This information is taken verbatim from the Puget Sound Blood Center’s Website:
Red Blood Cells
One unit of red blood cells (RBC) contains approximately 200 mL red blood cells, 100 mL Optisol AS-5® (a solution added to extend storage life) and ~30 mL plasma. All red blood cell transfusions must be ABO/Rh compatible with the recipient, so, in dire emergency, type O negative can be used for all patients. RBC do not provide viable platelets, nor do they provide clinically significant amounts of coagulation factors. RBC must be stored between 1-6° C and have a shelf life of 42 days.
RBC are indicated for patients with symptomatic anemia who are not treatable, within a reasonable amount of time considering their symptoms, with specific therapy such as iron, vitamin B12, folic acid or erythropoietin.
In a 70 kilogram adult, each unit should increase the hematocrit
Emergency Red Blood Cell Usage
Many hospitals have a limited supply of uncrossmatched type O RBC’s to be used for a bleeding patient in dire emergency. Type O, Rh-negative RBC’s can be transfused to people of any type with only a slight risk of hemolysis. This risk increases in patients who have previously been transfused or pregnant and may have formed antibodies. At most hospitals, a supply of uncrossmatched type O, Rh-positive RBC’s is also available. Type O, Rh-positive RBC’s can be used for women who are beyond childbearing age and in males over the age of 16. When Rh-positive RBC’s are used in an Rh-negative patient, there is a chance of a D immunization, and, therefore, should be used only in life-threatening emergencies. When type O, Rh positive RBC’s are available, the following algorithm should be followed:
1. For all patients under 16, use type O, Rh negative RBC’s.
2. For females under 50, use type O, Rh negative RBC’s.
3. For males older than 16 and women beyond childbearing, use type O, Rh-positive RBC’s.
4. If the supply of the appropriate Rh type has been exhausted, RBC’s of the other type should be used.
Rhogam®should be given within 48 hours of giving Rh positive blood to an Rh negative woman of childbearing age. If large amounts of Rh positive blood has been given a red cell exchange may be necessary.
Platelets are essential for the initial phase of hemostasis. Platelet concentrates also contain about 60 mL of plasma and small numbers of red and white blood cells. Platelet units must be maintained at room temperature and agitated during storage.
Pooled random donor platelet concentrates are prepared from platelets that have been harvested by centrifuging units of whole blood. Up to 8 units of platelets, each from a separate donor, can be pooled into a single bag for transfusion. Platelets expire 4 hours after pooling. All units are from the same ABO type. If ABO compatible platelets are unavailable, ABO incompatible platelets can be substituted with very little risk. The usual adult dose is 4-6 units of pooled random donor platelets.
Apheresis platelets are collected from a single donor and are equivalent to ~4-6 pooled units. An apheresis platelet concentrate contains 200-400 mL of plasma. They may be collected as a random unit (random apheresis platelets) or be obtained for a specific recipient from a family member or a volunteer HLA compatible “directed” donor. Apheresis platelets expire 4 hours after processing for release from the blood center unless incubated storage is available at the local hospital.
1. To prevent bleeding due to thrombocytopenia. The threshold of thrombocytopenia at which bleeding may occur will vary depending on the patient’s clinical condition. In general, spontaneous bleeding does not occur until the platelet count falls below 5,000 – 10,000/μL. The recommended “trigger” for prophylactic platelet transfusions in patients undergoing chemotherapy or hematopoietic stem cell transplantation is <10,000/μL. Other coexisting clinical conditions may increase this “threshold”.
2. In a bleeding patient a platelet count above 50,000 should be maintained. In a surgical patient, the necessary platelet count varies depending on the procedure. For most surgeries 30,000-50,000/μL will be adequate. For high risk procedures, such as neurologic or ophthalmologic surgeries, 100,000/μL is recommended.
3. Abnormal platelet function may be congenital, or due to medications, sepsis, malignancy, tissue trauma, obstetrical complications, extra corporeal circulation, or organ failure such as liver or kidney disease. Spontaneous bleeding may then occur at higher platelet counts. If platelet dysfunction is present, the patient with a disrupted vascular system (e.g. trauma or surgery) will require a higher platelet count to achieve hemostasis.
4. Family donor or HLA matched platelets are indicated when patients have become refractory to random donor platelet transfusions due to alloimmunization.
5. In several situations platelet transfusions may not be indicated unless there is significant bleeding. In autoimmune thrombocytopenias (e.g. ITP) transfusion increments are usually poor and platelet survival is short. Platelet transfusions may be contraindicated in patients with thrombotic thrombocytopenic purpura (TTP) unless there is clinically significant bleeding.
6. In pediatric patients, the usual platelet dose is 1 unit whole blood platelet per 10 kg child, or 5 mL/kg. A 50,000/ μL rise is expected.
*In a patient with a normal sized spleen and without platelet antibodies.
The survival of transfused platelets averages 3 to 5 days but will decrease if a consumptive process is present. Correction of a prolonged bleeding time in platelet dysfunction will depend on whether a condition exists that will affect the transfused platelets as well (e.g., antiplatelet agents, uremia).
Fresh Frozen Plasma (FFP) and Thawed Plasma
One unit of FFP or thawed plasma is the plasma taken from one unit of whole blood. FFP is frozen within eight hours of collection. FFP contains all coagulation factors in normal concentrations. Thawed plasma may be transfused up to 5 days after thawing and contains slightly decreased levels of Factor V (66+/-9%) and decreased Factor VIII levels (41+/-8%). Plasma is free of red blood cells, leukocytes and platelets. One unit is approximately 250 mL and must be ABO compatible. Rh factor need not be considered. Since there are no viable leukocytes, plasma does not carry a risk of CMV transmission or Graft Vs. Host Disease (GVHD).
Plasma transfusion is indicated in patients with documented coagulation factor deficiencies and active bleeding, or who are about to undergo an invasive procedure.
Deficiencies may be congenital or acquired secondary to liver disease, warfarin anticoagulation, disseminated intravascular coagulation, or massive replacement with red blood cells and crystalloid/colloid solutions. FFP should not be used for Hemophilia B (Factor IX) deficiency unless Factor IX concentrate is not available. FFP, but not thawed plasma, can be used for Factor V deficiency. Recombinant or Factor VIII concentrates should be used to replace Factor VIII.
Usually, there is an increase of at least 1.5 times the normal PT or PTT, or an INR ≥ 1.6 before clinically important factor deficiency exists. This corresponds to factor levels <30% of normal.
Reversal of warfarin anticoagulation with plasma is indicated only if significant bleeding or risk is present. Often it will require recurrent transfusion to maintain normal factor levels. Otherwise, reversal can be achieved by giving Vitamin K or holding warfarin two to three days prior to a planned procedure. Rapid reversal for life threatening bleeding may be achieved with recombinant Factor VIIa (Novo7®).
Plasma should not be used for volume expansion unless the patient also has a significant coagulopathy and is bleeding. Pediatric patients dosing is 10–15 mL/kg, to provide ~15–20% rise in factor levels.
Plasma – Dosage
Volume of 1 Unit Plasma: 200-250 mL
1 mL plasma contains 1 u coagulation factors
1 Unit contains 220 u coagulation factors
Factor recovery with transfusion = 40%
1 Unit provides ~80 u coagulation factors (40% of 220 u coagulation factors)
70 kg X .05 = plasma volume of 35 dL (3.5 L)
80 u = 2.3 u/dL = 2.3% (of normal 100 u/dL) 35 dL
In a 70 kg Patient:
1 Unit Plasma increases most factors ~2.5%
4 Units Plasma increase most factors ~10%
Initial Dose of FFP
10 cc/Kg (round up to nearest 200 cc) = #units FFP / 200 cc/unit FFP
Usually an increase in factor levels of at least 10% will be needed for any significant change in coagulation status, so the usual dose is four units, but the amount will vary depending on the patient’s size and clotting factor levels. Hematology consultation is advised concerning the dose of plasma.
* These numbers assume normal platelet function. Conditions that may affect platelet function include renal failure, medications, leukemias and myelodysplasias, and congenital disorders. Bleeding Time is a poor predictor of surgical bleeding. The Usefulness of Platelet Function Analysis (PFA) in predicting surgical bleeding is unknown.
Cryoprecipitate is prepared from plasma and contains fibrinogen, von Willebrand factor, factor VIII, factor XIII and fibronectin. Cryoprecipitate is the only adequate fibrinogen concentrate available for intravenous use.
Cryoprecipitate is available in pre-pooled concentrates of six units. Each unit from a separate donor is suspended in 15 mL plasma prior to pooling. For use in small children, up to 4 single units can be ordered. Each unit provides about 350 mg of fibrinogen.
Indications for Cryoprecipitate
Cryoprecipitate is indicated for bleeding or immediately prior to an invasive procedure in patients with significant hypofibrinogenemia (<100 mg/dL). Cryoprecipitate should not be used for patients with von Willebrand disease or Hemophilia A (Factor VIII deficiency) unless they do not (or are not known to) respond to DDAVP and recombinant and/or virally inactivated preparations are not available. It is not usually given for Factor XIII deficiency, as there are virus-inactivated concentrates of this protein available. Cryoprecipitate is sometimes useful if platelet dysfunction associated with renal failure does not respond to dialysis or DDAVP.
Usage and Therapeutic Effect
Cryoprecipitate – Dosage
1 bag contains ~350 mg Fibrinogen
6 bags (1pool) contains 2100 mg Fibrinogen
Recovery with transfusion = 75%
6 bags cryoprecipitate provides 1560 mg Fibrinogen
70 kg X .05 = plasma volume of 35 dL (3.5 L)
1560 mg = 45 mg/dL provided by 6 bag pool of cryoprecipitate
In a 70 kg Patient:
6 bags (1 pool) of cryo raises Fibrinogen 45 mg/dL
Fibrinogen replacement: Effect can be monitored by fibrinogen
level assay and clinical response.
Pediatric dosing for cyroprecipitate is 1 unit per 10 kg child,
which should increase fibrinogen by 60 – 100 mg/dL.
To replace factor VIII or von Willebrand factor: When specific factor concentrates are unavailable, the usual adult dose is a pool of 6 – 12 bags. Approximately 150 units of factor VIII and von Willebrand factor are provided per bag. A single donor may be used repeatedly for a young or mildly affected patient to limit donor exposures.
Fibrin glue:Although single units of cryoprecipitate are available for use in the preparation of fibrin glue to be applied locally for surgery, commercially available, virally inactivated concentrates have a higher fibrinogen concentration and are preferred for this purpose (Tisseel®). A patient may donate autologous plasma for processing into cryoprecipitate prior to a planned surgical procedure.