Exercise rehabilitation for elderly patients on chronic hemodialysis

Cardiopulmonary exercise testing in patients with end-stage kidney disease: principles, methodology and clinical applications of the optimal tool for exercise tolerance evaluation

Chronic kidney disease (CKD), especially end-stage kidney disease (ESKD), is associated with an increased risk for cardiovascular events and all-cause mortality. Exercise intolerance as well as reduced cardiovascular reserve is extremely common in patients with CKD. Cardiopulmonary exercise testing (CPET) is a non-invasive, dynamic technique that provides an integrative evaluation of cardiovascular, pulmonary, neuropsychological and metabolic function during maximal or submaximal exercise, allowing the evaluation of functional reserves of these systems. This assessment is based on the principle that system failure typically occurs when the system is under stress and thus CPET is currently considered to be the gold standard for identifying exercise limitation and differentiating its causes. It has been widely used in several medical fields for risk stratification, clinical evaluation and other applications, but its use in everyday practice for CKD patients is scarce. This article describes the basic principles and methodology of CPET and provides an overview of important studies that utilized CPET in patients with ESKD, in an effort to increase awareness of CPET capabilities among practicing nephrologists.

Physical Activity and Quality of Life in Hemodialysis Patients and Healthy Controls: A Cross-Sectional Study

Hemodialysis (HD) patients have lower functional abilities compared to healthy people, and this is associated with lower physical activity in everyday life. This may affect their quality of life, but research on this topic is limited. Therefore, the present study aimed to determine the relationship between habitual physical activity and quality of life in HD patients and healthy controls. Ninety-three HD patients and 140 controls participated in the study. Quality of life was assessed using a 36-item medical outcomes study short-form health survey (SF-36). Human Activity Profile (HAP) was used to assess habitual physical activity. The adjusted activity score (AAS) from HAP, age, gender, fat tissue index (FTI), lean tissue index (LTI), and Davies comorbidity score were analyzed as possible predictors of the Physical Component Summary (PCS) of the SF-36. Three sequential linear models were used to model PCS. In Model 1, PCS was regressed by gender and age; in Model 2 the LTI, FTI, and Davies comorbidity scores were added. Model 3 also included AAS. After controlling for age and gender (Model_HD 1: p = 0.056), LTI, FTI, and Davies comorbidity score effects (Model_HD 2: p = 0.181), the AAS accounted for 32% of the variation in PCS of HD patients (Model_HD 3: p < 0.001). Consequently, the PCS of HD patients would increase by 0.431 points if the AAS increased by one point. However, in healthy controls, AAS had a lower impact than in the HD sample (B = 0.359 vs. 0.431), while the corresponding effects of age and gender (Model_H 1: p < 0.001), LTI, FTI, and Davies comorbidity score (Model_H 2: p < 0.001) were adjusted for. The proportion of variation in PCS attributed to AAS was 14.9% (Model_H 3: p < 0.001). The current study results showed that physical activity in everyday life as measured by the HAP questionnaire is associated to a higher degree with the quality of life of HD patients than in healthy subjects. Routine physical activity programs are therefore highly justified, and the nephrology community should play a leading role in this effort.

Breaking the cycle of functional decline in older dialysis patients

Currently, older adults comprise nearly one-third of prevalent US dialysis patients, and this proportion will increase as the population ages. Older dialysis patients experience greater morbidity and mortality than nondialysis patients of the same age, and in part, it is related to progressive functional decline. Progressive functional decline, characterized by need for assistance with more than 2 activities of daily living, contributes to risk of hospitalization, further functional decline, and subsequent nursing home placement when a patient no longer functions independently at home. Progressive functional decline may appear to be unavoidable for older dialysis patients; however, comprehensive geriatric assessment (CGA) may alleviate the prevalence and severity of functional decline. This editorial summarizes common risk factors of functional decline and introduces CGA as a potentially transformative approach to breaking the cycle of functional decline in older dialysis patients.

Evaluation of physical activity and its relationship to health-related quality of life in patients on chronic hemodialysis

OBJECTIVE

The aim of this study was to investigate the relationship between physical activity and health-related quality of life (HRQOL) in patients on chronic hemodialysis.

METHODS

A total of 31 men (69.0 ± 11.1 years) and 17 women (66.9 ± 10.0 years) among 61 male and 30 female patients on chronic hemodialysis at Innoshima General Hospital, Onomichi, Japan, were enrolled in this cross-sectional study. Physical activity was evaluated using tri-axial accelerometers. HRQOL and psychological distress were also evaluated using the EuroQol questionnaire (EQ-5D) and the K6 questionnaire, respectively.

RESULTS

Physical activity evaluated by Σ[metabolic equivalents × h per week (METs·h/w)] was 8.1 ± 6.0 METs·h/w, and EQ-5D score was 0.754 ± 0.177. Among all patients, EQ-5D scores were significantly correlated with physical activity over 4 METs on non-hemodialysis treatment days (r = 0.426, p = 0.003). In women, EQ-5D scores were also correlated with physical activity over 4 METs on hemodialysis treatment days and non-hemodialysis treatment days. By stepwise multiple regression analysis, physical activity over 4 METs on non-hemodialysis treatment days was a determinant factor of EQ-5D even after adjusting for age and K6 scores.

CONCLUSION

Physical activity over 4 METs on non-hemodialysis treatment days might be associated with EQ-5D in patients on chronic hemodialysis, especially in women.

Current best evidence recommendations on measurement and interpretation of physical function in patients with chronic kidney disease

Chronic kidney disease (CKD) is becoming a serious health problem throughout the world and is one of the most potent known risk factors for cardiovascular disease. Deterioration of physical function is accelerated in patients with CKD to levels that significantly impact on clinically and patient-important outcomes such as morbidity, employment, quality of life and, ultimately, survival. However, meaningful interpretation of the existing physical function-related literature in adult patients with CKD is hindered, possibly due to inconsistent choice of methodology, assessment tools and reporting of data. The current comprehensive review of the literature aims to provide the theoretical rationale and framework for physical function assessment and to identify the prevailing approaches to (i) the characterization (classification and terminology), (ii) interpretation, and (iii) reporting of physical function assessment in people with CKD. Comprehensive assessment of physical function can provide important information about the presence of 'physiological impairment' at a body systems level (exercise tolerance under well controlled, laboratory-based procedures), 'functional limitations' (physical performance during tasks imitating usual daily, personal or occupational tasks) and 'functional disability' (via self-reported physical functioning in the context of a socio-cultural environment). The selection of physical function assessment tools should be guided by the primary purpose of the assessment (e.g. research or routine clinical monitoring), by the overall scientific 'soundness' of the chosen tool (e.g. validity, utility, reproducibility, responsiveness characteristics) and by operational factors (e.g. patient collaboration, cost, personnel expertise). Recommendations for tests, methods and protocols are therefore presented, for the assessment of cardiorespiratory and muscular fitness, physical performance and self-reported physical functioning. These recommendations are based on synthesis of available information as derived from controlled exercise training interventions in adult patients with CKD. Special considerations for physical function assessment and suggestions for future research are also addressed. Such an information synthesis might promote greater standardization of the physical function assessment of patients with CKD in routine clinical care or research settings. This would potentially lead to generation of adequate scientific decision-making criteria to help researchers and healthcare providers in selecting the most appropriate measures according to the physical function areas assessed, and to accurately and meaningfully characterize and compare patients' responses to therapeutic interventions.

Sustaining a hemodialysis exercise program: a review

This article reviews the literature addressing exercise programs for dialysis patients to identify elements necessary for sustaining exercise programs in this population. Literature searches for publications (January 1980-February 2009) in Medline (OVID), PubMed, CINAHL (EBSCO), EBSCOhost EJS, ProQuest Central, Web of Science, Cochrane Library, Google Scholar, ScienceDirect, SpringerLink (Kluwer), and Wiley Interscience (Blackwell) were performed. Reference lists from relevant articles were hand-searched for further publications. Criteria for inclusion included full-text primary research and review articles focused on exercise for adult hemodialysis patients. One hundred and seventy one publications were found with a primary focus on exercise in hemodialysis. Of these, 28 primary research and 14 review articles addressed one or more aspects of sustainability of hemodialysis exercise programs. Factors contributing to sustainable exercise programs included: dedicated exercise professionals; encouragement to exercise intradialytically; dialysis and medical staff commitment; adequate physical requirements of equipment and space; interesting and stimulating; cost implications need to be addressed; exercise is not for everyone; requires individual prescription; and there is no age barrier to exercise on hemodialysis.

Assessing the efficacy of exercise training in patients with chronic disease

PURPOSE

The purpose of this study was to evaluate the meaningfulness of exercise training responses in patients with end stage renal disease (ESRD).

METHODS

Eighteen ESRD patients [(mean +/- SD); 54.3 +/- 17.1 yr] completed a training regime progressing to accumulate 40 min of stationary cycling, three times per week for 6 months. .VO(2peak) determined via incremental cycle ergometer protocol, and .VO(2) kinetics determined from a transition from unloaded pedalling to an exercise intensity corresponding to 90% of VT, were assessed at baseline and at 3 and 6 months of training.

RESULTS

Repeated measures analysis of variance revealed significant changes (P < 0.05) on the time factor for .VO(2peak), VO(2)-V(T), and .VO(2) kinetics. Post hoc analysis revealed that .VO(2peak) and .VO(2) kinetics significantly (P < 0.05) improved at 3 months of training with no further improvements thereafter. Analysis of individual subject response data revealed that after 3 months of training, 61% of the patients improved .VO(2peak) by greater than the standard error of measurement (SEM = 0.07 L.min(-1)). At 6 months of training, approximately 89% of the patients improved by more than the SEM .VO(2) kinetics improved by more than the SEM (12.3 s) at 3 months of training in approximately 55% of the patients, with no increase in the number of patients exhibiting faster time constants after 6 months of training.

CONCLUSION

Although conventional statistical analyses indicate that exercise training favorably alters .VO(2peak) and oxygen uptake kinetics of patients with ESRD, it is apparent that considerable interindividual variability exists in the response to training. Consideration of the SEM data underscores the heterogeneity of adaptive response in this patient group and may be valuable in assessing the efficacy of therapeutic exercise rehabilitation.

Quality of life and rehabilitation of elderly dialysis patients

Chronologic age per se does not measure the ability of an individual to benefit from dialysis. Elderly patients gain added lifetime on dialysis that is satisfying, and elderly patients as a group often show better psychosocial adjustment to dialysis than do younger patients. However, the limitations in physical functioning that characterize chronic dialysis patients increase with patient age. The clinical challenge is to identify factors that contribute to patients' compromised functioning and to arrange targeted supportive services. An integrated comprehensive program can address elderly dialysis patients' multiple care needs. Strategies that improve outcomes by reducing the risks of elderly persons for increased disability, assisting them to function in their usual environment whenever possible, can also have benefits.

Dialysis in nursing homes

The number of geriatric end-stage renal disease (ESRD) patients in the United States is increasing disproportionately to other age groups on dialysis. Thus there will be more dialysis patients that will require the assistance of nursing homes or extended care facilities. Nursing homes may be beneficial for the geriatric patient in terms of social and physical rehabilitation. Many of these facilities, however, may not take care of or may not have the capacity to adequately care for dialysis patients. Such patients have a higher rate of peritonitis when on peritoneal dialysis (PD) and have higher mortality rates on hemodialysis (HD) or PD compared to similar dialysis patients in the community. Cooperation and communication between the dialysis center and the nursing home, given the complex management issues involved in the care of these patients, are essential. One promising approach to the care of elderly dialysis patients is an integration of nursing home and dialysis unit. Although another approach could be to more fully utilize the services of adult day care centers, this has proven logistically difficult and has not been reported to be successful since it was first suggested more than a decade ago.

Functional impairment, depression, and life satisfaction among older hemodialysis patients and age-matched controls: a prospective study

OBJECTIVE

To compare change over time in functional impairment, depression, and life satisfaction among older dialysis patients and age-matched controls.

DESIGN

Prospective cohort study over 3 years.

SETTING

Urban and rural communities throughout Georgia.

SUBJECTS

One hundred thirteen prevalent renal failure patients on in-center hemodialysis and 286 controls.

MAIN OUTCOME MEASURES

Ordinal functional impairment index and life satisfaction rating, and Center for Epidemiologic Studies Depression Scale.

RESULTS

Dialysis patients, compared with controls, reported significantly more functional impairment at baseline, and also at follow-up after adjusting for baseline impairment and covariates. Dialysis patients had higher depression scores at baseline, and also at follow-up after adjusting for baseline depression and covariates. In contrast, dialysis patients reported lower life satisfaction at baseline than did controls, but the two cohorts were not significantly different on reported life satisfaction at follow-up, after adjusting for baseline life satisfaction and race. In both cohorts, functional impairment and depression were significantly related.

CONCLUSION

Older dialysis patients' life satisfaction at a 3-year follow-up, which was similar to life satisfaction among age-matched controls, indicates the value of delivered dialysis care; the value of this care would be increased by reducing excess functional impairment in these patients.