[27] CHAPTER XI LESSON 2 Flashcards
include any adverse signs or symptoms associated with a transfusion and may be acute or delayed.
TRANSFUSION REACTIONS
may have immunologic or nonimmunologic causes. 1. Acute HTR are rare immunologic reactions that may be life-threatening and are usually caused by ABO incompatibilities. The associated hemolysis is intravascular. The most common signs of an acute hemolytic reaction are fever, chills, and hemoglobinuria. Dyspnea and hypotension leading to shock are seen in severe reactions. The most severe cases may result in DIC and renal failure. 2. Nonhemolytic febrile transfusion reactions are mild immunologic reactions that are caused by HLA class I antigens on transfused WBCs or platelets. They are the most common type of transfusion reaction (1 in every 200 transfusions). Fever and chills are the most common symptoms. The use of leukocyte filters when transfusing blood can help reduce the frequency of these reactions. 3. Allergic reactions are the second most common type of transfusion reactions. These acute immunologic reactions are typically associated with urticaria and are thought to occur in response to reactions between recipient antibodies and soluble proteins in the donor units. Antihistamines given before the transfusion can reduce the risk of an allergic reaction. Anaphylactic reactions are very severe allergic reactions. Although rare, they can be life-threatening. They are usually caused by antibodies to IgA.
Acute reactions
are rare immunologic reactions that may be life-threatening and are usually caused by ABO incompatibilities.
- Acute HTR
The associated hemolysis is intravascular.
- Acute HTR
The most common signs of an acute hemolytic reaction are fever, chills, and hemoglobinuria.
- Acute HTR
Dyspnea and hypotension leading to shock are seen in severe reactions.
- Acute HTR
The most severe cases may result in DIC and renal failure.
- Acute HTR
are mild immunologic reactions that are caused by HLA class I antigens on transfused WBCs or platelets.
- Nonhemolytic febrile transfusion reactions
They are the most common type of transfusion reaction (1 in every 200 transfusions).
- Nonhemolytic febrile transfusion reactions
Fever and chills are the most common symptoms.
- Nonhemolytic febrile transfusion reactions
The use of leukocyte filters when transfusing blood can help reduce the frequency of these reactions.
- Nonhemolytic febrile transfusion reactions
are the second most common type of transfusion reactions.
- Allergic reactions
These acute immunologic reactions are typically associated with urticaria and are thought to occur in response to reactions between recipient antibodies and soluble proteins in the donor units.
- Allergic reactions
Antihistamines given before the transfusion can reduce the risk of an allergic reaction.
- Allergic reactions
Anaphylactic reactions are very severe allergic reactions. Although rare, they can be life-threatening.
- Allergic reactions
They are usually caused by antibodies to IgA.
- Allergic reactions
is a life-threatening transfusion reaction caused by HLA antibodies.
- Transfusion-related acute lung injury (TRALI)
Symptoms are the same as those seen in adult respiratory distress syndrome and include acute respiratory distress, hypoxemia, pulmonary edema, fever, and hypotension.
- Transfusion-related acute lung injury (TRALI)
a. Bacterial contamination of the blood product
- Acute nonimmunologic reactions
b. Circulatory overload caused by too rapid transfusion
- Acute nonimmunologic reactions
c. Blood that has been hemolyzed by improper storage or mechanical stress (e.g., heart-lung machine)
- Acute nonimmunologic reactions
are characterized by the accelerated destruction of transfused RBCs and are most commonly associated with a secondary (amnestic) response to an RBC antigen.
- Delayed HTR
Delayed reactions may not be recognized for days, weeks, or even months after a transfusion, until a rapid decline in the recipient’s hematocrit is noticed.
- Delayed HTR
Patients may experience fever and mild jaundice.v
- Delayed HTR
The associated hemolysis is generally extravascular.
- Delayed HTR
IgG antibodies to Rh, MNS, Kell, Kidd, and Duffy antigens are often implicated.
- Delayed HTR
may be either acute or chronic.
- Transfusion-associated GVHD (TA-GVHD) reactions
An extremely high mortality rate is associated with TAGVHD.
- Transfusion-associated GVHD (TA-GVHD) reactions
These reactions occur when immunologically competent lymphocytes are transfused into an immunoincompetent host.
- Transfusion-associated GVHD (TA-GVHD) reactions
Bone marrow transplantation recipients may also develop TA-GVHD, but these patients typically have a chronic, milder disease with a much lower mortality rate.
- Transfusion-associated GVHD (TA-GVHD) reactions
The transfusion of irradiated units can prevent TA-GVHD in immunocompromised patients.
- Transfusion-associated GVHD (TA-GVHD) reactions
is a rare transfusion reaction usually seen in older female patients who have been sensitized to platelet antigens, either by previous transfusion or pregnancy.
- Post-transfusion purpura
These reactions are characterized by mild-to-severe immune thrombocytopenia with clinical bleeding in severe cases.
- Post-transfusion purpura
- Other nonimmunologic transfusion reactions include:
a. Citrate toxicity from anticoagulant
b. Hypothermia from transfusing cold blood
c. Hyperkalemia from the increased potassium levels in banked blood
d. Transfusion-induced hemosiderosis (iron overload) in patients who have undergone chronic transfusion
Investigating transfusion reactions requires strict adherence to the following steps:
1. All [?] must be checked for proper identification. Clerical error is the most common cause of HTR.
2. A [?] from the patient is centrifuged, and the serum or plasma is examined for icterus or hemolysis and compared against the pretransfusion sample.
3. A DAT is performed on a [?]. A DAT is performed on the pretransfusion specimen if the post-transfusion specimen has a positive DAT. An antigen-antibody incompatibility is assumed if the post-transfusion specimen DAT is positive, and the pretransfusion DAT is negative.
4. Other tests to further investigate the cause of the incompatibility may be performed
patient records and blood product containers
post-transfusion sample
post-transfusion EDTA specimen
Other tests to further investigate the cause of the incompatibility may be performed, including:
a. ABO and Rh on the recipient’s pretransfusion and post-transfusion specimens and on the donor units
b. Repeat compatibility testing with pretransfusion and post-transfusion specimens
c. Serum bilirubin on samples drawn 5 to 7 hours after transfusion
d. Gram’s stain on recipient’s plasma and culture of donor unit bag
e. Haptoglobin on pretransfusion and post-transfusion specimens
f. Urine hemoglobin
g. Coagulation studies
The first and most important step in ensuring that transfused blood will not transmit a pathogenic virus is
careful selection of the donor.
is usually spread by the fecal-oral route in communities where hygiene is compromised.
HAV
On infection with [?], the first positive test is HBV NAT and the first serologic marker to appear is HBsAg, followed by HBeAg and IgM anti-HBc within the first few weeks of exposure.
HBV
is an immune globulin prepared from persons with a high titer of anti-HBs and is used to provide passive immunity to health-care workers and others who are exposed to patients with HBV infection.
HBIG
A combined vaccine for [?] is available to provide immunity.
HAV and HBV
infection is common among drug addicts and can occur simultaneously with HBV infection; diagnosis depends on finding anti-HDV or HDV RNA in the serum.
HDV
Of all infections, 60% to 70% are asymptomatic. With the implementation of NAT, the window period has been reduced to 10 to 30 days.
HCV
is the leading cause of liver transplants in the United States.
HCV
is an emerging agent associated with transmission through transfusion and is the leading cause of hepatitis in the United Kingdom.
HEV
Diagnosis of infection is dependent on the presence of antibodies to both envelope and core proteins; HIV-positive persons with fewer than 200 CD4+ T cells per microliter are considered to have AIDS in the absence of symptoms
HIV-1 and HIV-2
Transfusion-associated infection is a concern for seronegative allogeneic organ transplant recipients and fetuses.
CMV
Reactivation of a latent infection can occur when an individual becomes severely immunocompromised.
CMV
The risk of infection for low-birth-weight neonates is not as great as it was in the past due to better transfusion techniques and management of their conditions.
CMV
detects the presence of anti- HIV and determines with which viral proteins the antibodies react.
WB confirmation test
The window period can be shortened by using the polymerase chain reaction, which detects infection before tests for antigen or antibody are positive.
HIV
is the most frequent cause of transfusion-transmitted infection.
Bacterial contamination
Because [?] for parasitic infections is not currently available, many blood banks have added questions to their donor questionnaire that address topics associated with risk for parasitic infection.
routine screening
are in use for plasma and platelet products and under development for red cell products.
Pathogen inactivation methods
These methods remove or reduce the residual risk of transfusion-associated disease due to the window period, virus variants, laboratory mistakes, and new, emerging diseases.
Pathogen inactivation methods
is a process mandated by the FDA that directs collection facilities to notify donors who test positive for viral markers, to notify prior recipients of the possibility of infection, and to quarantine or discard
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