Doing more with less: low-titer group O whole blood resulted in less total transfusions and an independent association with survival in adults with severe traumatic hemorrhage

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.

TXA combined with whole blood transfusion in trauma patients does not increase the risk of VTE but shock index does

INTRODUCTION

Previous studies have demonstrated the benefits of tranexamic acid (TXA) administration in combination with packed red blood cell (PRBC) transfusion in trauma patients without increasing the risk of venous thromboembolism (VTE). However, the effect of TXA in combination with whole blood (WB) has not been studied. Injury, abbreviated injury severity scores (ISS and AIS) and the need for blood transfusions are historically associated with VTE. The objective of this study was to determine the relationship between VTE and the combination of TXA administration and transfusion of PRBCs vs. WB.

METHODS

Our institutional trauma registry was queried for trauma patients between 2015 and 2022 who received either WB ​+ ​TXA or PRBC ​+ ​TXA either prehospital or within 4 ​h of arrival. Multivariate analysis was utilized to determine independent risk factors for VTE, which were defined as either a deep vein thrombosis (DVT) or a pulmonary embolism (PE). Model covariates included age, mechanism of injury (MOI), ISS, lower extremity AIS, comorbid conditions, and shock index (SI). Additional outcomes analyzed were hospital length of stay (LOS), ICU LOS, and ventilator days.

RESULTS

Three hundred and five patients had complete data and were included in the analysis. Of those, 251 received WB ​+ ​TXA and 54 received PRBC ​+ ​TXA. A total of 34 patients were found to have VTE event (11.1 ​%); 28 (11.2 ​%) and 6 (11.1 ​%) from the WB ​+ ​TXA and PRBC ​+ ​TXA groups, respectively. An elevated pre-hospital SI was independently associated with increased VTE rate (OR 1.85, 95 ​% CI 1.07-3.20). WB transfusion, TXA administration, ISS, and MOI did not influence the rate of VTE.

CONCLUSION

These data demonstrate that the combination of WB ​+ ​TXA administered to trauma patients has no higher risk of VTE than patients who receive PRBC ​+ ​TXA, a comparison that has not been studied clinically to date. Despite the pro thrombotic state enhanced by TXA and the decreased dilutional coagulopathy seen in WB resuscitation, there was no increased risk of VTE compared to TXA ​+ ​PRBC. There is no evidence that TXA combined with whole blood transfusion is associated with an increased risk of VTE. However, higher pre-hospital SI was associated with an elevated rate of VTE. These clinical features provide insight into patients who may be at an increased risk of developing VTE and may benefit from targeted prevention strategies.

Use of low titer O whole blood in infants and young children undergoing cardiac surgery with cardiopulmonary bypass

BACKGROUND

Low titer group O whole blood (LTOWB) is commonly used for severe bleeding in trauma patients. LTOWB may also benefit young children requiring cardiac surgery with cardiopulmonary bypass (CPB) at risk of severe bleeding.

STUDY DESIGN AND METHODS

In this retrospective study, children <2 years old who underwent cardiac surgery with CPB were included. Comparisons were performed between those receiving component therapy (CT) versus those receiving LTOWB plus CT (LTOWB+CT). Outcomes included drainage tube (DT) output and total transfusion volumes. Optimization-based weighting was used for adjusted analyses between groups.

RESULTS

There were 117 patients transfused with only CT and 127 patients transfused with LTOWB+CT. In the LTOWB+CT group, 66 were Group non-O and 61 were Group O. Total transfusion volumes given from the start of the operation until the first 24 h in the cardiac intensive care unit was a median (IQR) 41 (10, 93) mL/kg in the CT group and 48 (28, 77) mL/kg in the LTOWB+CT group, (p = .28). Median (IQR) DT output was 22 (15-32) in CT versus 22 (16-28) in LTOWB+CT groups, (p = .27). There were no differences in death, renal failure and a composite of death and renal failure between the two groups, but there were statistically fewer re-explorations for bleeding in the LTOWB+CT group (p < .001).

CONCLUSIONS

The use of LTOWB appears to be safe in <2 years old undergoing cardiac surgery and may reduce re-explorations for severe bleeding. Large trials are needed to determine the efficacy and safety of LTOWB in this population with severe bleeding.

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.

Whole blood: Total blood product ratio impacts survival in injured children

BACKGROUND

Some studies in both children and adults have shown a mortality benefit for the use of low titer group O whole blood (LTOWB) compared with component therapy for traumatic resuscitation. Although LTOWB is not widely available at pediatric trauma centers, its use is increasing. We hypothesized that in children who received whole blood after injury, the proportion of whole blood in relation to the total blood product resuscitation volume would impact survival.

METHODS

The trauma database from a single academic pediatric Level I trauma center was queried for pediatric (age <18 years) recipients of LTOWB after injury (years 2015-2022). Weight-based blood product (LTOWB, red blood cells, plasma, and platelet) transfusion volumes during the first 24 hours of admission were recorded. The ratio of LTOWB to total transfusion volume was calculated. The primary outcome was in-hospital mortality. Multivariable logistic regression model adjusted for the following variables: age, sex, mechanism of injury, Injury Severity Score, shock index, and Glasgow Coma Scale score. Adjusted odds ratio representing the change in the odds of mortality by a 10% increase in the LTOWB/total transfusion volume ratio was reported.

RESULTS

There were 95 pediatric LTOWB recipients included in the analysis, with median (interquartile range [IQR]) age of 10 years (5-14 years), 58% male, median (IQR) Injury Severity Score of 26 (17-35), 25% penetrating mechanism. The median (IQR) volume of LTOWB transfused was 17 mL/kg (15-35 mL/kg). Low titer group O whole blood comprised a median (IQR) of 59% (33-100%) of the total blood product resuscitation. Among patients who received LTOWB, there was a 38% decrease in in-hospital mortality for each 10% increase in the proportion of WB within total transfusion volume ( p < 0.001) after adjusting for age, sex, mechanism of injury, Injury Severity Score, shock index, and Glasgow Coma Scale score.

CONCLUSION

Increased proportions of LTOWB within the total blood product resuscitation was independently associated with survival in injured children. Based on existing data that suggests safety and improved outcomes with whole blood, consideration may be given to increasing the use of LTOWB over CT resuscitation in pediatric trauma resuscitation.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

Whole blood to total transfusion volume ratio in injured children: A national database analysis

BACKGROUND

Whole blood (WB) resuscitation is increasingly common in adult trauma centers and some pediatric trauma centers, as studies have noted its safety and potential superiority to component therapy (CT). Previous analyses have evaluated WB as a binary variable (any versus none), and little is known regarding the "dose response" of WB in relation to total transfusion volume (TTV) (WB/TTV ratio).

METHODS

Injured children younger than 18 years who received any blood transfusion within 4 hours of hospital arrival across 456 US trauma centers were included from the American College of Surgeons Trauma Quality Improvement Program database. The primary outcome was 24-hour mortality, and the secondary outcome was 4-hour mortality. Multivariate analysis was used to evaluate associations between WB administration and mortality and WB/TTV ratio and mortality.

RESULTS

Of 4,323 pediatric patients included in final analysis, 88% (3,786) received CT only, and 12% (537) received WB with or without CT. Compared with the CT group, WB recipients were more likely to be in shock, according to pediatric age-adjusted shock index (71% vs. 60%) and had higher median (interquartile range) Injury Severity Score (26 [17-35] vs. 25 [16-24], p = 0.007). Any WB transfusion was associated with 42% decreased odds of mortality at 4 hours (adjusted odds ratio [aOR], 0.58 [95% confidence interval, 0.35-0.97]; p = 0.038) and 54% decreased odds of mortality at 24 hours (aOR, 0.46 [0.33-0.66]; p < 0.001). Each 10% increase in WB/TTV ratio was associated with a 9% decrease in 24-hour mortality (aOR, 0.91 [0.85-0.97]; p = 0.006). Subgroup analyses for age younger than 14 years and receipt of massive transfusion (>40 mL/kg) also showed statistically significant survival benefit for 24-hour mortality.

CONCLUSION

In this retrospective American College of Surgeons Trauma Quality Improvement Program analysis, use of WB was independently associated with reduced 24-hour mortality in children; further, higher proportions of WB used over the total resuscitation (WB/TTV ratio) were associated with a stepwise increase in survival.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level III.

Maternal red blood cell alloimmunization prevalence in the United States

ABSTRACT

Hemolytic disease of fetus and newborn (HDFN) is a life-threatening disease mediated by maternal alloimmunization to red blood cell (RBC) antigens. Studies of maternal alloimmunization prevalence in the United States lack national data. This study describes prevalence and trends in alloimmunization in pregnancy in the United States. RBC antibodies (abs) were identified in a large, nationwide, commercial laboratory database from 2010 through 2021. The cohort comprised pregnancies for which the year of laboratory collection and patient's state of residence were available. Data were normalized based on US Centers for Disease Control and Prevention estimates of live births and weighted by year and US Census Division. Cochrane-Armitage tests assessed temporal trends of alloimmunization. Of 9 876 196 pregnancies, 147 262 (1.5%) screened positive for RBC abs, corresponding to an estimated prevalence of 1518 of 100 000 pregnancies. Of identified RBC abs, anti-D comprised 64.1% pregnancies (586/100 000). Prevalence of other high-risk RBC abs for HDFN included anti-K (68/100 000) and anti-c (29/100 000). Incidence of all 3 high-risk abs increased from 2010 to 2021 (all P < .001). Among almost 10 million pregnancies in the United States, comprising an estimated 14.4% of all pregnancies, 1.5% screened positive for RBC abs. Almost three-quarters (679/100 000 [74.3%]) of RBC abs identified were high risk for HDFN. Although prevalence of anti-D is difficult to interpret without the ability to distinguish alloimmunization from passive immunity, it remains problematic in HDFN, ranking second only to anti-K in critical titers. Given the sequelae of HDFN, new initiatives are required to reduce the incidence of alloimmunization in patients of reproductive potential.

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

OBJECTIVES

To assess if transfusion with low-titer group O whole blood (LTOWB) is associated with improved early and/or late survival compared with component blood product therapy (CT) in bleeding trauma patients.

DATA SOURCES

A systematic search of PubMed, CINAHL, and Web of Science was performed from their inception through December 1, 2023. Key terms included injury, hemorrhage, bleeding, blood transfusion, and whole blood.

STUDY SELECTION

All studies comparing outcomes in injured civilian adults and children who received LTOWB versus CT were included.

DATA EXTRACTION

Data including author, publication year, sample size, total blood volumes, and clinical outcomes were extracted from each article and reported following the Meta-analysis Of Observational Studies in Epidemiology guidelines. Main outcomes were 24-hour (early) and combined 28-day, 30-day, and in-hospital (late) mortality rates between recipients of LTOWB versus CT, which were pooled using random-effects models.

DATA SYNTHESIS

Of 1297 studies reviewed, 24 were appropriate for analysis. Total subjects numbered 58,717 of whom 5,164 received LTOWB. Eleven studies included adults-only, seven included both adults and adolescents, and six only included children. The median (interquartile range) age for patients who received LTOWB and CT was 35 years (24-39) and 35.5 years (23-39), respectively. Overall, 14 studies reported early mortality and 22 studies reported late mortality. LTOWB was associated with improved 24-hour survival (risk ratios [RRs] [95% CI] = 1.07 [1.03-1.12]) and late (RR [95% CI] = 1.05 [1.01-1.09]) survival compared with component therapy. There was no evidence of small study bias and all studies were graded as a moderate level of bias.

CONCLUSIONS

These data suggest hemostatic resuscitation with LTOWB compared with CT improves early and late survival outcomes in bleeding civilian trauma patients. The majority of subjects were injured adults; multicenter randomized controlled studies in injured adults and children are underway to confirm these findings.

Survey of policies at US hospitals on the selection of RhD type of low-titer O whole blood for use in trauma resuscitation

BACKGROUND

Low-titer group O whole blood (LTOWB) use is increasing due to data suggesting improved outcomes and safety. One barrier to use is low availability of RhD-negative LTOWB. This survey examined US hospital policies regarding the selection of RhD type of blood products in bleeding emergencies.

STUDY DESIGN AND METHODS

A web-based survey of blood bank directors was conducted to determine their hospital's RhD-type selection policies for blood issued for massive bleeding.

RESULTS

There was a 61% response rate (101/157) and of those responses, 95 were complete. Respondents indicated that 40% (38/95) use only red blood cells (RBCs) and 60% (57/95) use LTOWB. For hospitals that issue LTOWB (N = 57), 67% are supplied only with RhD-positive, 2% only with RhD-negative, and 32% with both RhD-positive and RhD-negative LTOWB. At sites using LTOWB, RhD-negative LTOWB is used exclusively or preferentially more commonly in adult females of childbearing potential (FCP) (46%) and pediatric FCP (55%) than in men (4%) and boys (24%). RhD-positive LTOWB is used exclusively or preferentially more commonly in men (94%) and boys (54%) than in adult FCP (40%) or pediatric FCP (21%). At sites using LTOWB, it is not permitted for adult FCPs at 12%, pediatric FCP at 21.4%, and boys at 17.1%.

CONCLUSION

Hospitals prefer issuing RhD-negative LTOWB for females although they are often ineligible to receive RhD-negative LTOWB due to supply constraints. The risk and benefits of LTOWB compared to the rare occurrence of hemolytic disease of the fetus/newborn (HDFN) need further examination in the context of withholding a therapy for females that has the potential for improved outcomes.

Transforming research to improve therapies for trauma in the twenty-first century

Improvements have been made in optimizing initial care of trauma patients, both in prehospital systems as well as in the emergency department, and these have also favorably affected longer term outcomes. However, as specific treatments for bleeding are largely lacking, many patients continue to die from hemorrhage. Also, major knowledge gaps remain on the impact of tissue injury on the host immune and coagulation response, which hampers the development of interventions to treat or prevent organ failure, thrombosis, infections or other complications of trauma. Thereby, trauma remains a challenge for intensivists. This review describes the most pressing research questions in trauma, as well as new approaches to trauma research, with the aim to bring improved therapies to the bedside within the twenty-first century.

War at Sea: Burn Care Challenges-Past, Present and Future

Throughout history, seafarers have been exposed to potential thermal injuries during naval warfare; however, injury prevention, including advances in personal protective equipment, has saved lives. Thankfully, burn injuries have decreased over time, which has resulted in a significant clinical skills gap. Ships with only Role 1 (no surgical capability) assets have worse outcomes after burn injury compared to those with Role 2 (surgical capability) assets. To prepare for future burn care challenges during a war at sea, Military Medicine must re-learn the lessons of World War I and World War II. Burn injuries do not occur in isolation during war and are associated with concomitant traumatic injuries. To care for burn casualties at sea, there is an urgent need to increase the availability of whole blood and dried plasma, resuscitation fluids that were ubiquitous throughout the naval force during World War II for both hemorrhagic and burn shock resuscitation. Furthermore, those providing trauma care at sea require formal burn care training and skills sustainment experiences in the clinical management of Burn, Trauma, and Critical Care patients. While burn education, training, and experience must be improved, modern high-energy weapons systems and anti-ship ballistic missiles necessitate concurrent investments in prevention, countermeasures, and personal protective equipment to decrease the likelihood of burn injury and damage resulting from these attacks.