A Lil' Boy's Journey to Live….

Archive for March, 2010

Plasmapheresis

Plasmapheresis

Definition

Plasmapheresis is a blood purification procedure used to treat several autoimmune diseases. It is also known as therapeutic plasma exchange.

Purpose

In an autoimmune disease, the immune system attacks the body’s own tissues. In many autoimmune diseases, the chief weapons of attack are antibodies, proteins that circulate in the bloodstream until they meet and bind with the target tissue. Once bound, they impair the functions of the target, and signal other immune components to respond as well.

Plasmapheresis is used to remove antibodies from the bloodstream, thereby preventing them from attacking their targets. It does not directly affect the immune system’s ability to make more antibodies, and therefore may only offer temporary benefit. This procedure is most useful in acute, self-limited disorders such as Guillain-Barré syndrome, or when chronic disorders, such as myasthenia gravis, become more severe in symptoms. In these instances, a rapid improvement could save the patient’s life. Neurologic diseases comprise 90% of the diseases that could profit from plasmapheresis.

Precautions

Patients with clotting disorders may not be suitable candidates for plasmapheresis.

Description

The basic procedure consists of removal of blood, separation of blood cells from plasma, and return of these blood cells to the body’s circulation, diluted with fresh plasma or a substitute. Because of concerns over viral infection and allergic reaction, fresh plasma is not routinely used. Instead, the most common substitute is saline solution with sterilized human albumin protein. During the course of a single session, two to three liters of plasma is removed and replaced.

Plasmapheresis requires insertion of a venous catheter, either in a limb or central vein. Central veins allow higher flow rates and are more convenient for repeat procedures, but are more often the site of complications, especially bacterial infection.

When blood is outside the body, it must be treated to prevent it from clotting. While most of the anticlotting agent is removed from the blood during treatment, some is returned to the patient.

Three procedures are available:

  • "Discontinuous flow centrifugation." Only one venous catheter line is required. Approximately 300 ml of blood is removed at a time and centrifuged to separate plasma from blood cells.
  • "Continuous flow centrifugation." Two venous lines are used. This method requires slightly less blood volume to be out of the body at any one time.
  • "Plasma filtration." Two venous lines are used. The pasma is filtered using standard hemodialysis equipment. It requires less than 100 ml of blood to be outside the body at one time.

A single plasmapheresis session may be effective, although it is more common to have several sessions per week over the course of two weeks or more.

Preparation

Good nutrition and plenty of rest make the procedure less stressful. The treating physician determines which of the patient’s medications should be discontinued before the plasmapheresis session.

Aftercare

The patient may experience dizziness, nausea, numbness, tingling, or lightheadedness during or after the procedure. These effects usually pass quickly, allowing the patient to return to normal activities the same day.

Risks

Reinfusion (replacement) with human plasma may cause anaphylaxis, a life threatening allergic reaction. All procedures may cause a mild allergic reaction, leading to fever, chills, and rash. Bacterial infection is a risk, especially when a central venous catheter is used. Reaction to the citrate anticoagulant used may cause cramps and numbness, though these usually resolve on their own. Patients with impaired kidney function may require drug treatment for the effects of citrate metabolism.

Plasma contains clotting agents, chemicals that allow the blood to coagulate into a solid clot. Plasma exchange removes these. Bleeding complications are rare following plasmapheresis, but may require replacement of clotting factors.

Normal results

Plasmapheresis is an effective temporary treatment for:

  • Guillain-Barré syndrome (an acute neurological disorder following a viral infection that produces progressive muscle weakness and paralysis)
  • Myasthenia gravis (an autoimmune disease that causes muscle weakness)
  • chronic inflammatory demyelinating polyneuropathy (a chronic neurological disorder caused by destruction of the myelin sheath of peripheral nerves, which produces symptoms similar to Guillain-Barré syndrome)
  • thrombotic thrombocytopenic purpura (a rare blood disorder)
  • Paraproteinemic peripheral neuropathies (a neurological disorder affecting the peripheral nerves)
  • blood that is too thick (hyperviscosity)

Other conditions may respond to plasmapheresis as well. Beneficial effects are usually seen within several days. Effects commonly last up to several months, although longer-lasting changes are possible, presumably by inducing shifts in immune response.

Resources
Books

Samuels, Martin, and Steven Feske, editors. Office Practice of Neurology. New York: Churchill Livingstone, 1996.

Key terms

Anaphylaxis — Also called anaphylactic shock, it is a severe allergic reaction to a foreign substance that the patient has had contact with. Penicillin is an example of a substance that causes severe allergic reactions for some people.

Antibody — Chemicals produced by the body to defend it against bacteria, viruses, or other cells foreign to the body (antigens). Each specific antibody reacts against a specific foreign body. Antibodies are also termed immunoglobulins.

Autoimmune — Autoimmune refers to the body’s development of intolerance of the antigens on its own cells.

Hemodialysis — A method to take out unwanted parts of the blood. The patient’s blood is run through a catheter and tubing into a machine called a dialyzer, which filters out the unwanted blood component.

Plasma — Plasma makes up 50% of human blood. It is a watery fluid that carries red cells, white cells, and platelets throughout the body.

Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.


plasmapheresis /plas·ma·phe·re·sis/ (plaz″mah-fĕ-re´sis) the removal of plasma from withdrawn blood, with retransfusion of the formed elements into the donor; generally, type-specific fresh frozen plasma or albumin is used to replace the withdrawn plasma. The procedure may be done for purposes of collecting plasma components or for therapeutic purposes.

Dorland’s Medical Dictionary for Health Consumers. © 2007 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

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3/12/10

I spoke to CHOP yesterday regarding Riley’s blood test last week.  Some of the antibody levels came down on their own.  They are not where they need to be for transplant so this is the plan…… CHOP went into Riley’s profile in the Organ Donor Sharing Network and took the antibodies he has out.  The hope being that it will bring more offers that maybe we weren’t getting because of the antibodies.  When an offer comes in…if the donor has the antibodies we will, at that time, go to CHOP and do a Plasmapheresis.  That will clean his blood of the antibodies.  After that he will go in for transplant!  CHOP has never done a Plasmapheresis right before transplant, but with Riley there are alot of things that are different!  Of course I asked if there was risk doing it before transplant, and I was told ANYTHING they do with Riley is risky!  So that’s the plan, right now, as far as the Plasmapheresis goes!

I also spoke to Pulmonary about what the doc told me last wk about the 3-6 months.  They were NOT happy that it was said!  I never really got answer as to if they agree or not, but throwing out numbers like that is not something they like to do.  Dr. Hanna, Riley’s Cardiac Transplant doc, will be back from vaca next week and I will talk to him!  First about what the other doc said, and then about what’s next!  We have nothing scheduled right now!  We are just waiting for the pager to go off!!  SUCKS!  If we are not going to do a Cath, though, we need to do something even if its more frequent echoes.  They aren’t very reliable, but they have to be better then nothing!

The next phase of waiting could possibly be getting admitted to CHOP.  Most children waiting for a heart are inpatient, but Riley has had an exemption to stay home.  Hopefully we will get an offer before the day comes when Riley has to wait in the hospital!

Also…..I asked what would happen if Riley had NO veins left.  I knew the answer, but wanted to check.  Riley would be put on ECMO.  ECMO is bypass, and not a long term answer, but it’s one last hope before nothing!  If he is on ECMO to long, though, his other organs will start to fail, and we’ll have to make a decision that I hope we NEVER have to make!  They did discuss apparently at length on Monday, though, that they would do whatever was necessary to keep one vein open.  Even if it meant ballooning it every other day!  I guess at that point the risk for the Cath goes out the window!  Hopefully, though, like ECMO we will not get to that point!!

Sooo……..we wait…..pray!!!

3/8/10

Riley had appts. last Thursday at CHOP to see the Transplant doctors.  Everything went fine, except for the conversations that took place!  Riley WILL NOT have a Cath. in 2 wks as originally thought.  We already knew that Riley was at high risk during Caths, but with the progression of his disease he is at EXTREME high risk for well….death!  So now we will depend on his echos and pulse ox to determine if he truly needs a Cath.  That’s a little scary for me because for 23 months of his life either have been dependable.  There is no good answer here except for transplant, and even that is not a perfect answer, but its the only hope we have! 

I told the doc it made me nervous not to do the Cath, because we can’t afford for another vein to disappear, and he pretty much told me…Cath or no Cath the veins will disappear!  That is what happens with this “Horrible Disease!”  So I asked…..then how much time do we have to get Riley transplant?  He answered……”6 months….well…..3 months….this disease is progressing rapidly!”   Can you imagine a doctor telling you your son has 3-6 months to live if he does not get transplanted??  It’s mind boggling!! I wouldn’t wish any of this on anyone!! 

Riley also had blood work Thursday.  They are testing his antibody level.  If it is elevated then he will be admitted to “clean his blood.”  I guess it’s like a transfusion.  We don’t want his antibody level to high, though, or when he gets transplanted they’ll just start attacking the new organs.  The results take about a week so we should know this week what’s going on.

On a little lighter note…….Riley got his Sure Step braces so hopefully that will help him get over this last hurdle of walking.

Also…..yesterday Riley ate some pears (baby food) willingly!!  He opened his mouth and all.  Even after gagging he was willing to take more!!  He did get to a point that he was “all done” but the fact that he was even willing to take the spoon was enough for me!!

Sooo…that’s really all for now!!  When I know the blood test results I will post again.

Thank you everyone for your thoughts and prayers!!  We need to keep praying..LOUD….God needs to save my son not take him!!

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