Dialysis vs Hemodialysis | Peritoneal dialysis vs Hemodialysis
One of the most appreciated inventions in the field of medicine is the dialysis machines and the principles involved in dialysis. Here a person, who has acute or chronic renal failure requires the excess harmful metabolites to be removed from the body, lest cause complications of excess potassium, urea, water, acids, etc. Before the advent of the dialysis techniques, it would have meant certain death. But, these equipments have made it possible to ride the worst of acute renal failure out, or to patiently wait for a donor kidney to be transplanted. Here, we will discuss the principles involved in dialysis and hemodialysis, and the benefits and risks of each of these procedures.
Dialysis
Dialysis, works on the principles of diffusion of solutes and ultra filtration across a semi permeable membrane. In diffusion, solutes of a higher concentration transport itself to a volume of solutes with a lower concentration. This works on the counter current principle, with blood travelling in one direction and dialysate travelling in the opposing direction, so that the harmful metabolites can diffuse from blood to the dialysate, and the deficient solutes can diffuse from dialysate into the blood. There are two main forms of dialysis. One is hemodialysis, which will be discussed in a while, and the other one is peritoneal dialysis. In peritoneal dialysis, the peritoneal membrane is used as the semi permeable membrane, with the dialysate allowed to stay there for about 20 minutes before it is removed from the body. The principle of dialysis is used in acute and chronic renal failure. This causes reduction in morbidity and mortality. Risks involved in these procedures include, hypovolemia, bleeding, infection, myocardial infarction, hyperkalemia, etc.
Hemodialysis
Hemodialysis, is a component of the dialysis principles, and a mechanized system used to perform the dialysis. An artificial semi permeable membrane is there, and using the principles of diffusion and counter current flow, this form of dialysis is implemented. One disadvantage of this technique is the requirement of a vascular access, either through a catheter or an arteriovenous fistula. But, this reduces the morbidity and mortality, and only requires dialysis for four hours every couple of days. But there has to be access to a dialysis centre, which is capable of managing any complications and with continued monitoring. A personal use hemodialyser is very expensive, and requires proper maintenance as well. The side effect profile is almost the same as before, with infections being specific to the bone and heart. Risk of bleeding is high due to the use of heparin.
What is the difference between Dialysis and Hemodialysis?
When you consider both these techniques, they both have the same basic principle. Dialysis, itself is an umbrella term, which includes all the techniques, along with hemodialysis. Thus, dialysis may involve peritoneal or hemodialysis. So the complete level of risks is higher in dialysis than in hemodialysis. But hemodialysis requires a vascular access, which peritoneal dialysis doesn’t require. Hemodialysis is associated with greater bleeding and hypovolemia with hyperkalemia than in peritoneal dialysis. Peritoneal dialysis can be done even in a small ward, but hemodialysis requires sophisticated equipment and other requirements. Hemodialysis can be done for 4 hours once in 3 days, but peritoneal dialysis is sometimes needed regularly. The effectiveness of hemodialysis is greater than peritoneal dialysis.
In summary, hemodialysis is the best method in a pre planned, equipped setting in preparation for a kidney transplant, whereas peritoneal dialysis is better in an emergency, poorly equipped, chronic patient.