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SAN FRANCISCO -- Surgeons should be extremely judicious in ordering fresh frozen plasma (FFP) as part of perioperative blood transfusions, suggested a nationwide analysis reported here.

Post-operative rates of both venous thromboembolism (VTE) and mortality were significantly higher in patients receiving FFP along with red blood cells, relative to those transfused only with red cells, according to Una Choi, a medical student at Johns Hopkins University in Baltimore.

Mortality within 30 days stood at 4.53% for those receiving FFP, compared with 3.13% with red cells only (P<0.0001), Choi reported at the American Society of Anesthesiologists annual meeting.

The same pattern applied to rates of 30-day VTE and episodes of related thrombotic conditions (all P<0.0001):

• All VTE: 3.92% vs 2.52%
• Pulmonary embolism: 1.93% vs 1.30%
• Disseminated intravascular coagulopathy: 0.96% vs 0.35%

Results were nearly identical when the analysis was restricted to cardiovascular surgeries, Choi reported. This is particularly important, she said, because such patients "may be more vulnerable" insofar as in-hospital transfusions are more common than with many other types of procedures.

Thus, she said, it's important to be cautious about transfusing "yellow" blood products during surgery, a category that also includes platelets and other non-red cells blood components.

The study was born from earlier research indicating that transfusions in general seem to raise VTE risk. Use of plasma in addition to red blood cells is common but its influence, if any, on VTE risk have not been well studied, Choi said. Aside from potential effects on clinical outcomes, another reason to care is that blood products are frequently in short supply; using only as much as necessary and no more is a vital management goal. There are cost implications as well.

For the current analysis, her group examined claims data collected in the TriNetX Diamond Network, which houses up-to-date health records from more than 210 million Americans. Choi's group searched for procedures involving transfusions performed from 2006 up to this year. Results were adjusted for patients' demographics, type of surgery, and comorbidities (Choi acknowledged, however, that the database did not include all the factors that might drive decisions to provide FFP).

The researchers identified some 16,600 patients receiving perioperative FFP; these were matched 1:1 to patients receiving non-FFP transfusions. Among the factors included in the matching were age, sex, race/ethnicity, BMI, and comorbidities. Cardiovascular procedures accounted for more than 85% of the total.

This being a records-based analysis, it's not certain why FFP would increase VTE risk beyond that already associated with transfusions generally. Choi speculated that, by altering the mix of clotting factors in a patient's system, FFP further promotes a proclivity to thrombosis.

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