The Efficacy of Low-Titer Group O Whole Blood Compared With Component Therapy in Civilian Trauma Patients: A Meta-Analysis

A prehospital protocol for transfusion of low-titer O-positive whole blood in patients with hemorrhagic shock in Los Angeles County: Modeling the risk of hemolytic disease of the fetus and newborn

BACKGROUND

The Los Angeles Development and Rapid Operationalization of Prehospital Blood (LA-DROP) pilot will protocolize prehospital administration of low titer O-positive whole blood (LTO + WB) to patients with hemorrhagic shock in Los Angeles County (LAC). We sought to quantify the risk of death from hemolytic disease of the fetus and newborn (HDFN) associated with RhD-negative alloimmunization in females of childbearing potential (FCPs) as a result of LA-DROP.

STUDY DESIGN AND METHODS

Retrospective data from LAC EMS databases were used in combination with estimates from published literature to assign probability distributions to each event in the sequence required for a transfusion of LTO + WB to result in a death from HDFN. Markov chain Monte Carlo simulation was used to derive risk estimates.

RESULTS

We estimated that the proposed prehospital transfusion strategy would result on average in one death from HDFN for every 10,000 transfusions in the overall population (95% confidence interval [CI] 6000-25,000) and for every 1800 transfusions in FCPs (95% CI 1000-4300). Based on the projected annual volume of transfusions under LA-DROP, this would result in one death due to HDFN approximately every 26 years (95% CI 15-64).

DISCUSSION

The estimated per-transfusion risk of HDFN is similar to previously published work from other populations. The estimated frequency of deaths from HDFN associated with LA-DROP is lower than some previously published calculations, likely because of narrower eligibility criteria for transfusion.

Expanding beyond trauma: Characterizing low titer group O whole blood (LTOWB) use in children requiring massive transfusion protocol activation

INTRODUCTION

Data regarding low titer group O whole blood (LTOWB) use for hemostatic resuscitation is largely derived from trauma cohorts; studies regarding its use in uninjured pediatric patients are lacking.

METHODS

The blood bank database from a single academic pediatric hospital with a massive transfusion protocol (MTP) allowing the use of LTOWB for any severe bleeding etiology was queried between 2016 and 2023. Pediatric (age <18 years) recipients of LTOWB were included; injured children were excluded. Data recorded included demographics, bleeding etiology, blood volumes, mortality (24-h and in-hospital), organ dysfunction, and, when available, posttransfusion biochemical markers of hemolysis.

RESULTS

Of 112 recipients of LTOWB, 16 met inclusion criteria. Median (IQR) age was 13 years (8-16) and 8/16 (50%) were male. MTP was most often activated on the day of admission (median (IQR) = day 0 (0-1)), and the bleeding etiology was variable, including perioperative (8/16; 50%), gastrointestinal bleed (5/16; 31%), and extracorporeal membrane oxygenation (ECMO) cannulation (3/16; 19%). The median (IQR) weight-adjusted volume of LTOWB transfused was 19 (10-26) mL/kg, and most children (13/16; 81%) received component blood products in addition to LTOWB. The 24-h mortality rate was 25% (4/16) and in-hospital mortality was 44% (7/16). The most common complication was AKI (10/16; 63%). There were no significant differences in biochemical hemolysis markers between group O (n = 7) and non-group O (n = 9) LTOWB recipients at any time point (p = .07-.99).

CONCLUSIONS

LTOWB use was feasible in the resuscitation of children with various bleeding etiologies requiring massive transfusion. Larger prospective investigations are needed to inform guidelines for optimal use in this cohort.

LEVEL OF EVIDENCE

Retrospective Observational Study.

A national database review of whole blood use among females of childbearing potential experiencing traumatic hemorrhage

INTRODUCTION

The use of low-titer O whole blood (LTOWB) for traumatic hemorrhage is growing. Most LTOWB for use in adults is RhD-positive, which presents potential risks to females of childbearing potential (FCP); however, data on practice patterns are lacking. We sought to assess the use of LTOWB among FCPs compared to similarly aged males in facilities with documented LTOWB capabilities.

METHODS

We compared FCP (females 15-50 years of age) to similarly aged males (or sex unclassified/undocumented) who were included in the Trauma Quality Improvement Program database from 2020 to 2022. This database records transfusion volumes administered within the first 4 h after admission and patient demographics. We compared LTOWB use among FCPs versus similarly aged males using descriptive, inferential, and multivariable statistics.

RESULTS

There were 79,298 that met inclusion for this analysis. There were 16,823 (21%) FCPs, of whom, 2759/16,823 (16%) received any volume of LTOWB compared to 16,310/62,475 (26%) of the males. Furthermore, among LTOWB recipients, the median (interquartile range) volume administered to FCPs was 1162 mL (500-1000) compared to 1352 mL (500-1000, p = .003) for males. In our multivariable logistic regression analysis, males had a higher odds for the receipt of LTOWB compared to FCPs (odds ratio 1.76, 95% confidence interval 1.68-1.84) after adjusting for age, mechanism of injury, and composite injury severity score. These findings persisted on sensitivity testing.

CONCLUSIONS

Males were more likely than FCPs to receive LTOWB during trauma resuscitation in unadjusted and adjusted analyses. The reasons for such differences require elucidation in future prospective studies.

Incorrect blood typing and mis-transfusion due to low-titer group O whole blood resuscitation

BACKGROUND

Resuscitation strategies for massive hemorrhage increasingly involve the use of low-titer group O whole blood (LTOWB) due to evidence suggesting improved patient outcomes. However, the potential risk of incorrect ABO typing following LTOWB administration, possibly leading to mis-transfusion, remains insufficiently explored. This case series aims to highlight the potential risk of ABO mistyping associated with LTOWB transfusions in trauma settings.

STUDY DESIGN AND METHODS

We retrospectively reviewed three cases involving trauma patients who received LTOWB transfusions at a high-volume urban Level 1 Trauma Center. ABO and RhD typing were performed using automated column agglutination technology (Ortho ID-MTS™), and discordant typing results prompted further investigations to confirm patients' true ABO type and identify mis-transfusions.

RESULTS

All three patients initially received LTOWB due to traumatic hemorrhage. Initial ABO typing after LTOWB administration incorrectly identified the patients as group O. Follow-up investigations later confirmed their true blood types as group A. Two cases resulted in subsequent inadvertent transfusions of ABO-incompatible plasma. Although no severe adverse clinical outcomes occurred, these events were reported to regulatory bodies as biologic product deviations.

DISCUSSION

Our findings highlight a rare but clinically significant risk of ABO typing errors following LTOWB transfusion, primarily due to contamination of patient samples with donor blood. Such errors carry the potential for acute hemolytic reactions, underscoring the critical need for strict adherence to sampling protocols. Whenever possible, ABO typing should be performed prior to LTOWB administration, and samples should be drawn from a site contralateral to the transfusion.

The effect of the proportion of low-titer O whole blood for resuscitation in pediatric trauma patients on 6-, 12- and 24-hour survival

INTRODUCTION

Hemorrhage is a leading cause of death in pediatric patients. Accumulating data suggest that low-titer group O whole blood (LTOWB) improves clinical outcomes in the pediatric population. We examined what ratio of LTOWB to total blood product conferred a survival benefit in transfused pediatric trauma patients.

METHODS

We retrospectively examined a cohort of injured subjects younger than 18 years from the Trauma Quality Improvement Program database who received any quantity of LTOWB and no documented prehospital cardiac arrest. We created a variable representing the volume of transfused LTOWB divided by the total volume of all transfused blood products administered within the first 4 hours of admission, that is, the proportion of LTOWB transfused. We analyzed increasing proportions of transfused LTOWB to determine whether there was an inflection point conferring increased survival.

RESULTS

From 2020 to 2022, 1,122 subjects were included in the analysis. The median (interquartile range) age was 16 (14-17) years. Firearms were the most common mechanism at 47% followed by collisions at 44%. The median composite injury severity score was 25 (16-34). Survival was 91% at 6 hours, 89% at 12 hours, and 88% at 24 hours. We noted an inflection point with improved survival at an LTOWB proportion of ≥30% of total volume of blood products received. The odds of survival at 6, 12, and 24 hours for those receiving ≥30% LTOWB was 1.85 (1.02-3.38), 2.09 (1.20-3.36), and 1.80 (1.06-3.08), and 3.55 (1.66-7.58), 3.71 (1.89-7.27), and 2.69 (1.44-5.02) when excluding those who died within 1 hour, respectively.

CONCLUSION

Among LTOWB recipients, we found that a strategy of using LTOWB comprising at least 30% of the total transfusion volume within the first 4 hours was associated with improved survival at 6, 12, and 24 hours.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

How do we implement a prehospital whole blood administration program for shock trauma patients on a statewide basis?

BACKGROUND

Since bleeding is a major cause of early mortality in trauma, there is continued interest in providing transfusion support as early as possible to trauma patients. Various approaches have been taken to accomplish this, including the rapid provision of blood products upon arrival at the hospital, as well as a variety of prehospital approaches. However, implementing prehospital blood availability statewide for use in all populations has been limited.

STUDY DESIGN AND METHODS

The program described for prehospital transfusion identifies a direct partnership between state EMS providers and the local blood center. Predictive modeling is compared to early outcome data of the first 100 patients who received whole blood from this program. Additional discussion contains key elements of the program, including planning, validation, and implementation.

RESULTS

Between May 2023 and July 2024, an average of 11 prehospital whole blood units were transfused per month against the projected average of 10-16 units administered per month, with the median time to transfusion of 29.2 min. The leading reason for blood administration was due to blunt trauma. Of the patients who were not in prehospital cardiac arrest prior to paramedic arrival or excluded for other reasons, approximately 95% survived to hospital discharge.

DISCUSSION

Implementation of prehospital whole blood across the state has demonstrated effectiveness early within the first year of the program. Continued process improvements will be implemented with statewide ground paramedic agency utilization of whole blood as well as expansion into aviation divisions for more expedient whole blood administration times.

Individualized and targeted coagulation management in bleeding trauma patients

PURPOSE OF REVIEW

This review aims to summarize current evidence on hemostatic management of bleeding trauma patients, with a focus on resuscitation strategies using either coagulation factor concentrates or fixed-ratio transfusion concepts. It discusses the potential benefits and limitations of both approaches.

RECENT FINDINGS

Recent studies have shown that coagulopathy caused by massive traumatic hemorrhage often cannot be reversed by empiric treatment. During initial resuscitation, a fixed-ratio transfusion approach uses the allogeneic blood products red blood cells, plasma, and platelets to mimic 'reconstituted whole blood'. However, this one-size-fits-all strategy risks both overtransfusion and undertransfusion in trauma patients.Many European trauma centers have shifted toward individualized hemostatic therapy based on point-of-care diagnostics, particularly using viscoelastic tests. These tests provide rapid insight into the patient's hemostatic deficiencies, enabling a more targeted and personalized treatment approach.

SUMMARY

Individualized, goal-directed hemostatic management offers several advantages over fixed-ratio transfusion therapy for trauma patients. However, there is a paucity of data regarding the direct comparison of these two approaches.

High-dimensional analysis of injured patients reveals distinct circulating proteomic profiles in plasma vs. whole blood resuscitation

Early blood product resuscitation is often essential for optimal trauma care. However, the effects of different products on the underlying trauma-induced coagulopathy and immune dysfunction are not well described. Here, we use high-dimensional analysis and causal modeling in a longitudinal study to explore the circulating proteomic response to plasma as a distinct component versus low-titer O whole blood (LTOWB), which contains plasma. We highlight the differential impacts of plasma and LTOWB on immune mediator levels and the distinct capacity of plasma to modulate coagulation by elevating fibrinogen and factor XIII and reducing platelet factor 4. A higher proportion of plasma in prehospital resuscitation is associated with improved admission time coagulation parameters in patients with severe shock and elevated brain injury markers and reduced post-admission transfusion volumes in those suffering from traumatic brain injury (TBI) and blunt injury. While LTOWB offers broad hemostatic benefits, our findings demonstrate specific advantages of plasma and support individualized transfusion strategies.

Advances in resuscitation and deresuscitation

PURPOSE OF REVIEW

This review aims to provide a perspective on fluid resuscitation strategies and emerging trends in deresuscitation, with a particular emphasis on fluid stewardship, monitoring, and personalized fluid management.

RECENT FINDINGS

Recent studies underscore a paradigm shift in resuscitation strategies. Notably, aggressive plasma volume expansion has been linked to higher morbidity and mortality, favoring conservative fluid resuscitation. Dynamic parameters, such as pulse pressure variation (PPV) and stroke volume variation (SVV) outperform static markers like central venous pressure (CVP) in predicting preload responsiveness. Advances in hemodynamic monitoring and automated closed-loop fluid administration demonstrate efficacy in optimizing resuscitation. Fluid stewardship, supported by machine learning, is reshaping deresuscitation practices, and promoting negative fluid balance to reduce complications. Moreover, next-generation closed-loop systems and fluid management personalization as part of precision medicine are emerging as future directions.

SUMMARY

Advances in fluid resuscitation challenge traditional practices, with evidence favoring personalized and goal-directed strategies. Technological innovations in hemodynamic monitoring, automated fluid control, and machine learning are driving precision fluid management. Fluid stewardship and deresuscitation aim to mitigate fluid accumulation syndrome and improve patient outcomes.

Early achievement of hemostasis defined by transfusion velocity: A possible mechanism for whole blood survival benefit

INTRODUCTION

Whole blood resuscitation is associated with survival benefits in observational cohort studies. The mechanisms responsible for outcome benefits have not been adequately determined. We sought to characterize the achievement of hemostasis across patients receiving early whole blood versus component resuscitation. We hypothesized that achieving hemostasis would be associated with outcome benefits and patients receiving whole blood would be more likely to achieve hemostasis.

METHODS

We performed a post hoc retrospective secondary analysis of data from a recent prospective observational cohort study comparing early whole blood and component resuscitation in patients at risk of hemorrhagic shock. Achievement of hemostasis was defined by receiving a single unit of blood or less, including whole blood or red cells, in any 60-minute period, over the first 4 hours from the time of arrival. Time-to-event analysis with log-rank comparison and regression modeling were used to determine the independent benefits of achieving hemostasis and whether achieving hemostasis was associated with whole blood resuscitation.

RESULTS

For the current analysis, 1,047 patients met the inclusion criteria for the study. When we compared patients who achieved hemostasis versus those who did not, achievement of hemostasis had significantly more hemostatic coagulation parameters, had lower transfusion requirements, and was independently associated with 4-hour, 24-hour and 28-day survival. Whole blood patients were significantly more likely to achieve hemostasis (88.9% vs. 81.1%, p < 0.001). Whole blood patients achieved hemostasis earlier (log-rank χ 2 = 8.2, p < 0.01) and were independently associated with over twofold greater odds of achieving hemostasis (odds ratio, 2.4; 95% confidence interval, 1.6-3.7; p < 0.001).

CONCLUSION

Achievement of hemostasis is associated with significant outcome benefits. Early whole blood resuscitation is associated with a greater independent odds of achieving hemostasis and at an earlier time point. Reaching a nadir transfusion rate early following injury represents a possible mechanism of whole blood resuscitation and its attributable outcome benefits.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

Forty-eight-hour cold-stored whole blood in paediatric cardiac surgery: Implications for haemostasis and blood donor exposures

BACKGROUND AND OBJECTIVES

Cold-stored whole blood (CS-WB) in paediatric cardiac surgery is making a resurgence, given its identified benefits compared to conventional blood component therapy (CT).

STUDY DESIGN AND METHODS

A single-centre retrospective study was conducted from January 2018 to October 2018 by including children <18 years of age undergoing cardiac surgery requiring cardiopulmonary bypass. ABO-compatible CS-WB from non-directed random donors was leukoreduced with platelet-sparing filters and compared with CT.

RESULTS

Fifty-seven patients (30, 53% CS-WB; 27, 47% CT) were studied. Patient demographics were similar, although CT patients were cooled to a lower intra-operative temperature. Blood product requirements 24 h post operation were less in the CS-WB group (11.1 vs. 26.7 mL/kg, p = 0.048). Twelve (40%) patients in the CS-WB cohort had more than one donor exposure versus 25 (93%) in the CT group (p < 0.001). CT patients compared to CS-WB patients had a greater decrease in pre-operative versus 48-h post-operative haemoglobin, platelets and prothrombin time. Patients who received CT compared to CS-WB had a trend towards higher median (interquartile range [IQR]) chest-tube output (mL/kg/h) in the first 4 h post cardiac intensive care unit (ICU) admission (2.1 [0.8, 3] vs. 1.6 [0.8, 2.2], p = 0.197). There was no difference in antifibrinolytic use, length of stay, sepsis, acute kidney injury or wound infection. Survival to discharge was similar.

CONCLUSION

CS-WB in paediatric cardiac surgery may reduce donor exposure and improve haemostatic balance. Future multi-centre prospective studies are needed to validate these findings and identify patients who would benefit from CS-WB in paediatric cardiac surgery.

Extracellular vesicles in ageing cold-stored whole blood may not compensate for the decreasing haemostatic function in vitro

BACKGROUND

Extracellular vesicles (EVs) have procoagulative properties. As EVs are known to accumulate in stored blood products, we compared the EV content and coagulation capacity of leukoreduced cold-stored whole blood (CSWB) with current prehospital and in-hospital component therapies to understand the role of EVs in the haemostatic capacity of ageing CSWB.

MATERIALS AND METHODS

Blood was obtained from 12 O RhD-positive male donors. CSWB was compared with in-hospital component therapy of red blood cells (RBCs), OctaplasLG and buffy-coat platelets and prehospital component therapy of RBC and lyophilized plasma. Samples were drawn on Days 1 and 14 of CSWB and RBC cold storage. Blood count, haemolysis markers, rotational thromboelastometry, sonorheometry and thrombin generation were analysed. EVs were analysed using nanoparticle tracking analysis and cellular origin was determined using imaging flow cytometry.

RESULTS

There was a trend towards increased production of both platelet and RBC-derived EVs during CSWB storage. Particle count increased during storage, whereas thrombin generation slowed down and in viscoelastic assays, clotting times prolonged, clot formation became impaired, and stiffness of the resulting clot decreased.

CONCLUSION

Both platelet and RBC-derived EVs increased in number in CSWB during storage. This did not appear to compensate for the in vitro decreasing haemostatic capacity of ageing CSWB, suggesting EVs produced during storage may not have active procoagulative effects, but rather reflect the ageing of blood cells.

Hemostatic function, immunomodulatory capacity, and effects of lipemia in cold-stored whole blood

BACKGROUND

Whole blood (WB) is increasingly being used for resuscitation of trauma patients. Although platelet-, red blood cell (RBC)- and plasma-specific parameters in cold-stored WB are well characterized, there has been limited investigation of biological response modifiers (BRMs), which may induce adverse reactions in recipients. The aim of this study was to evaluate the quality and function of RBC, platelets, plasma proteins, and BRMs in cold-stored WB during storage.

METHODS

WB (n = 24) was collected into collected into citrate-phosphate-dextrose (CPD) anticoagulant, held overnight, processed through a platelet-sparing filter, and stored at 2-6°C for 21 days. RBC, platelet, coagulation factor quality and function, and BRM concentrations were measured throughout the duration of storage.

RESULTS

WB was effectively leukoreduced, with 99.98% reduction in leukocyte count and 81% platelet count recovery following filtration. Five WB units were significantly lipemic, with a visible lipid layer appearing after being cold storage overnight. These were more turbid with higher hemolysis compared to non-lipemic units (p = .023). Despite a decrease in platelet count during storage (p < .001), hemostatic function as measured by thromboelastography was maintained for at least 21 days (R time and maximum amplitude; both p < .001). There was a significant increase in PF4, CD62P, and RANTES during cold storage (all p < .001).

DISCUSSION

WB retains hemostatic potential for at least 21 days of cold storage, and with further development, may be suitable for transfusion in Australia. Before implementation in Australia, quality control measures for lipemia and hemolysis would need to be defined as part of our manufacturing processes.

Evolution of whole blood trauma resuscitation in childbearing age females: practice patterns and trends

Background

The use of low titer group O whole blood (LTOWB) for resuscitation of patients with traumatic hemorrhage is becoming increasingly common. Practices regarding the administration of RhD-positive LTOWB to childbearing age females (CBAFs) vary between institutions due to concerns about RhD alloimmunization. This study examined practices related to LTOWB transfusion as they pertain to age and sex.

Methods

This was a secondary analysis of the Shock, Whole blood, and Assessment of TBI (traumatic brain injury) trial, a prospective, multicenter observational cohort study where outcomes following LTOWB transfusion were analyzed at seven level 1 trauma centers between 2018 and 2021, as well as a survey on transfusion practices at these centers conducted in 2023. The proportion of patients who received LTOWB or components was examined over the course of the study and grouped by age and sex, and the RhD group of injured CBAFs was documented.

Results

A total of 1046 patients were evaluated: 130 females aged <50 years (CBAFs), 77 females aged ≥50 years; 661 males aged <50 years, and 178 males aged ≥50 years. Among them, 26.2% of CBAFs received RhD-positive LTOWB, whereas 57.1%-66.3% of other sex/age groups received LTOWB. The proportion of CBAFs who received LTOWB increased significantly throughout the 4 years of this study. Except for older women in years 2 and 4, CBAFs were significantly less likely to receive LTOWB than all other groups for the study period and individual years. Among the 33 CBAFs who received LTOWB and for whom an RhD type was available, 4/33 (12.1%) were RhD-negative, while 9/95 (9.5%) CBAFs who received component therapy were RhD-negative. RhD blood product selection practices varied considerably between institutions.

Conclusions

Many institutions transfused LTOWB to CBAFs. Policies regarding RhD product selection varied. Of the total cohort, the proportion of RhD-negative CBAFs who received LTOWB increased over time but remained lower than all other groups.

Level of evidence

3.

An analysis of the effect of low titer O whole blood (LTOWB) proportions for resuscitation after trauma on 6-hour and 24-hour survival

INTRODUCTION

Hemorrhage is a leading cause of death. Blood products are used for the treatment of hemorrhagic shock. The use of low titer group O whole blood (LTOWB) has become more common.

METHODS

Data from patients ≥15 years of age in the Trauma Quality Improvement Program (TQIP) database that received ≥10 units of packed red cells and/or LTOWB within the first 4-h of hospital arrival were included. The proportion of LTWOB of total blood products administered was correlated to 6- and 24-h mortality.

RESULTS

12,763 met inclusion, 3827 (30 %) received LTOWB. On multivariable logistic regression (MVLR), there was no difference in survival at 6 h with a LTOWB. When assessing 24-h survival, there was improved survival with LTOWB ≥10 % (OR 1.18, 1.08-1.28).

CONCLUSIONS

In this analysis of TQIP data, patients receiving ≥10 units of PRBC or LTOWB, we found that higher proportions of LTOWB transfusion relative to the total volume of blood products transfused during the first 4 h were associated with improved 24-h, but not 6-h survival.

The Magic Number 63 - Redefining the Geriatric Age for Massive Transfusion in Trauma

INTRODUCTION

The arbitrary geriatric age cutoff of 65 may not accurately define older adults at higher risk of mortality following massive transfusion (MT). We sought to redefine a new geriatric age threshold for MT and understand its association with outcomes.

MATERIAL AND METHODS

The 2013-2018 Trauma Quality Improvement Program database was queried for all adults who received ≥10 units of packed red blood cells (pRBCs) within 24 h of admission. A bootstrap analysis using multiple logistic regression established transfusion futility thresholds (TTs), where additional pRBCs no longer improved mortality for various age cutoffs. The age cutoff at which the TT for those relatively older and relatively younger was statistically significant was used to define the new "geriatric" age for MT. Outcomes were then compared between the newly defined geriatric and nongeriatric patients.

RESULTS

The difference in TT first became significant when the age cutoff was 63 y. The TT for patients aged ≥63 y (new geriatric, n = 2870) versus <63 y (nongeriatric, n = 17,302) was 34 and 40 units of pRBCs, respectively (P = 0.04). Although geriatric patients had a higher Glasgow coma scale score (9 versus 6, P < 0.01) and lower abbreviated injury score-abdomen (3 versus 4, P < 0.01) than the nongeriatric, they suffered higher overall mortality (62% versus 45%, P < 0.01). A lower percentage of geriatric patients were discharged to home (7% versus 35%, P < 0.01).

CONCLUSIONS

The new geriatric age for MT is 63 y, with a TT of 34 units. Despite suffering less severe injuries, physiologically "geriatric" patients have worse outcomes following MT.