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ACCESS
An access (Vascular) is a route into the blood stream that allows enough blood flow for hemodialysis. Permanent access, a surgeon conects a vein to an artery. Can be done directly (fistula) or with a piece of synthetic tubing (graft). Temporary vascular access, catheter may be placed in a large central vein, such as the internal jugular vein in the neck.
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ACID
A substance with a PH below 7.0 that is capable of donating a hydrogen ion (H+). In the human body, acids are created when protein and other substances are broken down by cell membolism.
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ACUTE KIDNEY FAILURE
(Acute renal failure) is kidney failure with a sudden onset. It is most often caused by an illness, injury, or toxin that stresses the kidneys. In some cases, patients who survive acute kidney failure recover their kidney function with the temporary support of dialysis. Some patients die or develop Chronic Kidney Failure.
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ADSORB
To attract and hold on a surface. The dialyzer membrane adsorbs blood proteins to the walls of the hollow fibers during treatment. This can make reused dialyzers more biocompatible (like the body) that new ones if bleech is not used to remove the protein coating.
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ADVANCE DIRECTIVES
Outline a patients wishes for medical treatment in case he or she becomes to ill to make decisions. A living will is an example of and Advance Directive. The patients family and other healthcare team should be told of the patients wishes when an advance directive has been prepared and given a copy to keep.
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AFFERENT
Toward an organ.
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AIR DETECTOR
Air detector (or foam detector) checks blood in the venous line of the extracorporel circuit for air. Air in the patients bloodstream can interfere with blood flow or heartbeat, causing death. If the detector finds air, an alarm will sound, the blood pump will stop, and the venous bloodline will clamp to keep air from reaching the patient.
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AIR EMBOLISM
Occurs when air bubbles enter the bloodstream and are carried into a vessel small enough to be blocked by the air. The air embolus in the vessel acts like a clot, blocking the flow of blood. Dialysis machines have an air detector on the venous bloodline to help prevent this problem, which can be fatel.
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ALBUMIN
Albumin is a blood protein. Low serum albumin levels (<3.5g/dL) may mean that a patient is undernourished. Malnutrition is common in hemodialysis patients, and increase their risk of death.
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ALUM
Alum is an aluminum compound often added to city water supplies to remove sediment and make the water clearer. Aluminum can build up in the bodies and brains of dialysis patients. Aluminum in the water used for dialysis must be kept at low levels by treating the water used to make dialysate.
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ALUMINUM-RELATED BONE DISEASE (ARBD)
Bone disease caused by long-term exposure to aluminum builds up in the tissues at the point where new bones form, and can be seen on x-ray. Sources of aluminum include water used for dialysate, medications, and aluminum cookware. Aluminum-based phosphate binders are also a source, but are rarely used today. Symptoms of ARBD can include deep bone pain, muscle weakness, and fractures.
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AMYLOIDOSIS
The build-up of a protein called beta-2-microglobulin (B2M) in the soft tissues, bones, and joints. In dialysis patients, these deposits can cause arthritis-like joint pain and/or bone pain. High-flux dialysis membranes and/or nocturnal hemodialysis remove more B2M, which may help prevent or treat this disorder.
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ANAPHYLACTIC REACTION
(Anaphylaxis) is a rapid, severe immune response to an allergen. Hives, itching, or wheezing may be present. Anaphlatic shock may occur, causing hypotension, cardiac arrhythmia or arrest, spasms of the breathing passages, and swelling of the throat. This problem can be fatel.
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ANASTOMOSIS
Anastomosis is a surgical connection. In a vascular access, the anastomosis is the spot where a vein and artery are joined to form a fistula, or where the artificial vein is joined to the patients artery and vein for a graft. Dialysis needles should not be inserted into the area of the anastomosis.
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ANEMIA
A shortage of oxygen-carrying red blood cells. It causes severe fatigue, heart problems, trouble concentrating, reduced immune funtion, and many other problems. Anemia is common in chronic kidney disease due to less erythropoietin, iron deficiency and loss of blood through tests and hemodialysis treatements.
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ANESTHETIC
A drug that numbs the body to reduce pain. Local anestheics can be injected into a certain spot (such as the skin around a puncture site before neddle insertion). Or gels or creams can be applied to the skin to prevent pain at the site.
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ANEURYSM
An aneurysm is a ballooning or bulging of a weak spot in the blood vessel. Because severe bleeding van occur if an aneurysm ruptures, great care must be taken with a patient who has one. Aneurysms can occur if needles are inserted too often into the same small area of a fistula.
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ANGIOPLASTY
Angioplasty is a procedure to open a narrowed blood vessel (stenosis). In dialysis patients, angioplasty may be used for vascular access repair. A small balloon is threaded through the vessel into the access and gently inflated to push the walls of the vessel open.
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ANION
An anion is a negatively charged ion.
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ANNA
American Nephrology Nurses Association
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ANTEGRADE
Antegrade means forward moving, in dialysis it means in the direction of blood flow. The venous neddle should always be placed antegrade. The arterial needle may be placed either antegrade or retro-grade.
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ANTICOAGULANT
An anticoagulant is a blood-thinning drug used to keep clots from forming. Anticoagulants, such as heparin, are used to prevent clotting in the extracorporel circuit during hemodialysis.
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ANTIDIURETIC HORMONE (ADH)
Antidiuretic hormone (ADH; Vasopressin) is released by the pituitary gland in the brain. ADH helps prevent excess fluid loss by signaling healthy kidneys to reabsorb water. ADH also signals the blood vessels to constrict (tighten).
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ANTISEPTICS
Antiseptics are products that slow or stop the growth of bacteria and viruses. They are used to kill microorganisms to prevent infection and the spread of disease.
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APICAL PULSE
The apical pulse is felt on the chest wall directly over the heart.
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APNEA
Apnea is a temporary period when breathing stops.
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ARRHYTHMIA
An arrhythmia is an irregularity of the heartbeat. It may be felt as an extra pulse or heard directly over the heart.
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ARTERIAL PRESSURE MONITOR
A pressure sensor monitors pre-pump arterial pressure in the extracorporeal circuit between the patients access and the blood pump. A post-pump arterial pressure monitor measures pressure between the blood pump and the dialyzer. If the pressure reading is outside of set limits, an alarm will sound and the blood pump will stop.
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ARTERAL PRESSURE
In hemodialysis, arterial pressure is measured in the extracorporeal circuit between the arterial needle and the dialyzer. Pre-pump arterial pressure is measured from the the patients access to the blood pump. Post-pump arterial pressure is measured after the blood pump and before the dialyzer.
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ARTERIALIZE
When a fistula is created, strong arterial blood flow causes the vein to arterialize - it dilates (widens), thickens, and becomes more muscular, like an artery.
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ARTERIOVENOUS (AV) FISTULA
In dialysis, an arteriovenous fistula (AVF) is a surgical connecton between an artery and a vein beneath the skin of a an arm or leg to provide access to the blood. The force of blood flowing from the artery makes the vein larger and thicker. After an AVF matures, it can be pumctured repeatedly with dialysis needles and will provide the rapid flow rates needed for dialysis.
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ARTERIOLE
An arteriole is a small artery.
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ARTERY
A blood vessel that carries blood away from the heart at high pressure. Arteries deliver oxygenated blood to every part of the body.
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ARTIFICIAL
Artificial means man-made, often in imitation of something found in nature. The dialyzer is called an artificial kidney because it is a man-made filter that imitates the function of the human kidney. A piece of artificial vein is used to create a dialysis graft.tific
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ASCITES
Ascites is a build-up of fluid in the abdomen caused by liver damage, heart failure, malnutrition, or infection. Special ultrafiltration and other methods (abdominal drainage) may be needed to remove the excess fluid.
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ASPEPSIS
Asepsis is the absence of pathogens. Asepsis in dialysis is achieved by disinfection, equipment maintenance, and using aseptic technique for invasive procedures such as inserting dialysis needles.
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ASEPTIC
Aseptic means sterile or germ-free.
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ASEPTIC TECHNIQUE
A series of steps used to maintain a germ-free environment. Steps in aseptic technique include washing hands before touching items in sterile packages; touching sterile objects only to other sterile objects; cleaning blood ports or the patients skin with disinfectant before inserting a needle; and discarding any sterile supplies in wet, damaged, or torn packages. Peritoneal dialysis exchanges must be done using aseptic techniqaue to prevent infection.
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AAMI
Association for the Advancement of Medical Instrumentation (AAMI) develops voluntary standards for aspects of dialysis, including water treatment and dialyzer reprocessing. The AAMI Guidelines have beenadopted by the Centers for Medicare and Medicaid Services (CMS).
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AUSULTATE
Auscultate means to listen with a stethoscope. Auscultation of a patients vascular access is used to help diagnose problems like stenosis or thrombosis that can change the normal sound of the bruit.
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BACKFILTRATION
Movement of dialysate across the dialyzer membrane and into the patients blood. It can be caused by a change in the pressure or concentration gradient between the dialysate and the blood. Backfiltration may be more likely with high-flux dialyzer membranes, which have larger pores, and thus are more permeable. Backfiltration can harm patients because endotoxin in the nonsterile dialysate can enter the blood stream, causing infection and fever.
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BACKWASHING
Backwashing means forcing water backwards through a filter. This technique can be used to remove particles from clogged sediment filters in a water treatment system.
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BACTERIA
Bacteria are microscopic, single-celled organisms that can cause disease. Bacteria are classified as gram-positive or gram-negative by the color they turn on a standard laboratory test called a Grams Stain.
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BASE
Bases are chemicals capable of accepting a hydrogen ion (H+). A substance with a PH or greater than 7.0 is considered to be a base, or alkaline. In the body, bicarbonate is a base.
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BICARBONATE
Buffer used by the body to neutralize acids that form when the body breaks down protein and other foods. It is reabsorbed by healthy kidneys. Dialysis patients often have low levels of bicarbonate because their kidneys do not reabsorb enough. Thus they can't neutralize acids well. Bicarbonate is used in dialysate to help restore levels of bicarbonate in the body. Bicarbonate dialsate has two main disadvantages: it supports bacterial growth and it requires two concentrates (acid and bicarbonate) to prevent formation of scale (calcium carbonate or magnesium) that can interfere with equipment operation.
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BLOOD LEAK
A blood leak occurs when the delicate semipermeable membrane of the dialyzer tears, letting blood leak into the dialysate. Severe blood leaks can cause blood loss during treatment. Any blood leak will expose patients directly to the dialysate.
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ABCESS
An infection under the skin that looks like a blister or pimple filled with fluid or pus. If fistula needles are inserted into or near an abscess, infection of the fistula or graft or other tissues may occur.
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BLOOD LEAK DETECTOR
The blood leak detector is an alarm system on the hemodialysis delivery system. It monitors used dialsate for blood that would indicate a leak in the dialyzer membrane. The detector shines a beam of light through the dialysate and into a photo cell. A break in the light beam caused by blood cells triggers an alarm that stops the blood pump and clamps the venous line. This prevents further blood loss and contamination of the patients blood with dialysate.
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BLOOD PUMP
The blood pump is part of the hemodialysis delivery system. It pushes the patients blood through the extracorporeal circuit at a fixed rate of speed. During hemodialysis, the blood tubing is threaded between the pump head and rollers. The rollers move blood through the extracorporeal circuit and back to the patient.
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BLOOD PUMP SEGMENT
The blood pump segment is a durable, larger diameter section of the arterial blood tubing that is threaded through the roller mechanism of the blood pump.
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BLOOD TUBING
Blood tubing is the part of the extracorporeal circuit that carries blood from the patients vascular access through the arterial needle, to the dialyzer, and back to the patient through the venous needle. There are two segments of blood tubing: arterial (often color-coded red) and venous (often color-coded blue). Components of the blood tubing include patient connectors, dialyzer connectors, drip chamber/bubble trap, blood pump segment, and heparin and saline infusion lines.
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BLOOD UREA NITROGEN (BUN)
Urea is a waste product of protein metabolism, it is measured as blood urea nitrogen (BUN). Failed kidneys cannot remove urea, which builds up in the body between treatments. BUN is easy and low cost to measure, so it is used as a stand-in for other wastes that are harder to identify or measure. BUN leavels are the basis of the reduction ratio and urea kinetic modeling - methods used to assess the adequacy of dialysis.
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BOLUS
A bolus is a single, relatively large amount of something. In dialysis, heparin can be given by bolus: the full prescribed dose is given all at once.
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BONENT
Board of Nephrology Examiners - Nursing and Technology. This group offers an exam to become a certified Hemodialysis Technologist/Technician (CHT).
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BRACHIAL PULSE
The brachial pulse is the pulse felt in the crease of the elbow at the brachial artery.
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BRACHIOCEPHALIC FISTULA
A brachiocephalic fistula is the most common type of AV fistula of the upper arm. It is created by surgically joining the brachial artery and the cephalic vein.
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BRINE
Brine is concentrated saline solution. In dialysis water treatment, brine is used to flush the resin bed of a water softener. This recharges the softener with sodium chloride ions which are then exchanged with calcium and magnesium to soften the water.
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BRUIT
A bruit is a buzzing or swooshing sound caused by the high-pressure flow of blood through a patients AV fistula or graft. The bruit can be heard through a stethoscope at the anastomosis, and for some distance along the access.
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BUFFER
Abuffer is a substance that maintains the PH of a solution at a constant level, even when an acid or base is added. Bicarbonate is the buffer used in dialysis to maintain the PH of dialysate.
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BUTTONHOLE TECHNIQUE
In the buttonhole (constant-site) cannulation technique, dialysis needles are placed in a fistula (not a graft) into the same holes at the same angle. Over 3-4 weeks, this creates pierced earring-like tracks that guide the needles to the right spots. The patient or the same staff person should place the needles. Once the tracks are formed, special blunt needles are used to avoid cutting new tracks. Buttonhole cannulation is quick to do, less likely to infiltrate, and largely painless for the patient.
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BYPASS
Bypass is a safety feature of the hemodialysis delivery system that cuts off the flow of fresh dialsate to the dialyzer and shunts it to the drain. Bypass prevents unsafe dialysate (wrong conductivity, temperature, PH, or dialysate) from reaching the patient and causing harm.
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CALCIUM
Calcium is an element that exists as a cation (positively charged ion). In the body, calcium is an electrolyte needed for nerve and muscle function and to form normal bone. It is partly bound to protein in the blood. Too much or too little calcium in dialysate can cause severe complications or death for patients. Patient blood levels of calcium are checked monthly. Calcium in a dialysis feed water supply can combine with other substances to form scale that can clog dialysis equipment.
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CANNULATE
To cannulate means to put dialysis needles into a fistula or graft.
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CAPAILLARIES
Capillaries are the body's smallest blood vessels, where oxygenated blood crosses from arteries to veins, capillaries are smaller than a human hair; blood cells must line up single file to pass through. Unlike arteries and veins, capillary walls are semipermeable: they allow oxygen, nutrients, and waste products to pass through. In the kidneys, each glomerulus is a tiny ball of capilleries that filter out wastes from the blood.
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CARBON TANKS
Carbon tanks are water treatment devices that contain granular, activited carbon that adsorbs low molecular weight particles from water. Carbon tanks are mainly used to remove chlorine, chloramines, pesticides, industrial solvents, and some trace organic substances from water used for dialysis.
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CARDIAC ARREST
Cardiac Arrest occurs when the heart stops beating. Cardiac arrest can be a lethal side effect of some dialysis problems, such as too-warm dialysate, wrong dialysate concentration, hemolysis, severe blood loss, or a large amount of air in the bloodstream. Hyperkalemia (high blood potassium levels) can also cause cardiac arrest.
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CARDIAC OUTPUT
Cardiac output is the amount of blood passing through the heart in a certain period of time. Having an AV fistula or graft causes a 10% increase in cardiac output. This causes a 10% increase in the size of the heart. Patients who can't tolerate this increase in cardiac output are not able to have AV fistulae or grafts.
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CATABOLISM
Catabolism is a chemical process in which substances (proteins) are broken down into simpler substances in the body, producing wastes. These wastes (urea) are removed by healthly kidneys. In dialysis patients, they must be removed during treatment.
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CATHETER
A catheter is a plastic tube. In hemodiaysis, a catheter can be placed in a large, central vein for temporary or longer-term access. In peritoneal dialysis, a catheter is surgically placed in the abdomen to allow fresh dialysate to be infused into the peritoneum and used dialysate to be drained.
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CATION
A cation is a positively charged ion. In water treatment, cations can be removed by ion exchange or reverse osmosis to ensure safe water for dialysate and dialyzer reprocessing.
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CELLULOSE
Cellulose is a fiber that forms the cell walls of plants. Cellulose acetate was the first material used as a dialyzer membrane by Dr. Willem Kolff in 1942. It was also the first material used for reverse osmosis membranes for water treatment. To form a membrane, cellulose can be dissolved in a solution containing copper salts and ammonium, then spun into sheets of hollow fibers. Cellulose dialyzer membranes are the most likely to cause first-use syndrome, because they are not biocompatible.
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CENTRAL VENOUS STENOSIS
Central venous stenosis is narrowing of a central vein. This problem can damage vessels in the arm on the affected side so a patient can't have a vascular access. With only about 10 access sites in the body, it is vital to preserve as many as possible. Due to the risk of central venous stenosis, the subclavian vein is not recommended by the KDOQI guidelines as a hemodialysis catheter site. The internal jugular (IJ) is suggested instead.
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CBNT
Certified in Biomedical Nephrology Technology Certification is offered by the National Nephrology Certification Organization (NNCO).
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CCNT
Certified in Clinical Nephrology Technology Certification is offered by the National Nephrology Certification Organization, Inc (NNCO).
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CHLORAMINE
Chloramine is a mix of chlorine and ammonia, or chlorine and organic material. Ammonia may be added to city water to boost the germ-killing power of chlorine. Chloramine is an oxidant; it destroys microorganisms by breaking down their cell walls. Chloramines in dialysis water can cause a serious condition called hemolysis (rupture of red blood cells). Carbon tanks are used to remove chloramines from water used for dialysis.
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CHLORIDE
Chloride is a salt concentrate needed in dialysate and in the human body. Chloride combines with orher elements to form sodium chloride, potassium chloride, magnesium chloride, and calcium chloride.
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CHLORINE
The element chlorine is a greenish-yellow gas that can cause severe irritation to the lungs if inhaled. It is combined with other ingredients (such as sodium hypochlorite-bleach) to disinfect surfaces. Chlorine may also be added to city water supplies to destroy microoraganisms. Carbon tanks are used to remove chlorine and chloramines from water used for hemodialysis and dialyzer reuse.
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CHRONIC
Chronic means long-term.
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CHRONIC KIDNEY DISEASE (CKD)
Chronic Kidney Disease is a long, usually slow, progessive loss of nephrons.-and thus kidney function. CKD can take many years to develop. It is divided into stages based on the glomerular filtration rate (GFR).
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CLEARANCE (K)
Clearance is the amount of blood (in mL) that is completely cleared of a solute in one minute of dialysis at a given blood and dialysate flow rate. Dialyzer clearance affects treatment adequacy. Manufacturers test dialyzers with solutions other than blood (in vitro), so clearance of a dialyzer during treatment (in vivo) can vary from the manufacturers stated clearance.
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CLINICAL PRACTICE GUIDELINES
Clinical Practice Guidelines are recommendations to improve patient outcomes based on a thorough review of the medical research and/or expert opinion. The National Kidney Foundation (NKF) DOQI Clinical Practice Guidelines were recommendations for patient care written by a panel of experts who review medical studies. The NKF-Kidney Disease Outcomes Quality Initiative (KDOQI) updated the guidelines for key areas of nephrology, including anemia, hemodialysis adequacy, peritoneal dialysis adequacy, vascular access, heart disease, high blood pressure, bone disease, nutrition, chronic kidney disease, and managing lipid disorders. The goal of the KDOQI clinical practice guidelines is to improve patient outcomes.
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CMS
Centers for Medicare and Medicaid Services.
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COEFFICIENT OF ULTRAFILTRATION (Kuf)
The Kuf is the fixed amunt of fluid a dialyzer will remove from the patients blood per hour at a specified pressure. Kuf is also called the ultrafiltration factor (UFF) or ultrafiltration rate (UFR). It is expressed as milliliters (mL) per hour (hr) of water removed for each millimeter (mm) of mercury (Hg) of transmembrane pressure (TMP), or ML/hr/mmHg TMP. The higher the Kuf, the more fluid per mL of pressure will be removed. High-flux and high-efficiency dialyzers have higher Kufs than conventional dialyzers. Any Kuf above 8 requires volumetric control hemodialysis systems to precisely control the amount of fluid removed.
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COLONY-FORMING UNIT (CFU)
The number of CFU's in a water or dialysate sample is a measure of the number of living bacteria.
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COMPLEMENT ACTIVATION
Complement is a group of proteins in the blood serum that work to remove pathogens from the body. Complement Activation occurs when the system is exposed to a pathogen.
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CONCENTRATE
In dialysis, concentrate is one of two salt solutions (Acid and Bicarbonate) that are mixed together to form dialysate.
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CONCENTRATION
Concentration is the amount of solute dissolved in a measure of fluid. A highly concentrated solution has more solutes and less fluid. A less concentrated (more dilute) solution has less solute and more fluid. One task of healthy kidneys is to control the concentration of urine, so that the proper amounts of fluid and other substances are retained in the body. In dialysis, the concentration of each of these substances in dialysate must be correct to ensure a safe and effective treatment.
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CONDUCTIVITY
Conductivity is the ability of a fluid to transfer electrical charge. It is a measure of ions in solution. A conductivity meter measures the electrolyte compositon of dialysate to be sure it is within safe limits.
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CONDUCTIVITY MONITOR
The conductivity monitor checks conductivity of the dialysate to be sure it it correct. If the level is wrong, an alarm is triggered, and the machine goes into bypass so dialysate is shunted to the drain.
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CONGESTIVE HEART FAILURE (CHF)
Congestive heart failure occurs when the heart cannot pump out the blood it receives. Excess fluid backs up into the lungs. Fluid overload from too much fluid intake or not enough fluid removal at dialysis may lead to CHF in dialysis patients.
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CONTINUOUS AMBULATORY PERITONEAL DIALYSIS (CAPD)
CAPD is peritoneal dialysis with manual exchanges of dialysate done four or five times each day. CAPD exchanges can be done at home or work, and the patient can go about his or her day. Each exchange takes about 30 min. CAPD is continuous, so large amounts of wastes do no build up between treatments. This means that diet and fluids can be less restricted for CAPD than for hemodialysis. Because the patient can dialyze on his or her preferred schedule, this treatment is work-friendly.
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CONTINUOUS CYCLING PERITONEAL DIALYSIS (CCPD)
CCPD, also called automated peritoneal dialysis (APD), is PD using a cycler machine to do multiple exchanges of dialysate often at night while the patient sleeps. Because the patient can dialyze at night, leaving days free, this treatment is work-friendly.
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CONTINUOUS QAUALITY IMPROVEMENT (CQI)
CQI is a way to improve care by choosing an area that needs to be improved, analyzing the process of care, finding root causes,and then making and using a plan of change.
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CONTINUOUS RENAL REPLACEMENT THERAPY (CRRT)
CRRT is a slow, ongoing form of dialysis that uses the patients heart or a blood pump to move blood through an extracorporeal circuit. Usually CRRT is done for many hours to gently remove extra fluid and some wastes in patienst who are too ill or unstable for standard hemodialysis. A cartridge with a semi-permeable membrane (like a dialyzer) is used.
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CONVENTIONAL DIALYSIS
Conventional Dialysis uses a dialyzer with an in vivo Kuf below 6 to remove wastes and excess fluid from patients with kidney failure. Treatments are done three times a week, most often for three hours or more.
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CONVENTIONAL HOME DIALYSIS (HEMO)
Dialysis treatments are done three days a week by the patient and a partner at home. The patient and partner are trained for several weeks to use the dialysis machine, cannulate the access, do the treatment, draw blood test, keep records, and report problems. Because the patient can dialyze on his or her preferred schedule, this treatmen is work-friendly.
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COUNTERCURRENT FLOW
Countercurrent flow in a dialyzer occurs when blood moves in one direction and dialysate flows in the opposite direction. This allows for the most efficient dialysis, because it keeps the blood in constant contact with fresh dialysate.
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CREATININE
Creatinine is a wast product of muscle use that is removed by healthly kidneys. Larger people with more muscle normally have higher creatinine levels in their blood. Higher than normal creatinine levels may mean kidney disease.
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CREATININE CLEARANCE
Creatinine clearance is a urine test that measures how well the kidneys remove creatinine from the blood in a certain time period. As kidney disease worsens, creatinine clearance will fall to 10% of normal or less.
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CRENATION
Crenation is shriveling of blood cells that occurs if the blood cells are exposed to a solution that is more concentrated than blood. For example, crenation may occur if dialysate with too much concentrate is used (hypertonic solution). If crenation occurs, the blood will appear dark red. The condition can be fatal.
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CUFFED TUNNELED CATHETERS
Cuffed tunneled catheters used for dialysis access, are placed in a blood vessel through a tunnel created under the skin. Inside the tunnel tissue grows into an attached cuff. The cuff makes the catheter more stable and acts as a physical barrier against bacteria.
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CYANOSIS
Cyanosis is bluish-colored skin, lips, gums, and fingernail beds from lack of oxygen. It may be present in patients with methemoglobinemia, caused by exposure to dialysate water that contains nitrates.
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DEHYDATION
Dehydration occurs when the body does not have enough water. It may be caused by diarrhea, vomiting, excess sweating, or excess fluid removal at dialysis. A dehydrated patient may have low blood pressure, sunken eyes, listlessness (lack of interest in surroundings), and poor skin tone.
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DEIONIZATION TANK
Part of a water treatment system, a deionization tank uses beds of resin beads to remove unwanted ions from water used for dialysis. These unwanted ions are exchanged for hydrogen (H+) and hydroxide (OH) ions to form water (H2O).
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DIABETIC NEPHROPATHY
Diabetic nephropathy is kidney disease that results from diabetes. Type 2 diabetes, a shortage of or resistance to insulin, is the leading cause of kidney failure in the U.S. In type 1 diabetes, the immune system destroys the pancreas cells that make insulin. Diabetes is a disease of the blood vessels; it causes heart disease and nerve damage. Along with nephropathy, diabetes is the leading cause of blindness and loss of limb.
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DIALYSATE
Dialysate is a precise mixture of treated water and chemicals. It is used in dialysis to create a concentration gradient so wastes can be removed from the blood. Sodium, calcium, magnesium, chloride, potassium, glucose, and bicarbonate are usually included, in levels like those of normal blood. The concentrations must be very precise, and the dialysate must be mixed properly, or patients can be harmed.
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DIALYSIS
Dialysis is a process of removing wastes and excess fluid from the blood of people whose kidneys have failed. It may be done using a dialyzer (hemodialysis) or the patients peritoneum (peritoneal dialysis) as a filter.
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DIALYSIS DISEQUILIBRIUM SYNDROME
Dialysis disequilibrium syndrome is a condition in which rapid or drastic changes in the patients extracellular fluid affect the brain. Urea transfers more slowly from the brain tissue to the blood, so fluid is drawn into the brain, causing swelling. This syndrome occurs most often in acute renal failure, or when BUN values are very high.
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DIALYZER
The dialyzer, or artificial kidney, is a semi-permeable membrane inside a plastic cylinder. Dialyzers are used in hemodialysis to filter out wastes and fluid from the blood of patients with kidney failure. Ports of the cylinder permit blood and dialysate to flow in and out. The membrane keeps blood and dialysate apart, but allows an exchange of certain solutes and fluid to occur.
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DIASTOLIC
Diastolic blood pressure is the pressure of blood against the arteries when the heart rate is at rest (between beats). It is the bottom number of a blood pressure reading.
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DIFFUSION
Diffusion is movement of dissolved particles across a semi-permeable membrane from an area of higher solute concentration to an area of lower solute concentration. The process goes on until the concentration of solutes on both sides of the membrane are equal. In dialysis, diffusion works to remove wastes from the blood. The dialyzer membrane - or peritoneum in peritoneal dialysis - keeps blood and dialysate apart. Dialysate has no wastes, so wastes in the blood diffuse across the membrance into the dialysate. The rate of diffusion depends on the concentration difference between fluids (grandient), dialysate temperature, membrane pore size, and waste particle size. Diffusion is also called conductive solute transfer.
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DISINFECTANT
A disinfectant is a chemical or process (e.g., heat) that destroys or slows the growth of harmful microbes. To work, disinfectants need time, and must stay moist and in contact with a surface. Common equipment disinfectants include heat, bleach, formaldehyde, glutaraldehyde, renalin, citric acid, and amuchina. Disinfectants are also used to clean water treatment ports before taking a water sample, and to wipe off surfaces in the dialysis center.
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DISTAL
Distal means far. In anatomy, distal is far from the center of the body. The hands and feet are distal extremities.
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DIURETIC
A diuretic is a drug that increases the amount of urine produced. Some diuretics can cause hypokalemia because they promote the loss of potassium in the urine. Diuretics are the first line of treatment for high blood pressure, and may be used for kidney patients before they start dialysis. Once the kidneys stop making urine, diuretics are no longer effective.
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DOCUMENTATION
Documentation is information about a patients care written in the permanent medical record or chart. It is vital to track the patients progress, provide a means to follow up each patients response to treatment, and ensure continuity of care. A patients chart is legal evidence of the care he or she received.
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DRIP CHAMBER
An arterial or venous drip chamber monitors arterial or venous pressure in the extra-corporeal circuit. A bubble trap inside the drip chamber collects any air that enters the blood tubing.
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DRY WEIGHT
Dry weight is the patients weight without excess fluid. When dry weight is reached, there are no signs of fluid overload or dehydration; breathing is normal, with on signs of fluid in the lungs; and blood pressure is normal for the patient (not too high nor too low). "Target Weight" is the goal weight for a given treatment, and is usually determined by the dry weight.
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DWELL TIME
In hemodialysis, dwell time is the length of time a disinfectant must stay in a dialyzer to ensure disinfection while reprocessing. If a disinfectant is used on the hemodialysis delivery system, it must dwell in the fluid pathways long enough to kill bacteria, then be rinsed. In peritoneal dialysis, dwell time is the length of time dialysate stays in the patients abdomen before it is drained and replaced with fresh.
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DYSPENEA
Dyspnea means trouble breathing or shortness of breath. It can be a symptom of anemia, fluid overload, lung or heart problems, or other diaylsis problems such as an air embolism.
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ECCHYMOSIS
An ecchymosis is a bruise or bleeding under the skin. In dialysis patients, an ecchymosis can be a sign that too much herarin has been given or that not enough pressure was placed on the needle site after the needles were removed.
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EDEMA
Edema is water retention with swelling in body tissues. It occurs as a result of fluid overload or other conditions, such as congestive heart failure. This swelling may be seen in the patients eyelids, ankles, feet, hands, abdomen, or lower back area. "Pitting" edema is present when a finger pushed against the skin of the ankle leaves a dent. This should be reported to the nurse.
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EFFERENT
Efferent means away from an organ.
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ELECTROLYTE
An electrolyte is a compound that breaks apart into ions (electrically charged particles) when dissolved in water. Electrolytes send electrical signals along the nerves to the muscles, including the heart. In the body, healthy kidneys keep electrolytes in balance. Sodium, potassium, magnesium, chloride and calcium are electrolytes; each is added to dialysate in precise amounts.
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EMPTY BED CONTACT TIME (EBCT)
Empty Bed Contact Time is the amount of time that feed water must stay in contact with the charcoal bed in a carbon tank during water treatment to remove chlorine and chloramines.
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ENCEPHALOPATHY
Encepholopathy is a change in brain funtion that can be fatal. Symptoms include confusion, short-term memory loss, personality changes, speech problems, muscle spasms, hallucinations, seizures, and impaired thinking. One cause of encephalopathy is chronic exposure to high levels of aluminum. Sources of aluminum include dialsysate water, antacides, and cookware.
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ENDOCRINE FUNCTION
Endocrine function, making hormones, is one of the tasks of healthy kidneys. Kidneys make hormones that adjust blood pressure (angiotensin) and signal the bone marrow to make red blood cells (erythropoietin). Healthly kidneys also convert Vitamin D into an activated form that the body can use to absorb calcium to maintain healthly bones (calcitriol).
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ENDOTOXIN
Endotoxin (lipopolysaccharide) is a toxic part of the cell walls of some bacteria. Living bacteria can shed endotoxin, and it is released when the bacteria die. Endotoxin is not alive; disinfectants can't kill it. If endotoxin enters a patients body it can cause pyrogenic (fever) reactions. Endotoxin is a concern in water treatment and dialyzer reporcessing. It is controlled by reducing the number of bacteria in the water or removing it with an ultrafilter.
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END-STAGE RENAL DISEASE (ESRD)
ESRD is a legal term for complete and irreversible loss of kidney function. This is the last stage (stage 5) of chronic kidney failure, when dialysis or a transplant are needed for the patient to live. Patients have ESRD when their glomeruler filtration rate has dropped to <15, about 10% or normal.
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EQUILIBRIUM
Equilibrium is a state of balance. For example, diffusion and osmosis both continue until equilibrium has been reach: until the levels of solutes or fluid are equal on both sides of a semi-permeable membrane.
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ERYTHROPOIETIN (EPO)
Erythropoietin is a hormone made by healthy kidneys that signals the bone marrow to produce red blood cells.
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ESRD NETWORKS
The ESRD Networks were established by the U.S. government in 1978 to oversee dialysis centers and ensure that patients receive high quality care. The networks collects data, implement quality improvement, encourge rehabilitation, establish a grievance procudure for patients, and provide resource material to ESRD staff and patients. There are 18 regional ESRD networks in the U.S.
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ETHYLENE OXIDE (ETO)
ETO is a gas used by some manufacturers to sterlize new dialyzers. Patients who are herpersensitive to ETO may have first-use syndrome if a new dialyzer is not properly rinsed of ETO.
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EXCHANGE
In peritoneal dialysis, an exchange occurs each time used dialysate is replaced with fresh dialysate after a dwell period. Exchanges may be done by hand or by using a cycler machine.
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EXCRETORY FUNCTION
To excrete means to eliminate from the body. The excretory function of healthy kidneys acts to rid the body of wastes and excess fluid as urine. Urine contains excess water and a high concentration of waste products.
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EXSANGUINATION
Exsanguination is a severe loss of blood that may be fatal. Common causes of exsanguination at dialysis that can be prevented include needle dislodgement, bloodline seperation, access rupture, or a cracked dialyzer casing.
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EXTRACELLULAR
Extracellular means ouside the cells. About one third of the fluid in the body is extracellular, or between the cells and in the blood vessels. Fluid must move into the blood vessels to be removed by dialysis. The sodium level in dialysate helps ensure movement of fluid into the blood vessels so it can be removed during a treatment.
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EXTRACORPOREAL CIRCUIT
The extracorporeal circuit is the arterial bloodline, dialyzer, venous bloodline, and extracorporeal circuit monitors. It is an extension of the patients blood vessels outside of the body, bringing blood from the access to the dialyzer and back to the patient.
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EXTRACORPOREAL
Extracorporeal means outside the body. Hemodialysis is an extracorporeal therapy; it takes place outside the body.
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EXTRACORPOREAL CIRCUIT MONITORS
Extracorporeal circuit monitors include a blood flow monitor, arterial or venous pressure monitors (measured at drip chambers), an air detector, and a blood leak detector. They shut off the blood pump and clamp the venous bloodline if pressure limits are exceeded, air gets into the venous bloodline, or blood is detected in the spent dialysate.
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EXTRASKELETAL CALCIFICATION
Extraskeletal calcification occurs when calcium phospate crystals form in blood vessels or soft tissues. Though rare, it can cause gangrene, loss of limb, and death. Patients whose blood (serum) levels of calcium and phosphorus are high are at risk for extraskeletal calcification. Mottled, painful, purplish skin is a symptom of extraskeletal calcification that must be reported right away to the nurse or nephrologist.
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FEED WATER
Feed water is untreated tap water before it passes through a water treatment system. Feed water must pass through all of the components of a water treatment system before it is used for dialysis.
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