Page 1975 - Hematology_ Basic Principles and Practice ( PDFDrive )

Chapter 115 Transfusion of Plasma and Plasma Derivatives 1749

complement cascade, cytokine release, and pulmonary edema. TACO is also likely underdiagnosed and underreported. Studies show
Approximately 5% of TRALI is caused by the opposite mechanisms, that the mean age of patients who develop TACO range from about
which are recipient white cell antibodies against transfused donor 70 to 85 years. Additional known risk factors for TACO include
white cells. Nonimmune mechanisms are also postulated to mediate larger volumes of transfusion, greater plasma transfusion volume, and
TRALI, including bioactive lipids and CD40 ligand. a faster transfusion rate. The incidence of TACO is unknown, but it
TRALI is the most common cause of transfusion-associated is increasingly recognized clinically. Studies have reported the inci-
mortality in the United States and is usually associated with transfu- dence to range from 1 in 356 to 1 in 10,000 blood products transfused
sion of blood products containing large volumes of plasma containing or 1% to 8% of transfusion recipients, depending on the study popu-
white blood cell antibodies. Patients at higher risk include those with lation and data collection methodology, and are currently associated
shock, chronic alcohol abuse, positive fluid balance, higher peak with a mortality rate of 5% to 15% in the United States.
airway pressure, and current smoker. Signs and symptoms appear Symptoms include dyspnea, orthopnea, cough, chest tightness,
within 2 to 6 hours of transfusion and include respiratory distress cyanosis, hypertension, and headache. Symptoms usually present at
with dyspnea, tachypnea, hypoxia, fever, tachycardia, and hypoten- the end of transfusion but may occur up to 6 hours posttransfusion.
sion. Bilateral pulmonary infiltrates on chest x-ray may be seen with Diagnosis is based on the presence of cardiogenic pulmonary edema.
no evidence of left atrial hypertension. In cases of suspected TRALI, Management includes discontinuing transfusion, diuretic therapy,
the transfusion should be discontinued. Medical management is oxygen supplementation, and sitting the patient upright. Avoiding
primarily supportive, commonly with supplemental oxygen and rapid transfusion can prevent TACO, unless clinically indicated.
endotracheal intubation, if needed. Diuresis is not indicated, and the Transfusions should be administered slowly, usually 1 mL/kg/h,
role of steroids is unclear. The majority of patients improve within 2 particularly in patients at risk for TACO.
days, although TRALI has a 5% to 25% mortality rate.
Multiple strategies have been implemented to reduce the risk of
TRALI and have resulted in a substantial decline in its incidence. CRYOPRECIPITATE
First, donors implicated in prior TRALI reactions are deferred from
further blood donation. Second, multiparous female donors can be Cryoprecipitate is prepared from 1 unit of FFP thawed at 4°C. The
tested for HLA and HNA antibodies, and blood products with high precipitate is then refrozen and stored at −18°C or colder for 1 year.
volume plasma (i.e., plasma and apheresis platelets) are not made Cryoprecipitate, volume of 10 to 15 mL, contains 80 to 100 units
from those with high-titer antibodies. Third, plasma supplied to of factor VIII, 100 to 250 mg of fibrinogen, and 50 to 60 mg of
hospitals for transfusion can be only from male donors while the fibronectin as well as vWF and factor XIII.
female plasma is diverted for fractionation. Currently, these strategies Cryoprecipitate takes 10 to 15 minutes to thaw at 30°C to 37°C,
have reduced the risk of TRALI from 1 : 4000 to 1 : 12,000 without and then requires pooling before infusion. Prepooled (pooled before
significantly reducing blood product availability. storage) cryoprecipitate products are now available, easing the burden
of preparation on the transfusion services. Once pooled and thawed,
cryoprecipitate is maintained at 20°C to 24°C and outdates in 4
Allergic Reactions hours (6 hours if unpooled or pooled in a closed system).
Allergic transfusion reactions occur when preformed recipient anti-
bodies bind to transfused allergens. Allergic transfusion reactions Indications
occur in approximately 1% to 3% of plasma transfusions. Anaphy-
lactic reactions occur in approximately 1 in 20,000 to 1 in 50,000 Cryoprecipitate is used predominantly to treat bleeding associated
transfusions. The majority of allergic transfusion reactions are mild. with fibrinogen deficiency (Table 115.2). Cryoprecipitate should not
Mild reactions consist of urticaria with or without generalized pruri- be used to treat factor XIII, vWF, and factor VIII deficiencies, as
tus or flushing. More severe symptoms include hoarseness, stridor, virally inactivated factor concentrates are available. Human fibrinogen
wheezing, dyspnea, hypotension, gastrointestinal symptoms, and concentrate is also available and FDA approved, which is primarily
shock. Mild reactions can be treated with antihistamines, while more used for congenital fibrinogen factor deficiency in the United States
severe reactions can be treated with epinephrine, H1-receptor antago- and broader indications in Europe. Like plasma, recent studies also
nists, and steroids. indicate that actual administered doses of cryoprecipitate vary widely,
Anaphylactic reactions may be secondary to anti-IgA, usually suggesting inconsistent practice and uncertainty over the evidence
found in rare patients with IgA deficiency (0.13% of the population). informing optimal use. One large audit, for instance, demonstrated
Patients who have severe allergic reactions should be tested for IgA that across 25 Canadian hospitals and 4370 units of cryoprecipitate
deficiency and the presence of anti-IgA. If anti-IgA is identified, the transfusions, only 24% of transfusions were considered clinically
patient should receive plasma products from IgA-deficient donors or appropriate, and 34% of cryoprecipitate transfusions were deemed
washed RBC and platelets products. inappropriate according to published national guidelines (i.e.,
Premedication with antihistamine is used to mitigate allergic
transfusion reactions and is indicated in patients who have multiple
prior or moderate allergic reactions. Unlike platelet products, however, TABLE
which can be washed or concentrated before administration, there 115.2 Administration of Cryoprecipitate
are currently no other preventative measures, other than premedica-
tion, to diminish the risk or severity of allergic reactions in plasma Indicated
transfusion recipients. Consequently, oral premedication with anti- Congenital afibrinogenemia if fibrinogen concentrate unavailable
histamines can be given 30 to 60 minutes before a transfusion, while Dysfibrinogenemia
intravenous premedication can be given 10 minutes before a transfu- Factor XIII deficiency
sion in patients with a history of allergic reactions to plasma Fibrinogen deficiency
products. Massive transfusion
Reversal of thrombolytic therapy
Possibly Indicated
Transfusion-Associated Circulatory Overload Amniotic fluid embolism (used as last resort to replace depleted
fibronectin)
TACO results from vascular fluid volume overload following the Snake bites
transfusion of blood products, and is most common in very young Uremic bleeding
or elderly patients with cardiac dysfunction or positive fluid balance.