Units Of Red Blood Cells Research Articles

Recent secular trends of catheter-directed therapy for treatment of pulmonary embolism: a retrospective cohort study based on German national data

Abstract Background Various approaches exist for treatment of pulmonary embolism, including systemic lysis, catheter-directed therapy, or anticoagulation. Purpose This study aimed to describe recent secular trends of treatment strategies for patients with pulmonary embolism. Methods Data were interrogated from the Research Data Centre of the German Federal Statistical Office by ICD- and OPS-codes. 800,119 patients with pulmonary embolism, who were treated in German hospitals between 2007 and 2021, were analyzed and grouped according to the therapeutic strategy: no lysis or intervention, systemic lysis, ultrasound-assisted thrombolysis, catheter-directed lysis without ultrasound, retriever system, other transluminal thrombus removal, or surgical thrombectomy. In-hospital outcomes were investigated with focus on the last 8 years. Results Of all patients examined, 37,885 were treated with systemic lysis, 1,383 with ultrasound-assisted thrombolysis, 2,520 with catheter-directed lysis without ultrasound, 181 with a retriever system, 695 with other transluminal thrombus removal, and 1,037 with surgical thrombectomy. There was an increase in all catheter-directed therapies between 2007 and 2021 (from 102 to 735 procedures per year) with more than twice as many procedures from 2019 to 2021 (from 343 to 735 procedures). Between 2014 and 2021, 453,893 patients with main diagnosis of pulmonary embolism were included in the analysis. Mean age was 58.4-68.1 years in the observed groups. 42.5-52.2% were female. Highest rates of cor pulmonale were observed in patients undergoing surgical thrombectomy (87.7%) and systemic lysis (80.1%), which also applied to shock (26.2% and 25.7%), while both rates were lowest in patients without lysis or intervention (cor pulmonale: 25.4%, shock: 1.8%). The overall in-hospital mortality rate was 8.3%, ranging between 6.5% in the ultrasound-assisted thrombolysis group and 38.4% in the systemic lysis group. In catheter-directed therapies, the rate of major bleeding (>5 units of red blood cells) was 4.9%, ranging from 3.1% for catheter-directed lysis without ultrasound to 10.1% for other transluminal thrombus removal. The rate of intracerebral bleeding was 1.4%, with 0.0% for ultrasound-assisted thrombolysis and 4.4% for treatment with a retriever system. Conclusion In recent years, the use of catheter-directed therapy for pulmonary embolism has steadily increased. Rates of in-hospital major bleeding events and intracerebral bleeding were low.

Antepartum risk factors and outcomes of massive transfusion for elective cesarean section: a nationwide retrospective cohort study

BackgroundPostpartum hemorrhage is one of the leading causes of maternal mortality and morbidity. The etiology of postpartum hemorrhage exhibits variations in relation to the mode of birth; consequently, risk factors for massive transfusion in elective cesarean section might diverge from those encountered in vaginal birth or emergency cesarean section. The main purpose of this study was to investigate antepartum risk factors of massive transfusion for elective cesarean section.MethodsWe conducted a retrospective cohort study based on data from a nationwide system that collected inpatient medical records from tertiary hospitals in mainland China. We included women who had undergone elective cesarean section from January 2013 to August 2018. Primary outcome was massive transfusion defined as transfusion of more than eight units of red blood cells on the day of childbirth. Candidate risk factors were identified by the 10th revision of International Classification of Diseases Codes of admission diagnoses. The relationship between each factor and massive transfusion was assessed using multivariable logistic regression.ResultsA total of 294,695 women were included and 572 of them received massive transfusion (incidence: 194 per 100,000 elective cesarean sections). Maternal age [adjusted odds ratio (aOR) 1.22; 95% confidence interval (CI) 1.10–1.48], anemia (aOR 1.66; 95% CI 1.34–2.05), thrombocytopenia (aOR 3.54; 95% CI 2.39–5.05), coagulopathy (aOR 25.92; 95% CI 8.59–69.50), hypoalbuminemia (aOR 2.97; 95% CI 1.86–4.53), hepatic dysfunction (aOR 1.65; 95% CI 1.04–2.47), uterine scar (aOR 1.39; 95% CI 1.15–1.67), multiple pregnancy (aOR 2.84; 95% CI 1.74–4.38), polyhydramnios (aOR 2.52; 95% CI 1.19–4.68) and placenta previa (aOR 25.03; 95% CI 21.04–29.77) were associated with massive blood transfusion for elective cesarean section. Among the women receiving massive blood transfusion, 7 (1.2%) died during hospitalization, 126 (22.0%) needed hysterectomy, 25 (4.4%) uterine packing and 57 (10.0%) uterine artery ligation.ConclusionsTen risk factors of massive transfusion were identified in women undergoing elective cesarean section. Our findings may facilitate blood products preparation and provide opportunities for applying prophylactic strategies prior to cesarean section for women at high risk of massive transfusion.

Effectiveness of the Intrauterine Balloon Tamponade Compared With an Intrauterine, Vacuum-Induced, Hemorrhage-Control Device for Postpartum Hemorrhage

OBJECTIVE: To compare intrauterine balloon tamponade and vacuum-induced hemorrhage-control devices in a multicenter hospital system using a standardized three-stage postpartum hemorrhage response algorithm. METHODS: As part of a quality improvement project, data were prospectively collected through ongoing detailed hemorrhage case audits from 65 facilities from August 2022 to February 2024. Postpartum hemorrhage-control devices are recommended for stage 2 or 3 of the postpartum hemorrhage algorithm. The primary outcomes were 1) quantitative blood loss after device placement, 2) rate of packed red blood cell (RBC) transfusion, 3) use of 3 units of packed RBCs or more, and 4) device failure. RESULTS: During the 17-month observation period, there were 123,292 deliveries, and postpartum hemorrhage occurred in 5,931 (4.8%). Postpartum hemorrhage-control devices were used in 11.2% of cases (666 total, intrauterine balloon tamponade n=300, and vacuum-induced hemorrhage control n=366). For intrauterine balloon tamponade and vacuum-induced hemorrhage-control devices, quantitative blood loss (median and interquartile range) after device placement was similar at 194 (67–440) mL and 240 (113–528) mL (P=.40), respectively, as was the rate of any packed RBC transfusion (59.7% vs 50.0%, P=.08), transfusion of 3 packed RBC units or more (27.0% vs 24.9%, P=.53), and device failure (7.7% vs 8.5%, P=.70). Placement of either device at a quantitative blood loss between 1,000 and 1,499 mL compared with 1,500 mL or more resulted in significantly lower rates of packed RBC transfusion (39.1% vs 70.3%, P<.001), transfusion of 3 or more packed RBC units (13.7 vs 38.1%, P<.001), and device failure (3.4% vs 12.9%, P<.001). CONCLUSION: Transfusion and blood loss after device placement were similar with both hemorrhage-control devices. Earlier hemorrhage-control device placement reduced device failure and the need for transfusion.

Assessment of amino acids and metabolites in the supernatant of stored concentrates blood from sickle cell trait (SCT) and reference (non-SCT) donors.

Sickle cell trait (SCT) persons are significant donors, and discarding these blood units reduces their supplies, mainly in the third-world countries. This work focused on 12 metabolites associated with the red blood cell (RBC) storage lesion and 23 amino acids in the supernatants of packed RBC units from SCT and reference (non-SCT) donors stored in the same conditions. All samples of RBC concentrates were collected and separated from the storage of Colsan (Beneficient Association of Blood Collection), where they were routinely processed and separated as packed RBC units and stored in the refrigerator (2°-6°C). The supernatant samples of each packed RBC bag were separated by centrifugation at days 1, 7, 14, 21, 28 and 35 of storage and kept at -80°C till the metabolite analysis together. The quantitation of metabolites and amino acids examined in the supernatant of SCT and reference donors showed no statistical differences along the cold storage. Lactic acid and malic acid releases occur in three phases during RBC storage. Basic and acid amino acids and corresponding amides have low and stable values during the first 14 days of storage, followed by a steep increase. Our metabolomic results give elements that seem not to contraindicate the transfusion of RBC with SCT, besides its more structural fragility.

Red blood cell alloimmunization in transfused patients with hereditary hemorrhagic telangiectasia: A single centre retrospective study

BackgroundHereditary hemorrhagic telangiectasia (HHT) is a genetic blood vessel disorder which may lead to chronic bleeding and red blood cell (RBC) transfusions. Data on transfusion requirements and complications in HHT patients are sparse. Study Design and MethodsRetrospective chart review was conducted at St. Michael’s Hospital (SMH) in Toronto, Canada. All adults with a definite clinical diagnosis of HHT AND inpatient hospital visits between January 1, 2011 and December 31, 2020 AND had undergone transfusion compatibility testing at SMH, were identified. Data were abstracted from electronic medical records. Simple descriptive statistics were used to analyze data. Institutional Research Ethics Board approval was obtained. Results63 HHT patients underwent compatibility testing and were subsequently transfused at SMH. Median patient age at data abstraction was 70 years (Interquartile Range [IQR]: 18) and 35 (56 %) were female. RBC alloantibodies were found in 23 transfused patients (36.5 %) and were predominantly directed against Rh and Kell antigens: Anti-E (65 %), Anti-K (39 %) and Anti-c (22 %) were most common. Excluding an outlier who received 611 RBC units during the study period, the mean number of RBC units transfused per HHT patient at SMH was 22.1 units (Standard Deviation: 40.9, IQR: 17). Six (9.5 %) transfused patients experienced at least one transfusion reaction. ConclusionRBC alloimmunization rate was 36.5 % in our cohort of transfused HHT patients; this is much higher than described in the general population and another transfused HHT cohort. The most commonly observed alloantibodies were Rh and Kell, supporting our policy of prophylactic phenotypic matching for these antigens for all transfused patients with HHT.

Hematocrits of red blood cell units increase during storage due to changes in mean corpuscular volume, impacting outcomes of red cell exchange procedures

Abstract Introduction Hematocrits of red blood cell (RBC) units are generally not measured by blood centers or transfusion services. Red blood cell exchange (RCE) is commonly used to treat sickle cell disease, and a key parameter needed in RCE is the average hematocrit of RBC units. However, there is no consensus on the average hematocrit to use or how it is affected by storage. The goal of our study is to determine the average hematocrit of RBC units by measuring hematologic parameters RBC units during storage and performing statistical modeling of hematocrit changes over time. Methods We sampled aliquots of leukoreduced RBC units in AS-1 (n=10) using the Terumo TSCD-II Sterile Tubing Welder to sterilely collect ~15mL of RBCs in transfer-pack containers. Aliquots were collected weekly from Day 7 to Day 42 of storage. Complete blood counts were performed using the Sysmex XN-3100 Hematology Analyzer. We statistically modeled changes in RBC units during storage by utilizing Bayesian multilevel linear regression models, allowing for capturing effects at the individual RBC-unit level. Posterior distributions of model parameters were estimated and processed using Stan and the rethinking and rstan packages in R. Posterior distributions are summarized with posterior means and 95%-credible intervals in parentheses. Model selection was done by calculating Akaike weights using the widely applicable information criterion (WAIC) to signify statistical support for each model. Results Multilevel linear regression models of hematologic parameters as a function of storage time were developed. Hematocrits increased with a posterior mean of 1.4% (0.98–1.75%) per week of storage, with posterior mean hematocrits of: 61.9% (60.2–63.6%) on Day 7, 63.9% (61.5–66.4%) on Day 21, and 66.0% (62.8–69.7%) on Day 42. These results indicate that a single average cannot be used for RBC units since hematocrits dramatically increase during storage. Mean corpuscular volume (MCV) increased with a posterior mean of 2.31 fL (1.4–3.71) per week whereas hemoglobin remained stable with a posterior mean increase of 0.008 g/dL (-0.016–0.031) per week. Using these results, we subsequently developed a multilevel regression model of hematocrit as a function of MCV. The model using MCV (WAIC=100.2, weight=100%) was favored over the model using time (WAIC=120.0, weight=0%), suggesting that changes in MCV are driving the increasing hematocrits. Conclusion Our study is the first to leverage Bayesian statistics to carefully quantify the average hematocrits of RBC units during storage time and to demonstrate that increasing hematocrits are caused by changes in MCV. These results indicate that transfusion protocols must consider the age of RBC units for RCE calculations, and provisions (e.g., requiring use of fresh units for RCE) may help minimize the variability in post-exchange testing. Moreover, our findings suggest that transfusion services should regularly measure hematocrits of RBC units in their inventory.

Assessing the Effect of Changing the Average Hematocrit in Red Blood Cell (RBC) Units on the Post- Procedure Hematocrits of Patients Undergoing Erythrocytapheresis

Abstract Introduction/Objective Red cell exchange (RCE) is utilized as a therapeutic or prophylactic procedure for patients with sickle cell disease (SCD). When performing RCE, three hematocrits (Hct) are taken into account: pre-procedure and goal Hct for the patient and average Hct (avg-Hct) of the transfused RBC units. Although there is no definitive community consensus, many transfusion services employ RBC unit avg-Hct of 55% per available guidance. Our center anecdotally observed that utilizing RBC unit avg-Hct of 55% often resulted in post-procedure patient Hcts higher than intended goal Hct, potentially causing hyperviscosity. This study aims to examine the effect of changing the avg-Hct from 55% to 60% on the accuracy of post-procedure HCTs, with the 60% avg-Hct employed based on prior quality studies of RBC units at our facility. Methods/Case Report We performed a retrospective chart review for SCD patients receiving chronic, prophylactic RCE at a large academic hospital, collecting the following for each procedure: goal procedure Hct, number of RBC units exchanged, avg-Hct used, and pre-/post-procedure patient Hcts. Differences between goal Hcts and post- procedure Hcts for each procedure in the avg-Hct=55% and avg-Hct=60% groups were calculated. Next, mean calculated differences for both groups were compared using a two-sample t-test (P<0.05 was considered significant). Results (if a Case Study enter NA) From 1/2023–2/2024, 293 prophylactic RCEs were performed for SCD patients. Median number of RBC units per procedure was 7, with 51% of procedures (n=149) employing unit avg-Hct=55%, while 49% of procedures (n=144) used a unit avg-Hct=60%. Post-procedure patient Hct and goal Hct differences were statistically different according to unit avg-Hct values utilized (mean difference=1.31% for avg-Hct=55% vs mean difference=0.52% for avg-Hct=60%; P<0.0001). Conclusion Changing our protocol to use RBC unit avg-Hct=60% resulted in post-procedure patient Hcts significantly closer to intended goals. Utilization of a more accurate average-Hct value has a substantial impact on post-procedure Hct in RCEs and may limit adverse events.

Genotyping for Weak and Partial D Rh Status to Optimize Usage of Limited Blood Supplies

Abstract Introduction The Rh antigen group, expressed on erythrocytes and encoded by highly polymorphic RHD and RHCE genes on chromosome 1 (1p36-p34), is notable in transfusion medicine due to its high polymorphism, strong immunogenicity and ability to cause hemolytic transfusion reactions in patients and hemolytic disease of the fetus and newborn (HDFN). The D antigen specifically contains multiple epitopes with variations that include decreased expression (weak D) or loss of certain epitopes (partial D) which expose patients to risk of alloimmunization depending on the subtype of the Rh(D) antigen. Hence, serologic weak D testing followed by molecular testing is not performed except for donors testing negative for Rh(D) antigen and newborns typing negative for Rh(D) and born to Rh(D) negative mothers. Given the current shortages of blood supplies, understanding patients’ genotypes in the context of weak or partial D-typing and risk of alloimmunization can be essential in the management of increasingly limited supplies of red blood cell (RBC) units. Objective To further characterize patients that initially type negative for Rh(D) but positive for weak D with molecular testing to investigate risk of alloimmunization, retype the Rh(D) and avoid unnecessary use of Rh(D) negative RBC units during critical shortages of RBC units. Methods We collected the results of ABO/Rh(D) typing for patients with negative Rh(D) testing but positive weak D test over a period of four weeks in December 2023 and had D-variant molecular testing performed by a reference laboratory. Initial serologic ABO/Rh(D) was performed in tube followed by weak D testing by indirect Coombs test in tube. Results The total number of patients who initially tested negative for Rh(D) but positive (weak to +4) for weak-D was three patients. Two patients showed a probable genotype of RHD*01W.1 (RHD* weak type 1, 809T>G (V270G)) homozygous which indicated the presence of weak D+ type 1. Patients with weak D+ type 1 can receive Rh(D) positive red cell units, and they are not at risk of alloimmunization and developing anti-D. The third patient showed a probable genotype RHD*DVI type 2 homozygous (lack of Rh(D) exons 4 through 6) and indicated the presence of partial D antigen. Patients with partial D antigen should receive RH(D) negative red cell units as they are at risk of alloimmunization and developing anti-D. Conclusions Although the vast majority of Transfusion Medicine services do not perform the serologic weak D test with reflex to molecular testing, characterizing patients who test negative with initial serologic Rh(D) testing with serologic and molecular D-tests may aid in retyping the Rh(D) of patients during critical shortages, particularly for patients with ABO blood group O.

Evaluating RhD Assessment By Automated Methodology: A Potential ‘Blind Spot’ For RhD Variant Identification

Abstract Background Automated blood typing platforms are ideal for blood donor centers, given their broad recognition of RhD antigen variants, resulting in products from such donors to be labeled as RhD positive. However, this ‘blind spot’ for variants may be problematic for hospital-based transfusion services, since RhD variants may require provision of RhD- RBC units and Rh immune globulin. The extent to which automated methods accurately characterize variant D antigen expression is not known. As such, the objective of our study was to assess D typing results, as well as RHD genotyping, among two automated testing platforms at our facility. Methods The study site is a single tertiary care center with analysis done from 12/2020-1/2024. At our facility, all females <60 years of age with RhD antigen testing results of ≤2+ agglutination (0-4+ scale) via automated methods [solid phase testing 12/20-4/22 (Neo, Immucor, Norcross, GA) and gel testing 5/22-1/24 (Erytra, Grifols, Emeryville, CA)] are assessed by a tube RhD antigen test (Grifols reagents). If tube testing confirms a ≤2+ result (0-4+ scale), molecular variant D analysis is performed (Versiti, Milwaukee, WI). Patients typed as Rh negative with anti-D antibodies, or those with inconsistent D typing, are also subjected to genetic D testing. The Wilcoxon matched pairs signed rank test was employed for comparative data (P< 0.05 was deemed significant). Results Amongst tested patients, 73 demonstrated ≤2+ agglutination via an automated typing method, leading to variant D genetic analysis. Of these, 71% (n=52) harbored variant D antigens. Within this subgroup, 29 (56%) subjects exhibited variants associated with potential allo-anti-D development (n=5 partial D variants; n=24 weak D variants). Notably, 4 patients with partial D and 1 with weak D demonstrated allo-anti-D antibodies. Of 23 patients with variant D who underwent automated gel testing, 20 concurrent tube testing results were available. Gel testing revealed significantly stronger agglutination compared to tube testing (p < 0.001). In contrast, for paired solid phase and tube testing (n=11), there was no statistically significant difference in agglutination strength (p = 0.28). Conclusion Automated testing, particularly gel-based platforms, exhibits reduced sensitivity to RhD antigen variant identification when compared to tube testing, placing subsets of patients potentially at risk for forming allo-anti-D. Implementing protocols for verification of D status could enhance the sensitivity of variant D detection for facilities that largely rely on automated methods for antigen typing.

Serologic investigation and management of an antibody screen negative para-Bombay phenotype during pregnancy

Abstract Introduction/Objective Individuals with the Bombay and para-Bombay red blood cell (RBC) phenotypes express anti- H antibodies associated with acute hemolytic transfusion reactions. The rarity of compatible donor units creates unique logistical challenges. However, para-Bombay individuals have been shown to tolerate transfusion of non- Bombay RBCs without acute hemolysis. Therefore, accurate serologic identification and judicious management of blood products are crucial when planning to transfuse patients with anti-H. This is especially true during pregnancy, as early onset of labor and fetal distress can occur without warning. Methods/Case Report A 24-year-old gravida 2 para 1 (G2P1) at approximately 38 weeks gestation with the fetus in breech position was transferred to our hospital after anti-H antibodies were detected. Although our in-house antibody screen was negative on automated solid-phase red cell adherence (SPRCA) testing, manual tube testing revealed the presence of anti-H antibodies, and forward typing with Ulex europaeus lectin confirmed the absence of H-antigen. Further, Lewis B phenotyping and saliva neutralization demonstrated the presence of H-antigen in secretions, consistent with the O-para-Bombay phenotype. Finally, differential adsorption ruled out other clinically significant allo- antibodies. An external cephalic version (ECV) was initially planned since vaginal delivery carries lower bleeding risk than cesarean section (CS). Three frozen Bombay RBC units were obtained, with one possibly compromised before arrival. Four pre-warmed, cross-match compatible units of O-positive RBCs (non-Bombay) were also prepared. Acknowledging the unpredictability of ECV, the challenge of timing thawed frozen units, and the possibilities of massive hemorrhage versus wasting rare donor blood, our transfusion service ultimately recommended an elective CS with only one Bombay unit deglycerolized. The patient underwent an uneventful procedure without transfusion. Results (if a Case Study enter NA) NA Conclusion Overall, this case highlights key diagnostic and management considerations for patients with Bombay and para-Bombay phenotypes. First, automated SPRCA testing may provide false negative results for anti-H antibodies. Second, backup transfusion strategies for para-Bombay patients may include non-Bombay RBCs. Finally, the procurement, preparation, and use of rare donor blood products requires multidisciplinary clinical decision-making to optimize patient outcomes, especially for high-risk labor when unexpected acute bleeding events can occur.

Lost in the Ds: Unexplained Loss of Rh(D) Antigen Expression By Serological Testing In Two Patients

Abstract Introduction/Objective While the loss of ABOH antigens has been well documented, reduced-to-absent expression of the RHD antigen is comparatively rare. Here, we describe two cases with D antigen loss presenting associated clinical settings, smear results, and red blood cell (RBC) genotyping findings to elucidate this unusual phenomenon. Methods/Case Report Cases (n=2) were retrospectively reviewed based on discovery during routine serological testing in our Blood Bank. RhD blood typing was performed via gel methods [Grifols, Los Angeles, CA]. Clinical information and laboratory data were extracted via the electronic medical record. Case 1 is a 79-year-old female with metastatic breast cancer. She initially typed as D positive (4+) in at least two separate analyses, but her D front type progressively became weaker until turning entirely negative after several weeks. Spherocytes and stomatocytes were present on her peripheral blood smear. This patient received 10 D+ red blood cell (RBC) units without anti-D formation. RBC genotyping revealed traditional “dce” by standard polymerase chain reaction (PCR). Case 2 is a 61-year-old male with a history of pre-B acute lymphocytic leukemia post-stem cell transplant, myelodysplastic syndrome, and progressive loss of D antigen expression (4+ to 0). Standard RBC genotyping revealed “Dce” by PCR. The peripheral blood smear was significant for RBC anisopoikilocytosis with increased stomatocytes, spherocytes, and ovalocytes. Results (if a Case Study enter NA) NA Conclusion The disappearance of the D antigen is rare, and our experience suggests an association between malignancies (both hematopoietic and non-hematopoietic) and D antigenic loss. Beyond these disease associations, however, loss of RhD is not otherwise readily explained in either case. Further analysis to test for other RHAG and RHCE mutational variants is an ongoing area of investigation in these cases, as more sensitive testing may reconcile the traditional PCR results with our initial detection of the D antigen.

Quality Improvement Assessment of Massive Transfusion Protocol (MTP) Utilization and Blood Component Return to Blood Bank in a Level 1 Trauma Center

Abstract Introduction/Objective The goal of MTP in management of patients with hemorrhage is to restore coagulation factors, oxygen carrying capacity, and platelets by transfusing equal amount of plasma, RBC, and platelets. Upon activation of MTP, blood components are released in rounds until deactivation. This quality improvement study was initiated to assess blood products transfused versus returned during MTP activation at our Level1 Trauma Medical Center. Methods/Case Report Upon MTP activation, the Blood Bank (BB) prepares first round of cooler with components at 5:5:1 ratio of plasma, RBC, apheresis platelets. We reviewed retrospective MTP data of eleven-month, from 10/2022- 08/2023. We analyzed patterns of blood component usage by service line, number of MTP rounds issued, and number of units transfused versus returned. Results (if a Case Study enter NA) MTP data was reviewed for 195 patients. MTP activation by service line included emergency department 58.5%, medical ICU (MICU) 14.4%, and surgical ICU (SICU) 11.8%. In many MTP activations, only one round of components was released. Overall, an average of 1.5 rounds were issued. Data of units transfused and returned by component type showed more RBC (43.1%) units were transfused than plasma (39.4%) suggesting MTP transfusion did not follow 1:1:1 ratio. Out of all issued blood units 58% were returned. The high fraction of returned blood components suggests MTP activation may not always truly indicate massive hemorrhage. This finding, and the notable frequency of MTP activation for MICU and SICU patients suggests that individual component order on an emergency-release basis may have been the appropriate option. Conclusion In general, the data suggests implementation of a quality improvement initiative focused on increasing awareness of criteria for MTP activation, and training of staff surrounding MTP is essential. We recently implemented an electronic emergency transfusion order set that allows providers to order individual components for non-massively bleeding patients.

Flow cytometry for RBC damage and complement activation

Abstract Introduction Red blood cells (RBCs) express anionic phospholipids such as phosphatidylserine (PS) in their inner cell membrane layer. As RBCs age, physiochemical changes in their cell membranes, particularly exposure of PS on the outer membrane layer, lead to phagocytosis and clearance from circulation. PS in RBCs induces activation of the complement system, increasing binding of C3 to RBCs. Thus, quantifying PS-expressing (PS+) RBCs and complement deposition on RBCs (C3+) is a potential measure of RBC injury and may improve transfusion quality when used for predicting post-transfusion RBC recovery. Our goal was to develop a flow cytometry assay that quantifies PS+ and C3+RBCs and to assess how this assay correlates with the direct antiglobulin test for C3 (C3-DAT). Methods Using the Cytoflex S flow cytometer, we measured PS+ and C3+ RBCs using anti-annexin-PE (PS+RBC) and biotin-labeled anti-C3 with streptravidin-PE-Cy5 (C3+RBC). RBCs from healthy donors (NL-RBCs) with negative direct antiglobulin tests for C3 (C3-DAT) (n = 4) were analyzed. To assess the sensitivity of the assay and correlation with C3-DATs, complement control cells (CCC; Immucor) were used as a positive control for both PS+RBCs and C3+RBCs and diluted to different concentrations by mixing CCCs with NL-RBCs. Aliquots of diluted RBCs were analyzed blinded for C3-DAT. Differences between means for PS+RBC and C3+RBC were compared using two-sample t-test, and one-way ANOVA and Tukey’s HSD test were used to determine differences in C3+RBCs among a C3-DAT range of reactivities (0+ to 3+) in diluted CCC samples. P values less than 0.05 were statistically significant. Results In healthy, DAT-negative individuals, the mean positivity for PS+RBCs was 0.28% and for C3+RBCs was 0.34%, indicating that healthy individuals have very low percentages of RBCs with PS and C3 on their cell membrane surface. In CCC diluted samples, the mean C3+RBC percentage was 1.4% in negative C3-DAT samples, 5.9% in weak+ C3-DAT samples, 28.1% in 1+ C3-DAT samples, 67.2% in 2+ C3-DAT samples, and 99.0% in 3+ C3-DAT samples. One-way ANOVA revealed a statistically significant difference in C3+RBCs amongst all C3-DAT reactivities in diluted CCC samples (P<0.001), and Tukey’s HSD test found a mean difference in C3+RBCs percentage of 26.7% between 0+ and 1+ samples (P<0.001), 39.2% between 1+ and 2+ samples (P<0.001), and 31.8% between 2+ and 3+ samples (P<0.01). Undiluted CCC samples had a mean PS+RBC percentage of 7.0% and was statistically different from the PS+RBC percentage in NL-RBCs (P<0.01). Conclusion We describe a feasible assay to measure both PS+RBCs and C3+RBCs using flow cytometry in which CCC can be used as a positive control for PS+RBCs. This assay could serve to evaluate the quality of transfused RBC units and provide insights into the role of phosphatidylserine expression and complement deposition for RBC clearance.

Keeping The Stock Alive, A Dilemma of Hemovigilance

Abstract Introduction/Objective Being well-prepared for emergent blood transfusions is crucial in level 1 trauma centers. As advocates of hemovigilance, we follow protocols that encourage the appropriate use of group O, D- (O-) pRBCs. Moreover, by prioritizing using red blood cells with shorter shelf lives, we can better ensure that these valuable resources are not wasted. Methods/Case Report The number of O short-dated RBC units transfused in a level 1 trauma hospital in December 2023 was evaluated for type-specific distribution and utilization in bleeding patients and massive transfusion protocol. This study defines short-dated units as units expiring ≤7 days during transfusion. Results (if a Case Study enter NA) Of the 320 pRBCs evaluated, 59 were identified as short-dated units and 46(78%) were of the O- blood type. Interestingly, most O- units used for transfusion during this month (69%, 46/66) were short- dated; in comparison, only 5% (13/254) of group O, D+ (O+) units were transfused with a shorter shelf life. O- units were administered to 10 O- patients (17%), 27 O+ patients (46%), and 9 non-O blood type patients (15%). All short- dated O+ units were given to O+ patients, with 31% (4/13) used in massive transfusion protocols (MTP). None of the short-dated O- units were used in MTP, but over half (52%, 24/46) were utilized in patients experiencing bleeding. Conclusion Approximately 95% of individuals of African American descent have a blood type of D+. Given that this is the primary demographic we serve, it is unsurprising that our institution sees a relatively higher usage of O+ blood units, resulting in fewer short-dated O+ units being transfused. The cause of increased usage of short-dated O- is likely multifactorial, one of which is maintaining an adequate O- in our inventory for trauma patients. Balancing our preparedness for massive hemorrhage situations and hemovigilance for this blood type can be challenging for institutions like ours.

Transfusion burden and willingness to pay for temporary alleviation of anemia status in transfusion-dependent beta-thalassemia patients in China

BackgroundTransfusion-dependent β-thalassemia (TDT) is one of the global public health concerns highlighted by the World Health Organization. Patients with TDT require regular blood transfusion to survive. However, the availability of blood resources is extremely limited. The purpose of this study was to investigate transfusion burden and willingness to pay (WTP) for temporary remission of anemia status among patients with TDT and to explore the associated factors.MethodsAdult patients with TDT were recruited through cluster sampling across several high-incidence provinces in China. Consenting patients completed online questionnaires on demographic information, transfusion burden and WTP with real-time WeChat communication assistance from researchers. The guiding techniques of double-bounded dichotomous choices and open-ended questions in the contingent valuation method (CVM) were used to obtain participants’ WTP for 1 unit of leukocyte-depleted red blood cells. WTP calculations were performed using maximum likelihood estimation, with further insights gained through subgroup analysis based on gender, family monthly income level and convenience of blood transfusion.ResultsThe analysis included 149 TDT patients from five high-incidence provinces, with an average monthly income of $198.5. Patients received an average of 3.7 units per transfusion, 15.4 times annually, with an average WTP of $70.4 per unit (95% CI [62.0, 78.9]). Estimated WTP for temporary anemia alleviation per transfusion totaled $260.6, exceeding monthly income by 1.32 times. Higher WTP was observed among males, higher-income households, and those with at least junior education. Lower WTP was noted among patients with lower transfusion volumes and those needing to travel for transfusion or during hospitalization for blood transfusion.ConclusionHigh WTP indicated a strong desire for temporary anemia relief. Most TDT patients faced significant economic and transfusion burden. The evident gap in meeting clinical needed underscores the urgent demand for innovative treatments to reduce transfusion dependency, potentially transforming TDT care and improving socioeconomic well-being and clinical outcomes. These findings supported evidence-based decision-making for TDT pharmacoeconomics and efficient healthcare resource allocation in China.

High-Dose TXA Is Associated with Less Blood Loss Than Low-Dose TXA without Increased Complications in Patients with Complex Adult Spinal Deformity.

Tranexamic acid (TXA) is commonly utilized to reduce blood loss in adult spinal deformity (ASD) surgery. Despite its widespread use, there is a lack of consensus regarding the optimal dosing regimen. The aim of this study was to assess differences in blood loss and complications between high, medium, and low-dose TXA regimens among patients undergoing surgery for complex ASD. A multicenter database was retrospectively analyzed to identify 265 patients with complex ASD. Patients were separated into 3 groups by TXA regimen: (1) low dose (<20-mg/kg loading dose with ≤2-mg/kg/hr maintenance dose), (2) medium dose (20 to 50-mg/kg loading dose with 2 to 5-mg/kg/hr maintenance dose), and (3) high dose (>50-mg/kg loading dose with ≥5-mg/kg/hr maintenance dose). The measured outcomes included blood loss, complications, and red blood cell (RBC) units transfused intraoperatively and perioperatively. The multivariable analysis controlled for TXA dosing regimen, levels fused, operating room time, preoperative hemoglobin, 3-column osteotomy, and posterior interbody fusion. The cohort was predominantly White (91.3%) and female (69.1%) and had a mean age of 61.6 years. Of the 265 patients, 54 (20.4%) received low-dose, 131 (49.4%) received medium-dose, and 80 (30.2%) received high-dose TXA. The median blood loss was 1,200 mL (interquartile range [IQR], 750 to 2,000). The median RBC units transfused intraoperatively was 1.0 (IQR, 0.0 to 2.0), and the median RBC units transfused perioperatively was 2.0 (IQR, 1.0 to 4.0). Compared with the high-dose group, the low-dose group had increased blood loss (by 513.0 mL; p = 0.022) as well as increased RBC units transfused intraoperatively (by 0.6 units; p < 0.001) and perioperatively (by 0.3 units; p = 0.024). The medium-dose group had increased blood loss (by 491.8 mL; p = 0.006) as well as increased RBC units transfused intraoperatively (by 0.7 units; p < 0.001) and perioperatively (by 0.5 units; p < 0.001) compared with the high-dose group. Patients with ASD who received high-dose intraoperative TXA had fewer RBC transfusions intraoperatively, fewer RBC transfusions perioperatively, and less blood loss than those who received low or medium-dose TXA, with no differences in the rates of seizure or thromboembolic complications. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The incidence of donor white blood cell survival (transfusion-associated microchimerism) in Australian pediatric patients.

Donor leucocyte survival following red blood cell (RBC) transfusion, known as transfusion-associated microchimerism (TAM), can occur in some patients. In Australia, despite the introduction of leucocyte filtration (leucodepletion) during RBC manufacture, TAM has been detected in adult trauma patients. However, the incidence of TAM in Australian pediatric patients has not been analyzed. Patients aged 0-16 years were recruited across two cohorts. Retrospective participants had RBC transfusion between January 1, 2002 and November 15, 2017 and prospective participants received RBC transfusion between December 1, 2016 and November 25, 2020. Twelve bi-allelic insertion/deletion (InDel) polymorphisms were used to detect microchimerism amplification patterns using real-time PCR (RT-PCR) and droplet digital PCR (ddPCR). Of the retrospective cohort (n = 40), six patients showed amplification of InDel sequences indicating potential microchimerism. For three patients, minor InDel sequences were detected using RT-PCR only, two patients had minor InDel amplification using ddPCR only, and one patient had minor InDel amplification that was confirmed using both techniques. Amplification of minor sequences occurred in three patients who had received a bone marrow transplant in addition to RBC transfusion. In the prospective cohort (n = 25), no InDel amplification indicating potential microchimerism was detected using RT-PCR. Cell-based therapies had been administered in three patients where microchimerism amplification patterns were detected. Three patients have microchimerism that may be attributed to RBC transfusion. In prospective patients, who received leucodepleted and gamma-irradiated RBC units, no potential microchimerism amplification were detected. ddPCR may be a suitable technique for TAM analysis but requires further evaluation.

Tranexamic Acid During Radical Cystectomy

Among cancer surgeries, patients requiring open radical cystectomy have the highest risk of red blood cell (RBC) transfusion. Prophylactic tranexamic acid (TXA) reduces blood loss during cardiac and orthopedic surgery, and it is possible that similar effects of TXA would be observed during radical cystectomy. To determine whether TXA, administered before incision and for the duration of radical cystectomy, reduced the number of RBC transfusions received by patients up to 30 days after surgery. The Tranexamic Acid During Cystectomy Trial (TACT) was a double-blind, placebo-controlled, randomized clinical trial with enrollment between June 2013 and January 2021. This multicenter trial was conducted in 10 academic centers. A consecutive sample of patients was eligible if the patients had a planned open radical cystectomy for the treatment of bladder cancer. Before incision, patients in the intervention arm received a loading dose of intravenous TXA, 10 mg/kg, followed by a maintenance infusion of 5 mg/kg per hour for the duration of the surgery. In the control arm, patients received indistinguishable matching placebo. The primary outcome was receipt of RBC transfusion up to 30 days after surgery. A total of 386 patients were assessed for eligibility, and 33 did not meet eligibility. Of 353 randomized patients (median [IQR] age, 69 [62-75] years; 263 male [74.5%]), 344 were included in the intention-to-treat analysis. RBC transfusion up to 30 days occurred in 64 of 173 patients (37.0%) in the TXA group and 64 of 171 patients (37.4%) in the placebo group (relative risk, 0.99; 95% CI, 0.83-1.18). There were no differences in secondary outcomes among the TXA group vs placebo group including mean (SD) number of RBC units transfused (0.9 [1.5] U vs 1.1 [1.8] U; P = .43), estimated blood loss (927 [733] mL vs 963 [624] mL; P = .52), intraoperative transfusion (28.3% [49 of 173] vs 24.0% [41 of 171]; P = .08), or venous thromboembolic events (3.5% [6 of 173] vs 2.9% [5 of 171]; P = .57). Non-transfusion-related adverse events were similar between groups. Results of this randomized clinical trial reveal that TXA did not reduce blood transfusion in patients undergoing open radical cystectomy for bladder cancer. Based on this trial, routine use of TXA during open radical cystectomy is not recommended. ClinicalTrials.gov Identifier: NCT01869413.

Examining associations between social vulnerability and maternal morbidity among a multicentre cohort of pregnancies complicated by placenta accreta spectrum disorder in New York City

BackgroundPlacenta accreta spectrum (PAS) disorder is a source of severe obstetric morbidity and mortality worldwide. The objective of this paper was to evaluate the potential relationship between social vulnerability and...

Single vs. Double-Unit Transfusion In Patients With Hematological Disorders Undergoing Chemotherapy Or Stem Cell Transplantation: A Systematic Review And Meta-Analysis

There is no consensus to support the single unit-transfusion policy (1-RBC) over the double-unit transfusion policy (2-RBC) in patients with hematological disorders undergoing chemotherapy or stem cell transplantation. We searched PubMed, Embase, and Cochrane Library. Risk ratios (RR) and mean differences (MD) were pooled. Statistical analysis was performed using Review Manager and R software. Heterogeneity was assessed using I2 statistics. Hemoglobin (Hb) levels at discharge (MD -0.41 g/dL; 95% CI -0.53, -0.29 g/dL; p<0.01) and total RBC units used per admission (MD -0.82 units; 95% CI -1.60, -0.05 units; p=0.04) were significantly lower in patients who received 1-RBC, while length of hospital stay (MD 0.05 days; 95% CI -0.29, 0.39 days; p=0.89), severe bleeding (RR 1.52; 95% CI 0.85, 2.71; p=0.16) and mortality (RR 0.89; 95% CI 0.52, 1.53; p=0.69) showed no significant difference between groups. In patients with hematological disorders undergoing chemotherapy or stem cell transplantation, 1-RBC is associated with lower Hb levels at discharge and a reduction in the total number of RBC units used per admission, with no significant difference in terms of length of hospital stay, severe bleeding risk, transfusion-related adverse events and mortality.