Novel method for determining when a field-collected donor unit is sufficiently full.

BACKGROUND: Whole blood (WB) collections can occur downrange for immediate administration. An important aspect of these collections is determining when the unit is sufficiently full. This project tested a novel method for determining when a field collection is complete. METHODS: The amount of empty space at the top of WB units, destined to become LTOWB or separated into components, that were collected at blood centers or hospitals was measured by holding a WB unit off the ground and placing the top of a piece of string where the donor tubing entered the bag. The string was marked where it intersected the top of the column of blood in the bag and measured from the top. The WB units were also weighed. RESULTS: A total of 15 different bags, two of which were measured in two different filling volumes, from 15 hospitals or blood centers were measured and weighed. The most commonly used blood bag, Terumo Imuflex SP, had a median string length of 9 mm (range: 2-24 mm) and weighed a median of 565.1 g (range: 524.8-636.7 g). CONCLUSION: Pieces of string can be precut to the appropriate length depending on the type of bag before a mission where field WB collections might be required and a mark placed on the bag before the collection commences to indicate when the unit is full.

Rate of D-alloimmunization in trauma does not depend on the number of RhD-positive units transfused: The BEST collaborative study.

BACKGROUND: Evidence indicates the life-saving benefits of early blood product transfusion in severe trauma resuscitation. Many of these products will be RhD-positive, so understanding the D-alloimmunization rate is important. METHODS: This was a multicenter, retrospective study whereby injured RhD-negative patients between 18-50 years of age who received at least one unit of RhD-positive red blood cells (RBC) or low titer group O whole blood (LTOWB) during their resuscitation between 1 January, 2010 through 31 December, 2019 were identified. If an antibody detection test was performed ≥14 days after the index RhD-positive transfusion then basic demographic information was collected, including whether the patient became D-alloimmunized. The overall D-alloimmunization rate, and the rate stratified by the number of units transfused, were calculated. RESULTS: Data were collected from nine institutions. Five institutions reported fewer than 10 eligible patients each and were excluded. From the remaining four institutions, all from the USA, there were 235 eligible patients; 77 (random effects estimate: 32.7%; 95% CI: 19.1-50.1%) became D-alloimmunized. Three of the institutions reported D-alloimmunization rates ≥38.6%, while the remaining institution's rate was 12.2%. In both random and fixed-effects models, the rate of D-alloimmunization was not significantly different between those who received one RhD-positive unit and those who received multiple RhD-positive units. CONCLUSION: In this large, multicenter study of injured patients, the overall rate of D-alloimmunization fell within the range previously reported. The rate of D-alloimmunization did not increase as the number of transfused RhD-positive units increased. These data can help to inform RhD type selection decisions.

Single Plasma Unit Transfusions in Adults Are Either Unnecessary or Underdosed.

OBJECTIVES: Previous studies of blood product use have shown higher inappropriate use of plasma compared with other products. Given typical weight-based dosing of plasma, we hypothesized that single plasma transfusions in adults would either be a nontherapeutic dose or outside clinical guidelines. METHODS: A single-center, retrospective review of nonoperative, nonapheresis plasma use was conducted from January 2020 to April 2020. Plasma transfusions were reviewed for compliance with clinical guidelines formulated at our institution as well as national and society guidelines. RESULTS: During the study period, 313 units of plasma were transfused. Of these, 152 (48.6%) were given against institutional or national guidelines, 126 plasma units (40.3%) were transfused as single units, and 187 (59.7%) were given as part of multiple-unit transfusions. All single-unit plasma transfusions during the study period were either underdosed or outside clinical guidelines. Units transfused with an indication of "Other" were significantly more likely to be outside clinical guidelines. CONCLUSIONS: Nonoperative, nonapheresis plasma use is often outside clinical guidelines. Single-unit plasma transfusions in adults are a potential target for patient blood management programs seeking to minimize unnecessary plasma use.

THOR-AABB Working Party Recommendations for a Prehospital Blood Product Transfusion Program.

The evidence for the lifesaving benefits of prehospital transfusions is increasing. As such, emergency medical services (EMS) might increasingly become interested in providing this important intervention. While a few EMS and air medical agencies have been providing exclusively red blood cell (RBC) transfusions to their patients for many years, transfusing plasma in addition to the RBCs, or simply using low titer group O whole blood (LTOWB) in place of two separate components, will be a novel experience for many services. The recommendations presented in this document were created by the Trauma, Hemostasis and Oxygenation Research (THOR)-AABB (formerly known as the American Association of Blood Banks) Working Party, and they are intended to provide a framework for implementing prehospital blood transfusion programs in line with the best available evidence. These recommendations cover all aspects of such a program including storing, transporting, and transfusing blood products in the prehospital phase of hemorrhagic resuscitation.

Platelet Transfusion and In-Hospital Mortality in Veno-Arterial Extracorporeal Membrane Oxygenation Patients.

Thrombocytopenia is common during extracorporeal membrane oxygenation (ECMO), and platelets are sometimes transfused to meet arbitrary goals. We performed a retrospective cohort study of veno-arterial (VA) ECMO patients from a single academic medical center and explored the relationship between platelet transfusion and in-hospital mortality using multivariable logistic regression. One hundred eighty-eight VA ECMO patients were included in the study. Ninety-one patients (48.4%) were transfused platelets during ECMO. Patients who received platelet transfusion had more coronary artery disease, lower platelet counts at cannulation, higher predicted mortality, lower nadir platelet counts, more ECMO days, and more red blood cell (RBC) and plasma transfusion. Mortality was 19.6% for patients who received no platelets, 40.8% for patients who received 1-3 platelets, and 78.6% for patients who received 4 or more platelets ( P < 0.001). After controlling for confounding variables including baseline severity of illness, central cannulation, postcardiotomy status, RBC and plasma transfusion, major bleeding, and total ECMO days, transfusion of 4 or more platelets remained associated with in-hospital mortality; OR = 4.68 (95% CI = 1.18-27.28), P = 0.03. Our findings highlight the need for randomized controlled trials that compare different platelet transfusion triggers, so that providers can better understand when platelet transfusion is indicated in VA ECMO patients.

Blood usage at a large academic center in Maryland in relation to the COVID-19 pandemic in 2020.

BACKGROUND: Blood usage and collections were impacted throughout 2020 both by the severity of the COVID-19 pandemic as well as public health decisions affecting hospital operations. We sought to understand the longer-term effects of the pandemic on blood usage via changes in case volume and clinical intensity as well as whether the blood needs of COVID-19-positive patients differed from other transfused patients. STUDY DESIGN AND METHODS: A single-center retrospective study of blood use in 2020 as compared to 2014-2019 was conducted at a tertiary care center. Statistical analysis was performed in an R-based workflow. p values are reported using two-sided t-tests for total hospital blood usage and using Mann-Whitney U tests for comparisons of patient blood usage. RESULTS: Mean monthly red cell usage in 2020 decreased by 11.2% (p = .003), plasma usage decreased by 23.8%, (p < .001) platelet usage decreased by 11.4% (p < .001), and monthly cryoprecipitate use increased by 18% (p = .03). A linear regression model predicted significant associations between total blood usage and the year, number of Medicare eligible discharges, and Case Mix Index. COVID-19-positive patients requiring at least one blood product did not use significantly different amounts of red cells, plasma, or platelets from all other transfused patients. CONCLUSIONS: Year 2020 began with decreased blood usage that was normalized by late spring. Reassuringly, transfused COVID-19-positive patients in general and those requiring ICU level care do not use significantly increased amounts of blood as compared to similar transfused hospital patients.

Prehospital Plasma Transfusion: What Does the Literature Show?

BACKGROUND: Early initiation of blood products transfusion after injury has been associated with improved patient outcomes following traumatic injury. The ability to transfuse patients' plasma in the prehospital setting provides a prime opportunity to begin resuscitation with blood products earlier and with a more balanced plasma: RBC ratio than what has traditionally been done. Published studies on the use of prehospital plasma show a complex relationship between its use and improved survival. SUMMARY: Examination of the literature shows that there may be a mortality benefit from the use of prehospital plasma, but that it may be limited to certain subgroups of trauma patients. The likelihood of realizing these survival benefits appears to be predicted by several factors including the type of injury, length of transport time, presence of traumatic brain injury, and total number of blood products transfused, whether the patient required only a few products or a massive transfusion. When taken as a whole the evidence appears to show that prehospital plasma may have a mortality benefit that is most clearly demonstrated in patients with blunt injuries, moderate transfusion requirements, traumatic brain injury, and/or transport time greater than 20 min, as well as those who demonstrate a certain cytokine expression profile. KEY MESSAGES: The evidence suggests that a targeted use of prehospital plasma will most likely maximize the benefits from the use of this limited resource. It is also possible that prehospital plasma may best be provided through whole blood as survival benefits were greatest in patients who received both prehospital plasma and RBCs.

Anemia, sex, and race as predictors of morbidity or mortality after knee arthroplasty surgery.

BACKGROUND: Anemia is associated with poor outcome after major joint replacement surgery, but it is unclear whether sex and race modify its impact on outcome. We hypothesized that anemia would be associated with increased morbidity or mortality after knee arthroplasty surgery and that sex and race would be effect modifiers for this relationship. STUDY DESIGN AND METHODS: We performed a retrospective cohort study of elective knee arthroplasty patients between 2013 and 2018 using data from the National Surgical Quality Improvement Program. Morbidity or mortality after surgery was compared between patients without anemia, with mild anemia, and with moderate to severe anemia. Multivariable logistic regression was used to determine adjusted odds for morbidity or mortality with anemia. Interaction terms were entered into the model to test for effect modification by sex and race. RESULTS: 243 491 patients were included and 30 135 patients (12.4%) were anemic. Morbidity or mortality occurred in 3.7% of patients without anemia, 5.2% of patients with mild anemia, and 7.1% of patients with moderate to severe anemia (P < .001). After adjustment for confounding variables, mild anemia OR = 1.36 (95% CI = 1.28-1.45), and moderate to severe anemia OR = 1.92 (95% CI = 1.72-2.13) were associated with increased odds of morbidity or mortality. Sex, but not race, was a significant effect modifier with men having a greater increase in morbidity or mortality when anemic (P = .02). CONCLUSIONS: Anemia is associated with increased morbidity or mortality after knee arthroplasty surgery and men have a greater increase in perioperative risk than women when anemic.

Tools for rapid analysis of blood usage and inventory during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic caused downtrends in both blood collections and blood usage. Rapidly visualizing the impact of the pandemic and newly implemented hospital policies on usage could potentially inform blood ordering practices to help avoid wastage. STUDY DESIGN AND METHODS: Blood usage data were obtained from the laboratory information system. An R-based workflow was written in R Markdown for analysis and visualization. Reports were generated daily and shared with blood bank leadership. Selected reports were shared with institutional leadership, other departments, and collaborating blood suppliers. RESULTS: Mean daily transfusions dropped 42% from 3/9-13 to 3/16-20, with a significant decrease in usage of red cells, plasma, and cryoprecipitate. The greatest decline in use was seen in the general operating rooms, whereas outpatient transfusions remained steady. Weekly total blood usage decreased through the end of March into April and returned to normal levels in May. CONCLUSION: During two 5-weekday periods of changing hospital policies, overall blood usage decreased by almost half. Visualization of usage by hospital location showed a large decrease in general operating room usage after cancellation of elective procedures. This data visualization has informed decisions to modify standing product orders during an initial period of decreased usage as well as return to normal orders in later months.

Current state of whole blood transfusion for civilian trauma resuscitation.

BACKGROUND: Whole blood (WB) is rapidly emerging as the treatment modality of choice for the initial resuscitation of civilian trauma patients across the United States. The reemergence of WB has been rapid and driven in part by recognition of the importance of early plasma transfusion in the resuscitation process. STUDY DESIGN AND METHODS: The study was designed as a critical analysis of the available literature on WB transfusion in civilian trauma patients. Studies were included if they reported on transfusion of cold-stored WB used in a civilian setting and measured safety, feasibility, or a direct clinical outcome. RESULTS: Examination of the available literature supports the feasibility and safety of WB used in treatment of civilian trauma patients. The evidence regarding clinical outcomes, particularly with direct comparison to equivalent doses of component therapy, is more limited. The literature is predominantly descriptive and retrospective in nature and limited by the heterogeneity of clinical WB protocols being used. Based on this limited data set, there are limited conclusions that can be used to definitely support or refute the clinical superiority of WB to component therapy. CONCLUSION: Current literature supports the safety and feasibility of WB, but prospective randomized trials comparing WB to component therapy are needed to provide the definitive evidence on this topic.

Transfusion of Uncrossmatched Group O Erythrocyte-containing Products Does Not Interfere with Most ABO Typings.

BACKGROUND: Group O erythrocytes and/or whole blood are used for urgent transfusions in patients of unknown blood type. This study investigated the impact of transfusing increasing numbers of uncrossmatched type O products on the recipient's first in-hospital ABO type. METHODS: This was a retrospective cohort study. Results of the first ABO type obtained in adult, non-type O recipients (i.e., types A, B, AB) after receiving at least one unit of uncrossmatched type O erythrocyte-containing product(s) for any bleeding etiology were analyzed along with the number of uncrossmatched type O erythrocyte-containing products administered in the prehospital and/or in hospital setting before the first type and screen sample was drawn. RESULTS: There were 10 institutions that contributed a total of 695 patient records. Among patients who received up to 10 uncrossmatched type O erythrocyte-containing products, the median A antigen agglutination strength in A and AB individuals on forward typing (i.e., testing the recipient's erythrocytes for A and/or B antigens) was the maximum (4+), whereas the median B antigen agglutination strength among B and AB recipients of up to 10 units was 3 to 4+. The median agglutination strength on the reverse type (i.e., testing the recipient's plasma for corresponding anti-A and -B antibodies) was very strong, between 3 and 4+, for recipients of up to 10 units of uncrossmatched erythrocyte-containing products. Overall, the ABO type of 665 of 695 (95.7%; 95% CI, 93.9 to 97.0%) of these patients could be accurately determined on the first type and screen sample obtained after transfusion of uncrossmatched type O erythrocyte-containing products. CONCLUSIONS: The transfusion of smaller quantities of uncrossmatched type O erythrocyte-containing products, in particular up to 10 units, does not usually interfere with determining the recipient's ABO type. The early collection of a type and screen sample is important.

Electronic patient identification for sample labeling reduces wrong blood in tube errors.

BACKGROUND: Wrong blood in tube (WBIT) errors are a preventable cause of ABO-mismatched RBC transfusions. Electronic patient identification systems (e.g., scanning a patient's wristband barcode before pretransfusion sample collection) are thought to reduce WBIT errors, but the effectiveness of these systems is unclear. STUDY DESIGN AND METHODS: Part 1: Using retrospective data, we compared pretransfusion sample WBIT rates at hospitals using manual patient identification (n = 16 sites; >1.6 million samples) with WBIT rates at hospitals using electronic patient identification for some or all sample collections (n = 4 sites; >0.5 million samples). Also, we compared WBIT rates after implementation of electronic patient identification with preimplementation WBIT rates. Causes and frequencies of WBIT errors were evaluated at each site. Part 2: Transfusion service laboratories (n = 18) prospectively typed mislabeled (rejected) samples (n = 2844) to determine WBIT rates among samples with minor labeling errors. RESULTS: Part 1: The overall unadjusted WBIT rate at sites using manual patient identification was 1:10,110 versus 1:35,806 for sites using electronic identification (p < 0.0001). Correcting for repeat samples and silent WBIT errors yielded overall adjusted WBIT rates of 1:3046 for sites using manual identification and 1:14,606 for sites using electronic identification (p < 0.0001), with wide variation among individual sites. Part 2: The unadjusted WBIT rate among mislabeled (rejected) samples was 1:71 (adjusted WBIT rate, 1:28). CONCLUSION: In this study, using electronic patient identification at the time of pretransfusion sample collection was associated with approximately fivefold fewer WBIT errors compared with using manual patient identification. WBIT rates were high among mislabeled (rejected) samples, confirming that rejecting samples with even minor labeling errors helps mitigate the risk of ABO-incompatible transfusions.

Current Evidence for the Use of Prophylactic Transfusion to Treat Sickle Cell Disease During Pregnancy.

The role of prophylactic transfusion therapy for the treatment of sickle cell disease during pregnancy is unclear. An analysis of the existing literature shows a limited number of publications that address this issue and specifically compare clinical outcomes in this population based on a treatment strategy of prophylactic transfusion versus transfusion only for clinical indications (on-demand transfusion). The existing studies show a wide variation in study design and outcomes measured. The results of this analysis suggest that there are insufficient data to support a clinically significant difference in morbidity and mortality outcomes based on transfusion strategy. Additional prospective clinical studies need to be performed to adequately address the risks and benefits of prophylactic transfusion and guide clinical decision making.

Blood product transfusion and wastage rates in obstetric hemorrhage.

BACKGROUND: Bleeding emergencies can complicate pregnancies. Understanding the disposition of the products that are issued in this clinical setting can help inform inventory levels at hospitals where obstetric patients are seen. STUDY DESIGN AND METHODS: Patients who had an obstetric hemorrhage of any etiology between January 2013 and June 2017, and whose resuscitation began with uncrossmatched red blood cells (RBCs) or emergency-issued plasma or platelets (PLT), were included. The disposition of all blood products issued within 6 hours of the first uncrossmatched or emergency-issued product was documented, as was basic patient demographic information. RESULTS: In total, 301 women with an obstetric hemorrhage from seven academic institutions were identified. Their mean ± standard deviation age was 30.9 ± 6.1 years, 45.2% delivered by Cesarean section, and 40.5% delivered vaginally, while 12% did not deliver. The largest single etiology of hemorrhage was related to abnormal placentation. Of the 2280 issued RBC units, 55% were transfused, 43% were returned, and 2% were wasted. The rates of transfusion of the other blood products ranged from 58% for plasma units to 82% for cryoprecipitate. Seventeen percent of the issued cryoprecipitate units were wasted, the highest of any blood product. The rate of a patient receiving a transfusion when at least one blood product had been ordered ranged from 74% for PLTs to 91% for cryoprecipitate. CONCLUSION: Although the rates of receiving a transfusion of at least one blood product when one is ordered was high, many of the issued units were returned, especially for RBCs.

Changes in blood center red blood cell distributions in the era of patient blood management: the trends for collection (TFC) study.

BACKGROUND: As patient blood management becomes more widespread, fewer red blood cell (RBC) units have been transfused. This multinational study evaluated changes in blood center RBC distributions. STUDY DESIGN AND METHODS: Data on number and ABO and D groups of RBC distributions were obtained from several large American blood centers and national or provincial blood services (NPBS) from fiscal year (FY) 2010 through FY2014. Due to relatively larger numbers of distributions and differences in ABO and D groups between the Japanese Red Cross and the other NPBS, Japanese data were not included in distributions calculations. RESULTS: Data from seven American blood centers and eight NPBS were obtained. Overall, at both the American and the seven NPBS that were analyzed, there were declines in the number of RBC distributions between FY2010 and FY2014, 16.9 and 8.0%, respectively. The number of O- RBC distributions decreased by 9.0% at American blood centers but the proportion of RBC distributions that were O- increased by 9.3% during this time. The NPBS had 1.6% increase in O- RBC distributions and 10.5% increase in the proportion of O- distributions. The proportion of O+ distributions increased slightly over time at American centers (2.9%) while decreasing slightly (1.1%) at NPBS despite reductions in the absolute numbers of O+ distributions. Overall there was 2.6% decrease in the proportion of B+ and AB+ RBCs distributed and 13.6% absolute reduction in the number of these units distributed. CONCLUSION: Although overall RBC distributions have decreased over time, the proportion of O units has increased substantially.