515 Compliance with a Restrictive Blood Transfusion Strategy: Do We Actually Follow Scientific Evidence?

Introduction Many burn centers use a restrictive blood transfusion strategy based on randomized controlled trials in burn patients (e.g. Transfusion Requirements in Burn Care Evaluation -TRIBE) and non-burn populations (e.g. Transfusion Requirements in Critical Care – TRICC), which have demonstrated no increased morbidity or mortality between restrictive and liberal transfusion approaches. The purpose of this study was to evaluate the adherence to a restrictive hemoglobin transfusion trigger strategy of 7 g/dL. Methods Retrospective study of all patients admitted to an adult regional ABA-verified burn centre between 15/11/ 2015 and 15/6/2018 who received at least one unit of blood (RBC). We use a restrictive transfusion strategy that administers RBC for a hemoglobin (HGb) < 7 gm/dL, one unit at a time, with a pre and post HGb level for each RBC transfusion, unless the patient is actively bleeding and/or hemodynamically unstable. RBC transfusions in the operating room do not follow this policy and were not studied. Values are presented as mean ± SD or median (IQR) as appropriate. Results We studied 66 patients (30% female) with age 53.2 ± 18.3 years, % TBSA burn 22 (11–41), % TBSA full thickness burn 6.5 (0.5 -21.8), and with 41% having inhalation injury. Overall, there were 691 RBC transfusions (TXns). A pre-TXn HGb was obtained 95% of the time and was 6.8 (6.5–7) gm/dL. TXn for a HGb > 7 gm/dL occurred in 35%. A post TXn HGb was obtained for 92% of these TXns with a HGb of 7.6 (7.2–8) gm/dL. RBC TXns during nighttime (1700 to 0800, n=449) were given for a HGb trigger of 6.8 (6.4–6.9) and were not compliant with our restrictive strategy 22% of the time. Daytime transfusions (0800 to 1700, n=207) were given for a significantly higher HGb [7 (6.7–7.1), p< 0.001] with significantly more non-compliance with the restrictive strategy (50%, p< 0.001). We also compared TXns before and after the TRIBE publication. Pre-TRIBE TXns (n=484) were given for significantly lower HGb than 172 post TRIBE TXns [6.8 (6.4–7) vs 6.9 (6.6–7.1) gm/dL respectively, p=0.001] and at significantly lower rate of non-compliance with the 7 gm/dL threshold than post TRIBE transfusions (28.1% vs 37.8%, respectively, p=0.02). Conclusions While a pre-TXn HGb level was available for 95% of blood transfusions, approximately one-third were given for a HGb > 7 gm/dL. Transfusion during nighttime (being predominantly ordered by housestaff physicians) were administered at a significantly lower HGb trigger and with significantly better compliance with the restrictive strategy than daytime transfusions. Paradoxically, compliance with the restrictive strategy was worse following the TRIBE publication. Applicability of Research to Practice These results identify important areas for improvement in adherence to our restrictive transfusion strategy.

Recording and reconstructing 10 billion unbiased b hadron decays in CMS

The CMS experiment has recorded a high-purity sample of 10 billion unbiased b hadron decays. The CMS trigger and data acquisition systems were configured to deliver a custom data stream at an average throughput of 2 GB s−1, which was “parked” prior to reconstruction. The data stream was defined by level-1 and high level trigger algorithms that operated at peak trigger rates in excess of 50 and 5 kHz, respectively. New algorithms have been developed to reconstruct and identify electrons with high efficiency at transverse momenta as low as 0.5 GeV. The trigger strategy and electron reconstruction performance were validated with pilot processing campaigns. The accumulation and reconstruction of this data set, now complete, were delivered without significant impact on the core physics programme of CMS. This unprecedented sample provides a unique opportunity for physics analyses in the flavour sector and beyond.

New approaches for track reconstruction in LHCb’s Vertex Locator

Starting with Upgrade 1 in 2021, LHCb will move to a purely software-based trigger system. Therefore, the new trigger strategy is to process events at the full rate of 30MHz. Given that the increase of CPU performance has slowed down in recent years, the predicted performance of the software trigger currently falls short of the necessary 30MHz throughput. To cope with this shortfall, the Upgrade High Level Trigger currently uses impact parameter cuts on VELO tracks to reduce the amount of tracks which require further processing. The presented work introduces an alternative approach to determine the impact parameter while achieving a more reliable uncertainty prediction than the current method, which could potentially improve the physics quality of these cuts at a later time.

Trigger Strategies for Standard Diffusion in Interorganizational Networks

When establishing a new technological standard, multiple actors often have to build coalitions to overcome the inertia of the emergent collaboration network and to mobilize decisive levels of support. The authors suggest that the emergence of a standard in a networked field can be strategically influenced by focusing only on a subset of all actors. The study defined the choice of a specific set of standard-initializing organizations as the trigger strategy. A conceptual model was developed from interorganizational collaboration as a network comprised of a set of heterogeneous, interconnected nodes, qualified by their group membership and size. The authors employed network simulations identifying the value of different trigger strategies. Data on a network of airline collaboration was used to illustrate the model. Under most conditions considered, the study found a strong triggering potential of interrelated core cliques in comparison to other trigger strategies. The results suggest that this strategy should receive more attention in the future.