Weister, Timothy J.

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.

BACKGROUND: Intraoperative red blood cell (RBC) transfusion is common, yet transfusion strategies remain controversial as pretransfusion hemoglobin triggers are difficult to utilize during acute bleeding. Alternatively, postoperative hemoglobin values may provide useful information regarding transfusion practices, though optimal targets remain undefined. METHODS: This is a single-center observational cohort study of adults receiving allogeneic RBCs during noncardiac surgery from 2010 through 2014. Multivariable regression analyses adjusting for patient illness, laboratory derangements, and surgical features were used to assess relationships between initial postoperative hemoglobin values and a primary outcome of hospital-free days. RESULTS: A total of 8060 patients were included. Those with initial postoperative hemoglobin <7.5 or ≥11.5 g/dL had decreased hospital-free days [mean (95% confidence interval [CI]), −1.45 (−2.50 to −0.41) and −0.83 (−1.42 to −0.24), respectively] compared to a reference range of 9.5–10.4 g/dL (overall P value .003). For those with hemoglobin <7.5 g/dL, the odds (95% CI) for secondary outcomes included acute kidney injury (AKI) 1.43 (1.03–1.99), mortality 2.10 (1.18–3.74), and cerebral ischemia 3.12 (1.08–9.01). The odds for postoperative mechanical ventilation with hemoglobin ≥11.5 g/dL were 1.33 (1.07–1.65). Secondary outcome associations were not significant after multiple comparisons adjustment (Bonferroni P < .0056). CONCLUSIONS: In transfused patients, postoperative hemoglobin values between 7.5 and 11.5 g/dL were associated with superior outcomes compared to more extreme values. This range may represent a target for intraoperative transfusions, particularly during active bleeding when pretransfusion hemoglobin thresholds may be impractical or inaccurate. Given similar outcomes within this range, targeting hemoglobin at the lower aspect may be preferable, though prospective validation is warranted.

BACKGROUNDIntraoperative plasma transfusion is common, yet little is known regarding its effects on perioperative coagulation tests or clinical outcomes.STUDY DESIGN AND METHODSThis is a retrospective cohort study of adults receiving intraoperative plasma transfusion at a single center from 2011 to 2015. Relationships between plasma transfusion volume, changes in coagulation test values, and clinical outcomes, including a primary outcome of early postoperative red blood cell (RBC) transfusion, were assessed with multivariable regression analyses. Secondary outcomes included hospital mortality, intensive care unit (ICU)‐ and hospital‐free days, intraoperative RBC transfusions, and estimated blood loss.RESULTSA total of 3393 unique patients were included, with median (IQR) transfusion of 2 (2‐4) units. In multivariable analyses, higher plasma volumes were associated with worse outcomes, with each 1 mL/kg increase associated with increased odds for postoperative (1.02 [1.01‐1.03], p < 0.001) and intraoperative RBCs (1.17 [1.16‐1.19], p < 0.001) and fewer ICU‐ and hospital‐free days (mean difference [95% CI], –0.08 [−0.12 to −0.05], p < 0.001; and −0.09 [−0.13 to −0.06], p < 0.001, respectively). Greater decreases in international normalized ratio (INR) following plasma transfusion were associated with decreased odds of postoperative RBCs (0.35 [0.25‐0.47], p < 0.001), decreased mortality (0.50 [0.31‐0.83], p = 0.007), and increased mean ICU‐ (1.31 [0.41‐2.21], p = 0.004) and hospital‐free days (1.15 [0.19‐2.10], p = 0.018).CONCLUSIONIn patients receiving intraoperative plasma transfusion, higher transfusion volumes were associated with inferior clinical outcomes; however, greater improvements in INR were associated with improved outcomes. Future prospective studies are necessary to better define these relationships and to explore plasma transfusion triggers beyond the limitations of INR.

BACKGROUND: Transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) are the leading causes of transfusion-related fatalities. While these transfusion-related pulmonary complications (TRPCs) have been well detailed in adults, their burden in pediatric subsets remains poorly defined. We sought to delineate the incidence and epidemiology of pediatric TRPCs after intraoperative blood product transfusion. METHODS: In this retrospective cohort study, we evaluated all consecutive pediatric patients receiving intraoperative blood product transfusions during noncardiac surgeries between January 2010 and December 2014. Exclusion criteria were cyanotic heart disease, preoperative respiratory insufficiency, extracorporeal membrane oxygenation, and American Society of Anesthesiologists physical status VI. Medical records were electronically screened to identify those with evidence of hypoxemia, and in whom a chest x-ray was obtained within 24 hours of surgery. Records were then manually reviewed by 2 physicians to determine whether they met diagnostic criteria for TACO or TRALI. Disagreements were adjudicated by a third senior physician. RESULTS: Of 19,288 unique pediatric surgical patients, 411 were eligible for inclusion. The incidence of TRPCs was 3.6% (95% confidence interval [CI], 2.2–5.9). TACO occurred in 3.4% (95% CI, 2.0–5.6) of patients, TRALI was identified in 1.2% (95% CI, 0.5–2.8), and 1.0% (95% CI, 0.4–2.5) had evidence for both TRALI and TACO. Incidence was not different between males (3.4%) and females (3.8%; P = .815). Although a trend toward an increased incidence of TRPCs was observed in younger patients, this did not reach statistical significance ( P = .109). Incidence was comparable across subsets of transfusion volume ( P = .184) and surgical specialties ( P = .088). Among the 15 patients experiencing TRPCs, red blood cells were administered to 13 subjects, plasma to 3, platelets to 3, cryoprecipitate to 2, and autologous blood to 3. Three patients with TRCPs were transfused mixed blood components. CONCLUSIONS: TRPCs occurred in 3.6% of transfused pediatric surgical patients, with the majority of cases attributable to TACO, congruent with adult literature. The frequency of TRPCs was comparable between genders and across surgical procedures and transfusion volumes. The observed trend toward increased TRPCs in younger children warrants further consideration in future investigations. Red blood cell administration was the associated component for the majority of TRPCs, although platelets demonstrated the highest risk per component transfused. Mitigation of perioperative risk associated with TRPCs in pediatric patients is reliant on further multiinstitutional studies powered to examine patterns and predictors of this highly morbid entity.