Acute lung injury (TRALI)
TRALI is a rare but serious adverse event, a clinical syndrome with onset within 6 hours of transfusion that presents as acute hypoxemia, respiratory distress, and noncardiogenic pulmonary edema.
Among 17,771,193 total inpatient transfusion stays, the overall incidence of TRALI was 33.2 per 100,000. The rate was 55.9 for immunocompromised patients versus 28.4 for nonimmunocompromised patients. The rate ratio was 2.0 (P less than .001).
The difference by immune status may be caused by higher blood utilizations with more units transfused per stay among immunocompromised patients, a higher incidence of prior transfusions among these patients, higher use of irradiated blood components that may lead to accumulation of proinflammatory mediators in blood products during storage, or underlying comorbidities.
The overall rate increased from 14.3 in 2007 to 56.4 in 2018. The rates increased proportionally among both immunocompromised and nonimmunocompromised patients.
As with TRA, the incidence of TRALI was higher in patients with five or more units transfused, while the incidence declined with age, likely caused by declining blood use and age-related changes in neutrophil function, Dr. Menis said.
TRALI rates were slightly higher among men than among women, as well as higher among white patients than among nonwhite patients.
Overall, TRALI rates were higher for patients who received platelets either alone or in combination with RBCs and/or plasma. The highest rates were among patients who received RBCs, plasma and platelets.
Dr. Menis called for studies to determine what effects the processing and storage of blood components may have on TRALI occurrence; he and his colleagues also are planning regression analyses to assess potential risk factors for this complication.
Circulatory overload (TACO)
TACO is one of the leading reported causes of transfusion-related fatalities in the U.S., with onset usually occurring within 6 hours of transfusion, presenting as acute respiratory distress with dyspnea, orthopnea, increased blood pressure, and cardiogenic pulmonary edema.
The overall incidence of TACO among hospitalized patients aged 65 years and older from 2011 through 2018 was 86.3 per 100,000 stays. The incidences were 128.3 in immunocompromised and 76.0 in nonimmunocompromised patients. The rate ratio for TACO in immunocompromised versus nonimmunocompromised patients was 1.70 (P less than .001).
Overall incidence rates of TACO rose from 62 per 100,000 stays in 2011 to 119.8 in 2018. As with other adverse events, incident rates rose with the number of units transfused.
Rates of TACO were significantly higher among women than they were among men (94.6 vs. 75.9 per 100,000; P less than .001), which could be caused by the higher mean age of women and/or a lower tolerance for increased blood volume from transfusion.
The study results also suggested that TACO and TRALI may coexist, based on evidence that 3.5% of all TACO stays also had diagnostic codes for TRALI. The frequency of co-occurrence of these two adverse events also increased over time, which may be caused by improved awareness, Dr. Menis said.
Acute infections following transfusion can lead to prolonged hospitalizations, sepsis, septic shock, and death. Those most at risk include elderly and immunocompromised patients because of high utilization of blood products, comorbidities, and decreased immune function.
Among 8,833,817 stays, the overall rate per 100,000 stays was 2.1. The rate for immunocompromised patients was 5.4, compared with 1.2 for nonimmunocompromised patients, for a rate ratio of 4.4 (P less than .001).
The incidence rate declined significantly (P = .03) over the study period, with the 3 latest years having the lowest rates.
Rates increased substantially among immunocompromised patients by the number of units transfused, but remained relatively stable among nonimmunocompromised patients.
Infection rates declined with age, from 2.7 per 100,000 stays for patients aged 65-68 years to 1.2 per 100,000 for those aged 85 years and older.
As with other adverse events, AIFT rates were likely related to the blood components transfused, with substantially higher rates for stays during which platelets were transfused either alone or with RBCs, compared with RBCs alone. This could be caused by the room-temperature storage of platelets and higher number of platelets units transfused, compared with RBCs alone, especially among immunocompromised patients.
In all, 51.9% of AIFT cases also had sepsis noted in the medical record, indicating high severity and emphasizing the importance of AIFT prevention, Dr. Menis said.
The studies were funded by the FDA, and Dr. Menis is an FDA employee. He reported having no conflicts of interest.