Non-invasive monitoring of red blood cells during cold storage using handheld Raman spectroscopy.

BACKGROUND: The current best practices allow for the red blood cells (RBCs) to be stored for prolonged periods in blood banks worldwide. However, due to the individual-related variability in donated blood and RBCs continual degradation within transfusion bags, the quality of stored blood varies considerably. There is currently no method for assessing the blood product quality without compromising the sterility of the unit. This study demonstrates the feasibility of monitoring storage lesion of RBCs in situ while maintaining sterility using an optical approach. STUDY DESIGN AND METHODS: A handheld spatially offset Raman spectroscopy (RS) device was employed to non-invasively monitor hemolysis and metabolic changes in 12 red cell concentrate (RCC) units within standard sealed transfusion bags over 7 weeks of cold storage. The donated blood was analyzed in parallel by biochemical (chemical analysis, spectrophotometry, hematology analysis) and RS measurements, which were then correlated through multisource correlation analysis. RESULTS: Raman bands of lactate (857 cm-1 ), glucose (787 cm-1 ), and hemolysis (1003 cm-1 ) were found to correlate strongly with bioanalytical data over the length of storage, with correlation values 0.98 (95% confidence interval [CI]: 0.86-1.00; p = .0001), 0.95 (95% CI: 0.71-0.99; p = .0008) and 0.97 (95% CI: 0.79-1.00; p = .0004) respectively. DISCUSSION: This study demonstrates the potential of collecting information on the clinical quality of blood units without breaching the sterility using Raman technology. This could significantly benefit quality control of RCC units, patient safety and inventory management in blood banks and hospitals.

Longitudinal Changes in the Blood Supply and Demand in North-East-Germany 2005-2015.

BACKGROUND: Securing future blood supply is a major issue of transfusion safety. In this prospective 10-year longitudinal study we enrolled all blood donation services and hospitals of the federal state Mecklenburg-Western Pomerania. METHODS AND RESULTS: From 2005 to 2015 (time period with major demographic effects), whole blood donation numbers declined by 18%. In male donors this paralleled the demographic change, while donation rates of females declined 12.4% more than expected from demography. In parallel, red cell transfusion rates/1,000 population decreased from 2005 to 2015 from 56 to 51 (-8.4%), primarily due to less transfusions in patients >60 years. However, the transfusion demand declined much less than blood donation numbers: -13.5% versus -18%, and the population >65 years (highest transfusion demand) will further increase. The key question is whether the decline in transfusion demand observed over the previous years will further continue, hereby compensating for reduced blood donation numbers due to the demographic change. The population structure of Mecklenburg-Western Pomerania reflects all Eastern German federal states, while the Western German federal states will reach similar ratios of age groups 18-64 years / ≥65 years about 10 years later. CONCLUSIONS: Regular monitoring of age- and sex-specific donation and transfusion data is urgently required to allow transfusion services strategic planning for securing future blood supply.

Changes in use and outcomes after fibrinogen concentrate insurance coverage for critical obstetrical hemorrhage: a nationwide questionnaire survey in Japan.

Fibrinogen concentrate (FC) for acquired hypofibrinogenemia associated with critical obstetrical hemorrhage (COH) was covered by public medical insurance in September 2021 in Japan. We aimed to investigate changes in the policy of FC use and its effect on COH after insurance coverage. A primary survey covering September 2020 to August 2021 and a secondary survey covering September 2021 to August 2022 were conducted at 428 higher-level medical facilities. We investigated the policy of FC use in transfusion strategy and the maternal outcomes in COH. Among the hospitals that responded to both surveys, the number of facilities that use FC increased from 51.5 (101/196) to 78.6% (154/196) (P < 0.0001). The number of COH cases treated using FC increased from 14.3 to 24.3% (P < 0.0001) and that transfused with ≥ 10 units of red blood cells (RBCs) decreased from 36.8 to 29.8% (P = 0.001). The incidence of pulmonary edema reduced by 3.7-2.0% (P = 0.021), and transfusion-induced allergy by 1.9-0.7% (P = 0.008). No changes were observed in the incidence of thromboembolism, arterial embolization, or hysterectomy. The increased use of FC after insurance coverage led to changes in the transfusion strategy, which may be associated with decreases in transfusions of RBCs, pulmonary edema, and transfusion-induced allergies.

Assessing the quality of stored red blood cells using handheld Spatially Offset Raman spectroscopy with multisource correlation analysis.

In this work we employ Spatially Offset Raman Spectroscopy (SORS) to non-invasively identify storage-related changes in red blood cell concentrate (RCC) in-situ within standard plastic transfusion bags. To validate the measurements, we set up a parallel study comparing both bioanalytical data (obtained by blood-gas analysis, hematology analysis and spectrophotometric assays), and Raman spectrometry data from the same blood samples. We then employ Multisource Correlation Analysis (MuSCA) to correlate the different types of data in RCC. Our analysis confirmed a strong correlation of glucose, methemoglobin and oxyhemoglobin with their respective bioassay values in RCC units. Finally, by combining MuSCA with k-means clustering, we assessed changes in all Raman wavenumbers during cold storage in both RCC Raman data from the current study and parallel RCC supernatant Raman data previously acquired from the same units. Direct RCC quality monitoring during storage, would help to establish a basis for improved inventory management of blood products in blood banks and hospitals based on analytical data.

Oxygen in Red Blood Cell Concentrates: Influence of Donors' Characteristics and Blood Processing.

Objective: Unexpectedly wide distribution (<10 to >90%) of hemoglobin oxygen saturation (sO2) within red cell concentrates (RCCs) has recently been observed. Causes of such variability are not yet completely explained whereas the roles of oxygen and oxidative lesions during the storage of RCCs are known. The objectives of the present study are to characterize sO2 distribution in RCCs produced in a Swiss blood center and to investigate the influence of processing and donors' characteristics. Methods: The level of sO2 was measured in 1701 leukocyte-depleted RCCs derived from whole blood donations in both top-bottom (TB; component filtered, SAGM) and top-top (TT; whole blood filtration, PAGGSM) RCCs. The sO2 value was measured non-invasively through the PVC bag prior to storage by resonance Raman spectroscopy. Gender, age, blood type, hemoglobin level, and living altitude of donors, as well as process method and time-to-process were recorded. Results: Overall, the sO2 exhibited a wide non-Gaussian distribution with a mean of 51.2 ± 18.5%. Use of top-top kits resulted in a 16% higher sO2 (P < 0.0001) than with top-bottom ones. Waiting time before processing only had a modest impact, but the blood processing itself reduced the sO2 by almost 12% (P < 0.0001). sO2 was also significantly affected by some donors' characteristics. RCCs from men exhibited 25% higher sO2 (P < 0.0001) than those donated by women. Multivariate analysis revealed that the apparent correlation observed with hemoglobin level and age was actually due to multicollinearity with the sex variable. Finally, we noticed no significant differences across blood type but found that altitude of residence was associated with the sO2 (i.e., higher in higher living place). Conclusion: These data confirm wide sO2 distribution in RCCs reported recently. The sO2 was impacted by the processing and also by donors' characteristics such as the gender and the living altitude, but not by the hemoglobin level, blood group and donor age. This study provides new hints on the factors influencing red blood cells storage lesions, since they are known to be related to O2 content within the bags, giving clues to better process and to better store RCCs and therefore potentially improve the efficacy of transfusion.

Perioperative Patient Blood Management: common risk, common tasks, common responsibility / Perioperatív vérfelhasználás: közös kockázat, közös feladatok, közös felelosség.

Human red blood cell concentrate and platelet suspension are unstable preparations, therefore, they are not part of the international pharmaceutical market for biological and economic reasons. Consequently, they cannot be replaced by external sources. Human allogeneic erythrocyte and platelet preparations should therefore be considered as part of the common national wealth. The amount of transfused red blood cell concentrate has been declining in countries with advanced health systems in recent years. The changes were initially driven by the spread of the concept and practice of liberal and restrictive transfusion triggers. A complex, thoughtful system of perioperative blood utilization, the Patient Blood Management has later emerged, and a paradigm shift in the delivery of life-threatening perioperative bleeding has developed. At the same time, clinical practitioners are facing a new challenge of reducing willingness to donate blood worldwide. The rationalization of the use of human red blood cell concentrate and platelet suspension is essential in Hungary. As a health care measure, the currently rigidly earmarked financial resources available for allogeneic preparations and stable factor concentrates for the treatment of life-threatening haemorrhages need to be changed to be interoperable. The perioperative blood use could additionally be reduced by the widespread dissemination of the Patient Blood Management requiring complex coordinated educational interdisciplinary and logistical work. Orv Hetil. 2020; 161(37): 1545-1553.

Extracellular Vesicles in Red Blood Cell Concentrates: An Overview.

Red blood cell (RBC) concentrates may be stored for up to 42 days before transfusion to a patient. During storage extracellular vesicles (EVs) develop and can be detected in significant amounts in RBC concentrates. The concentration of EVs is affected by component preparation methods, storage solutions, and inter-donor variation. Laboratory investigations have focused on the effect of EVs on in vitro assays of thrombin generation and immune responses. Assays for EVs in RBC concentrates are not standardized. The aims of this review are to describe the factors that determine the presence of erythrocyte-EVs in RBC concentrates, the current techniques used to characterize them, and the potential role of EV analysis as a quality control maker for RBC storage.