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Fresh frozen plasma (FFP) is the plasma separated from a unit of whole blood and frozen at -18oC within 8 hours after collection. Each bag has a volume of 175 to 250 mL and contains between 1 and 2 units of each coagulation factor per mL and 400 to 800 mg of fibrinogen. FFP also contains fibrinolytic and complement factors. FFP carries the same risks of viral transmission as other blood components and can cause allergic reactions and fluid overload. FFP must be transfused within 24 hours after thawing. Pre-transfusion crossmatching is not necessary. Units of FFP should be ABO compatible whenever possible. Alternative ABO groups may be substituted as long as the recipients' red blood cells are compatible with anti-A or B antibodies present in the donor plasma. The following table provides guidelines for selection of compatible FFP units: ABO Compatible FFP
FFP Transfusion Guidelines The PT and aPTT begin to prolong out of the normal range when coagulation factor levels fall below about 30% of normal. Prolongation of the PT or aPTT up to about 1.5 times the midpoint of the normal range, which corresponds to coagulation factor levels of 20%, is not usually associated with spontaneous hemorrhage and does not increase the risk of bleeding during routine invasive procedures. However, the risk of bleeding is greater if the platelet count is decreased, platelet function is abnormal, the patient has massive trauma or is undergoing extensive surgery. General guidelines for FFP transfusion include:
Acquired abnormalities of hemostasis may occur with a variety of clinical disorders. These usually involve multiple plasma coagulation factor deficits and are more common than inherited plasma deficiencies that usually involve single coagulation factor deficiencies. Consequently, there is a concurrent derangement of several coagulation tests as shown in following table. Acquired Plasma Coagulopathies
The goal of FFP transfusion is to increase the plasma level of each coagulation factor above 30%. Each bag increases the level of any coagulation factor 2 to 3% and fibrinogen 8 mg/dL in an average adult. Usually, 10 to 15 mL of FFP per kg body weight is required to treat bleeding due to multiple factor deficiencies. This dose corresponds to 4 units in an adult. The PT and PTT should be rechecked before subsequent units are transfused. If the PT and PTT remain prolonged, more FFP is indicated. FFP may be needed for massive transfusions of greater than one blood volume in patients who have a demonstrable coagulopathy and continued bleeding. Thrombocytopenia is responsible for continued bleeding during massive transfusion more often than coagulation factor depletion. Platelet transfusion should be tried first if the platelet count is < 50,000/uL. A pool of 6 to 8 platelet concentrates or a single apheresis unit contains a plasma volume equivalent to 1 to 1.5 units of FFP. Often times, a platelet transfusion will correct both the thrombocytopenia and coagulopathy. If the coagulation tests remain elevated, then FFP can be given. Vitamin K deficiency may occur as an acquired defect in association with fat malabsorption, biliary obstruction, inadequate oral intake or treatment with broad-spectrum antibiotics. Some neonates born of malnourished mothers will also have vitamin K deficiency. When vitamin K replacement therapy is used, its effect does not begin until 6-12 hours after administration and is not complete until 36 hours. Occasionally, vitamin K deficient patients or patients receiving warfarin require immediate reversal of their anticoagulation because they are scheduled for an invasive procedure, their INR is supratherapeutic or they are bleeding. Bleeding risk factors include:
ACCP Warfarin Reversal Guidelines
For elective surgery, the best strategy for warfarin reversal is to discontinue warfarin 3 to 5 days prior to the procedure. Patients presenting with minor bleeding may be treated by withholding the next dose of warfarin and giving oral Vitamin K. Patients with greatly elevated INR's are at high risk for intracranial hemorrhage and should be given FFP concomitantly with vitamin K therapy. Fresh frozen plasma (FFP) is frequently ordered to quickly correct excessive anticoagulation due to warfarin. Published guidelines often recommend giving two to four units of FFP. However, actual data using current coagulation instruments and sensitive PT reagents has not been published. Ideally, each laboratory should develop their own guidelines based on their coagulation tests and FFP source. As illustrated in the following table the longer the pre-transfusion PT or INR, the greater the correction achieved with a single unit of FFP. An INR of 10 (PT 70 sec) can be corrected to < 3 (PT 30 sec) with only two units of FFP. However, four units of FFP are needed to correct an INR of 1.9 (PT 21 sec) to 1.5 (PT 15 sec). It is not necessary to correct the INR below 1.5 to achieve adequate hemostasis. Protime Correction by FFP
FFP is the treatment of choice for congenital factor deficiencies when more specific concentrates are not available. Examples include factors V and XI. Congenital Coagulation Factor Deficiencies
Dosing of FFP for congenital factor deficiencies is dependent upon the degree of factor deficiency and the half-life of the deficient factor(s). All of the factors noted above, except V and VII, have a half-life greater than 12 hours and do not need to be replaced more often than every 12 hours. A practical approach for an average adult would be to give:
Another alternative for the treatment of TTP is the use of cryo-poor plasma (CPP), which is the plasma remaining after preparation of cryoprecipitate. Compared to FFP, CPP contains decreased levels of fibrinogen, von Willebrand factor, and factors VIII and XIII. Both FFP and CPP contain vWF proteinase, which is believed to be the deficient factor causing TTP. Fibrinogen levels should be monitored following serial plasma exchanges with CPP, because of its decreased levels of fibrinogen. CPP does not appear to be any more effective than FFP. FFP can be used for prophylaxis in patients with hereditary angioedema who are undergoing oral surgery. Prophylaxis will prevent attacks of angioedema which are commonly precipitated by dental procedures and head and neck surgery. Infusion of 2 units of FFP the day before and again just prior to the procedure is recommended. Alternatively, short-term administration of danazol or stanozol can be used prior to head and neck procedures. Although FFP is recommended for prophylaxis, its use for treatment of an angioedema attack has not been established. Plasma transfusions have been reported to arrest attacks of angioedema. However, FFP could be hazardous because it contains complement factors C2 and C4 that may exacerbate the attack. FFP should be reserved for life threatening attacks. Future treatment options include C1 Inhibitor concentrates that have been used for years in Europe and are currently under clinical investigation in the United States. FFP should not be used as a volume expander, as a nutritional supplement, for the treatment of bleeding in the absence of documented coagulopathy, or as a standing order following surgery or massive transfusion. Thawed Plasma Some FFP wastage occurs because a decision is made not to transfuse after FFP has already been thawed or the patient expired after the FFP had been thawed. One way to prevent this type of wastage is to establish a thawed plasma policy that allows the blood bank to store plasma in the refrigerator for up to 5 days instead of the current 24 hours after thawing. Studies have shown that the labile coagulation factor levels remain at hemostatic levels; Factor V remains above 50% and Factor VIII above 45% even after 5 days of storage. Most hospitalized patients have elevated Factor VIII levels because of an acute phase reaction. In one clinical study, thawed plasma completely corrected prolonged PT & PTTs in 32 recipients and was not associated with any adverse effects. Thawed Plasma can be used for the same indications as FFP except treatment of patients with congenital factor V or VIII deficiencies. Also, it is probably not advisable to give only Thawed Plasma to patients undergoing massive transfusion. |
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