RRB Dialysis Technician key terms

The volume of plasma filtered by the glomeruli per unit time, normally about 125 mL/min. A falling GFR marks declining kidney function and helps stage chronic kidney disease and time dialysis initiation.

The microscopic functional unit of the kidney, comprising a glomerulus and its tubule. Each kidney holds roughly one million nephrons, which filter blood, reabsorb useful solutes and water, and secrete wastes into urine.

The process by which filtered water, electrolytes, glucose and amino acids move from the tubular lumen back into peritubular blood. Most reabsorption occurs in the proximal tubule, conserving substances the body needs to keep.

The arrangement of the loop of Henle and vasa recta that builds and preserves a concentrated medullary gradient. This gradient lets the collecting duct reabsorb water under antidiuretic hormone control, setting urine concentration.

A hormone produced mainly by peritubular kidney cells that stimulates red blood cell production in bone marrow. Injured kidneys make too little, so anemia is a common complication of advanced kidney failure.

Kidney damage or reduced filtration persisting at least three months, staged by GFR and albuminuria. Progressive loss of function leads to uremic symptoms and the need for kidney replacement therapy.

The clinical syndrome caused by retention of nitrogenous wastes and other toxins when kidney function fails. Features include nausea, itching, fatigue, confusion and, in severe cases, pericarditis or encephalopathy.

A sudden decline in kidney function over hours to days, shown by rising creatinine or falling urine output. Causes are grouped as prerenal, intrinsic renal and postrenal, and dialysis may be needed temporarily.

Movement of dissolved particles from an area of higher concentration to lower concentration through a semipermeable membrane. In dialysis it clears small solutes such as urea and potassium from blood into dialysate.

Passage of water across a semipermeable membrane from a region of lower solute concentration to higher solute concentration. Dialysate sodium and glucose levels are set to prevent unwanted water shifts during treatment.

Removal of plasma water across the dialyzer membrane driven by a pressure gradient. The rate is controlled by the prescription and determines how much fluid weight the patient loses per session.

The average pressure difference between the blood and dialysate sides of the dialyzer membrane. Raising TMP increases ultrafiltration; clotting or resistance in the circuit can change the delivered dose.

The volume of blood fully cleared of a solute per unit time, expressed in milliliters per minute. It reflects dialyzer efficiency and blood and dialysate flow rates for a given solute.

A dimensionless measure of dialysis dose: clearance (K) times treatment time (t) divided by urea distribution volume (V). Higher values indicate more urea removal and are linked to better outcomes.

The percentage fall in blood urea nitrogen across a dialysis session, calculated from pre- and post-treatment samples. It is a simpler alternative to Kt/V for judging delivered dose.

A therapy in which blood is pumped through an extracorporeal circuit and a dialyzer while dialysate flows on the other side of the membrane. Solutes diffuse out and excess fluid is removed by ultrafiltration.

A home therapy using the peritoneal membrane as the filter. Sterile dialysate is instilled through a catheter, dwells to allow exchange, then drains, and can be done continuously or in cycles.

A modality combining diffusive clearance with high-volume convective removal of fluid through a high-flux membrane, with replacement fluid given to the patient. It removes larger middle molecules than standard hemodialysis.

The artificial kidney device holding thousands of hollow fibers through which blood and dialysate flow on opposite sides of a semipermeable membrane. Surface area and flux rating determine its clearance performance.

A fluid made from treated water and concentrate that flows past the dialyzer membrane. Its electrolyte, acid and bicarbonate composition is set to correct blood chemistry without causing harm.

A water purification step in which pressure forces water through a semipermeable membrane, rejecting dissolved salts, bacteria and most contaminants. It produces the purified water used to mix dialysate.

The chain of filtration, softening, carbon adsorption, reverse osmosis and monitoring that prepares water for dialysate. Poor treatment can expose patients to bacteria, endotoxin or chemical contaminants.

The site through which blood is removed and returned during hemodialysis, such as an arteriovenous fistula, graft or central venous catheter. Reliable access is essential to deliver adequate treatment.

A surgical connection between an artery and a vein, usually in the forearm, that enlarges the vein so it can carry high blood flow. It is the preferred access because it lasts longer and infects less often.

The palpable vibration and audible rushing sound produced by blood flowing through a functioning fistula or graft. Loss of either suggests stenosis or clotting and needs prompt assessment.

A cannulation method in which needles are repeatedly placed into exactly the same fistula track, creating a stable tunnel. It can reduce pain and infiltration but requires strict aseptic care and consistent staff.

The return of already dialyzed blood directly back into the arterial needle without passing through the body. High recirculation lowers delivered clearance and often signals stenosis or needle malposition.

The body weight at which a patient is free of excess fluid yet not dehydrated, judged by symptoms and blood pressure. It guides the ultrafiltration goal for each session.

Excess body water causing weight gain, swelling, breathlessness and raised blood pressure. It results from inadequate ultrafiltration or high salt and fluid intake between treatments.

A fall in blood pressure during treatment, with dizziness, cramping, nausea or yawning. Common causes include rapid ultrafiltration, eating during treatment and impaired cardiac reserve.

A complication of rapid dialysis in which urea falls faster in blood than in brain, drawing water into brain cells. Symptoms range from headache and vomiting to seizures and coma, and prevention is by slower treatment.

Entry of air into the vascular system, usually from a loose connection or empty infusion line. Signs include sudden breathlessness, chest pain and collapse, and the emergency response is to stop the pump and position the patient appropriately.

Infection of the peritoneal cavity, the most serious complication of peritoneal dialysis. Cloudy effluent, abdominal pain and fever require prompt culture and antibiotic treatment.

Infection control practices applied to every patient regardless of diagnosis, including hand hygiene, gloves, gowns, eye protection and safe sharps handling. They reduce transmission of bloodborne pathogens in the dialysis unit.

Cleaning hands with soap and water or alcohol-based rub at defined moments, such as before and after patient contact and after removing gloves. It is the single most effective way to prevent dialysis-related infection.

Immunization against hepatitis B, recommended for all dialysis patients and staff because of high exposure risk. Antibody levels are checked periodically and booster doses given when protection wanes.

A specialist who assesses nutritional status and designs eating plans limiting sodium, potassium, phosphorus and fluid while meeting protein needs. Dietary counseling supports adequacy and reduces complications.

A medication taken with meals that binds dietary phosphorus in the gut so it is not absorbed. It helps prevent bone disease and vascular calcification in dialysis patients.

A blood potassium level above normal, dangerous because it can cause fatal cardiac arrhythmias. In dialysis patients it usually reflects dietary excess, missed treatments or certain medications.

An ongoing team process of measuring performance, identifying causes of shortfalls and testing changes to improve care. Dialysis units use it to track indicators such as adequacy, infection and anemia control.

A measurable marker of care quality, such as Kt/V, catheter infection rate or fistula use, tracked over time and compared with targets. Results guide improvement work and regulatory reporting.

The structured recording of adverse events and near misses, including needlestick injuries and machine faults, so causes can be analyzed and prevented. Reporting should be blame-free to encourage disclosure.

A patient's voluntary agreement to treatment after receiving understandable information about benefits, risks and alternatives. It must be obtained before procedures such as access surgery or modality changes.

The duty to protect personal health information from unauthorized access or disclosure. Staff discuss cases only with those involved in care and follow unit and legal privacy rules.

A collaborative process in which clinicians explain options and the patient's values and preferences shape the chosen plan. It is central when selecting dialysis modality or access type.