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Blood plasma, the fluid in which red Blood cells, Blood platelets and other Blood clotting factors are suspended, also can be collected by apheresis. For this process, whole Blood is drawn, Blood plasma is removed, and the red Blood cells are transfused back into the Blood donor. This Blood plasma collection process normally takes one to two hours to complete. Blood plasma is often collected from donors by a variety of entities, particularly commercial for-profit organizations that sell it to companies for manufacture into a variety of Blood products. These Blood products often undergo a purification process to make them safer. Some of these Blood products provide, among other things, clotting factors for people who suffer from abnormal bleeding disorders (hemophilia, etc.) Blood Products
The product of one unit of donated and unadulterated Blood plus ACD (anticoagulant/preservative). By definition, whole Blood contains one unit of plasma and cells. Whole Blood can be stored, normally and conventionally, for 5 weeks. Factors V and VIII are labile and are significantly decreased after 7 days.
If "fresh" (less than 24 hours since drawn,) whole Blood is still utilized in resuscitation of a patient who has been loosing a lot of Blood. Whole Blood is not used for "routine" Blood transfusion when red cells (RBC) will suffice. Since one unit of donated Blood can be broken down into one unit RBC, one unit platelets, and one unit fresh frozen plasma (FFP), and more, the use of whole Blood is considered to be a waste of resources.
One unit of red Blood cells (RBC) contains approximately 180ml (range 150 to 210 ml) of red cells, 100ml of Optisol®, and approximately 30ml (range 10 to 50 ml) of plasma. As an average, the total volume of a RBC unit is 310 ml (range 270 to 350 ml).
A unit of RBC is prepared from a whole Blood collection using a closed sterile system. Blood is drawn into a bag containing the anticoagulant CPD. Most of the platelet rich plasma is separated with a centrifuge and separated into an attached container. 100 ml of an additive nutritive solution (Optisol®) is added to RBC. Optisol® is a crystalloid solution containing sodium, dextrose, adenine and mannitol. The Optisol® supports red cell survival and extends the shelf life of the unit to 42 days. The added fluid volume of the Optisol® also reduces the unit's hematocrit to ~57% (range 50 to 65%), thereby improving the flow characteristics of the component. Optisol® is also known as AS-5.
All RBC transfusions must be ABO/Rh compatible with the recipient. Packed red Blood cells do not provide viable platelets or neutrophils, nor do they provide clinically significant amounts of coagulation factors. RBC must be stored between 1° to 6°C.
Indication - Red Blood cells are indicated for patients with symptomatic anemia that is not treatable with specific therapy such as iron, vitamin B12 or with folic acid.
Therapeutic Effect - In a 155-pound adult, one unit of RBCs can be expected to increase the hematocrit by approximately 3% or the hemoglobin by 1 gm/dl.
Indication - Washed red cells can be considered for patients who have had repeated hypersensitivity reactions to Blood or components despite prophylactic administration of antihistamines. It should be kept in mind, however, that the red cell washing procedure may not reduce the proteins enough to prevent hypersensitivity reactions (e.g. hypersensitivity to IgA). Controversial indicators for washed red Blood cells include complement mediated immune hemolysis and paroxysmal nocturnal hemoglobinuria.
Therapeutic Effect - A unit of washed red Blood cells will raise the hematocrit less than will a unit of red Blood cells because of an approximate 20% loss of red cells from the unit during the washing process.
Leuko reduced Red Blood CellsDescription - Leuko reduced red Blood cell units contain leukocytes in a specifically reduced amount.Blood processing centers use filtration to make leuko reduced red Blood cell units.
Indication - The most common indication for leuko reduced red Blood cells is for patients who have experienced two or more non-hemolytic febrile transfusion reactions. leuko reduced red cells are usually effective in preventing non-hemolytic febrile transfusion reactions for most patients.
leuko reduced red Blood cells are also effective in prevention of CMV transmission or HLA alloimmunization.
Therapeutic Effect - leuko reduced red Blood cells will have a slightly lower therapeutic effect than red cells that have not been leuko reduced. Depending on the filter used, there is a 10 to 15% loss of red cells with leuko reduction by filtration.
Because of the small number of these Blood products (components) requested and for inventory management purposes, divided RBC units are only available as type O. These units may be transfused to any ABO type recipient in any clinical circumstance, including intrauterine transfusion when the fetus’ ABO type may be unknown, as well as for exchange transfusion in neonates when fetal-maternal ABO incompatibility may be involved.
Divided red Blood cells units have a higher hematocrit, approximately 72%, higher than standard Optisol® preserved RBC units. Unprotected and unprepared divided Blood units expire 21 days after collection.
Therapeutic Effect - A divided red Blood cell unit will increase the hematocrit/hemoglobin the same as a standard red Blood cell unit when corrected for the weight of the child and the volume infused.
Platelets are cells essential for the coagulation of Blood. Platelet products also contain plasma (coagulation factors), some red cells and some white cells (leukocytes). Platelet products are usually cloudy and yellowish in color but may occasionally have a pink tone because of the presence of residual red cells. Platelets are stored at 68° to 75° Fahrenheit (room temperature) and require continuous gentle agitation. They can be stored at the Blood center for up to five days. When received for transfusion, both pooled and apheresis platelets will expire in less than four hours. Since preparation for transfusion involves processes such as pooling, volume reduction and leuko reduction which require entry into the component, a four hour expiration is placed on the platelets once preparation is started at the Blood center to avoid bacterial growth.
A Whole Blood Platelet Concentrate is prepared from whole Blood by an initial soft centrifugation to separate the red cells from the platelet rich plasma. A second harder centrifugation is used to concentrate the platelets that are then resuspended in 60 ml of residual plasma. Each unit contains a specific ratio/quantity of platelets. To provide an adequate dose of platelets for an adult, four to six platelet concentrates of the same Blood type are pooled at the Blood center prior to issue. Pooled platelets are generally issued ABO type compatible, but other types may be substituted. One should avoid, if possible, giving type A platelets to an O recipient. If the O recipient happens to have a high titer of anti-A, the post transfusion platelet increment will be reduced.
Platelets products contain an insufficient number of red cells to cause an incompatibility reaction. There are sufficient numbers of red cells, however, for an Rh negative person to be sensitized (develop Rh antibodies) if they receive Rh positive Blood. There is very little risk of the patient having an incompatibility reaction because the plasma in a pooled unit is combined from different donors thereby reducing the possibility that isoagglutinins (anti-A and/or anti-B) would be present in high titer. Due to the smaller Blood volumes of infants and small children, ABO compatible or reduced volume ABO incompatible platelets must be given.
Apheresis Platelets are obtained from one donor with the use of an apheresis machine. Blood is drawn from a donor’s arm into a self contained, single use Blood tubing/collection set which has been inserted into the apheresis machine. Blood does not come into contact with the apheresis machine itself. Anticoagulant is added to the Blood as it is drawn from the donor. The platelets are separated from the red cells, leukocytes and most of the plasma by centrifugation. The red cells, leukocytes and plasma are returned to the donor through his or her other arm, and the platelets are retained in a collection bag for later transfusion to a patient. The procedure takes approximately 60 to 90 minutes.
The majority of apheresis platelets collected contain less than a specific amount of leukocytes and are labeled as leukocyte reduced.
One apheresis collection of platelets generally contains 200 to 400 ml of plasma. Because of the possibility of a high titer of ABO antibodies in the donor plasma, the unit is volume reduced in cases of minor ABO incompatibility. Apheresis platelet concentrates can be collected from unselected community donors. This yields a product known as a Random Apheresis Platelet (RAP). Alternately the platelets may be drawn from a family or community donor who has been specifically matched to the patient on the basis of HLA (Human Lymphocyte Antigen) typing. This yields a product known as a Matched Apheresis Platelet (MAP).
Random Apheresis Platelets are available in two doses: Standard and Large. The standard dose contains a smaller average count of platelets (approximately equivalent to four units of pooled platelets). The standard dose is generally ordered for smaller patients, for those in whom a high platelet count is not required, and for patients who respond well to transfusion. The large dose contains, as the name would indicate, a greater average number of platelets, approximately equivalent to six units of pooled platelets. The large dose is generally ordered for larger and heavier patients, for those in whom a high platelet count is desired, and for those who do not respond well to transfusion.
As many platelets as possible are collected from HLA matched apheresis donors, therefore it is not necessary to specify dose when ordering these platelets.
Indications - Platelet transfusions are indicated for patients with bleeding due to either thrombocytopenia, platelet dysfunction or some combination of the two conditions. The point at which bleeding may occur varies depending on the patient’s condition. The majority of patients with normal platelet function will not experience bleeding until the platelet count drops below a certain point. In patients with abnormal platelet function, usually caused by drugs (e.g. aspirin or semi-synthetic penicillin), uremia or elevated split products of fibrinogen/fibrin, bleeding may occur with higher platelet counts. In patients undergoing surgery, bleeding may occur with relatively low platelet counts.
In addition to evaluating platelet count and patient condition, bleeding time may also be used in determining the need for platelet transfusions. A bleeding time twice the upper normal limit may be an indication for a platelet transfusion in a bleeding patient. HLA Matched platelets are indicated for patients who are refractory (demonstrate a poor post-transfusion platelets increment) to random donor platelets due to alloimmunization.
Patients with auto-immune thrombocytopenic purpura (ITP) should not receive platelet transfusions unless bleeding is significant or life threatening. Platelet transfusions given to patients with ITP will be rapidly removed from circulation by the patient’s anti-platelet antibodies and thus will be, at most, only of transient benefit.
Therapeutic Effect - Each unit of platelets prepared from donated whole Blood contains a certain number of platelets and can be expected to increase the platelet count of a 155-pound patient by a known approximate amount by one hour after transfusion. Since the usual dose for adults with platelet related bleeding is a pool of four to six units of platelet concentrates from whole Blood or one standard sized unit of apheresis platelets, an increase in the platelet count by one hour after transfusion is expected.
Patients demonstrating two consecutive platelet count increases of less than a known standard range at one hour after transfusion of four to six units of pooled platelets (or one unit of apheresis platelets) are considered refractory. Failure to achieve hemostasis or the expected increment in the platelet count may signify a refractory state. A refractory state to platelets may be caused by fever, sepsis, DIC, or splenomegaly or an immune response to the platelets also referred to as platelet alloimmunization. In patients with alloimmunization, HLA matched platelets may be necessary to control bleeding due to thrombocytopenia.
Indications - Granulocytes should be considered for patients with severe neutropenia (less than 200/µl) and a documented life-threatening bacterial or fungal infection not responsive to appropriate antibiotic therapy. Additional indications include neonates with clinical sepsis and patients with infections who have neutrophil function defects. After granulocyte therapy is initiated, it is generally continued once daily until the infection clears or the neutrophil count begins to recover.
Therapeutic Effect - Even though there may be a clinical effect, there may not be an increase in the recipient’s neutrophil count.
Indications - FFP is indicated for patients with documented coagulation factor deficiencies who are actively bleeding or who are about to undergo an invasive procedure. Causes of such deficiencies include congenital deficiency, liver disease, anticoagulation with warfarin or massive transfusion with red cells and crystalloid/colloid solutions. Factor deficiencies severe enough to be clinically significant are usually associated with prolongation of the coagulation screening tests (prothrombin time, partial thromboplastin time) at least 1.5 times the control value or an INR of 1.6. FFP is also indicated in treatment of thrombotic thrombocytopenic purpura (TTP), usually in conjunction with plasma exchange. FFP should not be used for volume expansion or nutritional support. Immune globulin preparations are available for the provision of immune proteins instead of FFP. Reversal of warfarin anticoagulation should be accomplished with Vitamin K rather than FFP if two to three days can be allowed for clotting factors to return to hemostatic levels. Massively bleeding patients may be given FFP along with red Blood cells to prevent dilution of clotting proteins.
Therapeutic Effect - One ml of FFP per 2.2 pounds of patient weight will raise most clotting factors by approximately 1%. FFP should be used as soon as possible after it is thawed and always within 24 hours after thawing. The amount of FFP needed depends on the patient’s clotting factor levels, levels needed to achieve a therapeutic effect, whether or not the patient is bleeding and the patient’s Blood volume. Clotting factor activity should be estimated by specific coagulation factor assays, or in emergencies, at least by coagulation screening tests.
Indication - Cryoprecipitate is indicated for bleeding or imminent invasive procedures for patients with significant hypofibrinogenemia (less than 100 mg/dl). Commercial Clotting Factor Concentrates made with viral inactivation methods are preferred over Cryo for hemophilia A and von Willebrand treatment.
The use of cryoprecipitate for the preparation of fibrin glue is increasing as applications in neurosurgery, orthopedic and ENT surgeries are expanding. Autologous units can be collected ahead of time and processed into Cryo to be used for fibrin glue.
Therapeutic Effect - When used for fibrinogen replacement, ten bags should provide enough fibrinogen to raise the fibrinogen 60 to 70 mg/dl in a 155 pound adult. Therapeutic effect can be monitored by fibrinogen levels and the patient’s clinical response.
Note: Cryoprecipitate transfusions may be prepared from a designated donor for some young or mildly affected patients with hemophilia A or von Willebrand disease to limit potential viral exposure through transfusions. These single donor Cryo products may have higher concentrations of factor VIII and von Willebrand factor than regular donor Cryo because of DDAVP used to stimulate the apheresis donor prior to collection. Multiple bags of high potency Cryo are then prepared from one collection.
A single unit (bag) of Cryo is usually adequate for the preparation of fibrin glue unless more than 10 ml is needed.
Indication - Factor VIII concentrate is indicated for the treatment of bleeding or imminent invasive procedures in patients with hemophilia A, (congenital factor VIII deficiency) and for patients with low titer factor VIII inhibitors. Regular prophylactic doses are often used, as well as daily doses in some hemophilic inhibitor patients to try to induce immune tolerance. Patients with von Willebrand’s disease respond to one specific, pasteurized intermediate purity concentrate in which that factor activity is relatively preserved.
Therapeutic Effect - Dosage is dependent on the nature of the injury, the degree of factor deficiency, the weight of the patient and the presence and level or absence of factor VIII inhibitors. The half life of circulating factor VIII is eight to twelve hours, therefore transfusions may need to be repeated every 12 to 24 hours to maintain hemostatic levels. Following surgery, it is necessary to maintain hemostatic levels for up to two weeks to prevent delayed bleeding and promote wound healing in the hemophilic patient.
Indication - Factor IX concentrates are indicated for patients with hemophilia B (factor IX deficiency), also called Christmas Disease, who are requiring treatment of bleeding or about to undergo invasive procedures. Low purity factor IX concentrate may be used in treatment of hemophilia A patients with high titer inhibitors. It may be of value to patients with congenital factors X or II (prothrombin) deficiency. "Activated" concentrates are also used for some factor VIII inhibitor patients.
Factor IX concentrates should not be used for patients with acquired combined deficiency of factor(s) II, VII, IX and/or X as plasma or whole Blood provides safer, more effective treatment in these patients. Purified factor IX concentrate is considerably more expensive than crude factor IX concentrates and is generally indicated only for hemophilia B patients who require repeated infusion and/or are at greater risk for thrombosis. A recombinant (synthetic) product was FDA approved in early 1997 and is recommended for hemophilia B patients with minimal or no prior exposure to plasma derived products or FFP. Low purity factor IX concentrates are contraindicated for patients with liver disease, as there has been an increased risk of thrombosis seen with the use of these products in this group of patients.
Therapeutic Effect - Dosage will depend on the patient factor level and the circumstances making the transfusion necessary. Treatment for bleeding generally requires every 12-hour or daily infusions until symptoms resolve. For major surgery in hemophilia patients, purified concentrate is indicated for ten to fourteen days (until sufficient wound healing has taken place to prevent re-occurrence of the bleeding condition). In hemophilia A patients with inhibitors, undergoing surgery or experiencing major bleeding episodes, the treatment may consist of infusions of the crude concentrates every eight to twelve hours.
Indication - Antithrombin III concentrates are approved for and indicated in reducing an acute increased risk of venous thrombo-embolic disorders in patients with symptomatic, congenital antithrombin III deficiency. This will usually be prophylactic therapy to correct levels from half-normal to around 100% during surgical procedures or periods of increased risk from immobility, etc. A potential role in acquired thrombic disorders or DIC is being investigated but has not been established.
Therapeutic Effect - Due to a short life, long term prophylaxis with antithrombin III infusions is not feasible (versus use of oral anticoagulants). The dosage is as indicated in the paper included in the package. This Blood product is an 'order item' norrnally available, in most areas, within two working days.
CMV transmission to susceptible patients is effectively prevented by use of either CMV seronegative, a donor determined to be negative for antibody to CMV, or leuko reduced, containing less than a certain range of leukocytes.
Cryoprecipitate and Fresh Frozen Plasma are cell free and have not been implicated in CMV transmission.
Indications - CMV negative Blood products are indicated for patients in the following categories, regardless of CMV status of the mother:
CMV negative Blood products are indicated for CMV negative patients in the following categories: Bone marrow or organ transplant recipients (if the marrow or the organ donor is also CMV negative); Potential candidates for transplant;
If CMV status is pending in these patients, CMV negative components are indicated. CMV negative components are not considered necessary for patients receiving chemotherapy.
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