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Skip to 0 minutes and 11 seconds Mechanisms of kidney dialysis Essentially, it’s a passive diffusion process. Since it also removes water by ultrafiltration. The filtrate may also contain some small molecule solutes. Dialysis equipment. Hemodialysis uses a hemodialyzer or the so called artificial kidney. On the other hand, peritoneal dialysis uses patient’s own peritoneum as the dialysis membrane. Let’s look at the setup of hemodialyzer. Arterial blood is siphoned into this arterial line to the hemodialyzer. Coming out of the hemodialyzer and returning to the venous or the vein of the patient through the venous line. If we look at this picture, it will show more clearly the process of hemodialysis. The blood is out of the artery. Here is a pump that determined the blood flow rate.

Skip to 1 minute and 36 seconds The line must be injected anticoagulant from time to time in order to prevent clotting. Entering into the hemodialyzer, out of the hemodialyzer. And before the blood is return to the vein, the air bubble must be removed. Here is the heart of the hemodialysis machine, that is the hemodialysis cartridge. Here the blood is in, the blood is out. The dialysis solution is in and the dialysis solution is out. And then solutes exchange takes place in the semipermeable membrane of the cartridge. Vascular access. That is how do we access the vascular system. The first is A-V fistula. A-V fistula is suitable for patient with large veins. A-V fistula lasts longer. It’s less likely to develop a clotting or infection. Graft.

Skip to 2 minutes and 54 seconds Graft is suitable for patient with smaller veins and it is an implant. The graft could have more problems compared with A-V fistula in terms of clotting and infection. And therefore need to be replaced more frequently. Catheter. Catheter is usually a temporary setup, for example for use in the drug detoxification situation. The catheter can clog, can become infected and therefore it is more problematic and then need to be replaced most frequently. The A-V fistula. Essentially, it’s the connection of the artery and the vein to let out the blood going through the dialyzer and returning to the vein of the patient. And a surgeon is needed to place the A-V fistula usually weeks or even months before hemodialysis starts.

Kidney Dialysis Equipment : Vascular Access

In this step, Prof. Lee illustrates the mechanisms of kidney dialysis and dialysis equipments.

To begin with, there are two mechanisms of kidney dialysis: passive diffusion and ultrafiltration.

Besides, there are two main dialysis methods: hemodialysis and peritoneal dialysis. For peritoneal dialysis, patients use their own peritoneum as the dialysis membrane.

By the clear equipment diagram, we can easily know how to set up.

In hemodialysis cartridge, there are three kinds of flow configuration: concurrent, counter-current, and crosscurrent.

Finally, we need to know there are three kinds of vascular access, including A-V fistula, Graft, and Catheter. Please notice their differences.

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This video is from the free online course:

Pharmacokinetics: Drug Dosing in Renal Disease

Taipei Medical University