Gajić, Ognjen

Objectives: Critically ill surgical patients may receive concomitant aspirin and therapeutic anticoagulation postoperatively, yet the safety of this practice remains unknown. We evaluated the risk of major bleeding with concomitant therapy compared with anticoagulation alone. Design: Observational cohort study. Inverse probability of treatment weighting was used to assess the association between concomitant therapy and a primary outcome of major bleeding. Setting: Postoperative ICUs at an academic medical center. Patients: Adults (≥ 18 yr old) receiving anticoagulation during postoperative ICU admission between 2007 and 2016. Interventions: None. Measurements and Main Results: Nine thousand five hundred eighteen anticoagulated patients were included, including 3,237 (34%) receiving aspirin. A total of 1,874 unique patients (19.7%) experienced a major bleeding event. In inverse probability of treatment weighting analyses, concomitant therapy was associated with increased odds for major bleeding (odds ratio, 1.20; 95% CI, 1.05–1.36; p = 0.006) compared with anticoagulation alone. An interaction test suggested a differential relationship between aspirin use and major bleeding based on aspirin use in the 7 days prior to anticoagulation, such that a strong association between aspirin and major bleeding was observed for recent initiators of aspirin (1.40; 1.13–1.72;p = 0.002) but not for those continuing prior aspirin use. Aspirin use prior to anticoagulation did not modify the relationship between concomitant therapy and new myocardial infarction or stroke (i.e., rates were not increased with aspirin discontinuation prior to anticoagulation). Conclusions: Concomitant aspirin and anticoagulation in critically ill surgical patients was associated with an increased rate of major bleeding. Future investigations are warranted to further define optimal management of antiplatelet therapy during anticoagulation in surgical patients.

BACKGROUND: The relationships between the ratios of transfused allogeneic blood products and clinical outcomes in patients with acute intraoperative hemorrhage are poorly defined. METHODS: To better define these ratios, we undertook a single-center, observational cohort study of all surgical patients (≥18 years) who received rapid transfusion defined by a critical administration threshold of 3 or more units of red blood cells (RBCs) intraoperatively within 1 hour between January 1, 2011 and December 31, 2015. Multivariable regression analyses were used to assess relationships between ratios of plasma to RBCs and platelets to RBCs at 3, 12, and 24 hours and clinical outcomes. The primary outcome was hospital mortality, with secondary outcomes of intensive care unit and hospital-free days. RESULTS: The study included 2385 patients, of whom 14.9% had a plasma-to-RBC ratio of 1.0+, and 47.6% had a platelet-to-RBC ratio of 1.0+. Higher plasma-to-RBC and platelet-to-RBC ratios were observed for patients who underwent cardiac, transplant, and vascular surgery and in patients with greater derangements in hemostatic laboratory values. Ratios did not differ by patient age or severity of illness. Higher ratios were not associated with improved clinical outcomes. Mortality differed by platelet-to-RBC but not plasma-to-RBC ratio, with the highest mortality observed with a platelet-to-RBC ratio of 0.1–0.9 at 24 hours (odds ratio, 3.34 [1.62–6.88]) versus no platelets ( P = .001). Higher plasma-to-RBC ratios were associated with decreased hospital-free days, although differences in clinical outcomes were not significant after exclusion of patients receiving only RBCs without component therapies. CONCLUSIONS: Transfusion ratios in surgical patients with critical intraoperative hemorrhage were largely related to surgical and hemostatic features rather than baseline patient characteristics. Higher ratios were not associated with improved outcomes.