Sustained exercise programs for hemodialysis patients: The characteristics of successful approaches in Portugal, Canada, Mexico, and Germany
Texto Integral @ b-onAbstract
Despite having good intentions, hemodialysis (HD) clinics often fail to sustain exercise programs that they initiate. There are many reasons for this, including a lack of funding, inadequate training of the clinic staff, a lack of exercise professionals to manage the program or train the staff, and the many challenges inherent to exercising a patient population with multiple comorbid diseases. Despite these barriers, there are several outstanding examples of successful exercise programs in HD clinics throughout the world. The aim of this manuscript is to review the characteristics of four successfully sustained HD exercise programs in Portugal, Canada, Mexico, and Germany. We describe the unique approaches they have used to fund and manage their programs, the varied exercise prescriptions they incorporate, the unique challenges they face, and discuss the benefits they have seen. While the programs differ in many regards, a consistent theme is that they each have substantial and committed support from the entire clinic staff, including the nephrologists, administration, nurses, dietitians, and technicians. This suggests that exercise programs in HD clinics can be successfully implemented and sustained provided significant effort is made to foster a culture of physical activity throughout the clinic.
Practical tips for nephrologists
- Exercise programs in dialysis clinics are best implemented and sustained if managed by exercise professionals (physical therapist, physiotherapist, kinesiologist, exercise physiologist).
- Simple exercise programs can be successfully implemented by the existing clinic staff with sustained encouragement from the clinic managers and nephrologists.
- Exercise programs at clinics should promote both intradialytic and out‐of‐clinic exercise.
- Web‐based and local community resources should be explored to develop and support hemodialysis exercise programs.
Areas for future research
- The cost effectiveness of employing exercise professionals in dialysis clinics.
- Demonstrate whether exercise programs reduce hard outcomes such as hospitalizations and mortality in dialysis patients.
- The most efficacious approaches for improving patient reported outcomes, such as QOL, restless legs, fatigue, and cramping.
1 INTRODUCTION
Many hemodialysis (HD) clinics have attempted to develop exercise programs with the goal of improving patient health and quality of life. Unfortunately, implementing sustainable exercise programs in clinics has been challenging. Much of what we know about the benefits of exercise in this population comes from funded research studies. However, these programs are often not maintained after the resources from the grant funding are exhausted. Motivated clinic staff or researchers often attempt to manage exercise programs in the absence of significant financial support or exercise professionals, but these programs often suffer due to other staff work obligations, inappropriate training, and limited resources. As a result, many HD clinics are littered with rarely used exercise equipment that mainly serve as dusty reminders of ambitious, but failed, attempts to implement and/or sustain a robust exercise program.
These implementation challenges have raised questions regarding the feasibility of sustaining exercise programs in HD clinics. While this question remains, there are a number of examples around the world where robust programs have been developed and sustained. In this chapter, exercise programs at specific clinics in four different countries will be highlighted: (a) Portugal; (b) Canada; (c) Mexico; and (d) Germany. The highlighted programs are each unique in many regards, including how they are funded, who manages the interventions, and the types of exercise or physical activity that is promoted. Details of these four highlighted programs are presented below.
1.1 Portugal
In September 2014, a single NephroCare Portugal HD unit implemented an intradialytic exercise program (IEP) for 3 months as part of an HD nurse higher degree research project. This project demonstrated improvements in patients’ physical function and overall quality of life without adverse events as well as without affecting dialysis adequacy. These results were well received by the NephroCare Portugal medical and executive boards who decided to expand the IEP to the national level. For this, a national IEP dedicated manager was appointed and all NephroCare Portugal dialysis units (n = 37) were invited to join the program.
The decision to participate was made by consensus of the medical director and the head nurse of each dialysis unit who had to designate two members from their medical and nursing staff as the local IEP managers. The local IEP managers received appropriate training and their dialysis unit was provided with all the necessary exercise equipment. The role of the local IEP managers is critical for the successful implementation of the program. They are responsible for supervising exercise training and assessment, keeping records up to date, training all local staff involved in the program, and reporting to the national IEP manager.
Portugal has an integrated funding model of end‐stage kidney disease. This integrates dialysis services and products (dialysis treatments, medications, laboratory services, vascular access care, blood transfusions, and complementary tests) that are reimbursed at a fixed rate/patient/week known as a “comprehensive price payment.”1 This reimbursement does not include any exercise or renal rehabilitation intervention, so the IEP is an investment fully funded by NephroCare Portugal.
Of interest, the establishment of a partnership between NephroCare Portugal and the Research Center in Sports Sciences, Health Sciences, and Human Development (CIDESD), a consortium of 10 higher education institutions spread across the country, has allowed that IEP receives yearly masters level exercise physiology student placements to support its implementation when available. However, the program runs independently of having students involved, as only some clinics are in the vicinity of a university where students are available, and the student internships generally run between September and June (during the academic year).
1.1.1 Exercise training protocol
The exercise training protocol was designed to be easy to learn for the majority of HD patients and with low supervision requirements for the dialysis staff. It is performed every dialysis between the first 30 minutes and the last 90 minutes of HD treatment. Exercise training is of moderate intensity measured by the Borg Scale (6‐20).2 Every exercise session includes aerobic training, comprising a warm‐up period (5‐minute cycling; ≤50 rpm; low resistance), a specific aerobic component (up to 60 minutes; 50‐70 rpm; increased resistance) and a cool‐down period (similar to warm‐up).
After 3 months of IEP, every patient is encouraged to begin strength training (performed after aerobic training) that consists of up to four sets (12 repetitions) of the following exercises: handgrip exercise using small balls with different resistance, isometric foot extension and leg extension (lower limb exercises performed against the dialysis chair), isotonic knee extension, knee flexion, hip abduction, and leg raise (lower limbs exercises performed using ankle weights).
Every 15 days, patients are encouraged to increase exercise volume. For the aerobic component, exercise duration first increases up to 60 minutes, followed by increases in cycling resistance. For the strength training, the number of sets first increases from 1 up to 4, followed by weight increases up to 4.5 kg. In its most complete version, each exercise session may last approximately 80 minutes. Table 1 details the exercise training protocol.
| Aerobic training |
|
| Strength training (after 3 mo) |
Upper limbs exercise
Lower limbs exercises
|
1.1.2 Inclusion and exclusion criteria
Inclusion and exclusion criteria were defined in collaboration with NephroCare Portugal medical board. Inclusion criteria are (a) physical capacity for IEP (ability to cycle), (b) HD vintage ≥2 months. Patients are excluded if: (a) high risk of vascular access hematoma; (b) cardiovascular risk; (c) systemic infection; (d) hemoglobin <8.5 g/dL.
Every 3 months, the IEP local managers have two full days (20 hours) set aside to fully dedicate to IEP patients, without any HD‐related tasks. At this time, they recruit new patients and perform the assessments of physical function on all the included patients. On the initial screening visit, all patients who met the inclusion criteria receive an explanation of the purpose, risks, and procedures of the IEP and patients are invited to sign an informed consent.
1.1.3 Measurements and records
With support from the information technology department, a digital platform was developed to monitor the IEP clinical implementation (patient′s uptake, adherence, attrition, and safety) and effectiveness (physical function and body composition—assessed every 3 months). Physical function tests include 8‐foot up and go (agility and dynamic balance), 30 seconds sit to stand (muscle resistance), five times sit to stand (muscle power), single leg stance (static balance), and hand dynamometer (handgrip strength). Body composition measures include adipose and lean tissue indexes (BCM; Fresenius Medical Care). Every 3 months, patients receive a certificate of participation that includes feedback on physical function and body composition measures. These measurements are performed by the local IEP managers.
The dialysis staff is responsible for the maintenance of exercise logs and each exercise session is rated according to the exercise prescription as: fully performed (patient complied with the exercise prescription), partially performed (patient exercised but did not complete the entire prescription), and not performed (patient did not exercise). Criteria for nonperformance or interruption of the exercise sessions were defined. Reasons for partially and not performed exercise sessions and adverse events are recorded. Only the local IEP managers are allowed to assign the inclusion and the dropout. The reasons for dropout are classified as voluntary, medical reason, inability, kidney transplant, unit transfer, death, or other. The local IEP managers are in charge of keeping all the records up to date. This is facilitated by automated task notifications from the digital platform.
Every year, the national IEP manager visits every unit and rates clinical implementation from 0 to 100 accordingly to a previously defined checklist (Table 2).
| Criteria | Score |
|---|---|
| Data from the digital platform | |
| Patients awaiting medical assessment (among the total patients of the HD unit) |
≥10%: 0 points <10%: 5 points |
| Patients included in the IEP (among the total patients of the HD unit) |
<10%: 0 points 10%‐19%: 2.5 points ≥20%: 5 points |
| Patients that refused the IEP (among the total patients of the HD unit) |
>15%: 0 points 5%‐15%: 2.5 points <5%: 5 points |
| Missing informed consents (among the patients included in the IEP) |
Yes: 0 points No: 5 points |
| Voluntary withdrawals (among the total patients that withdrew the IEP) |
≥70%: 0 points 51%‐69%: 1.25 points 26%‐50%: 2.5 points ≤25%: 5 points |
| Patients with adherence to exercise sessions more than 70% (among the patients included in the IEP) |
≤50%: 0 points 51%‐74%: 7.5 points ≥75%: 15 points |
| Patients performing strength training (among the patients included in the IEP for ≥3 mo) |
≤40%: 0 points 41%‐54%: 5 points ≥55%: 10 points |
| Missing exercise session records |
Yes: 0 points No: 10 points |
| Random IEP patient | |
| Physical function measures performed by the standardized operating procedures | 1 point for each physical function test |
| Exercise prescription up to date |
Yes: 10 points No: 0 points |
| Aerobic training |
Patient complied with warm‐up, specific aerobic component, and cool‐down? Yes: 10 points No: 0 points |
| Strength training |
Patients performed the strength exercises correctly? Yes: 10 points No: 0 points |
| Cleaning procedure of IEP material |
Was all the material cleaned between patients Yes: 10 points No: 0 points |
- Abbreviations: HD, hemodialysis; IEP, intradialytic exercise program.
1.1.4 Achievements
Since September 2016, when IEP was implemented at national level, 25 of the 37 dialysis units voluntarily adhered to the IEP (dialysis unit uptake: 67.6%). Table 3 displays clinical implementation outcomes achieved as of December 2018.
| Outcome | Results, % (n) |
|---|---|
| Patient′s uptake (total pool of 3281 patients in HD units offering IEP) | |
| Included | 14.6 (479) |
| Refused | 16.4 (538) |
| Dropped out | 16.7 (548) |
| Excluded (did not fulfill inclusion/exclusion criteria) | 34.9 (1145) |
| Candidates for IEP awaiting medical assessment | 17.4 (571) |
| Reasons for dropout (subtotal pool of 548 patients that dropped out) | |
| Inability | 7.8 (43) |
| Voluntary withdrawal | 55.4 (304) |
| Medical condition | 33.3 (182) |
| Other reason | 3.5 (19) |
| Primary reasons for exclusion (subtotal pool of 1145 excluded patients) | |
| Physical incapacity | 41 (469) |
| Cardiovascular risk | 22.9 (262) |
| Exercise sessions completion (total of 153 039 HD treatments) | |
| Fully performed | 71.1 (108 811) |
| Partially performed | 2.4 (3673) |
| Not performed at all | 26.5 (40 555) |
| Primary reasons for not performed exercise sessions (subtotal of 40 555 HD treatments) | |
| Refusal | 61.7 (25 022) |
| Pain | 3.5 (1419) |
| Interdialytic weight gain >5 kg | 3 (1217) |
| High risk of vascular access hematoma | 2.8 (1136) |
- Abbreviations: HD, hemodialysis; IEP, intradialytic exercise program.
1.1.5 Future challenges
Address exercise monotony
HD treatments per se is mentioned by the patients as boring and an initial advantage for recruiting patients is the notion that exercise will reduce treatment boredom. However, in long‐term patients, this advantage may be lost and lead to voluntary withdrawals.
Increase exercise volume/physical activity level
It is plausible that the exercise volume of the IEP may be insufficient to improve some health outcomes in such an advanced stage of the disease. As exercise is only a part of the whole physical activity concept, complementary and comprehensive interventions addressing the low physical activity levels, including on non‐HD days, may be a way to improve health outcomes.
Address refusals and voluntary withdrawals
We believe that one of the most effective strategies should focus on dialysis staff awareness and motivation for the importance of exercise in HD patients’ quality of life and health. Building this exercise culture through both staff and patient education and support can be maintained to provide HD patients the benefits of increased physical activity.
1.2 Alberta, Canada
Over the past 13 years, the provincial renal program in Alberta, Canada, has implemented and expanded its exercise and clinical kinesiology services for individuals with all levels of kidney disease. The support is tailored to meet the unique and varying needs of this diverse population. Initially, the primary focus was on intradialytic exercise (IDE) during HD treatments. The program now embodies the “Exercise is Medicine” culture3, 4 and also provides support for predialysis patients, home dialysis modalities, transplant prehabilitation/rehabilitation care, and inpatient early mobility interventions.
1.2.1 Intradialytic exercise program
The IDE program is kinesiologist‐led, assisted by nursing staff, health‐care aids, and kinesiology students. This team approach is key for success. Kinesiologists in this program have a 4‐year Bachelor of Science degree (and in some cases, a 2‐year master's degree) with certification(s) on clinical exercise for chronic disease management. The kinesiologists are required to assess new patients, conduct initial IDE monitoring, prescribe home exercise, or refer to community programs. They provide strategic counseling to enhance or maintain overall fitness, self‐management of musculoskeletal conditions, and endeavor to prevent falls through strength and balance training. Additionally, some locations offer resistance training equipment during HD (resistance bands, hand exercisers, ankle weights, stretching straps) and a home exercise equipment loan program.
Patients are medically cleared by the nephrologists in more complex cases (ie, cardiac history or several risk factors). Interestingly, very few patients are unable to exercise as many contraindications can be overcome and managed. Contraindications for this IDE program are severe aortic valve stenosis, myocardial infarction within the previous 3 months, decompensated congestive heart failure, a third‐degree AV block without a pacemaker, uncontrolled blood sugar, hypotension (<90/40 mm Hg) during HD, and physical limitations preventing use of the exercise equipment.
Four categories in the computer database determine the exercise status of all HD patients. Those approved for participation in the IDE program have an ACTIVE status, while others may be ON HOLD (ie, waiting for medical investigations or clearance), DECLINED (still requiring motivation, however, may still receive ongoing support with falls risk, mobility concerns, and pain management), or INELIGIBLE (ie, may dialyze in a bed with no bike access, be medically unstable, or have inoperable heart conditions).
Nurses oversee the safe delivery of the IDE exercise prescription (after patients have been provided the initial set up and safety orientation by the kinesiologist). Health‐care aides are trained to set up the bikes, making the IDE process very efficient. In addition, there is an ongoing presence of university students who register for practicum experiences in the HD clinics. The students gain valuable knowledge on clinical practice, while staff and patients are provided with additional support.
Finally, the rural HD clinics in Alberta all have “exercise champion” nurses. The exercise champions maintain the exercise program once the site has been fully established by a kinesiologist. Reassessments are done every 6 months, or if contacted earlier by the exercise champion.
1.2.2 Home modality exercise support
In Northern Alberta, peritoneal dialysis (PD) patients are thoroughly assessed by a kinesiologist and are prescribed an individualized exercise program depending on functional ability and needs. Patients receive follow‐up during subsequent assessments to ensure progress and safe biomechanics.
In Southern Alberta, all PD patients are provided with a resistance band and a general home strength prescription by the nurse. The nurses have received training from the kinesiologist on how to provide general exercise recommendations to patients. In addition, they can request exercise consults from the kinesiologist if patients have more comprehensive needs. The emphasis for PD patient support is centered on improving general strength, maintaining independence, and implementing core exercises.
Home HD patients throughout all of Alberta have direct contact with the kinesiologist for customized home/gym programs or referrals to community classes.
1.2.3 Inpatient early mobility program
In 2018, the need for prevention of muscle wasting during inpatient stays came to fruition with an Early Mobility Pilot Project. The kinesiologist‐led, nursing, and health‐care aid‐supported program aims to maintain strength and balance during a hospital stay. This pilot program has a research component to assess feasibility and cost benefits of a kinesiologist in an inpatient setting.
1.2.4 Prehabilitation for transplant candidates and rehabilitation post surgery
This exercise support through the transplant clinic in Calgary (Southern Alberta) is twofold; patients are prehabilitated before and rehabilitated after transplant. Patients are referred to this service when they are approximately 1 year away from cadaveric transplants or are working up for living donation transplants.
In the initial consultation, functional measures (30‐second sit to stand, gait speed, grip strength, and balance) are assessed to determine the level of frailty at baseline.5 Patients work with the kinesiologist to develop an action plan based on their goals, which can include a home‐based program, group exercise, and community resources. Following transplantation, the kinesiologist sees the kidney recipient in hospital and provides education on safe mobility guidelines and a home exercise program to assist with a gradual transition back to activity.
1.2.5 Kidney Exercise and Education Program (KEEP)
Three weekly wellness classes in Calgary are offered for free to anyone living with kidney disease and their spouse or caregiver. These classes are delivered by a kinesiologist and are held in spaces that have been donated by community centers, local recreation facilities, and churches. The main focus of the classes is to improve strength and balance for the maintenance of independence. The classes also provide patients with a much needed “community” where they are able to engage with their peers.
1.2.6 Growth and funding
This program has shown progressive growth over the years and has gained the acceptance of kinesiologists as key players in the kidney health‐care team. Since the first kinesiologist was hired in 2009, four more kinesiologists have been added and are currently overseeing hundreds of patients in Alberta. These five kinesiologists are full time staff and are paid by the provincial health‐care program, Alberta Health Services, which is taxpayer funded. They are known as allied health‐care professionals (grouped with social workers, registered dieticians, spiritual care, physiotherapists, and occupational therapists). The decision to hire these positions was made locally by management and executive leaders in the Northern Alberta and Southern Alberta renal programs.
1.2.7 Alberta IDE program outcomes
Currently, 395 patients (approximately 48% of eligible patients) perform IDE each week in 18 clinic programs. Research conducted in the provincial program has demonstrated enhanced leg strength (unpublished data), reduced hospital usage,6 feasibility of implementation,7, 8 high adherence,7 and improved dialysis adequacy.9 Most importantly, the exercise has been safely administered with minimal adverse events. A 3‐month quality improvement initiative investigation found only 1% of IDE sessions were followed by a symptomatic drop in blood pressure (unpublished data). In all cases, the affected patients had a resolution of symptoms and improvement of blood pressure when staff responded with standardized intradialytic hypotension management procedures.
Objectively, there have been significant improvements in patients’ physical ability at 6‐ and 12‐month reassessments. Patients are able to walk further during their 6‐minute walk test, have decreased time for the timed up and go test, and an increased number of sit to stands within 30 seconds. Furthermore, patients have commented on improvements to their overall energy, functional abilities, sleep, and quality of life, while better managing unpleasant side effects of HD treatments, such as restless legs and cramping (unpublished data).
1.2.8 Overcoming challenges
Staff workload
While there was some initial resistance to the addition of the IDE program, this has gradually dissipated over the years. The main concern was related to fears of increased workload by nursing staff, which was primarily overcome through continued managerial support, new hire orientations involving exercise training, and ongoing staff education. The complete set up and removal of a bike for a patient take approximately 3 minutes. After witnessing the patient benefits, most nursing staff have perceived this to be “worth the small effort.” The kinesiologists and health‐care aides also assist with set up. It is a team effort to get all patients more active.
Resistance training is done during HD at some locations, which requires no additional work for nursing staff because it is patient directed. In addition, nephrologists in our Alberta clinics are well informed of their role in promoting and medically clearing patients for IDE and exercise class referrals. Nephrologists’ support and sponsorship greatly enhance the adherence, and thus, the benefits patients receive through this program.
Bike/equipment issues
Due to the many hours of use the IDE bikes have every day, they require constant repair by the dialysis tech staff. The cost of parts and staff time to repair these bikes has motivated the renal program to start a gradual shift to replace the mechanical, chain‐driven bikes with magnetic resistance bikes at some sites. These magnetic bikes have been upgraded with wheels and a handle for easy portability in the HD clinics. A small section of a yoga mat or additional rubbery glue applied to the bottoms of the bikes prevents slippage on the unit floor when patients pedal with increased resistance.
Kinesiologist workload
There are challenges in all areas of healthcare with meeting the demands of an ever‐increasing workload. Active patients in the IDE program receive weekly contact with the kinesiologist; however, the culture of the provincial renal program is that “all patients can benefit from kinesiology services;” therefore, those not active in the IDE program in Calgary still receive consults and care regarding fall prevention, leg strength, mobility needs, post rehabilitation, and nonpharmacological pain management. This has resulted in an increase in nephrologists and nursing staff referring patients to kinesiologists for musculoskeletal needs. In addition, patients are asking more questions about how to self‐manage issues like chronic pain. This has resulted in an increase to the kinesiologists’ workload, which further demonstrates the high need for these professionals in the kidney care context. This has been partially resolved by the hiring of five kinesiologists in 10 years.
1.2.9 Conclusion
There is a sense of pride throughout the Alberta renal program regarding past accomplishments and excitement about future research and developments in the exercise program. Positive engagement between patients, caregivers, nephrologists, nursing staff, management, researchers, and other allied health‐care workers is ongoing. Growing renal exercise programs as a standard of care in Canada and other nations is still needed. With continuation of high‐quality research studies, funding, and knowledge transfer, there will become a time where exercise programming for kidney care is viewed as an essential service for patient quality of life.
1.3 Mexico City, Mexico
The aim of the HD unit at the Instituto Nacional de Cardiologia has been to offer high‐quality renal replacement therapy to low‐income noninsured patients in order to prepare them for kidney transplantation. The routine intradialytic exercise program was established in 1994. Prior to the exercise program being implemented, our patients suffered from severe malnourishment, and transplantation in these conditions was contraindicated. The intradialytic exercise program was introduced with the aim to improve patients’ nutritional and functional status. The program included a low intensity cycling intradialytic exercise program throughout the session using an ergonomic bicycle. The intradialytic exercise program was applied, supervised, and monitored only by HD staff (nephrology nurses and physicians). A position was developed on the sofa armchair so that patients with arteriovenous fistula did not move their arms while pedaling. Our program was never intended to be a research study. While we have presented our observations in abstract form at several professional meetings, we have not published the results in peer‐reviewed journals.
The first positive observations were seen in 17 young patients (10 men and 7 women) who were accepted to the kidney transplant program and who initially received HD as renal replacement therapy. They pedaled without resistance at 50 rpm using a Monark (Sweden) ergometer for 15 minutes every hour during the 4 hours session, three times a week for 12 weeks. We found that such intensity of exercise did not cause significant changes in blood pressure or heart rate and was well tolerated by patients. On average, participants recovered four kilograms (kg) of lean body weight and maintained a controlled pre‐HD blood pressure without antihypertensive medications. Interestingly, the recovery of muscle mass was observed in both lower and upper limbs. A control group that did not exercise during the same time period only gained 1 kg of weight. In addition, in the exercise arm, an improvement of 30% in the maximum oxygen consumption was observed.
Following this pilot study, we observed that the patients were able to keep pedaling without resistance throughout the entire duration of the session without discomfort and maintaining adequate blood pressure control without antihypertensive medications and without significant changes in heart rate. From then, exercise without resistance became part of the routine in all HD sessions.
Improved sleep quality was another observed benefit. When comparing the estimated alert rate using the Stanford Sleepiness Scale10 to assess how alert the patients are feeling during dialysis in a session without exercise vs a session with intradialytic exercise, we observed that patients with exercise do not fall asleep during the whole session, and therefore, we expect that this has a positive impact on the circadian sleep cycle although we did not specifically test for the latter. Finally, low intensity intradialytic exercise has a benefit on hemodynamics preventing intradialytic hypotension. Specifically, we observed that exercise was associated with better relative blood volume patterns, improving refill to the intravascular space, likely due to increase in peripheral vascular resistance and venous return.
1.3.1 Current exercise program status
Based on these observations, during the past 25 years, our clinic has implemented low‐resistance intradialytic exercise throughout each dialysis session as a standard of care. All patients in our clinic are now mandated to exercise during dialysis. This is possible in part due to the relatively small size of our clinic (about 40 total patients and 7 per shift), so the equipment requirements are not excessive. To date, we have enrolled 774 patients in this protocol (49% women; average age 32 ± 12 years; dialysis vintage of 10 ± 21 months). It is important to mention that our dialysis population is a mostly young and predominantly nondiabetic cohort (10% of the total population).
The intradialytic exercise policy is performed routinely when HD is prescribed. Patient participation is very high. The presence of a nephrology fellow within the dialysis units during all treatments in addition to the nursing staff motivate the patients to exercise throughout the session. Our nurses and fellows do not receive any special training for exercise implementation; however, exercise is stopped if any discomfort arises.
The safety profile from exercise has been established in our unit as follows: First, we have demonstrated that low cardiovascular impact exercise is safe and does not adversely affect hemodynamics. Second, our patients are transplant candidates and therefore have a thorough cardiovascular evaluation before initiating HD, including electrocardiogram, echocardiogram, and chest x‐ray.
Our program does not have any specific financial support for the exercise program. The bikes we use are rather inexpensive (<$100 each) and are paid for out of hospital funds used to support the dialysis unit. We do not have a specific evaluation system for the exercise program regarding quality and continuous improvement. However, the HD unit is integrated to the quality improvement hospital program, and therefore, continuous evaluation includes a patient satisfaction questionnaire performed twice a year, transplantation and infection rates reported every 6 months, vascular access, and hospitalizations. The total mortality rate over the past 25 years is 7%. We are aware that this is not comparable with other centers given the selection bias of accepting mostly transplant candidates. In addition, we also have very low hospitalization rates (0.2 per year for the last 100 patients).
1.3.2 Exercise in high‐risk dialysis patients
In addition to patients with diabetes mellitus and patients older than 65 years, the intradialytic exercise program has been introduced to some patients with high cardiovascular risk, including patients with low left ventricular ejection fraction and patients with ischemic and valvular disease. In these particular cases, exercise on HD is carried out with close cardiovascular monitoring including electrocardiogram, oxygen saturation, and central and peripheral skin temperature changes to monitor sympathetic nerve activation in response to ultrafiltration. Likewise, patients with physical limitations to exercise such as patients with lower limb amputations or patients with hip fractures due to mineral bone disease, paraplegia, or femoral vascular access have been offered alternative exercise programs such as weight lifting or electric bicycles.
In summary, we consider that routine intradialytic exercise implemented by clinic staff is feasible, even in the absence of external financial support. Moreover, it is associated with multiple benefits such as improved nutritional status, hemodynamic stability, sleep, and quality of life.
1.4 Saxony, Germany
Exercise programs as a part of dialysis routine treatment are still an exception in international nephrology despite the undisputed enormous therapeutic potential for patients with end‐stage renal disease. To overcome this deficit and to simultaneously address the major reasons for it, we developed and implemented a structured, cardiovascular, and resistance exercise program during dialysis.11 It is individually, prescribed similar to a medication, suitable for young and older, frail patients. Furthermore, it can be permanently integrated into the routine of a standard dialysis unit.
Support of this exercise program by a German health insurance company (AOK PLUS Krankenkasse in the German Federal states of Saxony and Thuringia) with 9 Euros/patient/training session covers the direct costs and also contributes to the patients’ motivation. Presently, we are working toward establishing certified exercise during dialysis to be paid by the statutory health insurance funds in all of Germany with a large‐scale multicenter trial.
In the past 5 years, approximately 400 dialysis patients in eight dialysis units have been exercising on a regular basis with the program described below with excellent adherence of 80%.11 This program is also the basis of an ongoing interventional, cluster‐randomized (1:1), multicenter trial (DiaTT) with 1100 patients undergoing HD.
1.4.1 Practical implementation
- 30 minutes endurance training and
- 30 minutes resistance training
The training sessions are performed three times a week during the first 3 hours of dialysis under direct supervision by an exercise specialist (physiotherapist or sports scientist with an additional training in intradialytic exercise), starting with a 5‐minute warm‐up and ending with 5‐minute cool‐down. For logistical reasons, in each session, one group starts with endurance training and a second one with resistance training. After 30 minutes, the groups swap the training. Participating patients are distributed over the dialysis shifts to minimize the number of ergometers needed and are grouped together in each shift to benefit from collective motivational effects.
The intensity of the exercise is monitored closely, and adjusted as needed, based on results from maximal exercise tests that provide new baseline parameters for the next training interval, namely maximal training heart and repetition rate for endurance and resistance, respectively (see overview in Figure 1).
1.4.2 Endurance training
Endurance training is normally heart rate controlled with the target heart rate stored on the memory card of the bikes. Each patient's target heart rate is calculated by Karvonen's method12 from maximal exercise stress testing before beginning the training and repeated every 6 months. The target heart rate is derived (see Figure 1) from the maximum heart rate determined during the maximum exercise test: participants undergo maximal incremental exercise on a nondialysis day using standard methodology by cycling ≥50 rpm on an electrically braked ergometer with three lead electrocardiogram and blood pressure monitoring. The test starts with a workload of 10 W increasing by 10 W every 2 minutes and continues until muscular fatigue, pathological electrocardiogram criteria, or new clinical symptoms. Alternatively, an exercise ECG can be performed.
All patients are connected to a heart rate monitor with continuous registration during exercise. The Karvonen method cannot be used to determine training intensity for all patients due to the high prevalence of autonomic dysfunction in this population. In these cases, training intensity is monitored by RPE. In all cases, training intensity should be perceived as moderately strenuous (levels 12‐13 on a Borg scale) by the patient.
1.4.3 Resistance training
Eight muscle groups (see Table 4) are trained with an individual target repetition rate (R) (see Figure 1) for each exercise in two sets of one minute each with 1‐minute break. Biceps and triceps (nonaccess arm) are trained with weights of 0.5, 1.0, 2.0, 4.0, and 7.0 kg according to patient′s strength. Patients are instructed to perform these exercises with their access arm at home. Similarly, for the abductor, elastic bands (resistance band®) with different resistances are used. Patients start with weights/resistance bands® inducing a subjectively perceived intensity of “somewhat hard.” The target repetition rate is derived from the maximal repetition rate (MRR) in a maximum strength test for all eight muscle groups: Patients are asked to perform as many repetitions as possible in one minute. If the MRR exceeded 25‐30 repetitions/min, a heavier weight or a more rigid resistance band® with more resistance is used for the biceps/triceps or abductor exercise.
| Muscle group | Exercise | Example |
|---|---|---|
| Arm flexors, biceps | Biceps curl |
|
| Shoulder and triceps | Shoulder press |
|
| Abductors | Abductors press with theraband® |
|
| Abductors | Abductors press with ball |
|
| Leg extensors | Leg press with ball |
|
| Leg flexors | Leg curl with ball |
|
| Body muscles and full body stabilization | Glute bridge |
|
| Abdominal muscles | Crunches |
|
Motivation strategies
Patients exercise together during dialysis, motivated by the trainer, dialysis staff, and physicians. The individual development of exercise capacity and training data is discussed every 3 months with the patient as part of the treatment including the adaption of the prescribed exercise intensity.
Outcome measurements and program assessment
In addition, quality of life (QoL) is assessed with the SF‐36 survey in all patients annually.15
Quality control of the program
The performance of the exercise programs in the different dialysis centers is evaluated annually. For this purpose, several training parameters including the number of exercising patients, frequency of training sessions, monthly averaged power achieved by each patient, results of performance‐based tests, and the qualifications of exercise professionals are reported every 6 months and evaluated by the “German Association for Rehabilitative Sports in Chronic Kidney Disease” (ReNi). ReNi puts together an annual quality report for the sponsoring health insurance company. Based on our inclusion criteria, approximately 90% of patients are eligible to participate in our program, and about 60%‐80% currently participate.
2 ADDITIONAL RESOURCES NEEDED
Exercise professionals: In a dialysis shift with 12‐18 exercising patients and six bikes professional exercise, supervision is needed for 2 hours. With training three times a week, this corresponds to a 0.14 full‐time equivalent.
Endurance training equipment: In each dialysis shift, three exercising patients can share one bike. We use Bed‐cycle ergometers (MOTOmed letto2; Reck‐Technik GmbH & Co KG Medizintechnik) that measure average power, total work, and distance cycled as well as the duration of each training session. These bikes permit heart rate–controlled training, requiring all patients to be connected to a heart rate monitor with continuous registration during exercise. It is advantageous if training data and target heart rate can be stored on a personalized memory card.
Resistance training equipment: This includes weights (dumbbells) of 0.5, 1, 2, 4, and 7 kg, elastic bands (resistance bands) with three different resistances and exercise balls of different sizes
3 PATIENTS SUITABLE FOR PARTICIPATION
We have a liberal inclusion policy that allows for almost 90% of all patients to participate in our program, including patients with multiple comorbidities, older patients, and patients with leg amputations. Our inclusion criteria are assessed by a nephrologist and include the following: (a) 18 years or older; (b) HD for more than 4 weeks; (c) confirmation by the nephrologist that the patient is able to exercise. Patients are excluded from exercise if they meet one of the following criteria: (a) unstable angina pectoris; (b) uncontrolled arterial hypertension (systolic blood pressure >180 mm Hg or diastolic BP >105 mm Hg on repeated measurements); (c) uncontrolled tachycardia; (d) acute severe infection.
4 WHAT WE CAN LEARN FROM SUCCESSFUL DIALYSIS EXERCISE PROGRAMS?
Many lessons can be learned from studying the characteristics of these unique exercise programs. First, it is encouraging that a variety of approaches can be used to implement and sustain exercise programs with high participation rates (see Table 5). Obtaining funding is clearly beneficial for running a successful program; however, it does not appear to be an absolute requirement (eg, the program in Mexico). Moreover, it is clear that exercise specialists that are hired to manage programs still require an engaged staff that can be trained to help facilitate it. The diversity of sources that have been used to fund these programs is particularly striking. One is funded primarily by industry (Portugal), one is subsidized by a private insurance company (Germany), one from a publicly funded health authority (Alberta), and one receives essentially no external funding (Mexico City). Not surprisingly, the program in Mexico City is the only one of the four that does not employ exercise specialists to manage the program.
| Country | Exercise type(s) | Managed by exercise specialist | Funding source | No. of clinics | Unique features |
|---|---|---|---|---|---|
| Portugal | IC and IRT | Yes | Dialysis provider | 25 | Master's level Kinesiology students help manage program for internship credit |
| Mexico | IC and IRT | No | Hospital | 1 | 100% of patients exercise at low intensity for duration of dialysis shift |
| Canada | IC, IRT, and home exercises | Yes | Government health care | 18 | Nurses mainly manage IC program, and patients are trained to conduct band‐based IRT |
| Germany | IC and IRT | Yes | Private insurance | 8 | Initial program provided pilot data used to fund multicenter RCT with 1100 patients (ongoing) |
- Abbreviations: IC, intradialytic cycling; IRT, intradialytic resistance training; RCT, randomized clinical trial.
While all focus mainly on intradialytic exercise, particularly intradialytic cycling, the volume and intensity of cycling differ significantly between the sites. Moreover, intradialytic resistance training is incorporated into each program to varying degrees and using significantly different approaches. There is also a varying emphasis on counseling patients how to incorporate at‐home or out‐of‐clinic exercise into their physical activity plan. Despite these differences, an underlying theme that appears to be consistent across the sites is that each has robust support from the attending nephrologists and other medical staff (nurses and technicians) at the clinics.
The critical question is how to convince payers (governments, insurance companies, or private dialysis providers) to support exercise programs in dialysis clinics. The programs highlighted here suggest several alternatives are possible, but these examples are the exception and not the norm. Some suggest this may require data demonstrating that exercise programs at clinics are cost effective, likely by reducing medication requirements, improving dialysis compliance, or reducing hard outcomes such as hospitalizations or mortality. By contrast, we argue that a greater emphasis should be placed on demonstrating that exercise improves patient‐reported outcomes, such as QOL, restless legs, fatigue, and cramping.
The approaches that are most efficacious for improving these different outcomes may vary. Indeed, data generated from the four remarkable programs highlighted in this manuscript, as well as from several ongoing large randomized clinical trials (eg, PEDAL; NCT02222402 and CYCLE; ISRCTN11299707), will add to the evidence base that will be needed to convince the major stakeholders that exercise programs should be incorporated into the standard of care for HD patients.
