Question

A patient with advanced renal failure is waiting for a suitable kidney donor for a transplantation operation. His blood urea nitrogen level is high and he is developing some of the signs of uraemia. What method can you adopt to keep this patient alive until a suitable donor can be found?

Answer 1

Hemodialysis can be used to keep the patient alive until a suitable donor can be found.

Malfunctioning of kidneys can lead to accumulation of urea in blood, a condition called uremia, which is highly harmful and may lead to kidney failure. In such patients, urea can be removed by a process called hemodialysis. Blood drained from a convenient artery is pumped into a dialysing unit after adding an anticoagulant like heparin. The unit contains a coiled cellophane tube surrounded by a fluid (dialysing fluid) having the same composition as that of plasma except for the nitrogenous wastes. The porous cellophane membrane of the tube allows the passage of molecules based on a concentration gradient. As nitrogenous wastes are absent in the dialysing fluid, these substances freely move out, thereby clearing the blood. The cleared blood is pumped back to the body through a vein after adding anti-heparin to it.