Hemodialysis I: Introduction

Hemodialysis filters waste, excess fluids, and toxins from the blood using a semipermeable membrane in a dialyzer while preserving essential components like blood cells.

It requires vascular access to allow rapid blood flow, usually achieved through an arteriovenous fistula or AVF.

AVF is surgically created by connecting an artery, such as the radial or brachial artery, to a vein, typically the cephalic or basilic vein.

This connection makes the vein enlarge and strengthen, a process called maturation, which usually takes 6 to 12 weeks.

Once the AVF has matured, two large-bore needles, usually 14 to 16 gauge, are inserted into the vein during dialysis to allow blood to flow in and out of the body.

If an AVF cannot be created due to vascular issues, such as peripheral vascular disease, an arteriovenous graft, or AVG, may be used.

AVGs are synthetic polytetrafluoroethylene tubes surgically placed beneath the skin to attach an artery to a vein.

They can be used within 2 to 4 weeks but carry a higher risk of complications, like infection and thrombosis.