Hemodialysis , also spelled hemodialysis , commonly called renal dialysis or just dialysis , is the process of purifying the blood of a person whose kidneys not functioning normally. This type of dialysis achieves extracorporeal removal of waste products such as creatinine and urea and free water from the blood when the kidney is in a state of renal failure. Hemodialysis is one of three renal replacement therapies (the other two are renal transplantation and peritoneal dialysis). An alternative method for extracorporeal separation of blood components such as plasma or cells is apheresis.
Hemodialysis may be an outpatient therapy or hospitalization. Hemodialysis is routinely performed in an outpatient dialysis facility, either specially constructed in a hospital or a stand-alone clinic. Less frequently hemodialysis is done at home. The dialysis treatment at the clinic begins and is staffed by specialized staff consisting of nurses and technicians; home dialysis treatments can be self-administered and administered or performed together with the help of a trained helper who is usually a family member.
Video Hemodialysis
Medical use
Hemodialysis is an option of renal replacement therapy for patients requiring acute dialysis, and for many patients as maintenance therapy. It provides excellent and fast solute cleansing.
A nephrologist (medical renal specialist) decides when hemodialysis is needed and various parameters for dialysis treatment. This includes the frequency (how many treatments per week), the length of each treatment, and the flow rate of the blood and dialysis solution, as well as the size of the dialyzer. The composition of the dialysis solution is also sometimes adjusted in terms of sodium and potassium and bicarbonate levels. In general, the larger the size of an individual's body, the more dialysis required. In North America and the UK, 3-4 hours of treatment (sometimes up to 5 hours for larger patients) given 3 times a week is typical. Sessions twice a week are restricted to patients who have substantial residual renal function. Four sessions per week are often prescribed for larger patients, as well as patients who have problems with excess fluid. Finally, there is an increased interest in home hemodialysis every day, ie 1.5 to 4 hour sessions given 5-7 times per week, usually at home. There is also an interest in nocturnal dialysis, which involves dialyzing patients, usually at home, for 8-10 hours per night, 3-6 nights per week. Nocturnal in-center dialysis, 3-4 times per week, is also offered on several dialysis units in the United States.
Maps Hemodialysis
Adverse effects
Losses
- Restricts independence, because the person undergoing this procedure can not travel due to availability of inventory
- Need more supplies such as high water and electricity
- Needs reliable technology like dialysis machine
- The procedure is complicated and requires the care giver to have more knowledge
- It takes time to set up and clean the dialysis machine, and sacrifice it with related machines and staff
Complications
Fluid shift
Hemodialysis often involves removal of fluid (via ultrafiltration), as most patients with renal failure secrete little or no urine. Side effects caused by too much fluid and/or discharge too quickly include low blood pressure, fatigue, chest pain, leg cramps, nausea and headaches. These symptoms may occur during treatment and may persist post-treatment; they are sometimes collectively referred to as hangover dialysis or dialysis dialysis. The severity of these symptoms is usually proportional to the amount and rate of removal of fluids. However, the impact of a certain amount or rate of fluid removal can vary greatly from person to person and day to day. These side effects can be avoided and/or severely reduced by limiting fluid intake between treatments or increasing the dose of dialysis for example. dialyzing more often or longer per treatment than standard three times a week, 3-4 hours per treatment schedule.
Related access
Because hemodialysis requires access to the circulatory system, patients undergoing hemodialysis may expose their circulatory system to microbes, which can lead to bacteremia, infections affecting heart valves (endocarditis) or infections affecting bone (osteomyelitis). The risk of infection varies depending on the type of access used (see below). Bleeding can also occur, again the risk varies depending on the type of access used. Infection can be minimized by strictly following infection control best practices.
Associated with Anticoagulation
Heparin is the most common anticoagulant used in hemodialysis, as it is generally well tolerated and can be rapidly reversed with protamine sulfate. Rarely, heparin allergy can be a problem and can cause low platelet counts. In such patients, alternative anticoagulants may be used. In patients at high risk of bleeding, dialysis may be performed without anticoagulation.
First-use syndrome
The first-use syndrome is a rare but severe anaphylactic reaction to the artificial kidney. Symptoms include sneezing, wheezing, shortness of breath, back pain, chest pain, or sudden death. This can be caused by sterile residue in the artificial kidney or material from the membrane itself. In recent years, the incidence of First Usage Syndrome has declined, due to increased use of gamma irradiation, steam sterilization, or electron beam radiation in lieu of chemical sterilization, and the development of new semipermeable membranes from higher biocompatibility. New methods for processing previously acceptable dialysis components should always be considered. For example, in 2008, a series of first-use reactions, including death, occurred due to contaminated heparin during the manufacturing process with overheated chondroitin sulfate.
Cardiovascular
Long-term complications of hemodialysis include hemodialysis-related amyloidosis, neuropathy and various forms of heart disease. Increased frequency and length of treatment have been shown to improve the excess fluid and cardiac enlargement normally seen in these patients. Because of these complications, the prevalence of complementary and alternative drug use among patients undergoing hemodialysis.
Vitamin Deficiency
Folate deficiency can occur in some patients with hemodialysis.
Mechanisms and techniques
The principle of hemodialysis is similar to other dialysis methods; it involves the diffusion of solutes across the semipermeable membrane. Hemodialysis uses reverse flow, in which the dialysate flows in the opposite direction of the bloodstream in the extracorporeal circuit. The reverse flow maintains the concentration gradient across the membrane at a maximum and increases the efficiency of dialysis.
Liquid removal (ultrafiltration) is achieved by altering the hydrostatic pressure of the dialysate compartment, causing free water and some solute dissolved to move across the membrane along the created pressure gradient.
The used dialysis solution may be a sterilized mineral ion solution. Urea and other waste products, potassium, and phosphate diffuse into the dialysis solution. However, the concentrations of sodium and chloride are similar to normal plasma concentrations to prevent loss. Sodium bicarbonate is added in higher concentrations than plasma to improve blood acidity. A small amount of glucose is also commonly used.
Note that this is a different process for related hemofiltration techniques.
Access
Three main methods are used to gain access to blood for hemodialysis: intravenous catheter, arteriovenous fistula (AV) and synthetic grafts. This type of access is affected by factors such as the expected time of the patient's renal failure and the condition of the blood vessels. The patient may have multiple access procedures, usually because the AV fistula or the transplant is mature and the catheter is still in use. Catheter placement is usually done with mild sedation, while fistulas and grafts require surgery.
Type
There are three types of hemodialysis: conventional hemodialysis, daily hemodialysis, and nocturnal hemodialysis. Below are the adaptations and summaries of the Ottawa Hospital brochure.
Conventional hemodialysis
Conventional hemodialysis is usually performed three times per week, for about 3-4 hours for each treatment, in which the patient's blood is pulled out through the tube at a level of 200-400 mL/min. The tube is connected to a 15, 16, or 17 needle inserted into a fistula or dialysis graft, or connected to a portable dialysis catheter. The blood is then pumped through the dialyzer, and then the processed blood is pumped back into the patient's bloodstream through another tube (connected to a second needle or port). During the procedure, the patient's blood pressure is closely monitored, and if it becomes low, or the patient develops other signs of low blood volume such as nausea, the dialysis officer may provide additional fluid through the machine. During treatment, the entire patient's blood volume (about 5000 cc) circulates through the machine every 15 minutes. During this process, dialysis patients are exposed to water for a week for the average person.
Daily hemodialysis
Daily hemodialysis is usually used by patients who perform their own dialysis at home. It's less stressful (softer) but requires more access. It's simple with a catheter, but it's more problematic with fistulas or grafts. "The buttonhole technique" can be used for fistulas that require frequent access. Daily hemodialysis is usually done for 2 hours six days a week.
Nocturnal hemodialysis
The nocturnal hemodialysis procedure is similar to conventional hemodialysis unless it is done three to six nights a week and between six and ten hours per session while the patient is asleep.
Tools
The hemodialysis machine pumps the patient's blood and dialysate through a dialyzer. The latest dialysis machines on the market are highly computerized and constantly monitor a variety of safety-critical parameters, including blood flow rate and dialysate; conductivity dialysis solution, temperature, and pH; and dialysate analysis for evidence of blood leakage or presence of air. Any readings that are out of the normal range trigger audible alarms to alert the patient care technician who monitors the patient. Manufacturers of dialysis machines include companies such as Nipro, Fresenius, Gambro, Baxter, B. Braun, NxStage and Bellco.
Water system
Extensive water purification systems are essential for hemodialysis. Because dialysis patients are exposed to large amounts of water, mixed with dialysate concentrate to form dialysate, even trace mineral contaminants or bacterial endotoxins can filter into the patient's blood. Because the damaged kidneys can not perform a function intended to remove impurities, ions that are inserted into the bloodstream through water can build up to dangerous levels, causing many symptoms or death. Aluminum, chloramine, fluoride, copper, and zinc, as well as bacterial fragments and endotoxins, have all caused problems in this regard.
For this reason, the water used in hemodialysis is carefully purified before use. Initially it was filtered and adjusted temperature and the pH was corrected by adding acid or base. Then softened. Furthermore, the water is run through a tank containing activated charcoal to absorb organic contaminants. Primary purification is then done by forcing water through a membrane with very small pores, called reverse osmosis membranes. This allows water to flow, but retains even a very small solute such as an electrolyte. Removal of the final electrolyte residue is carried out by passing water through a tank with ion exchange resins, which removes the remaining anions or cations and replaces them with hydroxyl ions and hydrogen, respectively, leaving ultra-pure water.
Even this level of water purification may not be enough. The recent trend is to pass this final pure water (after mixing with the dialysate concentrate) through the dialifer membrane. This provides another layer of protection by removing impurities, especially those from bacteria, which may have accumulated in water after passage through the original water purification system.
After purified water is mixed with dialysate concentrate, its conductivity increases, as water containing charged ions conducts electricity. During dialysis, the conductivity of the dialysis solution is continuously monitored to ensure that water and dialysate concentrations are being mixed in proper proportions. Both too concentrated dialysis solutions and excessive dilute solutions can cause severe clinical problems.
Dialyzer
The dialyzer is a device that actually filters the blood. Almost all dialyzers used today are from hollow fibers. A cylindrical bundle of hollow fibers, whose walls consist of semi-permeable membranes, anchored at each end into a pot compound (a kind of glue). The assembly is then inserted into a clear plastic cylindrical shell with four openings. One hole or port of blood on each end of the cylinder communicates with each end of the hollow fiber bundle. It forms a "blood compartment" of the dialyzer. Two other ports are cut to the side of the cylinder. It communicates with space around the hollow fiber, "dialysate compartment." Blood is pumped through the blood port through a very thin beam such as a capillary tube, and the dialysate is pumped through space around the fibers. Gradient pressure is applied when it is necessary to transfer fluid from the blood to the dialysate compartment.
Membrane and flux
The Dialyzer membrane comes with different pore sizes. Those with smaller pore sizes are called "low-flux" and those with larger pore sizes are called "high-flux." Some of the larger molecules, such as beta-2-microglobulin, are not completely removed with a low fluctuating dialyzer; of late, the trend has been using high-flux dialyzers. However, such dialyzers require newer dialysis machines and high-quality dialysis solutions to correctly control the rate of fluid removal and to prevent backflow of purified dialysis fluid to patients through the membrane.
Dialyzer membranes are usually made primarily of cellulose (derived from cotton linter). Such membrane surfaces are not very biocompatible, since exposed hydroxyl groups activate complement in the blood passing through the membrane. Therefore, "unsubstituted" cellulose membranes have been modified. One of the changes is to cover this hydroxyl group with acetate groups (cellulose acetate); the other is to mix some compounds that will inhibit the activation of complement on the membrane surface (modified cellulose). The original "unsubstituted" cellulose membranes are no longer widely used, whereas cellulose acetate and modified cellulose-dialyzer cellulose are still used. Cellulosic membranes can be made either in low flux or high flux configurations, depending on their pore size.
Another group of membranes are made of synthetic materials, using polymers such as polyarylethersulfone, polyamide, polyvinylpyrrolidone, polycarbonate, and polyacrylonitrile. This synthetic membrane activates the complement to a lower level than an unsubstituted cellulose membrane. Synthetic membranes can be made in low or high flux configurations, but most of the flux is high.
Nanotechnology is being used in some of the latest high-flux membranes to create a uniform pore size. The purpose of the high-flux membrane is to miss a relatively large molecule such as beta-2-microglobulin (MW 11,600 dalton), but not to miss albumin (MW ~ 66,400 dalton). Each membrane has pores of various sizes. As pore size increases, some high fluctuating dialyzers begin to let albumin pass blood to dialysate. This is considered undesirable, although one school of thought suggests that removing some albumin may be beneficial in terms of removing toxin-bound uremic toxins.
Membrane flux and yield
Whether using a high-flux dialyzer improves patient outcome is somewhat controversial, but several important studies have shown that it has clinical benefits. The NIH-funded HEMO trial compares survival and hospitalization in patients randomized to dialysis by low flux membrane or high flux. Although the primary outcome (all causes of death) did not reach statistical significance in the randomized group to use high-flux membranes, some secondary results were better in the high flux group. The Cochrane analysis has recently concluded that the benefits of membrane choice on the results have not been proven. A collaborative randomized trial from Europe, the MPO (Membrane Permeabilities Outcomes) study, comparing mortality in patients starting dialysis using flux or low flux membranes, found no significant inclination to improve survival in those using high flux membranes, and survival benefits live in patients with lower serum albumin levels or in diabetics.
Flux membrane and beta-2-microglobulin amyloidosis
High-flux dialysis membranes and/or intermittent on-line hemodiafiltration (IHDF) may also be useful in reducing complications from the accumulation of beta-2-microglobulin. Because beta-2-microglobulin is a large molecule, with a molecular weight of about 11,600 daltons, it does not pass at all through a low-flux dialysis membrane. Beta-2-M is removed with high-flux dialysis, but removed even more efficiently with IHDF. After a few years (usually at least 5-7), patients on hemodialysis begin to develop complications from accumulated beta-2-M, including carpal tunnel syndrome, bone cyst, and amyloid deposits in other joints and tissues. Beta-2-M amyloidosis can cause very serious complications, including spondyloarthropathy, and is often associated with shoulder joint problems. Observational studies from Europe and Japan suggest that the use of high-flux membranes in dialysis mode, or IHDF, reduces beta-2-M complications compared with ordinary dialysis using low flux membranes.
The size and efficiency of Dialyzer
Dialyzers are available in various sizes. A larger dialyzer with a larger membrane area (A) will usually release more solutes than the smaller dialyzer, especially at high blood flow levels. This also depends on the membrane permeability coefficient K 0 for the solute in question. So the efficiency of the dialyzer is usually expressed as K 0 A - product permeability and wide coefficients. Most dialyzers have a membrane surface area of ​​0.8-2.2 square meters, and the values ​​of K 0 A range from about 500 to 1500 mL/min. K 0 A , expressed in mL/min, can be considered a maximum dialyzer cleaning with very high blood flow and dialisate rates.
Reusing dialyzers
Dialyzer can be removed after each treatment or re-use. Reuse requires extensive high-level disinfection procedures. Reusable dialyzers are not shared between patients. There is an early controversy about whether reuse of dialyzers worsens patient outcomes. The consensus today is that the reuse of dialyzers, if done carefully and correctly, yields the same results as the use of single dialyzers.
Dialyzer Reuse is a practice that has existed since the invention of the product. This practice includes dialyzer cleaning which is used for reuse several times for the same patient. Dialysis Clinics reuse dialyzers to be more economical and reduce the high cost of "disposable" dialysis that can be very expensive and wasteful. Single use dialyzers are started only once and then discarded creating large amounts of bio-medical waste without mercy for cost savings. If done correctly, dialyzer reuse can be very safe for dialysis patients.
There are two ways of reusing dialyzers, manuals, and automated. Manual reuse involves cleaning the dialyzer by hand. The semi-disassembled dialyzer then flushed repeatedly before being rinsed with water. Then stored with disinfectant (PAA) liquid for 18 hours more until subsequent use. Although many clinics outside the US use this method, some clinics move on to more automated processes as the dialysis practice progresses. The new method of automatic reuse is achieved through medical devices that began in the early 1980s. These tools are useful for dialysis clinics who practice reuse - especially for large dialysis clinical entities - as they allow for multiple back-to-back cycles per day. The dialyzer is first cleaned by a technician, then automatically cleaned by the machine through a step-cycle process until finally filled with liquid disinfectant for storage. Although automatic reuse is more effective than manual reuse, newer technology has triggered more progress in the reuse process. When reused more than 15 times with the current methodology, dialyzer can lose B2m, medium molecular clearance and fiber pore structure integrity, which has the potential to reduce the effectiveness of patient dialysis sessions. Today, in 2010, newer and more sophisticated reprocessing technologies have proven the ability to completely eliminate the manual pre-cleaning process altogether and have also proven the potential to regenerate (fully restore) all dialyzer functions to a level roughly equivalent with disposable for more than 40 cycles. As medical replacement costs begin to fall even more, many dialysis clinics continue to operate effectively with reuse programs primarily because the process is easier and slimmer than ever.
Treatment treatments for hemodialysis patients
Adapted from the recommendations of nephrology nursing practice developed by the Canadian Nephrology and Technology Association (CANNT) based on the best evidence and clinical practice guidelines, nephrology nurses should:
Vascular Hemodialysis Access: Assess the previous fistula/graft and arm, after each dialysis or any shift: access flow, complications. Assess central venous catheter complications: tip placement, site exit, complication documents and alert appropriate health care providers on any matter. educating patients with proper fistula/graft cleaning and site out; by recognizing and reporting signs and symptoms of infection and complications.
Hemodialysis adequacy: Assess the patient constantly for inadequate signs and symptoms of dialysis. Assess the possibility of inadequate dialysis. Educate patients on the importance of receiving adequate dialysis.
Treatment of hemodialysis and complications: Perform a physical examination from head to toe before, during and after hemodialysis regarding complications and access security. Confirm and prescribe dialysis after reviewing most of the updates lab results. Overcome any patient concerns and educate patients when recognizing learning disparities.
Drug management and infection control practices: Collaborate with patients to develop a treatment regimen. Follow the infection control guide according to the unit protocol.
Epidemiology
Hemodialysis is one of the most common procedures performed in US hospitals in 2011, occurring in 909,000 residence (fixed rate 29 per 10,000 population). This represents a 68 percent increase from 1997, when there were 473,000 people staying. It is the fifth most common procedure for patients aged 45-64 years.
History
Many play a role in developing dialysis as a practical treatment for kidney failure, starting with Thomas Graham of Glasgow, who first presented the principle of dissolved transport across a semipermeable membrane in 1854. Artificial kidneys were first developed by Abel, Rountree, and Turner in 1913, the first human hemodialysis was by Hass (28 February 1924) and the artificial kidneys developed into clinically useful apparatus by Kolff in 1943-1945. This study shows that life can be prolonged in patients who die from renal failure.
Willem Kolff was the first to build a dialyzer working in 1943. The first successful patient treated was a 67-year-old woman in an uremic coma who regained consciousness after 11 hours of hemodialysis with a Kolff dialyzer in 1945. At the time of its creation, Kolff's goal was to provide life support during recovery from acute renal failure. After World War II ended, Kolff donated five dialyzers he made to hospitals around the world, including Mount Sinai Hospital, New York. Kolff gave a set of blueprints for his hemodialysis machine to George Thorn at Peter Bent Brigham Hospital in Boston. This led to the creation of the next generation of Kolff dialyzer, the Kolff-Brigham stainless steel dialysis machine.
According to McKellar (1999), a significant contribution to kidney therapy was made by Canadian surgeon Gordon Murray with the help of two doctors, a chemistry chemistry scholar, and research staff. Murray's work was done simultaneously and independently from Kolff. Murray's work led to the first man-made kidney built in North America in 1945-46, successfully used to treat 26-year-old women out of an uraemic coma in Toronto. The second-generation, less rustic, more compact, second-generation "Murray-Roschlau" dialerer was invented in 1952-53, whose design was stolen by German immigrant Erwin Halstrup, and passed as his own ("Halstrup-Baumann's" kidney).
In the 1950s, Willem Kolff's discovery of a dialyzer was used for acute renal failure, but it was not seen as a viable treatment for patients with chronic kidney disease stage 5 (CKD). At that time, doctors believed it was impossible for patients to dialysis indefinitely for two reasons. First, they think there is no man-made device that can replace kidney function in the long run. In addition, patients undergoing dialysis suffer from damaged veins and arteries, so after several treatments it becomes difficult to find blood vessels to access the patient's blood.
The original Kolff kidney is not very clinically useful, because it is not possible to remove excess fluid. Swedish Professor Nils Alwall wrapped a modified version of the kidney in a stainless steel canister, in which a negative pressure could be applied, in this way affecting the first truly practical application of hemodialysis, conducted in 1946 at Lund University. Alwall is also arguably the inventor of arteriovenous shunts for dialysis. He reported this first in 1948 where he used an arteriovenous shunt on a rabbit. Furthermore, he used a glass-like shunt, as well as a dialed-in dialyzer, to treat 1500 patients in renal failure between 1946 and 1960, as reported to the First International Nephrology Congress held in Evian in September 1960. Alwall was designated to the newly created Nephrology Chairman at Lund University in 1957. Next, he collaborated with Swedish businessman Holger Crafoord to find one of the key companies that would produce dialysis equipment in the last 50 years, Gambro. The earliest history of dialysis has been reviewed by Stanley Shaldon.
Belding H. Scribner, working with Wayne Quinton surgeon, modified the glass shunt used by Alwall by making it from Teflon. Another key improvement is to connect it to a short silicone elastomer tube. This forms the basis of what Scribner shunts, perhaps more accurately called Quinton-Scribner shunts. After treatment, circulation access will remain open by connecting two tubes outside the body using a small U-shaped Teflon tube, which will clog the blood from the tube in the artery back into the tube in the vein.
In 1962, Scribner started the world's first outpatient dialysis facility, the Seattle Artificial Kidney Center, later renamed the Northwest Kidney Center. Immediately the problem arises who should be given dialysis, because demand far exceeds the capacity of six dialysis machines at the center. Scribner decided that he would not make a decision about who would receive dialysis and who would not. Instead, the choice will be made by the anonymous committee, which can be regarded as one of the first bioethics committees.
For a detailed history of successful and unsuccessful attempts at dialysis, including pioneers like Abel and Roundtree, Haas, and Necheles, see this review by Kjellstrand.
See also
- Dialysis
- dialital disequilibrium syndrome
- Home hemodialysis
- Peritoneal dialysis
- Hemofiltration
- extracorporeal therapy
- Kidney replacement therapy
- A step-by-step description of hemodialysis
- Aluminum poisoning in people using dialysis
- Dialytrauma
References
External links
- Kidney and How They Work - (American) National Diabetes Institute and Digestive and Kidney Diseases (NIDDK), NIH.
- Treatment Methods for Kidney Failure - (United States) National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH.
- Treatment Methods for Kidney Failure: Hemodialysis - (United States) National Kidney and Urologic Diseases Information Clearinghouse, NIH.
- Online Community for Dialysis Patients by Dialysis Patients
- What is dialysis? - Canadian Kidney Foundation
- The European Federation of Renal Patients (CEAPIR)
- ARCH Project - European research project for model development to simulate haemodynamic changes induced by AVF surgery and long-term adaptation.
Source of the article : Wikipedia
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