Dmitry Rozenberg

Meeting Report: Consensus Recommendations for a Research Agenda in Exercise in Solid Organ Transplantation

With improved survival rates in solid organ transplantation there has been an increased focus on long‐term outcomes following transplant, including physical function, health‐related quality‐of‐life and cardiovascular mortality. Exercise training has the potential to affect these outcomes, however, research on the optimal timing, type, dose of exercise, mode of delivery and relevant outcomes is limited. This article provides a summary of a 2‐day meeting held in April 2013 (Toronto, Canada) in which a multi‐disciplinary group of clinicians, researchers, administrators and patient representatives engaged in knowledge exchange and discussion of key issues in exercise in solid organ transplant (SOT). The outcomes from the meeting were the development of top research priorities and a research agenda for exercise in SOT, which included the need for larger scale, multi‐center intervention studies, development of standardized outcomes for physical function and surrogate measures for clinical trials, examining novel modes of exercise delivery and novel outcomes from exercise training studies such as immunity, infection, cognition and economic outcomes. The development and dissemination of “expert consensus guidelines,” synthesizing both the best available evidence and expert opinion was prioritized as a key step toward improving program delivery.

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.

Physical rehabilitation for lung transplant candidates and recipients: An evidence-informed clinical approach.

Physical rehabilitation of lung transplant candidates and recipients plays an important in optimizing physical function prior to transplant and facilitating recovery of function post-transplant. As medical and surgical interventions in lung transplantation have evolved over time, there has been a demographic shift of individuals undergoing lung transplantation including older individuals, those with multiple co-morbidites, and candidates with respiratory failure requiring bridging to transplantation. These changes have an impact on the rehabilitation needs of lung transplant candidates and recipients. This review provides a practical approach to rehabilitation based on research and clinical practice at our transplant centre. It focuses on functional assessment and exercise prescription during an uncomplicated and complicated clinical course in the pre-transplant, early and late post-transplant periods. The target audience includes clinicians involved in pre- and post-transplant patient care and rehabilitation researchers.

Repeatability of usual and fast walking speeds in patients with chronic obstructive pulmonary disease.

RATIONALE:Evaluation of the role of walking speeds in chronic obstructive pulmonary disease (COPD) should be preceded by an assessment of its repeatability. This study aimed to establish the repeatability of the usual (susual) and fast (sfast) walking speeds among patients with stable COPD and determine the accuracy of manual measurement. METHODS:Participants demonstrated their susual and sfast over 10 m with speed calculated using a stopwatch; the accuracy was confirmed with optical sensors. The walks were repeated after a 5-minute rest; the session was repeated on 2 subsequent days. The coefficient of repeatability (CR) was calculated for both speeds, and their stability over days was determined. RESULTS:A total of 29 participants (forced expiratory volume in 1 second (FEV1) = 43 ± 25% predicted; FEV1/forced vital capacity (FVC) = 41 ± 13%; susual = 60.3 ± 11 m·min−1; sfast = 74.3 ± 11.5 m·min−1) completed the study. The CRs for the susual and sfast were 7.5 (95% CI: 5.0-10.0) and 7.1 (95% CI: 4.8-9.4) m·min−1, respectively. There was a small increase in the susual (5%; P < .001) on the second trial of every day and between successive days (5%; P < .001); the sfast was not different between trials (P = .09) and increased only between day 1 and day 2 (4%; P < .0001). There was no difference between the stopwatch and the sensor determined susual (−0.5 [95% CI: −1.1 to 0.1] m·min−1; P = .12). The small difference (−2.1 [95% CI: −2.7 to −1.5] m·min−1; P = .0001) between the methods for sfast was within the CR of the sfast. CONCLUSIONS:In patients with moderate to severe COPD, repeated measures of the susual and sfast using a stopwatch support the use of these tests for simple, quick assessments of disability.

Factors affecting discharge destination following lung transplantation

Lung transplant (LT) recipients requiring additional care may be referred to inpatient rehabilitation prior to discharge home. This study seeks to describe discharge destinations following LT, compare the characteristics of patients discharged to different destinations, and identify the predictors of discharge destination.

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. Georges 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.

Thoracic muscle cross‐sectional area is associated with hospital length of stay post lung transplantation: a retrospective cohort study

Low muscle mass is common in lung transplant (LTx) candidates; however, the clinical implications have not been well described. The study aims were to compare skeletal muscle mass in LTx candidates with controls using thoracic muscle cross‐sectional area (CSA) from computed tomography and assess the association with pre‐ and post‐transplant clinical outcomes. This was a retrospective, single‐center cohort study of 527 LTx candidates [median age: 55 IQR (42–62) years; 54% male]. Thoracic muscle CSA was compared to an age‐ and sex‐matched control group. Associations between muscle CSA and pre‐transplant six‐minute walk distance (6MWD), health‐related quality of life (HRQL), delisting/mortality, and post‐transplant hospital outcomes and one‐year mortality were evaluated using multivariable regression analysis. Muscle CSA for LTx candidates was about 10% lower than controls (n = 38). Muscle CSA was associated with pre‐transplant 6MWD, but not HRQL, delisting or pre‐ or post‐transplant mortality. Muscle CSA (per 10 cm2 difference) was associated with shorter hospital stay [0.7 median days 95% CI (0.2–1.3)], independent of 6MWD. In conclusion, thoracic muscle CSA is a simple, readily available estimate of skeletal muscle mass predictive of hospital length of stay, but further study is needed to evaluate the relative contribution of muscle mass versus functional deficits in LTx candidates.

Saving Time for Patients with Moderate to Severe COPD: Endurance Test Speed Set Using Usual and Fast Walk Speeds

Background: For assessing the effects of interventions on exercise tolerance, the tolerable duration (tlimit) of a high-intensity constant-speed endurance test is recommended. The test intensity is determined by the test speed (stest) which should be individualized to target a tlimit of 3 to 15 minutes. We determined the accuracy of setting the stest to achieve a targeted tlimit of 3 to 15 minutes using the participants easily measured and non-fatiguing usual (susual) and fast (sfast) walk speeds. Methods: Participants with COPD were asked to walk at their usual and fast walk speeds to establish their susual and sfast. This required that they walk for less than 1 minute. The individualized stest was calculated from a previously developed equation (0.57 x [sfast - susual]) + susual. Participants then completed a constant-speed endurance test, walking at this calculated stest to intolerance, to determine if the resultant tlimit occurred within 3 to 15 minutes. Results: Twenty-nine participants (forced expiratory volume in 1 second [FEV1] standard deviation [SD ]=43 [25] %predicted; FEV1 to forced vital capacity [FVC]ratio= 41 [13]%; susual = 57.3 [10.4] meters per minute (m·min-1 ); sfast = 71.7 [10.7] m·min-1) completed the study. During testing, 24 (83%) participants used supplemental oxygen and 16 (55%) used a walking aid. The derived stest was 65.6 [10.3] m·min-1 with the observed tlimit of 6.0 [5.0] minute. Twenty-four of 29 (83 %) endurance tests were within 3 to 15 minutes. Conclusion: Using the usual and fast walk speeds provides a simple, quick, inexpensive method for clinicians to set an acceptable endurance walk speed.