Internal Medicine - Renal System

Internal Medicine - Renal System

Discussion at a Dialysis Clinic

Mr. Smith is a 50 year old man who has recently commenced hospital hemodialysis having developed end-stage renal disease secondary to ADPKD. He has an arteriovenous fistula in place and attends for four-hourly dialysis sessions on a Monday, Wednesday and Friday at his local unit.

Parameters for Adequacy of Dialysis

The early investigators and nephrologists were surprised at the miraculous outcomes of therapeutic hemodialysis in sustaining life indefinitely. The dialysis aims to optimize both the duration, as well as, the quality of life. The single most accurate parameter for measuring the adequacy of dialysis is via Uremia, which is defined as a clinical syndrome due to renal failure. Hemodialysis produces its therapeutic effects by the diffusive removal of small solutes across a semi-permeable membrane (Depner, 2005, pp. 241-254). Thus, the concentration of urea is the most effective and accurate parameter to evaluate the adequacy of hemodialysis in the patient.

Laboratory parameters considered by Dialysis Team

Some other laboratory parameters that will be considered by the Dialysis team comprise of URR and Kt/V. URR refers to urea reduction ratio, which measures the removal of urea from the blood via hemodialysis. It is frequently expressed as a percentage, with the recommended minimum of 65%. However, URR is likely to vary considerably from treatment to treatment. Hence, a single value may not be of high concern. URR is measured once after 12-14 treatments.

Kt/V is another method of measuring dialysis adequacy. K (mL/min), in the measurement, refers to dialyzer clearance, which is the rate of blood passing through the dialyzer, and t is time. So, Kt represents the volume of fluid cleared from urea in one treatment. On the other hand, V stands for the total volume of water contain in the patient's body (Hemodialysis Dose and Adequacy, n.d.).

Parameters for Adequacy of Dialysis

In the earlier times, researchers and nephrologists were quite amazed at the several positive results from the therapeutic hemodialysis, in patients of renal failure. For such a complex organ as kidney, who could have thought that replacement with a simple diffusive removal of solutes from the blood can prove miraculous outcomes, and be an excellent educational resource. The goal of hemodialysis is to produce optimal duration, as well as, quality of life for renal failure patients, such as Mr. Smith. For the nephrologists, the principal parameter to measure an accurate dialysis adequacy is through the levels of urea in the bloodstream. Urea is the most toxic substance with drastic consequences, associated with renal failure. Uremia, defined as the clinical syndrome, results from the accumulation of urea, and the associated small solutes, in the blood. The relationship between uremia and renal diseases was not well-comprehended till dialysis reversed the syndrome. Uremia may lead to a toxic state, which is life-threatening. Hemodialysis is beneficial therapeutically due to its characteristic diffusive removal of small solutes across a semi-permeable membrane (Depner, 2005, pp. 241-254). Hence, the most effective and accurate parameter to check the ...