transfusion - related acute lung injury , also known as trali , is a rare , underreported but serious complication of blood transfusion . interaction of specific leukocyte antibodies from the donor with the leukocytes of the recipient causes noncardiogenic pulmonary edema indistinguishable from adult respiratory distress syndrome ( ards ) . the diagnosis is usually made on clinical grounds as a diagnosis of exclusion although demonstration of antileukocyte antibody in donor or rarely in the recipient can be helpful a 39-year - old female patient of american society of anesthesiologists ( asa ) grade 2 was presented for total abdominal hysterectomy . she was a known diabetic and hypertensive , well controlled with insulin and angiotensin converting enzyme ( ace ) inhibitors . blood counts , urea , creatinine , electrocardiograph , and chest x - ray were all normal , except for mild anemia ( hemoglobin 9.8% ) . airway maneuvers were smooth and recovery uneventful ; 1000 ml crystalloid was infused intraoperatively . for the next 24 h , patient was hemodynamically stable with good urine output . because hemoglobin was 8.4 g% and pcv ( packed cell volume ) 27% , whole blood transfusion was advised on the second postoperative day . after approximately 250ml of blood had been transfused transfusion was discontinued and remaining blood was found to be compatible when re - crossmatched . the donor was the patient 's brother and the whole blood did not undergo leukodepletion . patient received o2 by face mask , along with bronchodilators , steroids , and diuretics . chest x - ray showed bilateral nonhomogenous opacities but no cardiomegaly [ figure 1 ] . echocardiogram showed mild ra / rv dilatation possibly due to acute lung injury ( ali ) . third postoperative day abg ( arterial blood gas ) revealed ph 7.45 , po2 81 mmhg , spo2 96% , pco2 32 mmhg , and be 3.0 at 10 l / min flow of oxygen via face mask . after sedation and paralysis , she was intubated and ventilated on controlled mode using fio2 1 , peep 10 cm h2o resulting in a saturation of 100% . bronchodilator , steroid , and antibiotic therapy were continued . a clinical diagnosis of ali , probably transfusion related , on the fourth postoperative day , significant improvement occurred clinically , radiologically , and on abg , hence weaning was initiated . patient was successfully extubated on the sixth postoperative day and o2 was continued via face mask [ figure 2 ] . sixth postoperative day she was maintaining saturation on room air and was shifted to the ward on the seventh postoperative day . popovsky also published the first and largest series of trali cases in 1985 . in 1951 , barnard described the first case of fatal pulmonary edema accompanying transfusion therapy . the incidence is 1 in 5000 units transfused and up to 1 in 625 transfused patients , probably due to underreporting . the 58% mortality rate in trali cases distinguishes it from ards which has a mortality rate of 3050% . canadian consensus panel defines trali as a new episode of ali occurring during or within 6 h of a transfusion , not temporally related to another risk factor for ali . ali implies acute hypoxemia demonstrated by a pao2/fio2 ratio of < 300 ; spo2 < 90% on room air ; bilateral infiltrates on chest radiograph ; and no evidence of left atrial hypertension . if ali is due to other causes but still temporally related to transfusion , then trali is still a possibility . trali is associated with transfusion of whole blood , ffp ( fresh frozen plasma ) , platelets , cryoprecipitate , immunoglobulin , and stem cell preparations . directed donation from mother to child , or mother to father may present a higher risk due to sensitization of the mother to paternal antigen of the fetus during pregnancy ; 1015% incidence of trali has been seen in unleukodepleted blood transfusion . mechanism is immunologically mediated wherein ; wbc ( whole blood corpuscles ) antibodies were identified in donor serum as part of a transfusion reaction evaluation following trali . these react with patients granulocytes and hla ( human leukocyte antigens ) class i and class ii antigens . nonimmune mechanism has also been described where interleukin-6 lipid activation is possible when trali occurs without antileukocyte antibodies . it is postulated that the hla antibodies may cause the following sequence of events to occur to produce lung injury : ( 1 ) antibodies bind to and directly activate neutrophils ; ( 2 ) complement is activated resulting in the production of anaphylatoxins that promote neutrophil aggregation and sequestration in the pulmonary microvasculature ; ( 3 ) neutrophils marginate into the pulmonary vasculature and release enzymes , cytokines ( tumor necrosis factor - alpha , interleukin-1 , 6 , and 8) , and superoxide radicals that damage the blood vessels ; and ( 4 ) endothelial cell injury occurs resulting in pulmonary edema due to the accumulation of protein and fluid due to capillary leakage . autopsy findings in a patient who died of trali substantiate this mechanism.[1113 ] other predisposing factors ( general anesthesia , infection , recent surgery , exogenous cytokines , and massive transfusions ) have been suggested . the diagnosis of trali is essentially clinical by exclusion , further supported by demonstration of matching leukocyte antibodies in donor serum and increased neutrophil priming activity in the transfused blood . oxygen and ventilatory support appropriate for the degree of hypoxia and fluid administration for hypotension . steroids and diuretics , most cases show improvement within the first few hours and completely resolve within 2496 h. several approaches to the prevention of trali have been recommended . among these recommendations are ( 1 ) limit the amount of plasma transfused from implicated donors by transfusing either washed or frozen - deglycerolized red blood cells ; ( 2 ) indefinitely defer donors implicated in fatal trali ; ( 3 ) defer multiparous women as donors ; ( 4 ) screen donor units for leukoagglutinins ; ( 5 ) change manufacturing processes to limit accumulation of lipids during storage ; and ( 6 ) identify patients at risk for trali and use washed or fresh components for them . the listed preventive measures are potentially expensive and challenging to supply necessary products in a timely manner . however , many clinicians remain unaware of the condition because trali must be differentiated from a number of other conditions including ards , pneumonia , cardiac failure , circulatory overload , bacterial contamination , and acute hemolytic transfusion reaction . differentiation may be difficult and is a diagnosis of exclusion based on clinical signs and symptoms rather than laboratory testing . trali should be considered when a recently transfused patient develops acute respiratory distress.[1416 ] the possibility of trali in our case was the final diagnosis after ruling out the following differential causes . cardiogenic pulmonary edema was ruled out because there were no signs of fluid overload preoperatively and no cardiomegaly on x - ray . the ra / rv dilation on echo could have been due to hypoxic pulmonary vasoconstriction . as the desaturation was acute , blood counts were normal , and antibiotics were given preoperatively , we ruled out the possibility of a lung infection . aspiration pneumonia was excluded as patient was fasting ; the intubation / extubation procedures were uneventful , and resolution was rapid and complete . sepsis from the transfusion could also be ruled out as the blood counts were normal ; there was no multiorgan involvement and the resolution was rapid . the clinical setting did not support a possibility of anaphylaxis and could be ruled out when the blood was re - crossmatched . based on the clinical setting and response to treatment , trali was the probable diagnosis in our case after excluding the above differential diagnoses .
transfusion - related acute lung injury ( trali ) is a rare but serious complication of blood transfusion . 
 we present a suspected case of trali in a 39-year - old female patient who underwent total abdominal hysterectomy under uneventful general anesthesia . 
 the patient developed acute desaturation due to noncardiogenic pulmonary edema while receiving compatible blood transfusion on the second postoperative day . 
 as her symptoms were refractory to supportive treatment , she was mechanically ventilated for 3 days and successfully extubated on the fourth day . by exclusion , a clinical diagnosis of trali 
 was made . 
 the treatment for trali requires discontinuing transfusion and giving respiratory and cardiovascular support . 
 most cases show clinical improvement in first few hours and resolve completely within 96 h.