Is lupus anticoagulant testing with dilute Russell's viper venom clotting times reliable in the presence of inflammation?

Background: Testing for lupus anticoagulant (LA) is not recommended in case of inflammation as C-reactive protein (CRP) can interfere in vitro with the phospholipids present in the activated partial thromboplastin time test used to detect an LA. However, the potential interference of an acute phase protein (ie, CRP) in LA testing using the dilute Russell's viper venom (DRVV) test is poorly studied. Objectives: To study the effect of inflammation, as evidenced by increased CRP levels, on DRVV tests. Methods: First, a retrospective analysis (2013-2023) was performed: data on all LA workups were retrieved, and the association between CRP levels and DRVV screen, mix, and confirm clotting times was studied. Second, data on DRVV panels and CRP levels were extracted from 2 prospective studies involving intensive care unit patients to study the association between both variables. Third, CRP was added to normal pooled plasma at 6 relevant concentrations (up to 416 mg/L) to study the association between CRP itself and DRVV coagulation times. Results: In the retrospective analysis, DRVV screen and confirm clotting times significantly increased as CRP increased (increase of 0.11 seconds and 0.03 seconds per 1 mg/L increase of CRP level, respectively). In the prospective analysis, only DRVV screen was prolonged with high CRP levels (increase of 0.06 seconds for a 1 mg/L increase in CRP level); DRVV screen/confirm ratio was also increased with high CRP levels. In vitro, the addition of CRP did not significantly increase any DRVV clotting times. Conclusion: LA testing should be performed with much caution in the presence of inflammation as it may be associated with prolongation of both activated partial thromboplastin time and DRVV clotting times.

Optimizing O red blood cell concentrate usage in the emergency department in the era of patient blood management.

BACKGROUND: Emergency transfusion may require the availability of O-negative red blood cell concentrates without pre-transfusion testing. At the Cliniques Universitaires Saint-Luc, the emergency department was used to having access to two decentralized O-negative red blood cell concentrates. This study aims to analyze the consumption of O-negative red blood cell concentrates in emergency situations both before and after the implementation of a novel strategy aiming at optimizing stocks. This strategy provides a combined allocation of one unit of O-positive red blood cell concentrate and one unit of O-negative red blood cell concentrate decentralized in the emergency department and reserve the transfusion of the negative unit only to under 45-year-old women and under 20-year-old men. MATERIALS AND METHODS: A retrospective study was conducted of the transfusion and medical records of all patients who received immediate transfusions in the emergency department without pre-transfusion testing between 2008 and 2022. RESULTS: A total of 193 patients received O red blood cell concentrates without pre-transfusion testing in emergency situations between 2008 and 2022. During the first 24 h of hospitalization, 354 O-negative units were transfused. Mean ratios of number of O-negative bags between 2008 and 2020 was 1.98 unit/patient. After implementation of the new strategy, the ratio in 2021 was 1.46 unit/patient and drastically decreased in 2022 to 0.79 unit/patient. CONCLUSION: In situations of emergency, allocating O-negative units only for women younger than 45 years and men younger than 20 years could have saved 85% of O-negative red blood cell concentrates transfused (303/354) yet balancing the immunological risk. Limiting the number of delocalized units of O-negative red blood cell concentrates in the emergency department seems to lower O-negative consumption. With this strategy, the units spared could have been transfused to patients with greater needs (e.g., sickle cell patients or chronically transfused patients).

There is an urgent need to adopt a pull-flow logic for the supply of RBCs to meet patients' needs: A single center study.

BACKGROUND: Despite major demographic changes, several decisions and initiatives, among which Patient Blood Management, have led to a significant reduction in the transfusion of packed red blood cells (RBCs) in Belgium, as it has been observed in many countries. Unfortunately, not all blood groups were proportionately impacted and shortage in O D-negative RBCs is regularly or chronically observed. The goal of this study was to examine how to optimize the use and the supply of O D-negative blood in our academic hospital. METHODOLOGY: All blood transfusions performed at Cliniques universitaires Saint-Luc between January 1, 2019 and December 31, 2021 were reviewed. The blood group of the patients was compared with the blood group of the RBCs actually supplied and transfused. RESULTS: 49.823 RBCs transfusions were analyzed. The patients' needs didn't reflect those of a Caucasian population, with an increase of O (47.9%) and B (10.3%) for the ABO blood group, and a quite high proportion of R0r (8.6%) for the Rh blood group. Only two thirds of O D-negative RBCs were transfused to O rr or R0r patients. CONCLUSION: The application of PBM and the ethnic imbalance between blood donor and patient populations are two important risk factors for chronic shortages of O D-negative blood. To adapt blood component resources, it is essential to have a complete picture of the real needs of patients according to their blood group profile. Blood donor centers must adapt to the evolving needs of hospitals in order to plan future supplies in a "pull-flow" approach.