Maximal exercise capacity and peripheral skeletal muscle function following lung transplantation

Orthostatic Hypotension and Concurrent Autonomic Dysfunction: A Novel Complication of Lung Transplantation

Background

Persistent orthostatic hypotension (OH) is a lesser-known complication of lung transplantation (LTx). In this retrospective case series, we describe the clinical manifestations, complications, and treatment of persistent OH in 13 LTx recipients.

Methods

We identified LTx recipients who underwent transplantation between March 1, 2018, and March 31, 2020, with persistent symptomatic OH and retrospectively queried the records for clinical information.

Results

Thirteen patients were included in the analysis, 9 (69%) had underlying pulmonary fibrosis, and 12 (92%) were male. The median age, height, and body mass index at LTx were 68 years, 70 inches, and 27 kg/m², respectively. Six (46%) patients were deceased at the time of chart abstraction with a median (IQR) posttransplant survival of 12.6 months (6, 21); the 7 remaining living patients were a median of 19.6 months (18, 32) posttransplant. Signs and symptoms of OH developed a median of 60 (7, 75) days after transplant. Patients were treated with pharmacological agents and underwent extensive physical therapy. Most patients required inpatient rehabilitation (n = 10, 77%), and patients commonly developed comorbid conditions including weight loss, renal insufficiency with eGFR <50 (n = 13, 100%), gastroparesis (n = 7, 54%), and tachycardia-bradycardia syndrome (n = 2, 15%). Falls were common (n = 10, 77%). The incidence of OH in LTx recipients at our center during the study period was 5.6% (13/234).

Conclusions

Persistent OH is a lesser-known complication of LTx that impacts posttransplant rehabilitation and may lead to comorbidities and shortened survival. In addition, most LTx recipients with OH at our center were tall, thin men with underlying pulmonary fibrosis, which may offer an opportunity to instate pretransplant OH screening of at-risk patients.

Exercise training for adult lung transplant recipients

BACKGROUND

Pulmonary transplantation is the final treatment option for people with end-stage respiratory diseases. Evidence suggests that exercise training may contribute to speeding up physical recovery in adults undergoing lung transplantation, helping to minimize or resolve impairments due to physical inactivity in both the pre- and post-transplant stages. However, there is a lack of detailed guidelines on how exercise training should be carried out in this specific sub-population.

OBJECTIVES

To determine the benefits and safety of exercise training in adult patients who have undergone lung transplantation, measuring the maximal and functional exercise capacity; health-related quality of life; adverse events; patient readmission; pulmonary function; muscular strength; pathological bone fractures; return to normal activities and death.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register up to 6 October 2020 using relevant search terms for this review. Studies in the CKTR are identified through CENTRAL, MEDLINE, and EMBASE searches, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) were included comparing exercise training with usual care or no exercise training, or with another exercise training program in terms of dosage, modality, program length, or use of supporting exercise devices. The study population comprised of participants older than 18 years who underwent lung transplantation independent of their underlying respiratory pathology.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed all records identified by the search strategy and selected studies that met the eligibility criteria for inclusion in this review. In the first instance, the disagreements were resolved by consensus, and if this was not possible the decision was taken by a third reviewer. The same reviewers independently extracted outcome data from included studies and assessed risk of bias. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Eight RCTs (438 participants) were included in this review. The median sample size was 60 participants with a range from 16 to 83 participants. The mean age of participants was 54.9 years and 51.9% of the participants were male. The median duration of the exercise training programs for the groups undergoing the intervention was 13 weeks, and the median duration of training in the active control groups was four weeks. Overall the risk of bias was considered to be high, mainly due to the inability to blind the study participants and the selective reporting of the results. Due to small number of studies included in this review, and the heterogeneity of the intervention and outcomes, we did not obtain a summary estimate of the results. Two studies comparing resistance exercise training with no exercise reported increases in muscle strength and bone mineral density (surrogate outcomes for pathological bone fractures) with exercise training (P > 0.05), but no differences in adverse events. Exercise capacity, health-related quality of life (HRQoL), pulmonary function, and death (any cause) were not reported. Three studies compared two different resistant training programs. Two studies comparing squats using a vibration platform (WBVT) compared to squats on the floor reported an improvement in 6-minute walk test (6MWT) (28.4 metres, 95% CI 3 to 53.7; P = 0.029; and 28.3 metres, 95% CI 10.0 to 46.6; P < 0.05) with the WBVT. Supervised upper limb exercise (SULP) program improved 6MWT at 6 months compared to no supervised upper limb exercise (NULP) (SULP group: 561.2 ± 83.6 metres; NULP group: 503.5 ± 115.2 metres; P = 0.01). There were no differences in HRQoL, adverse events, muscular strength, or death (any cause). Pulmonary function and pathological bone fractures were not reported. Two studies comparing multimodal exercise training with no exercise reported improvement in 6MWT at 3 months (P = 0.008) and at 12-months post-transplant (P = 0.002) and muscular strength (quadriceps force (P = 0.001); maximum leg press (P = 0.047)) with multimodal exercise, but no improvement in HRQoL, adverse events, pulmonary function, pathological bone fractures (lumbar T-score), or death (any cause). One study comparing the same multimodal exercise programs given over 7 and 14 weeks reported no differences in 6MWT, HRQoL, adverse events, pulmonary function, muscle strength, or death (any cause). Pathological bone fractures were not reported. According to GRADE criteria, we rated the certainty of the evidence as very low, mainly due to the high risk of bias and serious imprecision.

AUTHORS' CONCLUSIONS

In adults undergoing lung transplantation the evidence about the effects of exercise training is very uncertain in terms of maximal and functional exercise capacity, HRQoL and safety, due to very imprecise estimates of effects and high risk of bias.

Early postoperative complications in lung transplant recipients

Lung transplantation has become an established therapy for end-stage lung diseases. Early postoperative complications can impact immediate, mid-term, and long-term outcomes. Appropriate management, prevention, and early detection of these early postoperative complications can improve the overall transplant course. In this review, we highlight the incidence, detection, and management of these early postoperative complications in lung transplant recipients.

Near-normal aerobic capacity in long-term survivors after lung transplantation

The clinical course of lung transplantation (LT) is diverse: some patients present chronic lung allograft dysfunction (CLAD) and progressive decline in pulmonary function, but others maintain normal spirometric values and active lives.

This is a multicentre study reporting, for the first time, near-normal peak V′_O2 values during cardiopulmonary exercise testing and normal exercise capacity in long-term lung transplant recipients without CLADhttps://bit.ly/35ftce3

Addressing the changing rehabilitation needs of patients undergoing thoracic surgery

The rehabilitation needs of individuals undergoing thoracic surgery are changing, especially as surgical management is increasingly being offered to patients who are at risk of developing functional limitations during and after hospital discharge. In the past rehabilitative management of these patients was frequently limited to specific respiratory physiotherapy interventions in the immediate postoperative setting with the aim to prevent postoperative pulmonary complications. In the past two decades, this focus has shifted toward pulmonary rehabilitation interventions that aim to improve functional status of individuals, both in the pre- and (longer-term) postoperative period. While there is increased interest in (p)rehabilitation interventions the majority of thoracic surgery patients are however currently on their own with respect to progression of their exercise and physical activity regimens after they have been discharged from hospital. There are also no formal guidelines supporting the referral of these patients to outpatient rehabilitation programs. The current evidence regarding rehabilitation interventions initiated before, during, and after the hospitalization period will be briefly reviewed with special focus on patients undergoing surgery for lung cancer treatment and patients undergoing lung transplantation. More research will be necessary in the coming years to modify or change clinical rehabilitation practice beyond the acute admission phase in patients undergoing thoracic surgery. Tele rehabilitation or web-based activity counseling programs might also be interesting emerging alternatives in the (long-term) postoperative rehabilitative treatment of these patients.

Quantity and quality of antigravity muscles in patients undergoing living-donor lobar lung transplantation: 1-year longitudinal analysis using chest computed tomography images

Background

Skeletal muscle dysfunction is a common feature in patients with severe lung diseases. Although lung transplantation aims to save these patients, the surgical procedure and disuse may cause additional deterioration and prolonged functional disability. We investigated the postoperative course of antigravity muscle condition in terms of quantity and quality using chest computed tomography.

Methods

35 consecutive patients were investigated for 12 months after living-donor lobar lung transplantation (LDLLT). The erector spinae muscles (ESMs), which are antigravity muscles, were evaluated, and the cross-sectional area (ESM_CSA) and mean attenuation (ESM_CT) were analysed to determine the quantity and quality of ESMs. Functional capacity was evaluated by the 6-min walk distance (6MWD). Age-matched living donors with lower lobectomy were evaluated as controls.

Results

Recipient and donor ESM_CSA values temporarily decreased at 3 months and recovered by 12 months post-operatively. The ESM_CSA of recipients, but not that of donors, surpassed baseline values by 12 months post-operatively. Increased ESM_CSA (ratio to baseline ≥1) may occur at 12 months in patients with a high baseline ESM_CT. Although the recipient ESM_CT may continuously decrease for 12 months, the ESM_CT is a major determinant, in addition to lung function, of the postoperative 6MWD at both 3 and 12 months.

Conclusion

The quantity of ESMs may increase within 12 months after LDLLT in recipients with better muscle quality at baseline. The quality of ESMs is also important for physical performance; therefore, further approaches to prevent deterioration in muscle quality are required.

The quantity of antigravity muscles in patients undergoing lung transplantation (LTx) will increase within 1 year after LTx. The quality of muscles is important for increase of muscle quantity as well as physical performance.https://bit.ly/3bItfB9

Effect of high-intensity training on peak oxygen uptake and muscular strength after lung transplantation: A randomized controlled trial

BACKGROUND

Peak oxygen uptake (VO_2peak) remains low after lung transplantation (LTx). We evaluated the effect of high-intensity interval training (HIIT) on VO_2peak, muscular strength, health-related quality of life (HRQOL), pulmonary function, and physical function after LTx.

METHODS

In this randomized controlled trial, 54 participants were enrolled from 6 to 60 months after LTx. The HIIT group (n = 25) followed a supervised HIIT program, consisting of endurance and strength trainings 3 times a week for 20 weeks. The control group (n = 29) received usual care. The primary outcome was a change in VO_2peak measured by cardiopulmonary exercise testing. The secondary outcomes were changes in 1-repetition maximum (1RM) for arm press and leg press, HRQOL (36-Item Short-Form Health Survey [SF-36]), pulmonary function (forced expiratory volume in 1 sec, diffusing capacity of the lungs for carbon monoxide), and physical function (1RM in handgrip, 15-sec stair run, and 30-sec chair stand).

RESULTS

A total of 46 participants completed the study, including 23 of 25 in the intervention group. For the primary outcome, the intention-to-treat analysis revealed a non-significant between-group difference for change in VO_2peak of 0.7 ml/(kg.min) (95% CI = ‒0.3, 1.8) (p = 0.17). The between-group differences for 1RM arm press and leg press and mental aspect of SF-36 were 4.9 kg (95% CI = ‒0.1, 9.9) (p = 0.05), 11.6 kg (95% CI = 0.1, 23.0) (p < 0.05), and 5.7 kg (95% CI = 0.9, 10.4) (p = 0.02), respectively. There were no between-group differences in pulmonary function or physical function. When excluding participants with an attendance of <70% (n = 16), the between-group difference for VO_2peak was 1.2 ml/(kg.min) (95% CI = 0.1, 2.4) (p = 0.032).

CONCLUSIONS

HIIT improved muscular strength and HRQOL but did not improve VO_2peak more than usual care after LTx. However, with acceptable adherence, HIIT appears to have beneficial effects on VO_2peak.

Perceptions towards physical activity in adult lung transplant recipients with cystic fibrosis

Background

Barriers and motives towards physical activity (PA) in lung transplant (LTx) recipients with cystic fibrosis (CF) are largely unknown. We aimed to explore perceptions towards PA in LTx recipients with CF to better understand individuals’ needs and preferences.

Methods

Participants completed an online survey at two Swiss LTx and one follow-up shared care centre between June and December 2018.

Results

One hundred and eleven individuals completed the survey (87.4% response rate). Overall, survey participants perceive PA as important for their daily life and health. Perceived motives of PA were improving muscle strength, endurance and quality of life (QoL), to feel better, fun, to achieve personal goals and having more energy for everyday life. Fatigue was the most common perceived barrier to PA and associated with poorer QoL (r = -0.43, p<0.001) and health status (r = -0.31, p = 0.001). Participants with lung allograft dysfunction (LAD, n = 20) reported lower habitual PA (p = 0.009) and health status (p = 0.011), and rated shortness of breath, bad weather and concerns regarding lung rejection higher than those without LAD (all p<0.05). When we asked how an optimal training programme should look like, the majority would prefer individual, non-supervised (60%), outdoor (77%), endurance training (90%), once or twice a week (47%) for 40–60 minutes (48%). Only a minority of patients (14%) would be willing to use exercise applications for their home-based training.

Conclusions

LTx recipients with CF value PA as important for their health. People with CF should be encouraged individually by their multidisciplinary transplant team to implement PA in their daily life, potential barriers should be identified and addressed. Overall, knowledge on perceived barriers and motives for PA should be considered in the development of future patient-centred PA programmes.

Determinants of the diminished exercise capacity in patients with chronic obstructive pulmonary disease: looking beyond the lungs

KEY POINTS

Peak oxygen uptake, a primary determinant of prognosis, mortality and quality of life, is diminished in patients with chronic obstructive pulmonary disease (COPD), with mounting evidence supporting an important role for peripheral dysfunction, particularly within skeletal muscle. In patients with severe COPD and activity-matched controls, muscle oxygen transport and utilization were assessed at peak effort during single-leg knee-extensor exercise (KE), where ventilation is assumed to be submaximal. This strategy removes ventilation as the major constraint to exercise capacity in COPD, allowing maximal muscle function to be attained and evaluated. During maximal KE, both convective arterial oxygen delivery to the skeletal muscle microvasculature and subsequent diffusive oxygen delivery to the mitochondria were diminished in patients with COPD compared to control subjects. These findings emphasize the importance of factors, beyond the lungs, that influence exercise capacity in this patient population and may, ultimately, influence the prognosis, mortality and quality of life for patients with COPD.

ABSTRACT

Peak oxygen uptake ( V ̇ O 2 peak ), a primary determinant of prognosis, mortality and quality of life, is diminished in patients with chronic obstructive pulmonary disease (COPD). Mounting evidence supports an important role of the periphery, particularly skeletal muscle, in the diminished V ̇ O 2 peak with COPD. However, the peripheral determinants of V ̇ O 2 peak have not been comprehensively assessed in this cohort. Thus, the hypothesis was tested that both muscle convective and diffusive oxygen (O2 ) transport, and therefore skeletal muscle peak O2 uptake ( V ̇ M O 2 peak ), are diminished in patients with COPD compared to matched healthy controls, even when ventilatory limitations (i.e. attainment of maximal ventilation) are minimized by using small muscle mass exercise. Muscle O2 transport and utilization were assessed at peak exercise from femoral arterial and venous blood samples and leg blood flow (by thermodilution) in eight patients with severe COPD (forced expiratory volume in 1s (FEV1 ) ± SEM = 0.9 ± 0.1 l, 30% of predicted) and eight controls during single-leg knee-extensor exercise. Both muscle convective O2 delivery (0.44 ± 0.06 vs. 0.69 ± 0.07 l min-1 , P < 0.05) and muscle diffusive O2 conductance (6.6 ± 0.8 vs. 10.4 ± 0.9 ml min-1  mmHg-1 , P < 0.05) were ∼1/3 lower in patients with COPD than controls, resulting in an attenuated V ̇ M O 2 peak in the patients (0.27 ± 0.04 vs. 0.42 ± 0.05 l min-1 , P < 0.05). When cardiopulmonary limitations to exercise are minimized, the convective and diffusive determinants of V ̇ M O 2 peak , at the level of the skeletal muscle, are greatly attenuated in patients with COPD. These findings emphasize the importance of factors, beyond the lungs, that may ultimately influence this population's prognosis, mortality and quality of life.

Evolution of Functional Exercise Capacity in Lung Transplant Patients With and Without Bronchiolitis Obliterans Syndrome: A Longitudinal Case-Control Study

INTRODUCTION

Bronchiolitis Obliterans Syndrome (BOS) is a debilitating disease with limited treatment options that threatens both the quality of life and long-term survival of lung transplant (LTx) recipients. This retrospective longitudinal case-control study was performed to compare the long-term functional evolution of LTx recipients with and without BOS.

METHODS

Twenty-four LTx recipients with BOS (BOS=Cases) and 24 without BOS (NON-BOS=Controls) were selected and individually matched according to age, gender, diagnosis and LTx characteristics. Measurements of 6-minute walking distance (6MWD), symptoms of dyspnea (BORG CR-10 scale), and comprehensive pulmonary function testing were performed before LTx and at annual follow-up assessments after LTx.

RESULTS

Peak FEV₁ after LTx was similar in both groups [FEV₁ (% predicted) 101±25 vs. 101±31, p=0.96] and BOS diagnosis in cases was established 3.6±2.5 years after LTx. At the final follow-up assessment (6.5±3.2 years after LTx) FEV₁ (% predicted) was 86±34 in NON-BOS vs. 44±17 in BOS (p<0.001). Evolution of 6MWD was different between groups (group by time interaction: p=0.002). Borg dyspnea scores were also significantly different between groups at the final evaluation (NON-BOS 3.3±1.7 vs. BOS 5.0±2.2; p=0.024).

CONCLUSIONS

We observed gradual reductions in functional exercise capacity and increasing symptoms of dyspnea in patients who developed BOS after LTx. As such, prospective studies seem warranted to explore whether rehabilitative interventions might be useful to improve symptoms and slow down deterioration of exercise capacity in these patients from the onset of BOS.

Medical Course and Complications After Lung Transplantation

Lung transplant prolongs life and improves quality of life in patients with end-stage lung disease. However, survival of lung transplant recipients is shorter compared to patients with other solid organ transplants, due to many unique features of the lung allograft. Patients can develop a multitude of noninfectious (e.g., primary graft dysfunction, pulmonary embolism, rejection, acute and chronic, renal insufficiency, malignancies) and infectious (i.e., bacterial, fungal, and viral) complications and require complex multidisciplinary care. This chapter discusses medical course and complications that patients might experience after lung transplantation.

Feasibility of Immediate in-Intensive Care Unit Pulmonary Rehabilitation after Lung Transplantation: A Single Center Experience

Background

Physical function may influence perioperative outcomes of lung transplantation. We investigated the feasibility of a pulmonary rehabilitation program initiated in the immediate postoperative period at an intensive care unit (ICU) for patients who underwent lung transplantation.

Methods

We retrospectively evaluated 22 patients who received pulmonary rehabilitation initiated in the ICU within 2 weeks after lung transplantation at our institution from March 2015 to February 2016. Levels of physical function were graded at the start of pulmonary rehabilitation and then weekly throughout rehabilitation according to criteria from our institutional pulmonary rehabilitation program: grade 1, bedside (G1); grade 2, dangling (G2); grade 3, standing (G3); and grade IV, gait (G4).

Results

The median age of patients was 53 years (range, 25 to 73 years). Fourteen patients (64%) were males. The initial level of physical function was G1 in nine patients, G2 in seven patients, G3 in four patients, and G4 in two patients. Patients started pulmonary rehabilitation at a median of 7.5 days (range, 1 to 29 days) after lung transplantation. We did not observe any rehabilitation-related complications during follow-up. The final level of physical function was G1 in six patients, G3 in two patients, and G4 in 14 patients. Fourteen of the 22 patients were able to walk with or without assistance, and 13 of them maintained G4 until discharge; the eight remaining patients never achieved G4.

Conclusions

Our results suggest the feasibility of early pulmonary rehabilitation initiated in the ICU within a few days after lung transplantation.

Evaluation of Skeletal Muscle Function in Lung Transplant Candidates

BACKGROUND

Lung transplantation (LTx) is offered to older and more complex patients who may be at higher risk of skeletal muscle dysfunction, but the clinical implications of this remain uncertain. The study aims were to characterize deficits in skeletal muscle mass, strength and physical performance, and examine the associations of these deficits with clinical outcomes.

METHODS

Fifty LTx candidates (58% men; age, 59 ± 9 years) were prospectively evaluated for skeletal muscle deficits: muscle mass using bioelectrical impedance, quadriceps, respiratory muscle and handgrip strength, and physical performance with the Short Physical Performance Battery. Comparisons between number of muscle deficits (low muscle mass, quadriceps strength and physical performance) and 6-minute walk distance (6MWD), London Chest Activity of Daily Living Questionnaire, and quality of life were assessed using one-way analysis of variance. Associations with pretransplant and posttransplant delisting/mortality, hospital duration, and 3-month posttransplant 6MWD were evaluated using Fisher exact test and Spearman correlation.

RESULTS

Deficits in quadriceps strength (n = 27) and physical performance (n = 24) were more common than muscle mass (n = 8). LTx candidates with 2 or 3 muscle deficits (42%) compared with those without any deficits (26%) had worse 6MWD = -109 m (95% confidence interval [CI], -175 to -43), London Chest Activity of Daily Living Questionnaire = 18 (95% CI, 7-30), and St. George's Activity Domain = 12 (95% CI, 2-21). Number of muscle deficits was associated with posttransplant hospital stay (r = 0.34, P = 0.04), but not with delisting/mortality or posttransplant 6MWD.

CONCLUSIONS

Deficits in quadriceps muscle strength and physical performance are common in LTx candidates and further research is needed to assess whether modifying muscle function pretransplant can lead to improved clinical outcomes.

Effects of Exercise and Sport in Solid Organ Transplant Recipients: A Review

Solid organ transplantation is the criterion standard treatment for many with end-organ failure and can offer a new independence from the burden of disease. However solid organ transplant recipients (SOTRs) remain at high risk of cardiovascular (CV) disease, and poor quality of life and physical functioning. Increasing physical activity and exercise can improve the health of the general population; however, the effects on those with a transplant remain unclear. Intensive exercise and sporting activity has the potential to be beneficial, although there remain concerns particularly around the effects on immune function and the CV system. This review summarizes what is known about the effects of exercise on determinants of health in SOTRs and then collates the available literature investigating the consequences of intensive exercise and sport on the health of SOTR. There is a paucity of high-quality research, with most evidence being case studies or anecdotal; this is understandable given the relatively few numbers of SOTRs who are performing sport and exercise at a high level. However, if suitable evidence-based guidelines are to be formed and SOTRs are to be given reassurances that their activity levels are not detrimental to their transplanted organ and overall health, then more high-quality studies are required.

Pre-transplant wasting (as measured by muscle index) is a novel prognostic indicator in lung transplantation

BACKGROUND

Frailty in non-transplant populations increases morbidity and mortality. Muscle wasting is an important frailty characteristic. Low body mass index is used to measure wasting, but can over- or underestimate muscle mass. Computed tomography (CT) software can directly measure muscle mass. It is unknown if muscle wasting is important in lung transplantation.

AIM AND METHODS

The aim of this single-center, retrospective cohort study was to determine whether pre-transplant low muscle mass (as measured by CT using Slice-O-matic software at L2-L3 interspace) was associated with post-transplantation mortality, hospital and intensive care unit length of stay (LOS), duration of mechanical ventilation, or primary graft dysfunction. Lung transplant recipients from 2000 to 2012 with a CT scan less than six months prior to transplant were included. Univariate, multivariate, and Kaplan-Meier analyses were conducted.

RESULTS

Thirty-six patients were included. Those with low muscle index (lower 25th percentile) had a worse survival (hazard ratio = 3.83; 95% confidence interval 1.42-10.3; p = 0.007) and longer hospital LOS by an estimated 7.2 d (p = 0.01) when adjusted for age and sex as compared to those with higher muscle index.

CONCLUSION

Low muscle index at lung transplantation is associated with worse survival and increased hospital LOS.

Employment after lung transplantation--a single-center cross-sectional study

BACKGROUND

359 lung transplantations were performed in Germany in 2013. The main goals of lung transplantation are to prolong survival and improve the quality of life. Both of these goals can be reflected in a return to employment. We report the first study of employment after lung transplantation in Germany.

METHODS

We evaluated the findings of a single-center, questionnaire-based cross-sectional investigation of the social and economic situation of 531 patients (September 2009 to March 2010) and obtained 5-year follow-up data in December 2014.

RESULTS

38% of the patients were employed after lung transplantation. They took a mean of ten sick days off from work each year; they did not have infections or organ rejection any more frequently than other patients. The fiveyear follow-up data showed no difference in the overall survival rate of employed and unemployed patients. Employment was associated with a better quality of life (80% [interquartiles: 70%, 95%]) versus 75% [interquartiles: 50%, 85%], p = 0.001). Factors associated with a return to employment included a higher educational level (odds ratio [OR] 2.6, 95%confidence interval [CI] 1.7-4, p = 0.001) and better physical fitness (OR 2, 95%CI 1.3-3.2, p = 0.001).

CONCLUSION

The rate of return to work after lung transplantation in Germany is similar to the rates observed in other countries. The findings of this study imply that employment improves the quality of life and does not endanger health. Thus, patients who have received lung transplants should be advised to return to work if possible.

Quadriceps exercise intolerance in patients with chronic obstructive pulmonary disease: the potential role of altered skeletal muscle mitochondrial respiration

This study sought to determine if qualitative alterations in skeletal muscle mitochondrial respiration, associated with decreased mitochondrial efficiency, contribute to exercise intolerance in patients with chronic obstructive pulmonary disease (COPD). Using permeabilized muscle fibers from the vastus lateralis of 13 patients with COPD and 12 healthy controls, complex I (CI) and complex II (CII)-driven State 3 mitochondrial respiration were measured separately (State 3:CI and State 3:CII) and in combination (State 3:CI+CII). State 2 respiration was also measured. Exercise tolerance was assessed by knee extensor exercise (KE) time to fatigue. Per milligram of muscle, State 3:CI+CII and State 3:CI were reduced in COPD (P < 0.05), while State 3:CII and State 2 were not different between groups. To determine if this altered pattern of respiration represented qualitative changes in mitochondrial function, respiration states were examined as percentages of peak respiration (State 3:CI+CII), which revealed altered contributions from State 3:CI (Con 83.7 ± 3.4, COPD 72.1 ± 2.4%Peak, P < 0.05) and State 3:CII (Con 64.9 ± 3.2, COPD 79.5 ± 3.0%Peak, P < 0.05) respiration, but not State 2 respiration in COPD. Importantly, a diminished contribution of CI-driven respiration relative to the metabolically less-efficient CII-driven respiration (CI/CII) was also observed in COPD (Con 1.28 ± 0.09, COPD 0.81 ± 0.05, P < 0.05), which was related to exercise tolerance of the patients (r = 0.64, P < 0.05). Overall, this study indicates that COPD is associated with qualitative alterations in skeletal muscle mitochondria that affect the contribution of CI and CII-driven respiration, which potentially contributes to the exercise intolerance associated with this disease.

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.

Child and family adjustment following pediatric solid organ transplantation: factors to consider during the early years post-transplant

Adjusting to life after transplant can be challenging to pediatric solid organ transplant recipients and their families. In this review, we discuss a number of important factors to consider during the first 2-3 yr after transplant (defined as the "early years"), including transitioning from hospital to home, returning to physical activity, feeding and nutrition, school reentry, potential cognitive effects of transplant, family functioning, and QOL. We highlight steps that providers can take to optimize child and family adjustment during this period.

Sarcopenia in lung transplantation: a systematic review

Lung transplant candidates and recipients have significant impairments in skeletal muscle mass, strength and function--individual measures of sarcopenia. Skeletal muscle dysfunction has been observed in the pre-transplant and post-transplant period and could have an important effect on transplant outcomes. A systematic review was performed to characterize the techniques used to study sarcopenia and assess the level of impairment throughout the transplant process. Electronic databases were searched (inception to July 2013) for prospective studies measuring at least 1 element of sarcopenia (muscle mass, strength, or function) in lung transplant patients. Eighteen studies were included, and study quality was assessed using the Downs and Black scale. A variety of measurements were used to evaluate sarcopenia in 694 lung transplant patients. Muscle mass in 7 studies was assessed using bioelectrical impedance (n = 4), computed tomography or magnetic resonance imaging (n = 2), or skin folds (n = 1), and was significantly reduced. Quadriceps strength was examined in 14 studies with computerized dynamometer (n = 10) and hand-held dynamometer (n = 4). Quadriceps strength was reduced in the pre-transplant period (mean range, 49%-86% predicted; n = 455 patients), further reduced immediately after transplant (51%-72%, n = 126), and improved beyond 3 months after transplant (58%-101%, n = 164). Only 2 studies measured lower extremity function (sit-to-stand test). A multitude of measurement techniques have been used to assess individual measures of sarcopenia, with reduced muscle mass and quadriceps strength observed in the pre-transplant and post-transplant period. Further standardization of measurement techniques is needed to assess the clinical effect of sarcopenia in lung transplantation.

Structural alterations of skeletal muscle in copd

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a respiratory disease associated with a systemic inflammatory response. Peripheral muscle dysfunction has been well characterized in individuals with COPD and results from a complex interaction between systemic and local factors.

OBJECTIVE

In this narrative review, we will describe muscle wasting in people with COPD, the associated structural changes, muscle regenerative capacity and possible mechanisms for muscle wasting. We will also discuss how structural changes relate to impaired muscle function and mobility in people with COPD. Key Observations: Approximately 30-40% of individuals with COPD experience muscle mass depletion. Furthermore, muscle atrophy is a predictor of physical function and mortality in this population. Associated structural changes include a decreased proportion and size of type-I fibers, reduced oxidative capacity and mitochondrial density mainly in the quadriceps. Observations related to impaired muscle regenerative capacity in individuals with COPD include a lower proportion of central nuclei in the presence or absence of muscle atrophy and decreased maximal telomere length, which has been correlated with reduced muscle cross-sectional area. Potential mechanisms for muscle wasting in COPD may include excessive production of reactive oxygen species (ROS), altered amino acid metabolism and lower expression of peroxisome proliferator-activated receptors-gamma-coactivator 1-alpha mRNA. Despite a moderate relationship between muscle atrophy and function, impairments in oxidative metabolism only seems weakly related to muscle function.

CONCLUSION

This review article demonstrates the cellular modifications in the peripheral muscle of people with COPD and describes the evidence of its relationship to muscle function. Future research will focus on rehabilitation strategies to improve muscle wasting and maximize function.

Impaired exercise capacity after lung transplantation is related to delayed recovery of muscle strength

Lung transplant recipients report reduced exercise capacity despite satisfactory graft function. We analysed changes in lung function, six-min walk distance (6MWD), and quadriceps strength in the first 26-wk post-transplant and examined what factors predict 6MWD recovery. All lung transplant recipients at a single institution between June 2007 and January 2011 were considered for inclusion. Lung function, 6MWD, and quadriceps strength corrected for body weight (QS%) were recorded pre- and two-, six-, 13-, and 26-wk post-transplant. Fifty recipients, of mean (± SD) age 42 (± 13) yr, were studied. Mean FEV1 % and 6MWD improved from 26.4% to 88.9% and from 397 to 549 m at 26 wk, respectively (both p < 0.001). QS% declined in the first two wk but had improved to above pre-transplant levels by 26 wk (p = 0.027). On multivariate analysis (n = 35), lower pre-transplant exercise capacity and greater recovery in muscle strength explained most of the improvement in exercise capacity. Delayed recovery of exercise capacity after lung transplantation is unrelated to delay in improvement in graft function, but occurs secondary to the slow recovery of muscle strength. Our findings show that additional controlled trials are needed to better understand the influence of exercise rehabilitation on improvement in exercise capacity post-transplantation.

Exercise training after lung transplantation improves participation in daily activity: a randomized controlled trial

The effects of exercise training after lung transplantation have not been studied in a randomized controlled trial so far. We investigated whether 3 months of supervised training, initiated immediately after hospital discharge, improve functional recovery and cardiovascular morbidity of patients up to 1 year after lung transplantation. Patients older than 40 years, who experienced an uncomplicated postoperative period, were eligible for this single blind, parallel group study. Sealed envelopes were used to randomly allocate patients to 3 months of exercise training (n = 21) or a control intervention (n = 19). Minutes of daily walking time (primary outcome), physical fitness, quality of life and cardiovascular morbidity were compared between groups adjusting for baseline assessments in a mixed models analysis. After 1 year daily walking time in the treated patients (n = 18) was 85 ± 27 min and in the control group (n = 16) 54 ± 30 min (adjusted difference 26 min [95%CI 8-45 min, p = 0.006]). Quadriceps force (p = 0.001), 6-minute walking distance (p = 0.002) and self-reported physical functioning (p = 0.039) were significantly higher in the intervention group. Average 24 h ambulatory blood pressures were significantly lower in the treated patients (p ≤ 0.01). Based on these results patients should be strongly encouraged to participate in an exercise training intervention after lung transplantation.

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.

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.

Benefits of home-based endurance training in lung transplant recipients

BACKGROUND

To investigate the effect of home-based exercise training on exercise tolerance, muscle function and quality of life in lung transplant recipients (LTR).

METHODS

Twelve LTR and 7 age-matched healthy subjects underwent exercise training (ET, 12-wk, 3×/wk, 40 min). Peak aerobic capacity VO2peak, endurance time (T(end)), minute ventilation (VE) quadriceps strength, percentage of type I fiber (%Ifb), fiber diameters and chronic respiratory questionnaire were assessed before and after ET. A positive response to ET was defined as an improvement in T(end) at least comparable to the mean change observed in healthy subjects.

RESULTS

Training significantly improved T(end) (+12 ± 11 min), isowatt during exercise (-5.5 ± 2.6L/min), muscle strength (+4.6 ± 2.6 kg) and dyspnea score (+0.6 ± 0.9) in LTR (p < 0.05), leading to recovery of T(end) and muscle strength up to healthy subjects' values. In responders (n = 6), VO2peak, %Ifb and fatigue score were improved after training (p < 0.05). Non-responders had lower %Ifb and greater delay between surgery and the beginning of the study than responders (56 [21-106] vs. 8 [2-59] months respectively, p = 0.03).

CONCLUSIONS

Home-based ET was effective to improve exercise tolerance, muscle strength and quality of life in LTR but more successful in patients with moderate muscle dysfunction and in the first years after transplantation. Multicenter and controlled-studies are needed to confirm the benefits and optimal modalities of home training in LTR.

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.

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).

Transplantation in Chronic Obstructive Pulmonary Disease

Lung transplantation is a surgical option for patients who fail optimization of medical treatment for the severe symptoms that result from COPD. This review will discuss patient selection, transplant listing, and the surgical technique for transplantation in COPD. Furthermore, it will describe transplant outcomes and its effects on recipient survival, pulmonary function, exercise capacity, respiratory muscle function, and quality of life. The respective roles of transplantation and lung volume reduction surgery as therapies for advanced disease will be outlined.

[Lung transplantation. Indications, long-term results and special impact of follow-up care]

Die Lungentransplantation ist bei weit fortgeschrittenen Lungenerkrankungen nach Ausschöpfung aller Therapiemöglichkeiten eine Therapieoption, welche die Lebensqualität und – bei bestimmten Indikationen (zystische Fibrose, Lungenfibrose, pulmonal arterielle Hypertonie) – Lebenserwartung verbessert. Die Anzahl verfügbarer Spenderorgane ist so gering, dass jeder 6. Patient auf der Warteliste verstirbt. Bei der Auswahl geeigneter Kandidaten sind neben der ursächlichen Lungen- oder Herz-Lungenerkrankung, das Alter, vorhandene Mobilität, Ernährungs- und Muskelstatus und extrapulmonale Begleiterkrankungen entscheidende Kriterien. Postoperative Komplikationen können durch die Operation bedingt, durch eine Transplantatabstoßung (akut oder chronisch), Atemwegskomplikationen, Infektionen und extrapulmonale Folgeerkrankungen auftreten. Die Nachsorge erfolgt immer in Kooperation mit dem Transplantationszentrum und hat in großen Zentren zu einer spürbaren Verbesserung der Langzeitergebnisse geführt.

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.

Effect of lung transplant and volume reduction surgery on respiratory muscle function

Lung transplantation and lung volume reduction surgery have opened a new therapeutic era for patients with advanced emphysema. In addition to providing impressive clinical benefits, they have helped us better understand how the chest wall and respiratory muscles adapt to chronic hyperinflation. This article reviews the effects of these procedures on respiratory muscle and chest wall function. Inspiratory (including diaphragm) and expiratory muscle strength are often close to normal after unilateral and bilateral transplantation, although some patients have marked weakness. After bilateral transplantation for emphysema, graft volume is normal at full inflation but remains greater than normal at end expiration, which results from structural changes in the chest wall. In contrast, patients with unilateral transplantation have a reduction in graft volume at full inflation. The mediastinum is displaced toward the graft at end expiration, which reduces the surface area of the diaphragm on the transplanted side, and it moves toward the native lung during tidal and full inspiration and toward the graft during tidal and forced expiration. Lung volume reduction produces an increase in contractility, length and surface area of the diaphragm, and increases its contribution to tidal volume; at the same time, neural drive to the muscle and respiratory load are reduced, such that diaphragm neuromechanical coupling is improved. Diaphragm configuration and rib cage dimensions are only minimally affected by the procedure. Single-lung transplantation and lung volume reduction favorably impact on the disadvantageous size interaction by which the lungs are functionally restricted by the chest wall in emphysema.

Skeletal muscle dysfunction in patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a debilitating disease characterized by inflammation-induced airflow limitation and parenchymal destruction. In addition to pulmonary manifestations, patients with COPD develop systemic problems, including skeletal muscle and other organ-specific dysfunctions, nutritional abnormalities, weight loss, and adverse psychological responses. Patients with COPD often complain of dyspnea on exertion, reduced exercise capacity, and develop a progressive decline in lung function with increasing age. These symptoms have been attributed to increases in the work of breathing and in impairments in gas exchange that result from airflow limitation and dynamic hyperinflation. However, there is mounting evidence to suggest that skeletal muscle dysfunction, independent of lung function, contributes significantly to reduced exercise capacity and poor quality of life in these patients. Limb and ventilatory skeletal muscle dysfunction in COPD patients has been attributed to a myriad of factors, including the presence of low grade systemic inflammatory processes, nutritional depletion, corticosteroid medications, chronic inactivity, age, hypoxemia, smoking, oxidative and nitrosative stresses, protein degradation and changes in vascular density. This review briefly summarizes the contribution of these factors to overall skeletal muscle dysfunction in patients with COPD, with particular attention paid to the latest advances in the field.

Lung transplantation and lung volume reduction surgery versus transplantation in chronic obstructive pulmonary disease

Lung transplantation and lung volume reduction surgery are surgical options for patients with advanced chronic obstructive pulmonary disease that is refractory to medical treatment. In this review, we discuss the differential indications for each procedure, as well as compare their risks and benefits. We also present an algorithm for selecting the most appropriate procedure for individual patients. Finally, we discuss the feasibility and role of lung transplantation after lung volume reduction surgery in the management of selected patients with chronic obstructive pulmonary disease.

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.