Hemoperfusion is a medical procedure which is used to cleanse the blood of toxins. During this process the blood is passed through an adsorbent material which attracts toxic substances. The adsorbent material is usually charcoal or activated carbon fixed to a solid surface inside a column. During treatment, the patient’s blood is passed through the column and toxins bind to the adsorbent material, allowing cleansed blood to flow out of the column. This process continues until as much toxic material as possible has been removed from the blood.
Hemoperfusion is usually carried out for one of three reasons. First, this process is used as a supportive treatment for people who are undergoing a liver transplant. Before and after the transplant itself, patients undergo blood cleansing so that the newly-transplanted liver is not overburdened. Hemoperfusion is also a type of dialysis, which is used as a supportive treatment for people with kidney failure. Finally, the procedure is used as an emergency medical treatment in cases where a patient has ingested a large amount of a substance which is toxic to the kidneys, such as barbiturates. In this instance the blood is cleansed to prevent acute kidney failure.
Hemoperfusion can successfully remove toxins or waste products which are present in a patient’s blood. In some cases, however, the toxins or waste products have left the blood and entered the tissues. If this occurs, this type of treatment cannot remove all the toxins, and kidney damage or other symptoms of toxicity may still occur. This is a common problem with tricyclic antidepressant overdoses, where treatment can remove most of the drug from the bloodstream, but by the time it is carried out a large amount of the drug has already entered the tissues.
The hemoperfusion process can take up to three hours. At the start of the treatment, the patient is fitted with two catheters: one is placed in an artery in the arm, and the second is placed in the closest large vein in the same arm. Both catheters are connected to the treatment unit, which includes the column of adsorbent material, and the catheter inserted in the vein is also connected to a blood pressure monitor. Throughout treatment, the patient is given small doses of heparin to prevent blood clotting.
There are some risks and side effects involved with this process. Although regular doses of heparin are given throughout the procedure, blood clotting is still a potential problem. In addition, the heparin can increase the risk of uncontrolled bleeding for a short time after the treatment. Infection is a risk if equipment is not sterilized adequately; however as long as treatment is carried out by someone who is properly qualified, this risk is minimal.