Transfusion reactions - TRALI & TACO

• TRALI - transfusion related acute lung injury
• TRALI is seen in 1 in 10,000 units transfused
• TRALI is a form of ARDS
• ARDS is acute respiratory distress syndrome
• TRALI arises within 6 hours of transfusion and usually resolves within 96 hours
• most cases of TRALI are evident sooner, in about 1-2 hours
• symptoms of TRALI include fever, chills, dyspnea, cyanosis, hypotension, hypoxemia, and new onset (or worsening) of pulmonary edema
• TRALI can also be associated with transient neutropenia or leukopenia
• all plasma-containing components have been implicated in TRALI: whole blood, RBCs, platelets, cryoprecipitate, and fresh frozen plasma
• hypotension differentiates TRALI from TACO
• volumes as small as 15 mL have led to TRALI
• in TRALI, alveoli fill with fluid (pulmonary edema)
• lung injury due to TRALI is usually transient and about 80% of patients improve in 48-96 hours
• the precise mechanism of TRALI is unkown
• possible causes of TRALI include the donor has antibodies to recipient WBC antigens or infused biological response modifiers (BRM)

  • either may initiate a sequence of events that leads to cellular activation and damage to the endothelial basement membranes in the lungs
• In TRALI, get pulmonary edema due to leakage (because of membrane damage) of protein rich fluid into alveolar space
• TRALI I - no risk factors for ARDS; acute onset, hypoxemia, bilateral pulmonary edema; onset within 6 hours of transfusion
• TRALI II - patient has risk factors for ARDS or has existing mild ARDS but has had a stable respiratory status in the 12 hours before the transfusion
• WBC antibodies - the source of the antibodies is usually the donor; these antibodies react with all recipient leukocytes; if the patient makes antibodies, they will only react with a few white cells in the donated blood
• BRMs - biological response modifiers
• BRMS - can accumulate during storage and can enhance PMN activity; PMNs can become activated and result in damage to the lung, capillary leakage, and pulmonary edema
• in comparison to TRALI, anaphylactic transfusion reactions: do not see fever and pulmonary edema
• TACO - transfusion associated circulatory overload is very similar to TRALI, except TACO is due to cardiac stress
• transfusion related sepsis: see high fever and low blood pressure
• treatment of TRALI: give respiratory support, like O2 or mechanical ventilation
• Treatment of TRALI: medication (pressor agents) to increase blood pressure
• prevention of TRALI: no way to really ID patients that are at risk of TRALI: can defer donors implicated in TRALI reactions and defer women who have had many pregnancies, more likely to have HLA antibodies in their blood; may be better to not use their plasma
• TACO - transfusion associated circulatory overload
• TACO has recently been recognized as an important complication
• TACO - can see pulmonary edema due to circulatory overload
• TACO - the greatest risk is to people over 70 and infants
• TACO - can also be an issue in people who can't regulate fluid balance
• TACO - usually caused by large volumes of component, but small volumes have been shown to cause it as well in susceptible patients
• signs and symptoms of TACO include seeing the following within several hours of transfusion: dyspnea, orthopnea, cyanosis, tachycardia, jugular venous distention, pedal edema, and increased blood pressure; can also see headache, dry cough, and tightness of chest
• TACO and TRALI are confused because you can see pulmonary edema with both
• a patient can experience TACO and TRALI at the same time
• the pulmonary edema in TACO is cardiogenic and responsive to diuretics
• hypertension is constant in TACO
• in TRALI, can have transient hypertension, but usually see hypotension
• treatment of TACO include stopping transfusion as soon as symptoms of TACO appear, sitting patient up, providing O2 and start diuretics to reduce intravascular volume; can perform therapeutic phlebotomy