Infomed Index

Acute disease

An acute disease is characterized by a rapid onset and/or a short duration. In medicine it can lead to severe, or lethal, clinical situations.

Apheresis

Greek means removal. It is a method consisting in circulating the blood outside of the person and removing one of its constituent. Apheresis can be done on donors, for example to collect platelets, or on patients in which case it is named therapeutic apheresis.

Blood purification

This term defines any therapeutic apheresis technique which allows cleaning some of the blood constituents in order to obtain a clinical improvement of the patient. For example hemodialysis, hemofiltration and plasma exchange are blood purification techniques.

Chronic disease

A chronic disease is slowly progressing and long-lasting. It can be continuously present or recurrent in which case relapse and remission phases will come one after the other.

Convection – filtration

The convective, or filtration, process is the migration of substances across a semi-permeable membrane from the side having the higher pressure to that of lower pressure.

Dialysate

The dialysate is the fluid injected on the outside other than blood of the small tubes (capillaries) made of a semi-permeable membrane inside which the blood flows in order to obtain a diffusion process.

Diffusion - osmosis

The diffusion, or osmotic, process is the migration of substances across a semi-permeable membrane from the side having the higher concentration to that of lower concentration of that substance.

Disposables

A disposable medical device is one which is used only once and then discarded.

Hemofilter

A hemofilter is a filter containing a semi-permeable membrane having a pore size of 0.5-1 nm which allows water and solutes to pass through and retains most of the proteins and in particular albumin.

Plasma

Plasma is the yellow watery part of the blood. It contains no cells but water, proteins and solutes.

Plasmafilter

A plasmafilter is a filter containing a semi-permeable membrane having a pore size of 400-500 nm which allows water, solutes and proteins to pass through and retains the red and white cells as well as the platelets.

Plasmapheresis

Plasmapheresis is an apheresis in which the whole plasma is removed from blood. The term is often used for methods where only some plasma constituents are removed or where the removed plasma is replaced by a substitution fluid.

Plasma fractionator

A plasma fractionator is a filter containing a semi-permeable membrane having a pore size of 10-30 nm which allows water, solutes and the smaller proteins such as albumin to pass through and retains larger ones such as LDL-cholesterol, fibrinogen and antibodies.

Single needle

A single needle blood access uses a single puncture. The blood circulation is obtained by cycles which starts by pumping the blood and accumulating it inside an expansion chamber and continues by the return of this blood to the patient.

Ultrafiltrate

The ultrafiltrate is the fluid filtrated through a hemofilter. Its content is close to that of urine.