Acute Kidney Failure

Acute loss of renal function. There is a good chance of recovery of renal function if the cause of the acute kidney failure can be eliminated. Depending on the severity of renal function loss, intermittent or continuous dialysis treatment may be necessary.

Adequacy

The term refers to the quality of dialysis treatment. To measure adequacy, tests are performed to see if enough fluid and substances have been removed from the patient’s blood.

Albumin

A protein that can be used to monitor a patient’s nutritional condition.

Anemia

Reduced oxygen transport capacity of the blood, measured as reduced hemoglobin content in the blood.

Anticoagulant

An agent (e. g. heparin) that prevents the clotting of blood (see Blood Coagulation).

Apheresis

Process of obtaining blood from a donor or a patient to separate or remove certain components (thrombocytes, plasma) before reinfusing the remainder.

Arterio-venous (AV) fistula

A direct surgically created connection between an artery and a vein in a patient. This connection forms a large blood vessel with an increased blood flow, providing access for hemodialysis.

Artery

A blood vessel that carries blood from the heart to the body.

Automated Peritoneal Dialysis (APD)

Machine (cycler) supported version of peritoneal dialysis treatment usually performed at night.

Biocompatibility

Ability of a material, system or solution to perform without an undesired, clinically significant response from the host.

Bioimpedance

Procedure for measuring the water content of the body. Alternating voltage electrodes measure the relationship between the alternating current and the alternating voltage flowing through the body.

Blood

Fluid circulating in the body composed of plasma and cells (red blood cells, white blood cells, platelets, etc.). The main function of blood is to transport oxygen, nutrients and hormones to tissues and to remove waste products (such as carbon dioxide and urea). Blood also regulates the water and electrolyte balance and helps fight off contaminants as part of the immune system.

Blood cells, red (Erythrocytes)

Cells responsible for transporting oxygen from the lungs into the body. They are created with the help of erythropoietin, a hormone produced in the kidneys.

Blood cells, white (Leukocytes)

Cells that defend the human body against infection. They are involved in allergic reactions and destroy damaged, old and dead cells in the body.

Blood coagulation

A complex process during which blood forms solid clots. It is an important part of hemostasis whereby a damaged blood vessel wall is covered by a fibrin clot that stops hemorrhaging and helps repair the damaged vessel. Disorders in coagulation can lead to increased hemorrhaging and / or thrombosis and embolism. During dialysis treatment, blood coagulation is inhibited with anticoagulants such as heparin.

Bloodlines

System of tubes connecting a patient’s blood circulation with a dialyzer during extracorporeal dialysis treatment.

Blood platelets (Thrombocytes)

The part of blood responsible for healing wounds. Blood platelets form clots and release substances into the blood to generate the body’s healing response.

Blood pressure

Pressure exerted by the blood on the walls of the blood vessels. Unless indicated otherwise, blood pressure is understood to mean arterial blood pressure, i.e. the pressure in the large arteries, such as the brachial artery (in the arm). The arterial pressure is higher than the pressure of the blood in other vessels.

Buffer

Substance that reduces pH changes that occur in a system during the introduction of an acid or a base.

Catheter

A flexible tube inserted through the skin into a blood vessel or cavity to draw out body fluid or infuse fluid. In peritoneal dialysis a catheter is used to infuse dialysis solution into the abdominal cavity and drain it out again.

CE certification

Proof of compliance with European Union directives for medical devices.

Chronic Kidney Disease

Slow and progressive loss of kidney function over several years, often resulting in permanent kidney failure. Since the renal function cannot be recovered, the patient has to be treated with renal replacement therapy, i.e. kidney transplantation or dialysis.

Clearance

A quantitative parameter to describe dialysis performance in terms of uremic toxin removal.

Composite rate

Medicare reimbursement rate for dialysis treatment.

Continuous Ambulatory Peritoneal Dialysis (CAPD)

A type of peritoneal dialysis treatment where the dialysis solution is exchanged manually, generally four times a day.

Dialysate

Fluid used in the process of dialysis.

Dialysis

Form of renal replacement therapy where a semipermeable membrane – in peritoneal dialysis the peritoneum of the patient, in hemodialysis the membrane of the dialyzer – is used to selectively filter solute from the patient’s blood into the dialysate.

Dialyzer

Special filter used in hemodialysis for removing toxic substances and excess water from the blood. The dialyzer is sometimes referred to as the “artificial kidney”.

Dialyzer membrane

Semipermeable barrier in the dialyzer to separate the blood from the dialysate.

Diffusion

An exchange in the chemical concentration of twofluids that are divided by a semipermeable membrane. The molecules move from one fluid to the other, with metabolic toxins being transferred through the membrane into the dialysate.

Disease Management

Integrated concept of patient care that takes into account all medical aspects of an illness.

Dry weight

Targeted optimal body weight of the patient, achieved by removing excess water during dialysis.

Dwell time

In peritoneal dialysis, this is the amount of time the dialysis solution remains in the patient’s abdominal cavity during an exchange.

End-Stage Renal Disease (ESRD)

Terminal kidney failure accompanied by long-term complications such as renal anemia, hypertension and other cardiovascular problems, as well as bone disease, loss of appetite and malnutrition (see also “Chronic Kidney Failure”).

Erythropoiesis-stimulating agents (ESA)

Recombinant human EPO that is commonly prescribed to patients on dialysis who suffer from anemia.

Erythropoietin (EPO)

Hormone that stimulates red blood cell production.

Extracorporeal

Situated or occurring outside the body.

FDA

The U.S. Food and Drug Administration.

Glomerular filtration rate (GFR)

The U.S. National Kidney Foundation categorizes kidney disease into five stages based on the glomerular filtration rate (GFR). The GFR indicates the volume of liquid that the kidneys filter from the blood per minute (primary urine). This ranges from more than 90 ml / min in healthy kidneys (stage 1) to less than 15 ml / min (stage 5) when dialysis or a kidney transplant is needed. Persons with stage 4 chronic kidney disease (CKD) have advanced kidney damage (GFR of 15 to 29 ml / min); it is highly likely that these patients will need dialysis or a kidney transplant in the near future.

Health Maintenance Organization (HMO)

Special form of private health insurance in the U.S. where the insured are members and treatment is provided by contract physicians (or member physicians) of the organization.

Hemodiafiltration (HDF)

Special type of ESRD treatment combining the advantages of hemodialysis and hemofiltration. High elimination rates are achieved for substances with small and large weight molecules via diffusive and convective mechanisms respectively.

Hemodialysis (HD)

ESRD treatment method where the patient’s blood flows outside the body through disposable bloodlines into a special filter, the dialyzer. The dialysis solution carries away waste products and excess water, and the cleaned blood is returned to the patient. The process is controlled by a hemodialysis machine that pumps blood, adds anticoagulants, regulates the purification process, and controls the mixing of the dialysis solution and its flow rate through the system. A patient typically receives three treatments per week, lasting from three to six hours each.

Hemofiltration (HF)

A type of ESRD treatment that does not use dialysate. The solutes are removed using convective forces to filter plasma water through a semipermeable membrane. Substitution fluid is used to replace the volume removed by filtration.

Hemoglobin

Substance in red blood cells that carries oxygen around the body.

Heparin

Universal anticoagulant substance that is administered during hemodialysis to inhibit blood coagulation during the dialysis treatment.

High-flux dialyzers

Dialyzers containing highly permeable membranes that allow for the effective removal of water and large uremic toxins such as β2-microglobulin.

Hypervolaemia

Increased blood volume.

Incidence

Number of patients who are newly diagnosed with a specific disease during a certain period of time.

ISO

International Standards Organization.

Kidney

Two kidneys are located at the rear of the abdominal cavity, one each on the right and left side of the spinal column. These vital organs are approximately 11 cm long and weigh only 160 grams each. The kidneys ensure a regulated acid-base balance by filtering excreta and producing urine. Approximately 1,700 liters of blood normally pass through the kidneys every 24 hours.

Kidney transplantation

A surgical procedure to implant a kidney from a donor.

Kt / V

Indicator to evaluate treatment quality. It is calculated by dividing the product of urea clearance (K) and the length of treatment (dialysis time, t) by the filtration rate of certain toxic molecules (the urea distribution volume in the patient, V)

Low-flux dialyzers

Dialyzers with low permeability, e. g. for water.

Medicare / Medicaid

A program developed by the federal U.S. Social Security Administration that reimburses health insurances and providers of medical services for medical care to individuals over 65, with ESRD or the disabled.

Medicare Modernization Act (MMA)

Reform of Medicare, the public health insurance system providing medical care for the elderly as well as dialysis patients without private insurance. The reform affects the composite payment rates for the treatment of end-stage renal disease patients and became effective in 2005.

Membrane permeability

An indication of the “openness” of a dialyzer membrane for blood or dialysis fluid constituents.

Osmosis

Passage of water from the blood through a semipermeable membrane. In osmosis, as opposed to diffusion, molecules move only in one direction.

Peritoneal dialysis (PD)

Dialysis treatment method using the patient’s peritoneum, i.e. the tissue that covers the inner surface of the abdominal cavity and the abdominal organs, as the dialyzing membrane for blood purification. A sterile dialysis solution is introduced and removed through a catheter that has been surgically implanted into the patient’s abdominal cavity. The solution absorbs toxins and excess water. Most treatments are supported by a machine, the cycler, and are administered by the patients in their home or workplace several times a day or during the night.

Plasma

Liquid part of the blood containing water, proteins and other substances such as electrolytes and hormones. Blood cells are not part of the plasma.

Polysulfone

A polymer used to produce dialyzer membranes. It is characterized by extreme thermal stability, chemical resistance and blood compatibility.

Prevalence

Number of all patients who suffer from a specific disease during a certain period of time.

Transplantation

Taking an organ or tissue from the body and grafting it into another area of the same body or into another individual.

Ultrafiltration

The convective transport of solutes through a dialyzer or hemofilter membrane due to a decrease in hydrostatic pressure.

Ultrafiltration rate

Rate of fluid removal from the patient’s blood circulation measured in ml / min. This rate has to be chosen carefully. If the rate is too high, the cardiovascular stability of the patient is put at risk; if it is too low, the patient’s excess water cannot be removed.

Vascular access (Shunt)

Method to connect a patient’s blood circulation to the dialyzer. The vascular access must enable sufficient blood flow and connection to the dialyzer as often as necessary, normally three times a week. Adequate vascular access is a prerequisite for hemodialysis. The early recognition of problems during vascular access is essential for the blood to flow.

Vein

A blood vessel that carries blood to the heart.

Xenotransplantation

Transplantation of tissues or organs from one species to another.