| Abstract|| |
Home hemodialysis (HHD) has proved to be a useful form of renal replacement therapy. The economic advantage of HHD is well established and interest in it is renewed. Once it has been decided to establish a HHD program, a well developed strategic plan is required. This should address financial and logistical issues and establish policies that will address responsibilities of both patients and HD centers. The recruitment of patients is facilitated by ensuring that all incident patients have early access to an education program describing all forms of renal replacement therapy that the regional renal program provides. Patients and members of the predialysis education program should understand the selection process criteria in advance. Once the assessment is completed and the patient agrees to the proceedings, a plan of action should be established for enrolling the patient into the program and initiating training. Patients' education program should take into consideration principles of adult learning. When choosing dialysis equipment for home use, the needs and preferences of the patients should be respected. As a rule of thumb, the equipment should be simple to use, yet still provide adequate and reliable therapy. Deciding where to set up and position the HHD equipment is important. Installation of HHD machine at home requires a continuous supply of accessories. Before establishing a HHD program, commitment of the dialysis center to provide and maintain the infrastructure of the program is mandatory. The estimated patients suitable for HHD are less than 15% of all prospective dialysis patients. Generally, those who are have greatly improved quality of life and by using modalities such as nocturnal and daily dialysis can have improved physical well-being with considerable potential cost savings.
Keywords: Home Hemodialysis, Equipment, Water, Monitoring, Cost, Economy
|How to cite this article:|
Alhomayeed B, Lindsay R M. Technical aspects of home hemodialysis. Saudi J Kidney Dis Transpl 2009;20:185-91
| Introduction|| |
Home hemodialysis (HHD) was pioneered in Boston, London and Seattle in the early 1960s as a means of providing dialysis to more patients at a time when funding of this treatment was limited. It proved to be a useful form of renal replacement therapy and in early years enjoyed considerable growth. HHD largely disappeared in North America, following the introduction of Medicare funding for dialysis. The economic advantage of HHD is well established and interest in it is renewed.
Once it has been decided to establish a HHD program, a well developed strategic plan is required. This should address financial and logistical issues and establish policies that will address responsibilities of both patients and HD centers. These policies usually vary from program-to-program because of different health measures in countries, provinces, and cities.
The best way to review the technical requirements of setting up an HHD program is to consider the clinical pathway of patients from recruitment through home management to program exit and to examine the resources necessary at each stage [Figure 1].
| Stage 1: Patient recruitment|| |
The recruitment of patients is facilitated by ensuring that all incident patients have early access to an education program describing all forms of renal replacement therapy that the regional renal program provides.
Early referral of pre-dialysis patients to an appropriate clinic is therefore ideal. This educational program should state the potential benefits of the program and address any fears that patients may have about caring for themselves at home.
The best way to achieve this goal is to have prospective patients meet patients already on a HHD program. The patients should perceive that the program is well organized including installation, maintenance, and policies for equipment in addition to adequate support network.
Patients and members of the pre-dialysis education program should understand the selection process criteria in advance. The team for the implementation of the pre-dialysis program should include nurses, physicians, social workers, and dietitians.
On the other hand, with prevalent dialysis patients, discussing the medical and psychological suitability of prospective candidates for HHD with the referring hospital and renal team in advance will help in understanding and predicting potential problems, which may prevent unnecessary risks and stress to patients and their families.
Appropriate assessment at an early stage during patients' journey with chronic kidney disease is the key to assuring a successful transition to HHD and minimizing patients dropout.
Afterwards, the patients should undergo a physical assessment that include vision, hearing, dexterity and communication such as the presence of back pain, arthritis, or amputation that may interfere with the patient ability to open packages, use clamps and cannulate. Furthermore, assessing patients' hemodynamic stability and dry weight during dialysis and evaluating the cardiovascular risk profile cannot be overemphasized.
Establishing a reliable vascular access for hemodialysis is very important. Ideally patients should have A-V fistulas or synthetic bridging grafts created that are easily self-cannulated by patients. Permacath catheters are acceptable as long as they remain free of infection, provide reasonable blood flow, and require minimal adjustments.
Involvement of the social worker in assessing the psychological suitability and coping skills of the patient usually helps in determining whether a patient is a suitable candidate for HHD. Indeed it is not appropriate to try to teach someone who is severely depressed or stressed to the point where he or she cannot sleep. On the other hand, it is not necessary to be a high school graduate to perform HHD successfully; common sense is the most important aspect.
Going through these basic steps of evaluation is the best way devised to select patients for HHD. Once the assessment is completed and the patient agrees to the proceedings, a plan of action should be established for enrolling the patient into the program and initiating training.
During the period of assessment, a detailed check list of critical parameters to help identify services that may require upgrading at home prior to the initiation of HHD should be utilized [Table 1].
As a program necessity, it is recommended that HHD should adhere to standardized technical requirements created and outlined by biomedical engineering and hospital personnel with experience in planning and facilities development. The standards should incorporate numerous components of HHD installation, including the assessment of the patients' residence.  In our program, a patient's residence should meet all government codes of electrical and plumbing standards before installation is initiated. Furthermore, a hospital architect or biomedical engineering specialist should first conduct a home visit to assess water, sewage, electricity and space. Accordingly, some level of renovation before HHD can begin may be recommended. Thus a program policy that outline the contracting, coordinating, and monitoring of any home renovations should first be developed.  A policy that addresses the removal of HD equipment should be developed in the event that a patient returns to an in-center program, obtains a successful kidney transplant, or expires. The financial obligations for both patient and institution should be clearly stated at outset.
It is also useful to develop a policy for determining what safety devices are necessary to support the various forms of vascular access used by HHD patients such as lock boxes and interlink devices for patients with catheters. A decision to involve an interventional nephrologist to provide vascular access maintenance should also be entertained during the assessment period. 
A hemodialysis facility's malpractice carrier should be notified of the intention to establish a HHD program to ensure that liability coverage is appropriate and well understood.  Any additional required insurance, once hemodialysis equipment is installed, is also an important consideration, as equipment failure may cause extensive water damage to a patient's home.
| Stage 2: Patients' training and education|| |
Patients' education program should be established and take into consideration principles of adult learning. At the beginning of the program, a clear outline has to be delivered to the patients with respect to what is expected of them and their assistants regarding training time and responsibilities. This will eliminate "surprises and confusion". In our program, the patients are responsible for most of the treatment and the assistants are involved to a limited degree such as vascular cannulation. However, there may be times when a longstanding hemodialysis patient can no longer act as the principal actor, and the assistant is so secure in management that he or she can take over that role. Not all patients require an assistant. In our program, several patients carry out overnight dialysis while sleeping alone in the house. Obviously, such patients need to be rigorously selected. Before commencing training, the HHD program needs to ensure that previous engagements made by the patients and their assistants are not going to interfere with training; on average, the training time is one month. To ensure that successful and comfortable transition to home therapy is made, patients, assistants, and training nurses should be in agreement that the training will succeed.
| Stage 3: Choice and installation of hemodialysis equipment|| |
When choosing dialysis equipment for home use, the needs and preferences of the patients should be always taken in consideration. As a rule of thumb, the equipment should be simple to use, yet still provide adequate and reliable therapy. The screens should be easy to read and machine controls should be accessible from a seated position so the dialysis treatment can be conducted easily from a dialysis chairs or the patients' beds.  Lower blood flow rates of 200 mL/min and dialysate flow rates of 100-200 mL/min are necessary to support long, slow nocturnal dialysis treatment.  Nocturnal HHD patients also benefit from machines designed to provide maximum comfort so they can sleep through each dialysis session. Moreover, HHD machines should ensure variable functional parameters and control acessibility for the patient from a lying down position. Additional considerations include noise level, external communication capability, and internet connectivity for remote monitoring and data downloading. 
Practically, the ideal dialysis machine should be easily managed by the HHD patients who can simply hook up, receive dialysis treatment, and then leave. The machines should be easily transportable to give patients the opportunity to travel.
A number of hemodialysis technologies have been developed by the dialysis industry for home use. Examples of these include the NxStage (Lawrence, MA, USA), Fresenius 2008-HHD (Waltham, MA, USA), Gambro AK 95 (Lund, Sweden), and Bellco Formula Domus Home Care (Mirandola, Italy) systems. Each system utilizes schemes to (hopefully) make the procedure easier and safer, by computerized monitoring, sterilization techniques, and biofeedback control systems.
Deciding where to set up and position the HHD equipment is important. The usual location is on the floor of the dwelling that provides the easiest access for installation and maintenance of the dialysis machine and water treatment equipment.  Moreover, patients' preferences for site, modality of treatment (e.g. daily versus nocturnal), convenience, capacity of the existing building services, living space finishing, and conditions of the environment should also be taken into consideration. For environmental purposes, adequate storage space for disposable items such as dialyzers and tubing is necessary and appropriate measures for medical waste disposal should be established.
Water treatment system is another important issue. While the patient on three times a week conventional hemodialysis requires 360 L of water per week, a nocturnal HHD patient dialyzing six times a week requires approximately 840 L per week. Thus, the efficacy (in providing "pure" water) of the water treatment equipment installed in the home is critical. 
Two types of water treatment systems are typically used for HHD treatment; a small portable reverse osmosis (RO) system and the deionization (DI) system. The selection of the water treatment system depends on a variety of factors including program policy, water system support and service, patient training and responsibilities, and system safety and reliability. 
RO is the most commonly used system in HHD programs. [Table 2] lists the standard components and features required to install a water treatment system for HHD patients. The RO system for home use should be small, quiet, and compatible with the patient's hemodialysis machine. Water treatment system can be installed adjacent to the hemodialysis machine as noise level may not be an important issue for HHD carried during the day, while the noise level of water system might affect the patients' ability to sleep in case of nocturnal HHD, which dictates its installation in another room. 
| Stage 4: Maintenance|| |
Once installation of hemodialysis equipment is established, a monthly conducted surveillance of HHD water system that includes microbiological, endotoxin and RO sterilization, in addition to regularly scheduled biomedical visits on to maintain the hemodialysis machine and the other related equipment.
| Stage 5: 'Fallback' support in-hospital or outpatient|| |
HHD patients feel secure when support is provided to facilitate their dialysis journey either in-hospital, admission to hospital for any reason, and outpatient follow-up. The support usually results in a strong relationship between the patients and the HHD team.
| Stage 6: Equipment supplies and delivery|| |
Installations of HHD machine at home requires a continuous supply of accessories. This includes dialysers, lines (156-365 sets/year), pure water filters and concentrate in addition to dialysis-related medications. Furthermore, two important safety devices should attached to the HHD machine; water detectors that stop the water supply in case of water leakage and enuresis alarm sensors fixed near the vascular access in case of blood leakage.
| Stage 7: Remote monitoring|| |
Nocturnal HHD patients may feel more secure if they are monitored as they dialyze overnight. The basic requirements for monitoring include installation of phone line, modem, and computer with internet connection. The hospital HHD unit needs to have a server, and a multiplexer modem with appropriate software systems.
One example of successful remote monitoring was established for patients in our daily/ nocturnal hemodialysis study.  The patients were monitored via the initial connection between home and hospital on a dedicated phone line.  A monitor was hired to remain on duty each night from 22:00 until 08:00h. Once the connection was established and hemodialysis machine was turned on, the machine parameters were updated approximately every 20 seconds on display screens viewed at the hospital. Adverse events that triggered audible signals could be detected easily by the hospital monitor by accessing the individual screens of the patients for details. If the patients failed to respond to the alarm within a specified period, the monitoring team would telephone the patients at home. If any patient failed to answer the phone, the monitoring team would call a previously identified person or the local emergency number to check on the patient.
In the London study,  it was found that the main reasons for alarms pertained to vascular access. The concern in these situation is that while an arterial disconnect will cause an immediate air alarm and stop the blood pump, a venous disconnect will not lead to a machine alarm until the blood pressure falls so low in order to trigger an arterial pressure alarm. Accordingly, a considerable blood loss was possible. One method of eliminating this problem was to use some form of a single needle device. Any drop in dialysis efficiency is more than compensated by the prolonged duration of the overnight treatment.
There is a variability of HHD programs in the use of remote monitoring depending upon local, state, province or country legal requirements (e.g. New York State, USA). The London Study results suggested that all patients might be monitored for the first three months of home nocturnal therapy and thereafter only for those showing concern.  As monitoring is expensive, it may be done on the basis of an economy scales i.e. one monitoring unit for several dialysis programs.
| Stage 8: Infrastructure|| |
Before establishing a HHD program, commitment is mandatory. The HHD unit should fill certain requirements starting from training areas for the patients and assistants. A fully equipped clinic should be available for the outpatient monitoring of HHD patients. The frequency of follow-up of such patients in clinic is variable and relies on multiple factors including their medical history, urea kinetic modeling, and newly emerging medical or psychosocial concerns.
The personnel requirements for HHD unit include a head manager who is responsible for continuity of work, able to solve any emerging problems, and helpful as a reference for other personnel. One nurse is needed for every one and a half patients trained and one nurse for every 20 patients followed up. A round the clock on call nurse should be available to give backup technical support to the patient. Two and a quarter remote monitoring program personnel are required for every 100 patients. One biomedical engineer should be responsible for every 25 patients and on call 12 hours a day seven days a week.
Meeting and secretarial rooms are other important components of an HHD unit. At least one meeting every month should be held to discuss all HHD patients with involvement of all team members including nephrologists, nurses and social workers. The frequency of this meeting depends on the number of patients involved in the program.
A separate remote monitoring room should be established if overnight monitoring is used. This room has to be fully equipped with all the required phone and computer connections. Technically challenging problems related to hemodialysis machines require a biomedical maintenance space.
Finally, a transport system should be available to insure adequate delivery and supply of HHD equipment.
| Conclusion|| |
HHD is an attractive method of providing dialysis for both patient and provider. HHD patients have to be selected and less than 15% of all prospective dialysis patients will be suitable. Generally, those who are have greatly improved quality of life and by using modalities such as nocturnal and daily dialysis can have improved physical well-being with considerable potential cost savings.
| References|| |
|1.||Mehrabian S, Morgan D, Schlaeper C, Kortas C, Lindsay R. Equipment and water treatment considerations for the provision of quotidian home hemodialysis. Am J Kidney Dis 2003; 42:S66-70. |
|2.||Lockridge RS Jr, Spencer M, Craft V, et al. Nocturnal home hemodialysis in North America. Adv Renal Replace Ther 2001;8:250-6. |
|3.||Francoeur R, Digiambatista A. Technical considerations for short daily home hemodialysis and nocturnal home hemodialysis. Adv Renal Replace Ther 2001:8:268-72. |
|4.||Heidenheim A, Leitch R, Kortas C, Lindsay R. Patient monitoring in the London Daily/Nocturnal Hemodialysis Study. Am J Kidney Dis 2003;42:S61-5. |
R M Lindsay
Room A2-345, London Health Sciences Centre, 800 Commissioners Road East, London, Ontario
[Table 1], [Table 2]