reduction surgery

Since the publication of the last edition of the Handbook of Physiology, lung transplantation has become widely available, via specialized centers, for a variety of end-stage lung diseases. Lung volume reduction surgery, a procedure for emphysema first conceptualized in the 1950s, electrified the pulmonary medicine community when it was rediscovered in the 1990s. In parallel with their technical and clinical refinement, extensive investigation has explored the unique physiology of these procedures. In the case of lung transplantation, relevant issues include the discrepant mechanical function of the donor lungs and recipient thorax, the effects of surgical denervation, acute and chronic rejection, respiratory, chest wall, and limb muscle function, and response to exercise. For lung volume reduction surgery, there have been new insights into the counterintuitive observation that lung function in severe emphysema can be improved by resecting the most diseased portions of the lungs. For both procedures, insights from physiology have fed back to clinicians to refine patient selection and to scientists to design clinical trials. This section will first provide an overview of the clinical aspects of these procedures, including patient selection, surgical techniques, complications, and outcomes. It then reviews the extensive data on lung and muscle function following transplantation and its complications. Finally, it reviews the insights from the last 15 years on the mechanisms whereby removal of lung from an emphysema patient can improve the function of the lung left behind.

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.

Pulmonary hypertension in patients with bronchiolitis obliterans syndrome listed for retransplantation

Bronchiolitis Obliterans Syndrome (BOS) is a major cause of morbidity and mortality post-lung transplantation. Pulmonary hypertension (PH) may complicate the course of patients with advanced lung disease. We sought to characterize the prevalence of PH in patients with BOS. We performed a retrospective analysis of lung transplant recipients with BOS relisted for transplantation with the United Network for Organ Sharing (UNOS). Right heart catheterization (RHC) data were required for analysis. Eighty patients with BOS qualified for the analysis. PH was present in 32.5% of patients with an average mean pulmonary artery pressure (mPAP) of 32.3 mmHg (range: 26-63 mmHg). Of these, 42.3% had an elevated pulmonary capillary wedge pressure. There was no difference in PH prevalence between bilateral (26.5%) and single lung recipients (41.9%), nor did it differ by primary disease. There was no correlation between pulmonary function data and the presence or severity of PH. There was no difference in oxygen requirements or 6-min walk distance between patients with and without PH. This is the first report of PH in patients with BOS. Many of these cases occur in association with diastolic dysfunction. Although no impact on functional status or outcomes was discerned, further studies appear warranted.

Physical functional outcomes after cardiothoracic transplantation

The study of patient healthcare outcomes after cardiothoracic transplantation has increased substantially over the last 2 decades. Physical function after heart, lung, and heart-lung transplantation has been studied using both subjective and objective measures. The majority of reports in the literature on physical function after cardiothoracic transplantation are descriptive and observational. The purposes of the article are to review and critique the existing literature on cardiothoracic recipients' subjective and objective physical function, including respiratory function for heart-lung and lung transplant recipients. In addition, the literature on sexual function in cardiothoracic recipients is examined, the gaps in the literature are identified, and recommendations are given for future research.

Increased diaphragmatic strength and tolerance to fatigue after bilateral lung transplantation: an electromyographic study

We evaluated the diaphragmatic function of seven patients with severe chronic respiratory failure before and after a bilateral lung transplantation (BLT), with follow-up at one year of pulmonary function tests, maximal inspiratory mouth pressure (MIP) and surface diaphragmatic electromyogram (Edi). The patients were asked to sustain target inspiratory pressures at -15, -30, and -50 cmH(2)O. We measured the endurance time (Tlim) to sustain inspiratory efforts and the power spectrum density function of Edi at each inspiratory maneuver. The Edi power spectra was analysed in terms of median frequency (MF), total power (TP) and energies in high-and low-frequency bands (EL and EH). Before BLT, a defect of the diaphragmatic function was evident: MIP was 62+/-7% of the predicted value and the Tlim measured at each inspiratory effort was very short ( 13+/-1 s, 10+/-1 s and 8+/-1 s at pressures of -15, -30, and -50 cmH(2)O, respectively). One month after BLT, the Tlim began to increase at all target inspiratory pressures and at 6 months MIP recovered to normal values. One month after BLT, there was a significant decrease in TP measured at the beginning of each inspiratory efforts and also an increase in the concomitant MF value. BLT markedly accentuated the maximal variations of TP, MF and low-frequency Edi energy. Some hypotheses are raised to explain this dramatic improvement in diaphragmatic function after BLT.

Impaired exercise performance after successful liver transplantation

BACKGROUND

Recipients of heart, lung, and kidney transplants have impaired peak exercise performance (peak Vo2 40% to 60% predicted, reduced anaerobic threshold [AT]) without evidence of ventilatory or cardiac limitations. The aim of this study was to determine whether similar exercise impairment occurs in liver transplant recipients.

METHODS

We studied eight healthy liver transplant recipients (age 42+/-9 [SD] years, 6 male, 31+/-13 months posttransplant). Immunosuppression included FK506 or cyclosporine, azathioprine or mycophenolate mofetil, and prednisone. Subjects underwent lung function testing and cardiopulmonary exercise testing on a cycle ergometer.

RESULTS

Peak exercise oxygen consumption (Vo2) was 22+/-8 ml/min/kg (66+/-20% predicted maximum). No subject demonstrated exercise desaturation or ventilatory limitation (peak minute ventilation 55+/-8% predicted maximum voluntary ventilation). Peak heart rate was 87+/-8% of predicted maximum. Early AT was evident (1.2+/-0.34 L/min, 48+/-11% predicted Vo2max).

CONCLUSIONS

Liver transplant recipients exhibit impaired peak exercise performance similar to that observed after other solid organ transplants, possibly as a result of chronic deconditioning or myopathy related to immunosuppressive medications.

Care before and after lung transplant and quality of life research

Lung transplantation is a growing surgical option for patients with end-stage lung and pulmonary vascular diseases. After completing an extensive evaluation and meeting the selection criteria, patients are listed for either single or bilateral-sequential lung transplantation. Immediate postoperative management requires detailed attention to fluid management, monitoring for infection, reperfusion injury, pulmonary hygiene, and pain management. Length of stay depends on the patient's condition before transplant and postoperative complications. Discharge from the hospital can be as early as 7 days after transplantation. Newer immunosuppressive medications offer more options for treating and preventing rejection. Advanced practice nurses, such as coordinators, case managers, nurse practitioners, and clinical nurse specialists, are uniquely positioned to play key roles in coordinating the care of transplant patients across settings and both before and after the transplant procedure. The perioperative needs of lung transplant patients and the impact of this complex procedure on the recipients' and family's quality of life merit further investigation by clinicians and researchers.

Lung transplantation at the turn of the century

Lung transplantation has become a viable treatment option for patients with end-stage lung disease. Donor selection and organ allocation must follow specific guidelines. Single, bilateral, and living-donor lobar transplantation have all been performed successfully for a variety of diseases. Complications include reimplantation response and airway complications. Rejection may occur in the hyperacute, acute, or chronic settings and requires judicious management with immunosuppression. Infection and malignancy remain potential complications of the commitment to lifelong systemic immunosuppression. Survival statistics have remained encouraging and continue to improve with experience. Improved exercise tolerance and quality of life have been demonstrated in the years following transplantation. Remaining obstacles include limited donor organ availability, long-term graft function, and patient survival. However, ongoing advances in immune tolerance and standardized training of physicians in the care of transplant patients should carry lung transplant forward in the twenty-first century.

Symptom experiences of lung transplant recipients: comparisons across gender, pretransplantation diagnosis, and type of transplantation

PURPOSES

To investigate symptom experiences of patients who have single and bilateral-sequential lung transplantation and to determine whether differences exist according to gender, pretransplantation diagnosis, and type of transplantation procedure.

DESIGN AND METHODS

In the context of a descriptive, comparative survey design, surviving recipients of single and bilateral-sequential lung transplants (n = 56) were mailed a symptom frequency and distress questionnaire. The response rate was 85.7% (n = 48). The average time since the recipients' lung transplantations was 1.5 +/- 0.7 years.

RESULTS

Recipients of lung transplants reported that several symptoms (eg, muscle weakness, shortness of breath with activity, and changed appearance) were both frequently occurring and quite distressing. Other symptoms were identified as being distressing, but not frequently occurring, or vice versa. Significant (P <.05) differences were found for symptom experiences among pretransplant diagnostic groups and between genders and types of transplant procedures.

CONCLUSIONS

These findings elucidate the symptom experiences of recipients of lung transplants and suggest that subgroup differences exist. The data provide a basis for strengthening patient and family education and for developing symptom management strategies. Further investigation of the symptom experiences of the recipients of lung transplants is needed, especially in relation to subgroups.

Respiratory and limb muscle function in lung allograft recipients

Lung transplantation recipients have reduced exercise capacity despite normal resting pulmonary and hemodynamic function. The limiting factor may be contractile dysfunction of skeletal muscle. To test this postulate, we measured limb and respiratory muscle function in nine clinically stable lung allograft recipients (six men and three women, aged 30 to 65 yr, at 5 to 102 mo after transplantation) with reduced exercise capacity. Respiratory muscle strength was tested by measuring maximal inspiratory and expiratory pressure (MIP and MEP, respectively). Ankle dorsiflexor muscle strength was measured during maximal voluntary contraction (MVC). In a subset of six recipients, we also measured contractile properties and fatigue characteristics of the tibialis anterior muscle, using electrical stimulation of the motor point. Data were compared with values from age- and sex-matched control subjects. MIP values of transplant recipients did not differ from control values; however, MEP was blunted by 30% relative to control (p < 0.05), and MVC was decreased by 39% (p < 0.05). The force-frequency relationships and fatigue characteristics of the tibialis anterior were not different between the patient and control groups. We conclude that stable lung allograft recipients experience expiratory and lower limb weakness that may contribute to exercise intolerance.

Cardiopulmonary exercise testing before and after lung and heart-lung transplantation

Heart-lung (HLT) and lung transplantation (LT) have been shown to be effective procedures for patients with end-stage cardiopulmonary disorders. As yet, few data exist on the exercise performance of patients before and after thoracic transplantation except with regard to 6-min walk tests. In this article we report cardiopulmonary exercise test results of lung and heart-lung transplant recipients in comparison with their pretransplant values. We studied 103 consecutive recipients of single-lung (n = 46), bilateral lung (n = 32), and heart-lung (n = 25) transplants. Cardiopulmonary exercise testing with a cycle ergometer was performed before and shortly after surgery. Before transplantation, all patients showed severe exercise intolerance and markedly impaired parameters reflecting cardiopulmonary function (e.g., work capacity: 20 +/- 11% predicted; oxygen uptake: 34 +/- 12% predicted; oxygen pulse: 50 +/- 18% predicted; functional dead space ventilation: 57 +/- 10% of minute ventilation; alveolar-arterial oxygen difference during exercise: 79 +/- 15 mm Hg). At 55 +/- 9 d after transplantation, transplant recipients reached maximum oxygen uptakes in the range of 22 to 71% of predicted values; the peak oxygen uptake was increased after transplantation (13.1 +/- 3.4 ml/min/kg versus 10.4 +/- 3.8 ml/min/kg; p < 0.001). Work capacity, oxygen pulse, tidal volume, and peak minute ventilation did not differ in patients following single- or double-lung tranplantation or HLT. Ventilatory factors did not appear to limit exercise capacity in any group. Despite the persistent limitations in aerobic capacity and work rate seen in many of the recipients, cardiopulmonary performance is reasonably well restored shortly after LT and HLT.

Exercise and organ transplantation

Life-saving treatment of disease by organ transplantation has become increasingly important. Annually over 35,000 transplantations of vital organs are carried out world-wide and the demand for knowledge regarding exercise in daily life for transplant recipients is growing. The present review describes whole-body and organ reactions to both acute exercise and regular physical training in persons who have undergone heart, lung, liver, kidney, pancreas or bone marrow transplantation. In response to acute exercise, the majority of cardiovascular, hormonal and metabolic changes are maintained after transplantation. However, in heart transplant recipients organ denervation reduces the speed of heart rate increase in response to exercise. Furthermore, lack of sympathetic nerves to transplanted organs impairs the normal insulin and renin responses to exercise in pancreas and kidney transplant recipients, respectively. In contrast, surgical removal of sympathetic liver nerves does not inhibit hepatic glucose production during exercise, and denervation of the lungs does not impair the ability to increase ventilation during physical exertion. Most studies show that physical training results in an improved endurance and strength capacity in almost all groups of transplant recipients, which is of importance for their daily life. With a little precaution, organ transplant recipients can perform exercise and physical training and obtain effects comparable with those achieved in the healthy population of similar age.

Cellular adaptations of skeletal muscles to cyclosporine

The aim of this study was to evaluate the cellular response of the diaphragm, extensor digitorum longus (EDL), and soleus (Sol) muscles to clinically relevant doses of cyclosporine administered to male rats over 4 wk. Control rats were provided with vehicle only. Muscle fiber types, cross-sectional areas, indexes of capillarity, and succinate dehydrogenase (SDH) activity were determined by quantitative histochemistry. Myosin heavy chain isoforms were identified by SDS-PAGE, and their proportions were measured by scanning densitometry. Serum cyclosporine level, 20-24 h after the last dose of cyclosporine, was 145 +/- 81 ng/ml. Final body weight and muscle mass were similar between the cyclosporine and control groups. In the diaphragm, EDL, and Sol, no differences were observed between the groups with regard to fiber type proportions, fiber cross-sectional areas, and proportions of myosin heavy chain isoforms. In the EDL, reductions, both in SDH activity in type I, IIx, and IIb fibers (-26 to -37%) and in indexes of capillarity (-18 to -37%), were noted. In the Sol, SDH activity and capillarity were similar between the groups. In the diaphragm of cyclosporine-treated rats, there was significant reduction in the number of capillaries around individual fibers (-5%), whereas levels of SDH activity tended to be lower. This suggests that activation history may in part determine muscle-specific responses to cyclosporine. We speculate that reduced oxidative activity and capillarity of some limb muscles contribute to reduced exercise capacity and the "deconditioned state" observed in patients receiving cyclosporine after successful solid-organ transplantation.

Aerobic endurance training program improves exercise performance in lung transplant recipients

STUDY OBJECTIVE

To determine whether an aerobic endurance training program (AET) in comparison to normal daily activities improves exercise capacity in lung transplant recipients.

PATIENTS AND STUDY DESIGN

Nine lung transplant recipients (12+/-6 months after transplant) were examined. All patients underwent incremental bicycle ergometry with the work rate increased in increments of 20 W every 3 min. Identical exercise tests were performed after 11+/-5 weeks of normal daily activities and then after a 6-week AET. The weekly aerobic training time increased from 60 min at the beginning to 120 min during the last week. Training intensity ranged from 30 to 60% of the maximum heart rate reserve.

RESULTS

Normal daily activities had no effect on exercise performance. The AET induced a significant decrease in resting minute ventilation from 14+/-5 to 11+/-3 L/min. At an identical, submaximal level of exercise, a significant decrease in minute ventilation from 47+/-14 L/min to 39+/-13 L/min and heart rate from 144+/-12 to 133+/-17 beats/min, before and after the AET, was noted. The increase in peak oxygen uptake after AET was statistically significant (1.13+/-0.32 to 1.26+/-0.27 L/min).

CONCLUSIONS

These data demonstrate that normal daily activities do not affect exercise performance in lung transplant recipients > or = 6 months after lung transplantation. An AET improves submaximal and peak exercise performance significantly.

Cystic fibrosis: bilateral living lobar versus cadaveric lung transplantation

Living donor transplantation is now an acceptable option that should be considered for selected cystic fibrosis patients with end-stage lung disease. Two lungs obtained from live donors can adequately support an adult cystic fibrosis patient. The morbidity from lobectomy to the healthy donor is minimal.

Early and long-term functional outcomes in unilateral, bilateral, and living-related transplant recipients

Lung transplantation offers the possibility of improved quality of life and survival in patients with severe pulmonary and pulmonary vascular disease. Since the first human lung allotransplantation in 1963, survival has moved from hours or days into the present era of long-term (years) survival in many recipients. Measurement of outcome has now extended to measurement of exercise capacity and quality of life. A substantial improvement in quality of life is seen; however, exercise capacity remains moderately impaired in spite of the return (in many) of near normal cardiopulmonary function, suggesting peripheral limitation to exercise. Recently, fiber type changes and abnormal oxidative metabolism have been shown in the skeletal muscle of stable lung transplant recipients. This suggests a persistence of a pretransplant skeletal muscle injury and/ or the effects of post-transplant immunosuppression (particularly Cyclosporin A and corticosteroids).

Early and long-term functional outcomes following lung volume reduction surgery

In the past 3 years, lung volume reduction surgery has become the most controversial topic in the clinical management of patients with emphysema. Although literature has added to the understanding of the procedure, many important issues remain unclear. This article emphasizes functional and basic physiologic changes that occur following lung volume reduction surgery in patients with emphysema.

Pulmonary transplantation

OBJECTIVE

More than 2700 lung transplants have been performed since the initial clinical success in 1983. The evolution in the techniques of lung transplantation and patient management and the effects on results are reviewed.

SUMMARY BACKGROUND DATA

Improvements in donor management, lung preservation, operative techniques, immunosuppression management, infection prophylaxis and treatment, rejection surveillance, and long-term follow-up have occurred in the decade following the first clinically successful lung transplant. A wider spectrum of diseases and patients treated with lung transplant have accentuated the shortage of suitable lung donors. The organ shortage has led to the use of marginal donors and a limited experience using living, related donors.

METHODS

Changes in techniques and patient selection and management are reviewed and controversial issues and problems are highlighted.

RESULTS

One-year survival of greater than 90% for single-lung transplant recipients and greater than 85% for bilateral lung transplant recipients have been achieved. Complications caused by airway complications has been reduced greatly. Obliterative bronchiolitis develops in 20% to 50% of long-term survivors and is the leading cause of morbidity and mortality after the first year after transplant.

CONCLUSIONS

Lung transplantation has evolved into an effective therapy for a wide variety of causes of end-stage lung disease. Wider applicability requires solutions to the problems of donor shortage and development of obliterative bronchiolitis.

Cardiopulmonary exercise testing following allogeneic lung transplantation for different underlying disease states

OBJECTIVES

To assess the exercise response to single lung transplantation in chronic airflow obstruction (CAO), idiopathic pulmonary fibrosis (IPF), and pulmonary vascular disease (PVD) vs double lung transplantation at well-defined time points after transplantation, and to define the change in exercise response in SLT and DLT over the first year after transplantation.

DESIGN

Prospective study.

SETTING

Tertiary referral hospital.

PATIENTS

Fourteen stable SLT recipients (6 with CAO, 4 with IPF, 4 with PVD) and 11 stable DLT recipients.

MEASUREMENTS

Spirometry, lung volumes, diffusion lung capacity for carbon monoxide (DLco) and MVV measured prior to exercise at 3 months (n = 25) then at 3-month intervals up to a maximum of 12 months post-transplantation (n = 18 [12 SLT and 6 DLT]). Symptom-limited cardiopulmonary exercise tests at same time points (n = 25 at 3 months, n = 18 [12 SLT and 6 DLT] at 3-month intervals up to 12 months). Breathlessness was estimated by visual analogue scale prior to exercise and at peak exercise.

RESULTS

At 3 months, FEV1 percent predicted was lower for SLT-CAO and SLT-IPF vs DLT (p < or = 0.05). Mean FEV1/FVC was lower for SLT-CAO vs all other groups (p < or = 0.05). The FVC, MVV, and DLco/VA were similar for all groups. The TLC and RV were higher for the SLT-CAO group compared with all others. The TLC was lower for SLT-PVD compared with DLT. Exercise responses were similar in all groups studied without a statistically significant difference in achieved VO2, work rate, O2 pulse, anaerobic threshold, heart rate response, respiratory rate, VE/MVV, and VT/VC. The change in O2 saturation during exercise was the least in recipients of DLT. Maximal achieved VO2 rose from 3 to 6 months after SLT but dropped by 9 to 12 months after transplantation. Maximal achieved VO2 trended up from 3 to 6 months after DLT but dropped by 9 to 12 months after transplantation. Maximal achieved work rate rose in both SLT and DLT from 3 to 9 to 12 months after transplantation. There was no significant difference in breathlessness at rest and peak exercise measured between recipients of SLT or DLT.

CONCLUSIONS

Minor differences in pulmonary function and change in O2 saturation occur between recipients of SLT and DLT during the first posttransplant year. These differences are most pronounced when comparing SLT-CAO with DLT. However, there is no significant difference in exercise capacity between SLT for CAO, IPF, PVD, and DLT. The rise in maximum achieved VO2 over the first 6 months after transplantation may reflect the effects of exercise training and should be taken into account when examining aerobic response after transplantation.