Final answer:
Middle molecule clearance in dialysis is evaluated using specific markers to determine the dialysis membrane efficiency. Substances like vitamin B12 are often employed for this purpose. The clearance of substances such as urea is measured to assess dialysis machine performance.
Step-by-step explanation:
A marker used to determine the middle molecule clearance of a dialyzer is a specific molecule that can be detected and measured to assess how well the dialyzer is removing molecules of similar size from the blood during dialysis. In clinical practice, substances like vitamin B12, which is a middle molecule, are frequently used as markers to evaluate the performance of dialysis membranes.
Dialysis is a medical procedure that uses a semipermeable membrane to remove waste products, excess water, and toxins from the blood when the kidneys are not functioning properly. The efficiency of a dialysis machine can be assessed by measures such as clearance tests, which indicate how effectively the machine removes certain substances from the blood.
The clearance of a substance, when related to hemodialysis, refers to the volume of plasma from which the substance is completely cleared per unit of time during the dialysis process. For example, the urea clearance test calculates how quickly urea is removed from the blood based on urine volume and urea concentration in the urine. This is instrumental in monitoring the adequacy of the dialysis treatment.