Hemoperfusion | |
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MeSH | D006464 |
Hemoperfusion orhæmoperfusion (seespelling differences) is a method of filtering theblood extracorporeally (that is, outside the body) to remove atoxin. As with other extracorporeal methods, such ashemodialysis (HD),hemofiltration (HF), andhemodiafiltration (HDF), the blood travels from the patient into a machine, gets filtered, and then travels back into the patient, typically by venovenous access (out of avein and back into a vein).
In hemoperfusion, the blood perfuses a filter composed ofartificial cells filled withactivated carbon or anothermicroporous material. Smallmolecules insolution within theserum (such as the toxin) cross the membranes into the microporous material (and get trapped therein), but formed elements (theblood cells) brush past the artificial cells just as they brush past each other. In this way, the microporous material's filtering ability can be usedwithout destroying the blood cells.
First introduced in the 1940s, hemoperfusion was refined during the 1950s through 1970s, and then introduced clinically for the treatment ofpoisoning in the 1970s and 1980s. It is sometimes used to treatdrug overdose, sometimes in conjunction with the other extracorporeal techniques previously mentioned.[1]
The USFood and Drug Administration (FDA) defines sorbent hemoperfusion as follows:
″(a) Identification. A sorbent hemoperfusion system is a prescription device that consists of an extracorporeal blood system similar to that identified in the hemodialysis system and accessories (876.5820) and a container filled with adsorbent material that removes a wide range of substances, both toxic and normal, from blood flowing through it. The adsorbent materials are usually activated-carbon or resins which may be coated or immobilized to prevent fine particles entering the patient's blood. The generic type of device may include lines and filters specifically designed to connect the device to the extracorporeal blood system. The device is used in the treatment of poisoning, drug overdose, hepatic coma, or metabolic disturbances.″[2]
Hemoperfusion is also used in the treatment of specific intoxications, such asvalproic acid,theophylline, andmeprobamate.[3][4]
Despite its availability, this technique is only infrequently utilized as a medical process used to remove toxic substances from a patient's blood.[5]
Two types of hemoperfusion are commonly used:[citation needed]
Complications of hemoperfusion may includethrombocytopenia,leucopenia,hypoglycemia, and some reduction in clotting factors, with recovery typically occurring in 1–2 days. Risk of bleeding is also higher because of the high heparin dose and reduction in platelets and clotting factors.[6]
During hemoperfusion, the blood passes through a column with absorptive properties aiming at removing specific toxic substances from the patient's blood. It especially targets small- to medium-sizedmolecules that tend to be more difficult to remove by conventionalhemodialysis. The adsorbent substance most commonly used in hemoperfusion are resins andactivated carbon.[7] Hemoperfusion is anextracorporeal form of treatment because the blood is pumped through a device outside the patient's body.[citation needed]
Its major uses include removingdrugs orpoisons from the blood in emergency situations, removing waste products from the blood in patients withkidney failure, and as a supportive treatment for patients before and afterliver transplantation.[8]