Hemodialysis Units, Renal, Continuous Replacement Therapy
Definition : Hemodialysis units designed for the continuous replacement of the main activity of the kidneys by removing water and wastes at a slow and steady rate (i.e., continuous renal replacement therapy [CRRT] machines). Blood is removed via an extracorporeal circuit, using either arteriovenous access (typically femoral artery to femoral vein) or a venous-venous access (e.g., jugular, femoral, subclavian vein), passed through an extracorporeal dialyzer that allows the transfer of substances usually by diffusion to decrease biochemical abnormalities as well as fluid, electrolyte, and acid-base imbalances; and returned to the patient (i.e., a hemodialysis procedure). These units frequently have capabilities to perform other procedures, such as filtration and fluid replacement (usually calcium and lactate) by convection (hemofiltration) and a combination of hemodialysis and fluid replacement by diffusion and convection (hemodiafiltration). CRRT unit's main components are usually a dialysate-delivery system that delivers the previously prepared dialysate solution from a bag to the dialyzer, the extracorporeal blood-delivery circuit that slowly circulates a portion of the patient's blood through the dialyzer and returns to the patient, a disposable dialyzer with specialized membrane filters in which solute exchange takes place, and devices to perform fluid replacement. Each component has its own monitoring and control circuits. Continuous renal replacement units are intended for temporary continuous partial replacement of renal functions in hemodynamically unstable patients with acute renal failure and excess urea in blood (i.e., uremia, also known as azotemia) and/or fluid overload; they are also used for the treatment of other critical diseases, such as refractory pulmonary edema, pericarditis, hypothermia, or poisonings with a dialyzable toxin.
Entry Terms : "Hemodialysis Units, Continuous Replacement Therapy" , "Continuous Renal Replacement Therapy Units" , "CRRT Units"
UMDC code : 23426