Stubbs, James

Importance Patients undergoing cardiac surgery with cardiopulmonary bypass often require platelet transfusions for bleeding. Platelets are routinely stored at room temperature (20-24 °C) for up to 5 to 7 days; however, cold storage (1-6 °C) may allow for increased storage duration without loss of hemostatic function. Objective To determine the maximum cold-storage duration, up to 21 days, for which cold-stored platelets (CSPs) are noninferior or superior in hemostatic efficacy to room-temperature platelets (RTPs) when transfused in actively bleeding patients undergoing cardiac surgery with cardiopulmonary bypass. Design, Setting, and Participants A phase 3, multicenter, randomized, partially blinded, adaptive, noninferiority, storage duration–ranging trial conducted in pediatric and adult patients undergoing cardiac surgery with planned cardiopulmonary bypass at 27 sites in the US and Australia from December 2021 to March 2025. Statistical analysis was conducted from September 9 to October 3, 2025. Intervention Patients were randomized 2:1 to receive CSPs with a maximum of 21 days of storage vs RTPs with a maximum of 7 days of storage. Main Outcomes and Measures The primary outcome was a hemostatic efficacy score with values ranging from 1 to 5 and higher values indicating greater bleeding. The noninferiority margin was 1 point. The success criterion was met if at least 1 cold-storage duration of 7 days or more had a posterior probability of noninferiority of at least 97.5%. The secondary outcome was 24-hour chest tube output. Results Of the 1000 patients who underwent platelet transfusion, 989 were included in the primary analysis (650 CSPs and 339 RTPs). The cohort had a mean (SD) age of 42.1 (30.1) years and 67.8% were male. CSPs were noninferior to RTPs for the primary outcome, with a probability of greater than 99.9% for all cold-storage durations. Pooled across storage durations, CSPs had a mean difference from RTPs of 0.09 (95% credible interval, −0.06 to 0.23). Median (IQR) chest tube output at 24 hours (8.9 mL/kg [5.2-15.4] for CSPs vs 8.4 mL/kg [5.5-15.9] for RTPs; difference in medians, 0.4 [95% CI, −1.0 to 1.5]) was not statistically different between study groups. In a post hoc analysis, as all storage durations were noninferior, considering the CSPs as a single group, the hemostatic efficacy score was similar between both groups: mean (SD) of 3.08 (1.15) CSPs vs 2.99 (1.10) RTPs. There were no differences in venous or arterial thrombotic events, transfusion-associated adverse events, acute respiratory distress syndrome, kidney failure, septic shock, and mortality between the study groups, except for increased reexploration rates in the CSP group. Conclusions and Relevance For patients undergoing cardiac surgery, CSPs stored up to 21 days are noninferior to RTPs for the control of active surgical bleeding. Use of CSPs may allow for increased availability of platelets by reducing wastage and shortages and may allow for incorporation of platelets into inventory at locations where platelets cannot be maintained due to the 5- to 7-day shelf life of RTPs. Trial Registration ClinicalTrials.gov Identifier: NCT04834414

Background ‘Exception from informed consent’ research requires community consultation to ensure that the views of the local population have been considered. Using market research companies to distribute surveys across local populations is attractive because it ensures adequate response rates. It is not known whether individuals who respond to surveys are typical of the targeted communities. The purpose of this study is to compare the demographics of the survey respondents with that of the general population in the same area. Methods This is an analysis of data collected as part of the ‘Trauma Resuscitation with Group O Whole Blood or Products’ (TROOP) trial. The surveys used a commercial market research service to reach the communities of interest and consisted of 18 questions designed to evaluate respondents’ willingness to be enrolled in the TROOP trial and the demographics of survey respondents. Results Catchment populations varied from 0.5 to 9.4 million residents, with a total of 33.5 million. The racial and ethnic composition of the population (and the survey respondents, in brackets) was 44.8% (57.0%) white, 25.7% (13.4%) Hispanic, 12.7% (19.4%) black, 8.0% (2.5%) multiracial, 7.9% (4.4%) Asian, 0.7% (0.9%) Native American, and 0.2% (0.5%) Islanders. Of the male population (and survey respondents, in brackets), 12.2% (15.3%) were aged 18years to 24 years, 20.5% (22.3%) aged 25 years to 34 years, 18.1% (24.9%) aged 35 years to 44 years, 16.3% (18.5%) aged 45 years to 54 years, 15.5% (14.8%) aged 55 years to 64 years, and 17.4% (4.3%) aged 65 years and over. Of the female population (and survey respondents, in brackets), 11.0% (18.5%) were aged 18 years to 24 years, 18.4% (22.6%) aged 25 years to 34 years, 16.4% (23.5%) aged 35 years to 44 years, 15.0% (17.3%) aged 45 years to 54 years, 18.5% (14.1%) aged 55 years to 64 years, and 20.6% (3.9%) aged 65 years and over. Conclusions For this trial, using a market research company to distribute community surveys resulted in respondents that are broadly representative of the geographic areas where the trial will be conducted, except for individuals over the age of 65 years and older. This finding provides reassurance to investigators and institutional review boards that the views expressed by respondents are representative of the population where the trial will be conducted. Level of evidence III

Background Delayed cold storage of room temperature platelets may extend shelf life from 5 to 14 days. The study hypothesized that the use of delayed cold-stored platelets in cardiac surgery would be associated with decreased postoperative platelet count increments but similar transfusion and clinical outcomes compared to room temperature-stored platelets. Methods This is an observational cohort study of adults transfused with platelets intraoperatively during elective cardiac surgery between April 2020 and May 2021. Intraoperative platelets were either room temperature-stored or delayed cold-stored based on blood bank availability rather than clinical features or provider preference. Differences in transfusion and clinical outcomes, including a primary outcome of allogenic transfusion exposure in the first 24 h postoperatively, were compared between groups. Results A total of 713 patient encounters were included: 529 (74%) room temperature-stored platelets and 184 (26%) delayed cold-stored platelets. Median (interquartile range) intraoperative platelet volumes were 1 (1 to 2) units in both groups. Patients receiving delayed cold-stored platelets had higher odds of allogeneic transfusion in the first 24 h postoperatively (81 of 184 [44%] vs. 169 of 529 [32%]; adjusted odds ratio, 1.65; 95% CI, 1.13 to 2.39; P = 0.009), including both erythrocytes (65 of 184 [35%] vs. 135 of 529 [26%]; adjusted odds ratio, 1.54; 95% CI, 1.03 to 2.29; P = 0.035) and platelets (48 of 184 [26%] vs. 79 of 529 [15%]; adjusted odds ratio, 1.91; 95% CI, 1.22 to 2.99; P = 0.005). There was no difference in the number of units administered postoperatively among those transfused. Platelet counts were modestly lower in the delayed cold-stored platelet group (−9 × 109/l; 95% CI, −16 to −3]) through the first 3 days postoperatively. There were no significant differences in reoperation for bleeding, postoperative chest tube output, or clinical outcomes. Conclusions In adults undergoing cardiac surgery, delayed cold-stored platelets were associated with higher postoperative transfusion utilization and lower platelet counts compared to room temperature-stored platelets without differences in clinical outcomes. The use of delayed cold-stored platelets in this setting may offer a viable alternative when facing critical platelet inventories but is not recommended as a primary transfusion approach. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Recent combat experience reignited interest in transfusing whole blood (WB) for patients with life‐threatening bleeding. US Army data indicate that WB transfusion is associated with improved or comparable survival compared to resuscitation with blood components. These data complement randomized controlled trials that indicate that platelet (PLT)‐containing blood products stored at 4°C have superior hemostatic function, based on reduced bleeding and improved functional measures of hemostasis, compared to PLT‐containing blood products at 22°C. WB is rarely available in civilian hospitals and as a result is rarely transfused for patients with hemorrhagic shock. Recent developments suggest that impediments to WB availability can be overcome, specifically the misconceptions that WB must be ABO specific, that WB cannot be leukoreduced and maintain PLTs, and finally that cold storage causes loss of PLT function. Data indicate that the use of low anti‐A and anti‐B titer group O WB is safe as a universal donor, WB can be leukoreduced with PLT‐sparing filters, and WB stored at 4°C retains PLT function during 15 days of storage. The understanding that these perceived barriers are not insurmountable will improve the availability of WB and facilitate its use. In addition, there are logistic and economic advantages of WB‐based resuscitation compared to component therapy for hemorrhagic shock. The use of low‐titer group O WB stored for up to 15 days at 4°C merits further study to compare its efficacy and safety with current resuscitation approaches for all patients with life‐threatening bleeding.