Prediction of blood volume to be processed to achieve a target number of CD34+ cells: Development, validation and implementation of a formula.

BACKGROUND AND OBJECTIVES: Calculation of blood volume (BV) to be processed to achieve the target number of CD34+ cells can be accomplished by using collection efficiency 2 (CE2) formula. Our aim was to develop a BV web formula. MATERIALS AND METHODS: We calculated CE2 from aphereses performed between January 2015 and March 2020 in allogeneic donors and patients. From May 2020 to May 2021, we validated a formula: BV = ((Target CD34+ cells in the product)/(CD34+ pre-apheresis cells × CE2)) × 100. Subsequently, we compared the outcome of the procedures carried out before formula implementation (pre-formula), when standard three total BV collection was performed. RESULTS: CE2 was assessed in 384 apheresis procedures before formula implementation. CE2 was higher in allogeneic donors than in patients (53% ± 17% vs. 48% ± 15%, p = 0.008). CE2 was higher in multiple myeloma and non-Hodgkin lymphoma than Hodgkin's lymphoma (48% ± 15%, 48% ± 15% and 42% ± 13%, respectively; p = 0.008). Our formula (available on a website: Publisheet) was prospectively used in 54 individuals. The formula was very accurate: predicted versus observed CD34 + cells/kg collected had an r-value of 0.89 (p < 0.0001). We compared their results with 78 pre-formula individuals. In the post-formula group, a greater BV was processed in patients and less BV in allogeneic donors. Among individuals under 60 years of age, it was significantly less frequent than the need for more than one apheresis in the post-formula group. CONCLUSION: Formula calculations were accurate. Formula implementation allowed the optimization of the procedures and reduced the rate of individuals in need of apheresis for more than 1 day.

Transfusion support in COVID-19 patients: Impact on hospital blood component supply during the outbreak.

BACKGROUND: During the COVID-19 outbreak, most hospitals deferred elective surgical procedures to allow space for the overwhelming number of COVID-19 patient admissions, expecting a decrease in routine blood component requirements. However, because transfusion support needs of COVID-19 patients are not well known, its impact on hospital blood supply is uncertain. The objective of this study was to assess the effect of the COVID-19 pandemic on transfusion demand. STUDY DESIGN AND METHODS: Transfusion records during the peak of the COVID-19 pandemic (March 1-April 30, 2020) were reviewed in our center to assess changes in blood requirements. RESULTS: During this period 636 patients received a total of 2934 blood components, which reflects a 17.6% reduction in transfusion requirements with regard to the same period of 2019, and blood donations in Madrid dropped by 45%. The surgical blood demand decreased significantly during the outbreak (50.2%). Blood usage in the hematology and oncology departments remained unchanged, while the day ward demand halved, and intensive care unit transfusion needs increased by 116%. A total of 6.2% of all COVID inpatients required transfusion support. COVID-19 inpatients consumed 19% of all blood components, which counterbalanced the savings owed to the reduction in elective procedures. CONCLUSION: Although only a minority of COVID-19 inpatients required transfusion, the expected reduction in transfusion needs caused by the lack of elective surgical procedures is partially offset by the large number of admitted patients during the peak of the pandemic. This fact must be taken into account when planning hospital blood supply.