Hemapharesis Flashcards
Hemapheresis
Apheresis- means to separate out through force, hema-blood. Blood is removed and then separated into different components, some being retained/discarded while others are returned to the patient/donor
Where did the idea for apheresis technology come from?
Continuous flow centrifugation cream separator invented in 1877
Why do we add anticoagulant during apheresis
because you don’t want the blood to clot when you pull it out of the patients
Anticoagulant used during apheresis
citrate is most common but heparin or a combination of both have been used
How are the blood components separeated
either using a filter (sepeation based off size) or centrifugation (cell seperation based off cell density) typically centrifugation is how it’s separated
HES
hydroxy ethyl starch- WBCs and RBCs have similar densities in order to ensure separation you add HES and it causes reduction of zeta potential on RBCs so that they have a rouleaux effect and stick together, its much easier to separate from the WBCs “Sedimenting Agent”
apheresis column technology
uncommon, is used to push the specified blood component through this column (adsorption) to adsorb out what ever you want to eliminate from the component i.e. specific antibody or LDL at pathogenic levels
Discontinuous vs. continuous apheresis
usually in patients it’s continuous, meaning you are both pulling blood out, separating it while transfusing back the portion that you are not concerned about with some form of subsitute of what will be lacking. In donor’s it’s usually discontinuous, they usually pull the donation then spin it down and then transfuse it back later on. Discontinuous (Large extracorporeal volume) continuous (small extracorporeal volume)
membrane separation
basically filtration with membrane that is too small for rbcs to cross, allows plasma through
Filtration
not commonly seen in US, not mainly platforms are FDA approved and it’s only good for plasmapheresis
Filtration
not commonly seen in US, not mainly platforms are FDA approved and it’s only good for plasmapheresis/ plasma exchange
Efficiency of plasma proteins removal in 1 volume exchange
60-65% of plasma proteins good and bad are removed with one volume plasma exchange
uses of RBC exchange through apheresis
malarial infection, sickle cell disease
Leukapheresis
seperating out blood cells, usually done in patients with extremely high white counts due to Leukemia (AML most common)>CML>ALL not usually CLL
Reasons for plasmapheresis/ exchange
HUS, TTP, Guillain Barre Syndrome Myasthenia Gravis CIDP- chronic inflammatory demylenating polyneuropathy Autoimmune Renal Disease Hyperviscosity Syndromes
Essential thrombocytosis
Essential thrombocytosis (primary thrombocythemia) is a nonreactive, chronic myeloproliferative disorder in which sustained megakaryocyte proliferation leads to an increase in the number of circulating platelets. with this you could bleed or clot, if the count is very high there is a lot of binding to vwF, stimulating almost vwDisease state, where bleeding occurs
reasons for thromapheresis
removal of platelets with thrombocytosis
What aspect do apheresis machines need to be able to control
the Separation Factor
Elutriation
a combination of centrifugation and filtration for cell separation
List components from least dense to most dense
Plasma> platelets> lymphocytes> monocytes>granulocytes > RBCs
Packing factor
same as separation factor just different term. This is a combination of the centrifugal time and the centrifugal acceleration rate(G).
Continuous
Blood is processed and separated in a continuous way. Once the tubing set is primed, the separation chamber is not emptied till the end of the process. Medium – small ECV. No pediatric tubing sets are necessary; instead, a blood prime is performed with smaller patients.
Discontinuous
Blood is processed in batches of a size that can be tolerated by the subject. Once the separation of that blood is completed, the separation chamber must be emptied to repeat the process (cycle) again. Large extracorporeal volume (ECV). Pediatric tubing sets (with smaller ECV) must be used with small patients.
Discontinous centrifugal apheresis systems
Haemonetics: PCS-2, MCS+ 8150 and 9000, Cymbal
Therakos UVAR-XTS
Continuous centrifugal apheresis systems
TerumoBCT: COBE Spectra, Trima, Trima Accel, Spectra
Optia
Fenwal (Fresenius Kabi): Amicus, Alyx.
Fresenius Kabi: AS 104, Com.Tec
Tubing of apheresis machines
sterile and disposable plastic- for one time use
Risks to hemapheresis
bleeding, bruising, clot, infiltration-infrection, also citrate reaction
Citrate reaction symptoms
tingling numbness funny sensation around mouth and vibration in chest if no action is taken can worsen to convulsions tetany or cardiac arrhythmia
Citrate reaction treatment
pausing aphereis, oral calcium then slow down the rate and IV calcium if necessary
Vasovagal reaction
h.r. and b.p drop fainting, more common in donors then patients
Rare hemapheresis reactions
allergic reaction ( to sterilizing gas used in kit preparation or any other component? air embolism (blood blockage due to air bubble) and hemolysis but this is rare with current technology and following procedures, If central venous line placement risks involved with making that placement
difference in extravascular/intravascular
The problem is the concentration between the two, if we remove antibodies/cells from the intravascular space and put back in the body the concentration between the extra/intra vascular spaces will be different causing it to equalize by moving things back to the intravascular space to compensate
How effecient is apheresis
typically 60-65%
Maximum of donor’s blood volume that can be collected through apheresis
15%
how many red cells can be collected during donor apheresis
two red cell bags, or one red cell and one other type of component bag
How many platelets can be derived from an apheresis donation
single, double or triple plus one bag of either red cells or plasma
How many plasma units can be derived from an apheresis donation
4 plasma units at one time or platelet/plasma/red cell combination
How frequently can donor donate DR
Double red, two red cell units through apheresis, can be donated only 3 times in one year, must wait 1 weeks
Lipid removal
liposorver technology- closed circuit with columns. first filtration removes plasma, returns red cells to patient. Plasma goes through propriety column removes ‘bad cholesteral’ two columns alternate one is being flushed so it can process additional plasma
Lipid removal is used for:
Familial hypercholesteremia the mainindication. Long four hour procedure done every two weeks for persons entire life
Platelet Depletion - what is is, why it’s done
can be done to decrease the count attempt to avoid complications but no a definitive treatment, chemotherapy must follow. Too many platelets as high as 1 million, bleeding or clotting, organ function compromised, myeloproliferative disorder such as polycythermia vera
Leukodepletion- what it is why it’s done
too many whites cells especially sticky blasts (above 100k) AML and CML are more common, may be used in ALL not really used in CLL. With sticky blasts and increased white blood cells it makes blood more viscous and sludgy. causes lung and brain functionality problems, this is an urgent procedure in a sick patient, usually exchange two blood volumes. Must be followed by chemotherapy, leukodepletion is not a definitive treatment
Photopheresis machine
Therakos cellex photophoresis machine, only machine on market in US
what is photophoresis
works by collecting mononuclear cells and then exposing them to UV rays after addition of psoralen, can be done using machine, all steps in one, or you can collect the MNC separately and then do the addition of psoralen/UV infuse back separately
what is photophoresis used for?
Graft vs. host disease in BMT, and cutaneuous T cell lymphoma and solid organ rejections, this can cause bleeding and photosensiyivity
Immunomodulation
promotes immune system to decrease attacks on wrong targets in organ rejection and GvHD and increases their activity against tumor cells in lymphoma
Red Cell exchange what it is
Must have good access in both arms, patients have been extensively transfused typically, Connected to a system that pulls out the whole blood, spins it down transfuses back the plasma portion and blood is then replaced with blood units
Red cell exchange why it’s done
most common indication is sickle cell disease, eithr acute, or chronic to keep HGBS less than 30% prevent stroke. Can also be used as a treatment for severe malaria falciparum infection, by removing parasite infected red cells from circulation
Avoiding iron overdose in red cell exchange
hemodilution can be used, replace 1-2 units with normal saline and then perform regular exchange
Problemse with red cell exchang
Exposes patient to a lot of donors, if this is chronic regular treatment, hospitals matching for Rh and Kel to prevent alloimmunization
Plasma Exchange -why
MOst common procedure done, TTP, Myasthenia Gravis and Guillain Barre syndrome, some kidney diseases and vasculitis syndromes. Idea is to removes disease causing antibody or immune complex
Plasma exchange-how
Replacement fluid is either FFP (TTP) or more commonly 5% albumin. Albumin is usually supplemented with calcium to avoid citrate reaction, also if continual treatment, need to monitor PT/PTT levels of patient if receiving albumin, may need an FFP transfusion if prolonged.
ASFA
American society for apheresis
ASFA guidelines
has list of disease that apheresis treatment should work for, Category 1 and 2 are good, 3 needs to be discussed and 4 should not be done, based off of the expected response of the disease to the treatment
patients that need apheresis:
are more likely to be admitted in a hospital, sick and needing skilled care, most procedures for this use central lines. you need a separate consent obtained by treating physicial as well as specific order for apheresis
Therapy Donors
People that donate units of blood that is required to be removed as therapy in treatment of the patient. They have a separate DHQ, donation could be stimulated or unstimulated. Some of these are healthy donors and some are patients.
Spectra Opia
equiptment used in extracting granulocytes, two arm continuis instrument
Graunlocyte QC
must be 1 x 10^10 granulocytes and must be ABO compatible
Important fact of granulocyte shelf life
only good for 24 hours, cannot wait for testing, donor is prescreened 48 hours prior
Granulocyte donor and transfusion
Given simulating agent prior to collection commonly steroid G-CSF and sedimenting agent during collection, CMV status should be matched, should be irradiated usually donated by friends/family
Platelet donor platelet count
must be greater than 150,000. Can use last value if obtained post donation and greater than or equal to 150,000
Time interval between one red cell donation or whole blood donation
8 weeks, 56 days
