Measurement of haemolysis markers following transfusion of uncrossmatched, low-titre, group O+ whole blood in civilian trauma patients: initial experience at a level 1 trauma centre

Implementation of a prehospital whole blood program: Lessons learned

Early blood administration by Emergency Medical Services (EMS) to patients suffering from hemorrhagic shock improves outcomes. Prehospital blood programs represent an invaluable resuscitation capability that directly addresses hemorrhagic shock and mitigates subsequent multiple organ dysfunction syndrome. Prehospital blood programs must be thoughtfully planned, have multiple safeguards, ensure adequate training and credentialing processes, and be responsible stewards of blood resources. According to the 2022 best practices model by Yazer et al, the four key pillars of a successful prehospital program include the following: (1) the rationale for the use and a description of blood products that can be transfused in the prehospital setting, (2) storage of blood products outside the hospital blood bank and how to move them to the patient in the prehospital setting, (3) prehospital transfusion criteria and administration personnel, and (4) documentation of prehospital transfusion and handover to the hospital team.  This concepts paper describes our operational experience using these four pillars to make Maryland's inaugural prehospital ground-based low-titer O-positive whole blood program successful. These lessons learned may inform other EMS systems as they establish prehospital blood programs to help improve outcomes and enhance mass casualty response.

Use of whole blood in pediatric trauma: a narrative review

Balanced hemostatic resuscitation has been associated with improved outcomes in patients with both pediatric and adult trauma. Cold-stored, low-titer group O whole blood (LTOWB) has been increasingly used as a primary resuscitation product in trauma in recent years. Benefits of LTOWB include rapid, balanced resuscitation in one product, platelets stored at 4°C, fewer additives and fewer donor exposures. The major theoretical risk of LTOWB transfusion is hemolysis, however this has not been shown in the literature. LTOWB use in injured pediatric populations is increasing but is not yet widespread. Seven studies to date have described the use of LTOWB in pediatric trauma cohorts. Safety of LTOWB use in both group O and non-group O pediatric patients has been shown in several studies, as indicated by the absence of hemolysis and acute transfusion reactions, and comparable risk of organ failure. Reported benefits of LTOWB included faster resolution of shock and coagulopathy, lower volumes of transfused blood products, and an independent association with increased survival in massively transfused patients. Overall, pediatric data are limited by small sample sizes and mostly single center cohorts. Multicenter randomized controlled trials are needed.

Low-titer group O whole blood in military ground ambulances: Lessons from the Israel Defense Forces initial experience

BACKGROUND

Cold-stored low-titer group O whole blood (LTOWB) has become increasingly utilised in both prehospital and in-hospital settings for resuscitation of traumatic haemorrhage. However, implementing the use of LTOWB to ground medical teams has been limited due to logistic challenges.

METHODS

In 2022, the Israel Defense Forces (IDF) started using LTOWB in ambulances for the first time in Israel. This report details the initial experience of this rollout and presents a case-series of the first patients treated with LTOWB.

RESULTS

Between January-December 2022, seven trauma patients received LTOWB administered by ground IDF intensive care ambulances after presenting with profound shock. Median time from injury to administration of LTOWB was 35 min. All patients had evidence of severe bleeding upon hospital arrival with six undergoing damage control laparotomy and all but one surviving to discharge.

CONCLUSIONS

The implementation of LTOWB in ground medical units is in its early stages, but continued experience may demonstrate its feasibility, safety, and effectiveness in the prehospital setting. Further research is necessary to fully understand the indications, methodology, and benefits of LTOWB in resuscitating severely injured trauma patients in this setting.

Decreased rate of blood donors with high ABO antibody titers in Japan and the underlying factors: Comparisons between 2010 and 2021

BACKGROUND AND OBJECTIVES

Previously (2007), it was reported that ABO antibody titers in Japanese blood donors had decreased significantly compared to 20 years before. Here we evaluated whether further decrease of antibody titers had occurred in recent years, and the potential factors associated with changes in antibody titers.

MATERIALS AND METHODS

Serum/plasma from random blood donors in 2010 and 2021 (2010: 3369, 2021: 5796 donors) was classified into low, middle, and high ABO antibody titers according to the reactivity of diluted serum/plasma (2.5-fold and 20-fold) by an automated microplate system. The rates of low/high titer in the two periods were compared. Logistic regression and age-gender-BMI subgroup analyses were conducted to identify the factors that contributed to changes in antibody titers.

RESULTS

Compared to 2010, the rate of donors with high ABO antibody titers was　decreased in 2021 for both anti-A and anti-B (anti-A, 2010: 23.8%, 2021: 19.3%; anti-B, 2010: 23.8%, 2021: 16.4%). In logistic regression analysis, age was found to significantly affect both anti-A and anti-B antibody titers (anti-A, adjusted odds ratio 0.36, 95% CI 0.31-0.41; anti-B, 0.42, 0.37-0.47), and BMI (0.82, 0.73-0.92) and other time-related factors (0.79, 0.71-0.88) significantly affect anti-B antibody titers. Subgroup analysis revealed decreased rate of high anti-B titers in the higher age group in 2021.

CONCLUSION

The rate of high ABO antibody titers, especially high anti-B titers, was significantly decreased in 2021, and our results suggested an association with aging and obesity of blood donors as well as other time-related factors.

What is the Role of Whole Blood Transfusions on Trauma Patients?

Whole blood use in trauma has historically been limited to military use, but in recent years, there has been increasing data for use in civilian trauma. Emerging clinical data demonstrate an associated survival benefit, while some authors have also identified decreased use of an overall number of blood products and decreased complications. Use of whole blood is gradually moving toward becoming the standard of care in the hemorrhaging trauma patient.

Whole blood transfusion in the treatment of acute hemorrhage, a systematic review and meta-analysis

BACKGROUND

Whole blood (WB) transfusion received renewed interest after recent armed conflicts. The effectiveness as compared with blood component transfusion (BCT) is, however, still topic of debate. Therefore, this study investigated the effect of WB ± BCT as compared with BCT transfusion on survival in trauma patients with acute hemorrhage.

METHODS

Studies published up to January 16, 2023, including patients with traumatic hemorrhage comparing WB ± BCT and BCT were included in meta-analysis. Subanalyses were performed on the effectiveness of WB in the treatment of civilian or military trauma patients, patients with massive hemorrhage and on platelet (PLT)/red blood cell (RBC), plasma/RBC and WB/RBC ratios. Methodological quality of studies was interpreted using the Cochrane risk of bias tool. The study protocol was registered in PROSPERO under number CRD42022296900.

RESULTS

Random effect pooled odds ratio (OR) for 24 hours mortality in civilian and military patients treated with WB as compared with BCT was 0.72 (95% confidence interval [CI], 0.53-0.97). In subanalysis of studies conducted in civilian setting (n = 20), early (4 hours, 6 hours, and emergency department) and 24 hours mortality was lower in WB groups compared with BCT groups (OR, 0.65; 95% CI, 0.44-0.96 and OR, 0.71; 95% CI, 0.52-0.98). No difference in late mortality (28 days, 30 days, in-hospital) was found. In military settings (n = 7), there was no difference in early, 24 hours, or late mortality between groups. The WB groups received significant higher PLT/RBC ( p = 0.030) during early treatment and significant higher PLT/RBC and plasma/RBC ratios during 24 hours of treatment ( p = 0.031 and p = 0.007). The overall risk of bias in the majority of studies was judged as serious due to serious risk on confounding and selection bias, and unclear information regarding cointerventions.

CONCLUSION

Civilian trauma patients with acute traumatic hemorrhage treated with WB ± BCT as compared to BCT had lower odds on early and 24-hour mortality. In addition, WB transfusion resulted in higher PLT/RBC and plasma/RBC ratios.

LEVEL OF EVIDENCE

Systematic Review and Meta-Analysis; Level III.

The Implementation of a Prehospital Whole Blood Transfusion Program and Early Results

INTRODUCTION

In far-forward combat situations, the military challenged dogma by using whole blood transfusions (WBTs) rather than component-based therapy. More recently, some trauma centers have initiated WBT programs with reported success. There are a few Emergency Medical Service (EMS) systems that are using WBTs, but the vast majority are not. Given the increasing data supporting the use of WBTs in the prehospital setting, more EMS systems are likely to consider or begin WBT programs in the future.

OBJECTIVE

A prehospital WBT program was recently implemented in Palm Beach County, Florida (USA). This report will discuss how the program was implemented, the obstacles faced, and the initial results.

METHODS

This report describes the process by which a prehospital WBT program was implemented by Palm Beach County Fire Rescue and the outcomes of the initial case series of patients who received WBTs in this system. Efforts to initiate the prehospital WBT program for this system began in 2018. The program had several obstacles to overcome, with one of the major obstacles being the legal team's perception of potential liability that might occur with a new prehospital blood transfusion program. This obstacle was overcome through education of local elected officials regarding the latest scientific evidence in favor of prehospital WBTs with potential life-saving benefits to the community. After moving past this hurdle, the program went live on July 6, 2022. The initial indications for transfusion of cold-stored, low titer, leukoreduced O+ whole blood in the prehospital setting included traumatic injuries with systolic blood pressure (SBP) < 70mmHg or SBP < 90mmHg plus heart rate (HR) > 110 beats per minute.

FINDINGS

From the date of onset through December 31, 2022, Palm Beach County Fire Rescue transported a total of 881 trauma activation patients, with 20 (2.3%) receiving WBT. Overall, nine (45%) of the patients who had received WBTs so far remain alive. No adverse events related to transfusion were identified following WBT administration. A total of 18 units of whole blood reached expiration of the unit's shelf life prior to transfusion.

CONCLUSION

Despite a number of logistical and legal obstacles, Palm Beach County Fire Rescue successfully implemented a prehospital WBT program. Other EMS systems that are considering a prehospital WBT program should review the included protocol and the barriers to implementation that were faced.

Low Titer Group O Whole Blood In Injured Children Requiring Massive Transfusion

OBJECTIVE

The aim of this study was to assess the survival impact of low-titer group O whole blood (LTOWB) in injured pediatric patients who require massive transfusion.

SUMMARY BACKGROUND DATA

Limited data are available regarding the effectiveness of LTOWB in pediatric trauma.

METHODS

A prospective observational study of children requiring massive transfusion after injury at UPMC Children's Hospital of Pittsburgh, an urban academic pediatric Level 1 trauma center. Injured children ages 1 to 17 years who received a total of >40 mL/kg of LTOWB and/or conventional components over the 24 hours after admission were included. Patient characteristics, blood product utilization and clinical outcomes were analyzed using Kaplan-Meier survival curves, log rank tests and Cox proportional hazards regression analyses. The primary outcome was 28-day survival.

RESULTS

Of patients analyzed, 27 of 80 (33%) received LTOWB as part of their hemostatic resuscitation. The LTOWB group was comparable to the component therapy group on baseline demographic and physiologic parameters except older age, higher body weight, and lower red blood cell and plasma transfusion volumes. After adjusting for age, total blood product volume transfused in 24 hours, admission base deficit, international normalized ratio (INR), and injury severity score (ISS), children who received LTOWB as part of their resuscitation had significantly improved survival at both 72 hours and 28 days post-trauma [adjusted odds ratio (AOR) 0.23, P = 0.009 and AOR 0.41, P = 0.02, respectively]; 6-hour survival was not statistically significant (AOR = 0.51, P = 0.30). Survivors at 28 days in the LTOWB group had reduced hospital LOS, ICU LOS, and ventilator days compared to the CT group.

CONCLUSION

Administration of LTOWB during the hemostatic resuscitation of injured children requiring massive transfusion was independently associated with improved 72-hour and 28-day survival.

Recognizing life-threatening bleeding in pediatric trauma: A standard for when to activate massive transfusion protocol

BACKGROUND

Traumatic hemorrhage is the most common cause of preventable death in civilian and military trauma. Early identification of pediatric life-threatening hemorrhage is challenging. There is no accepted clinical critical administration threshold (CAT) in children for activating massive transfusion protocols.

METHODS

Children 0 to 17 years old who received any transfusion in the first 24 hours after injury between 2010 and 2019 were included. The type, volume, and time of administration for each product were recorded. The greatest volume of weight-adjusted products transfused within 1 hour was calculated. The cut point for the number of products that maximized sensitivity and specificity to predict in-hospital mortality, need for urgent surgery, and second life-threatening bleeding episode was determined using Youden's index. A binary variable (CAT+) was generated using this threshold for inclusion in a multivariable logistic regression model.

RESULTS

In total, 287 patients were included. The median (interquartile range) age was 6 (2-14) years, 60% were males, 83% sustained blunt trauma, and the median (interquartile range) Injury Severity Score was 26 (17-35). The optimal cutoff to define CAT+ was >20 mL/kg of product; this optimized test characteristics for mortality (sensitivity, 70%; specificity, 77%), need for urgent hemorrhage control procedure (sensitivity, 65%; specificity, 74%). and second bleeding episode (sensitivity, 77%; specificity, 74%). There were 93 children (32%) who were CAT+. On multivariate regression, being CAT+ was associated with 3.4 increased odds of mortality (95% confidence interval, 1.67-6.89; p = 0.001) after controlling for age, hypotension, Injury Severity Score, and Glasgow Coma Scale. For every unit of product administered, there was a 10% increased risk of mortality (odds ratio, 1.1; p < 0.001).

CONCLUSION

Transfusion of more than 20 mL/kg of any blood product within an hour should be used as a threshold for activating massive transfusion protocols in children. Children who meet this CAT are at high risk of mortality and need for interventions; this population may benefit from targeted, timely, and aggressive hemostatic resuscitation.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

Blood banking considerations in pediatric trauma

ABSTRACT

Transfusion of blood products to a hemorrhaging pediatric trauma patient requires seamless partnership and communication between trauma, emergency department, critical care, and transfusion team members. To avoid confusion and delays, understanding of blood banking principles and mutually agreed upon procedures and policies must be regularly updated as knowledge evolves. Because pediatric patients require specialized considerations distinct from those in adults, this brief review covers transfusion principles, policies, and procedures specific to the resuscitation of pediatric trauma patients.

Use of Cold-Stored Whole Blood is Associated with Improved Mortality in Hemostatic Resuscitation of Major Bleeding: A Multicenter Study

OBJECTIVE

The aim of this study was to identify a mortality benefit with the use of whole blood as part of the resuscitation of bleeding trauma patients.

SUMMARY BACKGROUND DATA

Blood component therapy (BCT) is the current standard for resuscitating trauma patients, with whole blood (WB) emerging as the blood product of choice. We hypothesized that the use of WB versus BCT alone would result in decreased mortality.

METHODS

We performed a 14-center, prospective-observational study of trauma patients who received WB versus BCT during their resuscitation. We applied a generalized linear mixed-effects model with a random effect and controlled for age, sex, mechanism of injury (MOI), and injury severity score (ISS). All patients who received blood as part of their initial resuscitation were included. Primary outcome was mortality and secondary outcomes included AKI, DVT/PE, pulmonary complications, and bleeding complications.

RESULTS

A total of 1,623 (WB: 1,180(74%), BCT: 443(27%)) patients who sustained penetrating (53%) or blunt (47%) injury were included. Patients who received WB had a higher shock index (0.98 vs. 0.83), more comorbidities, and more blunt MOI (all P<0.05). After controlling for center, age, sex, MOI, and ISS, we found no differences in the rates of AKI, DVT/PE or pulmonary complications. WB patients were 9% less likely to experience bleeding complications and were 48% less likely to die than BCT patients (P<0.0001).

CONCLUSIONS

Compared with BCT, the use of WB was associated with a 48% reduction in mortality in trauma patients. Our study supports the use of WB use in the resuscitation of trauma patients.

Receipt of at least 4 units of low titer group O whole blood with titer <100 does not lead to hemolysis in adult trauma patients

BACKGROUND

The serological safety of transfusing low titer group O whole blood (LTOWB) with an anti-A and anti-B titer of <100 was evaluated in group O and non-group O trauma recipients.

METHODS

Civilian adult trauma patients who received ≥4 units of leukoreduced LTOWB during their initial resuscitation and who survived for >24 h after admission at two level 1 trauma centers were included in this retrospective study. Lactate dehydrogenase (LDH), total bilirubin, haptoglobin, potassium, creatinine were evaluated on the day of LTOWB transfusion (day 0) and on the next 3 days.

RESULTS

There were 77 injured recipients evaluated: 39 non-group O and 38 group O. The median (IQR) number of transfused LTOWB units was 4 (4-6) and 4 (4-5), respectively, and the maximum number of units was 8 and 11, respectively. The non-group O patients received a median (IQR) volume of 1710 ml (1368-2070) of ABO-incompatible plasma. Comparing non-group O to group O recipients, there were no significant differences in the median haptoglobin, LDH, or creatinine concentrations at any time point. The median concentration of total bilirubin was significantly higher amongst the non-group O recipients on days 1 and 2, while on day 0 the median potassium concentration was significantly higher amongst the group O recipients. All median elevated values were within the laboratory's normal range. Amongst the non-group O recipients there were no reported transfusion reactions.

CONCLUSION

Receiving at least four LTOWB units (anti-A&B titer <100) was not associated with biochemical/clinical evidence of hemolysis in adult trauma patients.

Low-Titer Group O Whole-Blood Resuscitation in the Prehospital Setting in Israel: Review of the First 2.5 Years' Experience

Introduction

The Israeli Defense Forces Medical Corps (IDF-MC) implemented the use of low-titer group O whole blood (LTOWB) as the first-choice resuscitation fluid in the IDF airborne Combat Search and Rescue Unit (IDF-CSAR) for aerial evacuation of both military and civilian casualties in June 2018 for injured patients with hemorrhagic shock and at least one of the following: systolic blood pressure <90 mm Hg, heart rate >130 beats/min, deterioration of consciousness without head injury or hemoglobin concentration ≤7 g/dL.

Method

All casualties treated with LTOWB by IDF-CSAR providers from June 2018 to January 2021 were included. Demographic and prehospital treatment data were collected in order to check compliance and adherence to the IDF-MC guidelines. This is a follow-up retrospective report.

Results

Overall, 1,608 LTOWB units were supplied to the IDF-CSAR during the study period. Of these, 33 were transfused to 27 casualties; 17 (69%) with blunt injury, 8 (29.6%) with penetrating injuries, and 1 (3.7%) with gastrointestinal bleeding without trauma. The leading cause of injury was motor vehicle accidents. A total of 23 casualties received 1 unit of LTOWB, 3 received 2 units and 1 patient received 4 units. Two casualties were children. The median heart rate was 120 beats/min, 8 (29.6%) casualties had heart rates >130 beats/min. Median systolic blood pressure was 95 mm Hg, 7 (26%) casualties had blood pressure <90 mm Hg. The median Glasgow Coma Score was 14. No adverse reactions were documented following the administration of LTOWB. 77.8% of patients received LTOWB in adherence to the guidelines.

Conclusion

Appropriate administration of LTOWB has improved over time in IDF-CSAR. Using LTOWB is feasible and simpler than administering packed red blood cells and plasma concurrently. Further efforts are needed to introduce LTOWB in other prehospital and in-hospital scenarios, with an increase in the maximum antibody titer threshold, to meet the expected increase in demand.

Back to the Future: Whole Blood Resuscitation of the Severely Injured Trauma Patient

ABSTRACT

Following advances in blood typing and storage, whole blood transfusion became available for the treatment of casualties during World War I. While substantially utilized during World War II and the Korean War, whole blood transfusion declined during the Vietnam War as civilian centers transitioned to blood component therapies. Little evidence supported this shift, and recent conflicts in Iraq and Afghanistan have renewed interest in military and civilian applications of whole blood transfusion. Within the past two decades, civilian trauma centers have begun to study transfusion protocols based upon cold-stored, low anti-A/B titer type O whole blood for the treatment of severely injured civilian trauma patients. Early data suggests equivalent or improved resuscitation and hemostatic markers with whole blood transfusion when compared to balanced blood component therapy. Additional studies are taking place to define the optimal way to utilize low-titer type O whole blood in both prehospital and trauma center resuscitation of bleeding patients.

Is the whole greater than the sum of its parts? The implementation and outcomes of a whole blood program in Ecuador

BACKGROUND

Hemorrhagic shock is a major cause of mortality in low-income and middle-income countries (LMICs). Many institutions in LMICs lack the resources to adequately prescribe balanced resuscitation. This study aims to describe the implementation of a whole blood (WB) program in Latin America and to discuss the outcomes of the patients who received WB.

METHODS

We conducted a retrospective review of patients resuscitated with WB from 2013 to 2019. Five units of O+ WB were made available on a consistent basis for patients presenting in hemorrhagic shock. Variables collected included gender, age, service treating the patient, units of WB administered, units of components administered, admission vital signs, admission hemoglobin, shock index, Revised Trauma Score in trauma patients, intraoperative crystalloid (lactated Ringer's or normal saline) and colloid (5% human albumin) administration, symptoms of transfusion reaction, length of stay, and in-hospital mortality.

RESULTS

The sample includes a total of 101 patients, 57 of which were trauma and acute care surgery patients and 44 of which were obstetrics and gynecology patients. No patients developed symptoms consistent with a transfusion reaction. The average shock index was 1.16 (±0.55). On average, patients received 1.66 (±0.80) units of WB. Overall mortality was 13.86% (14 of 101) in the first 24 hours and 5.94% (6 of 101) after 24 hours.

DISCUSSION

Implementing a WB protocol is achievable in LMICs. WB allows for more efficient delivery of hemostatic resuscitation and is ideal for resource-restrained settings. To our knowledge, this is the first description of a WB program implemented in a civilian hospital in Latin America.

LEVEL OF EVIDENCE

Level IV.

Hemostatic Resuscitation in Children

Trauma is a major source of morbidity and mortality for children worldwide; life-threatening hemorrhage is a primary cause of preventable death. Essential interventions in children with life-threatening hemorrhage include hemostatic resuscitation and mechanical control of bleeding. Herein we review pediatric hemostatic resuscitation, a strategy that addresses both hemorrhagic shock and the coagulopathic complications described in patients with major hemorrhage. Some components of hemostatic resuscitation may include: early and aggressive resuscitation with blood products, minimizing crystalloid and hemodilution, antifibrinolytic adjuncts such as tranexamic acid, and the novel use of low-titer group O whole-blood (LTOWB) transfusion in injured children. The following selection of important publications address the current state of hemostatic resuscitation strategies in pediatric trauma patients as well as the remaining knowledge gaps and areas for further research.

Cold-stored whole blood and platelet counts in severe acute injury: A comparison of four retrospective cohorts

BACKGROUND

Low-titer group O whole blood (LTOWB) is attractive for acute trauma care as it delivers concentrated and balanced hemostatic resuscitation in single large bags. Whether cold-stored LTOWB can sustain platelet counts is unclear.

STUDY DESIGN AND METHODS

Four cohorts of trauma patients-three historic, one retrospective-were identified by their urgency of blood use. Admission and all subsequent platelet counts over the first 24 h of care were compared with t-tests. The cohorts were as follows: 1292 patients at Maryland Shock Trauma as described by Stansbury and colleagues in 2013; 35 patients enrolled locally in the 1:1:2 arm of the pragmatic randomized optimal plasma and platelet ratios (PROPPR) trial; 34 patients enrolled locally in the 1:1:1 arm of PROPPR; and 59 patients receiving more than 3 units of LTOWB enroute to or at our Level 1 trauma center, 2019-2020.

RESULTS

Mean age of LTOWB units transfused was 9 ± 5 days and mean dose was 5 ± 2 units. All four cohorts were profoundly injured (mean Injury Severity Score ≥ 31), with mean first platelet counts 204-228 K/μ and subsequent counts approximately 100 k/μl lower. Through the first 24 h of care, mean platelet counts decreased least, 79 and 83 10³ /μl, in the 1:1:1 PROPPR and LTOWB cohorts. Mean platelet counts in patients transfused with LTOWB remained stable after the third hour of care.

DISCUSSION

LTOWB transfusion was associated with lesser mean decrease in platelet counts during the first 24 h after injury, similar to those observed among patients receiving components 1:1:1 component in the PROPPR study.

A pilot study of stored low titer group O whole blood + component therapy versus component therapy only for civilian trauma patients

BACKGROUND

This pilot assessed transfusion requirements during resuscitation with whole blood followed by standard component therapy (CT) versus CT alone, during a change in practice at a large urban Level I trauma center.

METHODS

This was a single-center prospective cohort pilot study. Male trauma patients received up to 4 units of cold-stored low anti-A, anti-B group O whole blood (LTOWB) as initial resuscitation followed by CT as needed (LTOWB + CT). A control group consisting of women and men who presented when LTOWB was unavailable, received CT only (CT group). Exclusion criteria included antiplatelet or anticoagulant medication and death within 24 hours. The primary outcome was total transfusion volume at 24 hours. Secondary outcomes were mortality, morbidity, and intensive care unit- and hospital-free days.

RESULTS

Thirty-eight patients received LTOWB, with a median of 2.0 (interquartile range [IQR] 1.0-3.0) units of LTOWB transfused. Thirty-two patients received CT only. At 24 hours after presentation, the LTOWB +CT group had received a median of 2,138 mL (IQR, 1,275-3,325 mL) of all blood products. The median for the CT group was 4,225 mL (IQR, 1,900-5,425 mL; p = 0.06) in unadjusted analysis. When adjusted for Injury Severity Score, sex, and positive Focused Assessment with Sonography for Trauma, LTOWB +CT group patients received 3307 mL of blood products, and CT group patients received 3,260 mL in the first 24 hours (p = 0.95). The adjusted median ratio of plasma to red cells transfused was higher in the LTOWB + CT group (0.85 vs. 0.63 at 24 hours after admission; p = 0.043. Adjusted mortality was 4.4% in the LTOWB + CT group, and 11.7% in the CT group (p = 0.19), with similar complications, intensive care unit-, and hospital-free days in both groups.

CONCLUSION

Beginning resuscitation with LTOWB results in equivalent outcomes compared with resuscitation with CT only.

LEVEL OF EVIDENCE

Therapeutic (Prospective study with 1 negative criterion, limited control of confounding factors), level III.

The rebirth of the cool: a narrative review of the clinical outcomes of cold stored low titer group O whole blood recipients compared to conventional component recipients in trauma

There has been renewed interest in the use of low titer group O whole blood (LTOWB) for the resuscitation of civilian casualties. LTOWB offers several advantages over conventional components such as providing balanced resuscitation in one bag that contains less additive/preservative solution than an equivalent volume of conventional components, is easier and faster to transfuse than multiple components, avoids blood product ratio confusion, contains cold stored platelets, and reduces donor exposures. The resurgence in its use in the resuscitation of civilian trauma patients has led to the publication of an increasing number of studies on its use, primarily amongst adult recipients but also in pediatric patients. These studies have indicated that hemolysis does not occur amongst adult and pediatric non-group O recipients of a modest quantity of LTOWB. The published studies to date on mortality have shown conflicting results with some demonstrating a reduction following LTOWB transfusion while most others have not shown a reduction; there have not been any studies to date that have found significantly increased overall mortality amongst LTOWB recipients. Similarly, when other clinical outcomes, such as venous thromboembolism, sepsis, hospital or intensive care unit lengths of stay are evaluated, LTOWB recipients have not demonstrated worse outcomes compared to conventional component recipients. While definitive proof of the trends in these morbidity and mortality outcomes awaits confirmation in randomized controlled trials, the evidence to date indicates the safety of transfusing LTOWB to injured civilians.

Variation of anti-A and anti-B titers in group O potential blood donors: A pilot study

BACKGROUND

Resuscitation with fresh whole blood is vital to preserving life on the battlefield. Transfusing low titer O whole blood (LTOWB), defined as anti-A and anti-B titer levels of <1:256, is safe because LTOWB alleviates the risk for hemolytic transfusion reactions. Because of possible variations in titer levels over time, a study was needed using US Navy and Marine Corps personnel to assess how these titers change across two assessments.

METHODS

Retrospective data from group O marines and sailors (M = 25 years of age; range, 19-35 years) stationed in the San Diego region were acquired from the Armed Services Blood Program and the Composite Health Care System. Of 972 group O donors between January 2016 and November 2019, 55 donors with 2 samples were identified (N = 55). Analysis included contrasting rates of high (≥1:256) and low (<1:256) anti-A and anti-B titers on the initial and second blood tests, along with the time between testings.

RESULTS

The average time between testing was 332 days (range, 35-1,121 days), which far exceeded the recommended 90-day interval (p < 0.00001). Only 45% met the 90-day recommendation. Titer status changed frequently, from low to high (anti-A, 18%; anti-B, 13%; LTOWB to not LTOWB, 21%) or from high to low (anti-A, 62%; anti-B, 78%; not LTOWB to LTOWB, 62%).

CONCLUSIONS

Anti-A and anti-B titers change frequently enough to warrant testing immediately before deployment and even during deployment. The observed time elapsed between testing is unacceptably long. The present pilot study provides a foundation for a larger formal study to more fully characterize titer changes over repeated testing.

LEVEL OF EVIDENCE

Diagnostic test, level IV.

Adverse events after low titer group O whole blood versus component product transfusion in pediatric trauma patients: A propensity-matched cohort study

BACKGROUND

Low titer group O whole blood (LTOWB) is used as the initial resuscitative fluid in an increasing number of pediatric trauma and massive bleeding transfusion protocols. There is little data on adverse events following its transfusion in pediatric trauma patients.

STUDY DESIGN AND METHODS

Blood bank records were queried for pediatric recipients of at least one unit of red blood cells (RBCs) (component group) or LTOWB (LTOWB group) within 24 h of admission between May 2013 and August 2020. Subjects with early death (<72 h) were excluded. Propensity-score matching of LTOWB and component groups was performed. Adverse events were recorded, including transfusion reaction, thromboembolism, acute kidney injury, sepsis, and organ failure based on PELOD-2 score, along with hospital and ICU length of stay (LOS) and ventilator days.

RESULTS

Thirty-six LTOWB recipients were matched to 36 conventional component recipients. Subjects were 52% male, with blunt injury mechanism (82%), median (IQR) injury severity score = 27 (21-35), and 26% in-hospital mortality. The groups were well matched in terms of demographics and injury characteristics. There were no clinically or statistically significant differences in adverse outcomes including reported transfusion reaction, organ failure, acute kidney injury, sepsis/bacteremia, and venous thromboembolism. Hospital LOS, ventilator days, mortality, and functional disability at discharge were also not significantly different. The LTOWB group had significantly shorter ICU LOS compared to the component group.

CONCLUSION

LTOWB transfusion did not increase the risk of adverse events in children. However, larger studies are required to confirm these results.

Injured recipients of low-titer group O whole blood have similar clinical outcomes compared to recipients of conventional component therapy: A single-center, retrospective study

INTRODUCTION

Low-titer group O whole blood (LTOWB) is being increasingly transfused to injured patients. This study evaluated a range of clinical outcomes to determine if receipt of LTOWB predisposed recipients to worse outcomes compared to recipients of conventional component therapy (CCT).

METHODS

A retrospective analysis of trauma patients who received at least 3 units of LTOWB (LTOWB group) versus those that received at least 3 units of RBCs, 1 unit of plasma and 1 unit of platelets but no LTOWB (CCT group) during the first 24 h of their admission was performed. Causal treatment effects were explored using propensity score matching (PSM) and coarsened exact matching (CEM). Important clinical outcomes were evaluated.

RESULTS

There were 165 CCT and 155 LTOWB recipients eligible for matching. PSM and CEM reduced covariate imbalances between the CCT and LTOWB groups, with the exception that males remained over-represented in the LTOWB group due to the hospital's former resuscitation policy of not administering RhD-positive LTOWB to females <50. In both of the matched analyses, the LTOWB group received a median of 4 LTOWB units. There were no significant differences in 6-, 24-h mortality or 30-day mortality between groups, nor were there differences in the frequency of other clinical outcomes such as acute kidney injury, sepsis, venous/arterial thromboembolism; delta MODS was lower for the LTOWB recipients in the exact match group.

CONCLUSION

In both matched analyses, administration of a median of four LTOWB units did not result in a different frequency of major clinical outcomes including mortality.

Effectiveness and safety of whole blood compared to balanced blood components in resuscitation of hemorrhaging trauma patients - A systematic review

INTRODUCTION

Hemorrhage is a leading cause of death among trauma patients, and is the most common cause of preventable death after trauma. Since the advent of blood component fractioning, most patients receive blood components rather than whole blood (WB). WB contains all of the individual blood components and has the advantages of simplifying resuscitation logistics, providing physiological ratios of components, reducing preservative volumes and allowing transfusion of younger red blood cells (RBC). Successful experience with fresh whole blood (FWB) by the US military is well documented. In the civilian setting, transfusion of cold-stored low titer type O whole blood (LTOWB) was shown to be safe. Reports of WB are limited by small numbers and low transfusion volumes.

STUDY DESIGN

We conducted a systematic review of the available published studies, comparing efficacy and safety of resuscitation with WB to resuscitation with blood components, in hemorrhaging trauma patients, using MEDLINE, EMBASE and ISI Web of Science. The main outcomes of interest were 24 hour and 30-day survival, blood product utilization and adverse events. Two reviewers independently abstracted the studies and assessed for bias. Sub-group analyses were pre-planned on the FWB and LTOWB groups separately.

RESULTS

Out of 126 references identified through our search strategy, five studies met the inclusion criteria. Only one study of FWB showed a significant benefit on 24 hour and 30-day survival. Other studies of both FWB and LTOWB showed no statistically significant difference in survival. There is an apparent benefit in blood product utilization with the use of WB across most studies. There were no reports of transfusion related reactions, however there was an increase in the organ failure rates in the FWB groups.

CONCLUSIONS

WB was not associated with a significant survival benefit or reduced blood product utilization. Nonetheless, it seems that the use of LTOWB is safe and might carry a significant logistic benefit. The quality of the existing data is poor and further high quality studies are required.

Whole Blood, Fixed Ratio, or Goal-Directed Blood Component Therapy for the Initial Resuscitation of Severely Hemorrhaging Trauma Patients: A Narrative Review

This narrative review explores the pathophysiology, geographic variation, and historical developments underlying the selection of fixed ratio versus whole blood resuscitation for hemorrhaging trauma patients. We also detail a physiologically driven and goal-directed alternative to fixed ratio and whole blood, whereby viscoelastic testing guides the administration of blood components and factor concentrates to the severely bleeding trauma patient. The major studies of each resuscitation method are highlighted, and upcoming comparative trials are detailed.

Hemostatic defects in massive transfusion: an update and treatment recommendations

INTRODUCTION

Acute hemorrhage is a global healthcare issue, and remains the leading preventable cause of death in trauma. Acute severe hemorrhage can be related to traumatic, peripartum, gastrointestinal, and procedural causes. Hemostatic defects occur early in patients requiring massive transfusion. Early recognition and treatment of hemorrhage and hemostatic defects are required to save lives and to achieve optimal patient outcomes.

AREAS COVERED

This review discusses current evidence and trials aimed at identifying the optimal treatment for hemostatic defects in hemorrhage and massive transfusion. Literature search included PubMed and Embase.

EXPERT OPINION

Patients with acute hemorrhage requiring massive transfusion commonly develop coagulopathy due to specific hemostatic defects, and accurate diagnosis and prompt correction are required for definitive hemorrhage control. Damage control resuscitation and massive transfusion protocols are optimal initial treatment strategies, followed by goal-directed individualized resuscitation using real-time coagulation monitoring. Distinct phenotypes exist in trauma-induced coagulopathy, including 'Bleeding' or 'Thrombotic' phenotypes, and hyperfibrinolysis vs. fibrinolysis shutdown. The trauma 'lethal triad' (hypothermia, coagulopathy, acidosis) has been updated to the 'lethal diamond' (including hypocalcemia). A number of controversies in optimal management exist, including whole blood vs. component therapy, use of factor concentrates vs. blood products, optimal use of tranexamic acid, and prehospital plasma and tranexamic acid administration.

The use of whole blood in traumatic bleeding: a systematic review

Hemostatic resuscitation is currently considered a standard of care for the management of life-threatening hemorrhage, but in some critical settings the access to high quantities of blood components is problematic. Whole blood (WB) transfusion has been proposed as an alternative modality for hemostatic resuscitation of traumatic major bleeding. To assess the efficacy and safety of WB in trauma-associated massive bleeding, we performed a systematic review of the literature. We selected studies comparing WB transfusions to transfusion of blood components (COMP) in massive trauma bleeding; both randomized clinical trial (RCT) and observational studies were considered. The outcomes were mortality (30-day/in-hospital and 24-h mortality) and adverse events/transfusion reactions. The effect sizes were crude odds ratio (OR), adjusted OR and hazard ratio (HR). The methodological quality of studies was assessed using the Cochrane Risk of Bias tool for RCTs, and the ROBIN-1 tool for observational studies. The overall quality of the available evidence was assessed with the GRADE system. One RCT (2 reports) and 6 cohort studies were included (3642 adult patients; 675 receiving WB, 2967 receiving COMP). Three studies were conducted in military setting, and 4 in civilian setting. In the overall analysis, 30-day/in-hospital and 24-h mortality did not differ significantly between groups (very low quality of the evidence due to high risk of bias, imprecision and inconsistency). After adjustment for baseline covariates in three cohort studies, the OR for mortality was significantly lower in WB recipients compared to COMP (OR 0.22; 95% CIs 0.10/0.45) (moderate grade of evidence). Adverse events and transfusion reactions were overlooked and not consistently reported. The available evidence does not allow to draw definite conclusions on the short-term and long-term efficacy and safety of WB transfusion compared to COMP transfusion. Further well designed research is needed.

Low titer group O whole blood resuscitation: Military experience from the point of injury

INTRODUCTION

In the far forward combat environment, the use of whole blood is recommended for the treatment of hemorrhagic shock after injury. In 2016, US military special operations teams began receiving low titer group O whole blood (LTOWB) for use at the point of injury (POI). This is a case series of the initial 15 patients who received LTOWB on the battlefield.

METHODS

Patients were identified in the Department of Defense Trauma Registry, and charts were abstracted for age, sex, nationality, mechanism of injury, injuries and physiologic criteria that triggered the transfusion, treatments at the POI, blood products received at the POI and the damage-control procedures done by the first surgical team, next level of care, initial interventions by the second surgical team, Injury Severity Score, and 30-day survival. Descriptive statistics were used to characterize the clinical data when appropriate.

RESULTS

Of the 15 casualties, the mean age was 28, 50% were US military, and 63% were gunshot wounds. Thirteen patients survived to discharge, one died of wounds after arrival at the initial resuscitative surgical care, and two died prehospital. The mean Injury Severity Score was 21.31 (SD, 18.93). Eleven (68%) of the causalities received additional blood products during evacuation/role 2 and/or role 3. Vital signs were available for 10 patients from the prehospital setting and 9 patients upon arrival at the first surgical capable facility. The mean systolic blood pressure was 80.5 prehospital and 117 mm Hg (p = 0.0002) at the first surgical facility. The mean heart rate was 105 beats per minute prehospital and 87.4 beats per minute (p = 0.075) at the first surgical facility. The mean hospital stay was 24 days.

CONCLUSION

The use of cold-stored LTOWB at POI is feasible during combat operations. Further data are needed to validate and inform best practice for POI transfusion.

LEVEL OF EVIDENCE

Therapeutic study, level V.

Whole blood for blood loss: hemostatic resuscitation in damage control

Hemorrhagic shock and its complications are a major cause of death among trauma patients. The management of hemorrhagic shock using a damage control resuscitation strategy has been shown to decrease mortality and improve patient outcomes. One of the components of damage control resuscitation is hemostatic resuscitation, which involves the replacement of lost blood volume with components such as packed red blood cells, fresh frozen plasma, cryoprecipitate, and platelets in a 1:1:1:1 ratio. However, this is a strategy that is not applicable in many parts of Latin America and other low-and-middle-income countries throughout the world, where there is a lack of well-equipped blood banks and an insufficient availability of blood products. To overcome these barriers, we propose the use of cold fresh whole blood for hemostatic resuscitation in exsanguinating patients. Over 6 years of experience in Ecuador has shown that resuscitation with cold fresh whole blood has similar outcomes and a similar safety profile compared to resuscitation with hemocomponents. Whole blood confers many advantages over component therapy including, but not limited to the transfusion of blood with a physiologic ratio of components, ease of transport and transfusion, less volume of anticoagulants and additives transfused to the patient, and exposure to fewer donors. Whole blood is a tool with reemerging potential that can be implemented in civilian trauma centers with optimal results and less technical demand.

Whole Blood is Superior to Component Transfusion for Injured Children: A Propensity Matched Analysis

OBJECTIVE

To compare a propensity-matched cohort of injured children receiving conventional blood component transfusion to injured children receiving low-titer group O negative whole blood.

SUMMARY OF BACKGROUND DATA

Transfusion of whole blood in pediatric trauma patients is feasible and safe. Effectiveness has not been evaluated.

METHODS

Injured children ≥1 years old can receive up to 40 mL/kg of cold-stored, uncrossmatched whole blood during initial hemostatic resuscitation. Whole blood recipients (2016-2019) were compared to a propensity-matched cohort who received at least 1 uncrossmatched red blood cell unit in the trauma bay (2013-2016). Cohorts were matched for age, hypotension, traumatic brain injury, injury mechanism, and need for emergent surgery. Outcomes included time to resolution of base deficit, product volumes transfused, and INR after resuscitation.

RESULTS

Twenty-eight children who received whole blood were matched to 28 children who received components. The whole blood group had faster time to resolution of base deficit [median (IQR) 2 (1-2.5) hours vs 6 (2-24) hours, respectively; P < 0.001]. The post-transfusion INR was decreased in whole blood vs component cohort [median (IQR) 1.4 (1.3-1.5) vs 1.6 (1.4-2.2); P = 0.01]. Lower plasma volumes [median (IQR) = 5 (0-15) mL/kg vs 11 (5-35) mL/kg; P = 0.04] and lower platelet volumes [median (IQR) = 0 (0-2) vs 3 (0-8); P = 0.03] were administered to the whole blood group versus component group. Other clinical variables (in-hospital death, hospital length of stay, intensive care unit length of stay, and ventilator days) did not differ between groups.

CONCLUSIONS

Compared to component transfusion, whole blood transfusion results in faster resolution of shock, lower post-transfusion INR, and decreased component product transfusion. Larger cohorts are required to support these findings.

Re-introducing whole blood for transfusion: considerations for blood providers

Whole blood is the original blood preparation but disappeared from the blood bank inventories in the 1980s following the advent of component therapy. In the early 2000s, both military and civilian practice called for changes in the transfusion support for massive haemorrhage. The 'clear fluid' policy was abandoned and replaced by early balanced transfusion of platelets, plasma and red cells. Whole blood is an attractive alternative to multi-component therapy, which offers reduced hemodilution, lower donor exposure and simplified logistics. However, the potential for wider re-introduction of whole blood requires re-evaluation of haemolysins, storage conditions and shelf-life, the need for leucocyte depletion/ pathogen reduction and inventory management for blood providers. This review addresses these questions and calls for research to define the optimal whole blood product and the indications for its use.

A comparison between leukocyte reduced low titer whole blood vs non-leukocyte reduced low titer whole blood for massive transfusion activation

BACKGROUND

Hemorrhagic shock is the leading cause of survivable death in trauma patients and recent literature has focused on resuscitation strategies including transfusing low-titer group O whole blood (LTOWB). Debate remains regarding whether leukocyte reduced (LR) whole blood is of clinical benefit or detriment to patients requiring massive transfusion. This study compares survival outcomes between LR-LTOWB and non-LR LTOWB.

STUDY DESIGN AND METHODS

The objective of this prospective, observational study was to detect any difference in 24-hour survival between patients receiving LR-LTOWB and non-LR LTOWB during their massive transfusion activation. Secondary objectives were to report any difference in ICU LOS, ventilation days, in-hospital survival, and hospital LOS. Data collected included patient sex, age, mechanism of injury, Injury Severity Score (ISS), Trauma Injury Severity Score (TRISS), cause of death, and number of LTOWB transfused.

RESULTS

A total of 167 patients received 271 LTOWB transfusions. There were 97 patients that received 168 units of LR-LTOWB while 70 patients received 103 units of non-LR LTOWB. The two study groups were comparable in terms of age, sex, ISS, TRISS, and the number of LTOWB transfused. The use of LR LTOWB during the initial massive transfusion activation in traumatically injured patients was not associated with increased 24-hour survival compared to when using non-LR LTOWB. No transfusion associated adverse events were reported.

CONCLUSIONS

The administration of either LR or non-LR LTOWB was not associated with >24 hours survival in patients presenting with massive hemorrhage. The high cost and the rapid decline in platelet count of LR whole blood may be a consideration.

Safety profile and impact of low-titer group O whole blood for emergency use in trauma

PURPOSE

Following US military implementation of a cold-stored whole blood program, several US trauma centers have begun incorporating uncrossmatched, group O cold-stored whole blood into civilian trauma resuscitation. We set out to evaluate the safety profile, transfusion reactions events, and impact of low-titer group O whole blood (LTO-WB) at our center.

METHODS

In November 2017, we added LTO-WB to each of our helicopters and to our emergency department (ED) refrigerator, alongside that of existing red blood cells and plasma. We collected information on all patients with trauma receiving prehospital or ED transfusion of uncrossed, emergency release blood products between November 2017 and June 2018. Patients were divided into those receiving any LTO-WB and those receiving only red blood cell and or plasma (COMP). Serial hemolysis panels were obtained at 3 hours, 24 hours, and 48 hours. All data were run using STATA 12.1. Statistical significance was set at p < 0.05.

RESULTS

One hundred ninety-eight patients received LTO-WB and 152 patients received COMP. There were no differences in age, sex, or mechanism. The LTO-WB patients had higher chest Abbreviated Injury Scale scores (median, 3 vs. 2; p = 0.027), as well as worse arrival base excess (median, -7 vs. -5; p = 0.014) and lactate (5.1 vs. 3.5; p < 0.001). The LTO-WB patients received less post-ED blood products than the COMP patients (median, 0 vs. 3; p = 0.001). There was no difference in survival (LTO-WB, 73%; COMP, 74%; p = 0.805). There were only two suspected transfusion reactions, both in the COMP group (p = 0.061). There was no difference in hemolysis panel values. Controlling for age, severity of injury, and prehospital physiology, LTO-WB was associated with a 53% reduction in post-ED blood product transfusion (odds ratio, 0.47; 0.23-0.94 95% CI; p = 0.033) and two-fold increase in likelihood of survival (odds ratio, 2.19; 1.01-4.76 95% CI; p = 0.047).

CONCLUSION

Low-titer group O whole blood has similar evidence of laboratory hemolysis, similar transfusion reaction rates, and is associated with a reduction in post-ED transfusions and increase likelihood of survival.

LEVEL OF EVIDENCE

Therapeutic, Level II.

Early experience with transfusing low titer group O whole blood in the pre-hospital setting in Israel

BACKGROUND

The Israeli Defense Force Medical Corps (IDF-MC) recently implemented the use of low titer group O whole blood (LTOWB) in the airborne combat search and rescue unit (CSAR) for both military and civilian patients during transport to definitive care. LTOWB is preferentially used by the CSAR instead of red blood cell units and freeze-dried plasma (FDP) for patients with signs of hemorrhagic shock. Ten percent of group O donors were eligible to donate LTOWB as they had anti-A and -B IgM titers of <50.

METHODS

All patients treated by CSAR providers with LTOWB between July 2018 and June 2019 were included.

RESULTS

Between July 2018 and June 2019, eight patients have received 10 units of LTOWB. All patients suffered blunt injuries, 6 out of 8 (75%) of whom were due to motor vehicle accidents. Four patients (4 out of 8, 50%) received a single LTOWB unit, two patients (2 out of 8, 25%) received two units. Two pediatric patients received fewer than one unit of LTOWB. Median (range) heart rate was 130 (30-150) bpm, median systolic blood pressure was 107 (80-124) mmHg, and median Glasgow coma scale was 8 (on a scale of 3-15). For four (4 out of 8, 50%) patients, LTOWB was the only blood product used for volume resuscitation. All six adult patients were treated with 1 g of tranexamic acid at the point of injury.

CONCLUSIONS

The CSAR has successfully implemented a LTOWB program for the pre-hospital treatment of bleeding patients, and as its experience grows this product will be made available to other units and in civilian hospitals.

Cold-stored whole blood: A better method of trauma resuscitation?

BACKGROUND

Cold-stored whole blood (CWB) provides a balance of red blood cells, plasma, and platelets in less anticoagulant volume than standard blood component therapy (BCT). We hypothesize that patients receiving CWB along with BCT have improved survival compared with patients receiving only BCT.

METHODS

We performed a dual-center case-match study of trauma patients who received CWB and BCT at two urban, Level-I Trauma Centers. Criteria to receive CWB included boys 16 years of older, women older than 50 years, SBP less than 90 mm Hg, and identifiable source of hemorrhage. We performed a 2:1 propensity match against any trauma patient who received 1 unit or greater of packed red cells during their initial trauma bay resuscitation. Endpoints included trauma bay mortality, 30-day mortality, laboratory values at 4 hours and 24 hours, and overall blood product utilization. Comparisons were made with Wilcoxon-ranked sum and Fisher's exact test, p less than 0.05 was significant.

RESULTS

Between both institutions, a total of 107 patients received CWB during the study period with 91 being matched to 182 BCT patients for analysis. Hemodynamic parameters of the patients in both groups at the time of presentation were similar. The CWB patients had higher mean hemoglobin (10 ± 2 g/dL vs. 11 ± 2 g/dL; p < 0.001) and hematocrit (29.2 ± 6.1% vs. 32.1 ± 5.8%; p < 0.001) at 24 hours. Importantly, trauma bay mortality was less in CWB patients (8.8% vs. 2.2%;p = 0.039). Thirty-day mortality was not different in CWB patients, and there were no differences in the total amount of blood products transfused at the 4-hour and 24-hour periods.

CONCLUSION

Cold-stored whole blood offers the benefit of a balanced resuscitation with improved trauma bay survival and higher mean hemoglobin at 24 hours. A larger, prospective study is needed to determine whether it has a longer-term survival benefit for severely injured patients.

LEVEL OF EVIDENCE

Therapeutic, level III.

Contemporary resuscitation of hemorrhagic shock: What will the future hold?

Resuscitation of the critically ill patient with fluid and blood products is one of the most widespread interventions in medicine. This is especially relevant for trauma patients, as hemorrhagic shock remains the most common cause of preventable death after injury. Consequently, the study of the ideal resuscitative product for patients in shock has become an area of great scientific interest and investigation. Recently, the pendulum has swung towards increased utilization of blood products for resuscitation. However, pathogens, immune reactions and the limited availability of this resource remain a challenge for clinicians. Technologic advances in pathogen reduction and innovations in blood product processing will allow us to increase the safety profile and efficacy of blood products, ultimately to the benefit of patients. The purpose of this article is to review the current state of blood product based resuscitative strategies as well as technologic advancements that may lead to safer resuscitation.

Review of massive transfusion protocols in the injured, bleeding patient

PURPOSE OF REVIEW

Massive haemorrhage is a significant cause of mortality and morbidity in a variety of clinical settings, although most research has been related to trauma patients. Military studies from recent conflicts found that higher ratios of plasma to red blood cells (RBCs) were associated with increased survival in injured soldiers, and subsequent trials in civilian populations showed similar decreased mortality. Over the last decade, massive transfusion protocols (MTPs) have become an important component in the treatment of the massively bleeding patient. This review is intended to summarize the more recent findings and trends in massive transfusion.

RECENT FINDINGS

There have been several observational studies suggesting that higher ratios of plasma to RBC and platelets to RBC are associated with improved survival but there is a paucity of randomized studies relating to specific ratios, dosages, timing, and guidance. Other studies have developed and assessed scoring systems used to initiate MTPs and specific tests used to guide MTPs. Finally, the specific blood components and adjuncts that constitute a MTP are the subject of further ongoing research.

SUMMARY

The absence of a universal definition of massive bleeding or massive transfusion, heterogeneity in patients suffering from massive bleeding, and the difficulty in predicting which patients will require a massive transfusion all contribute to the difficulty of studying massive transfusion. However, there is evidence that higher plasma : RBC ratios correlate with improved survival, and that adjuncts to transfusion play a key role. Furthermore, recent validations of massive haemorrhage scoring systems should allow more consistent and appropriate triggering of massive transfusions.

Opportunities for standardization of cold stored, low-titre group O WB products

Interest in the use of cold-stored low-titre, group O whole blood (LTO-WB) in civilian trauma medicine has motivated regional and national blood services to explore the operational implications of providing this product to their hospital customers. While simpler to produce, store and administer than conventional blood components, LTO-WB is only distributed by a limited number of civilian blood services to date. To improve the availability of LTO-WB, there are still a number of clinical and basic research challenges that need to be addressed including 1. Standardization of the methods and definitions for what constitutes "low-titre" whole blood; 2. Updating regulatory standards for the in vitro quality of cold stored whole blood; 3. Development of standards for the post-storage component separation of red blood cells from cold stored whole blood; and 4. Optimization of the logistics for collection and distribution of cold stored whole blood in regional and national blood systems. The main objective of this concise overview is to highlight the opportunities for future research and product development efforts that will improve the availability of standardised LTO-WB products in emergency cases to the benefit of all concerned.

Cold-stored whole blood platelet function is preserved in injured children with hemorrhagic shock

BACKGROUND

Recent data demonstrate the safety of uncrossmatched cold-stored whole blood (WB) transfusion in pediatric trauma patients. The hemostatic capabilities of platelets within the cold-stored WB unit have been demonstrated via in vitro studies and animal models. However, platelet function has not been evaluated in pediatric recipients of cold-stored WB transfusions.

METHODS

Injured children, 2 years or older and 10 kg or greater with hemorrhagic shock received up to 30 mL/kg of cold-stored, low titer (<50) anti-A and -B, leukoreduced, group O- WB during their initial resuscitation. Patients were included if (1) they received WB and no conventional platelets, and (2) platelet count and thromboelastography maximum amplitude were measured both before and after transfusion. These data and relevant clinical outcomes (mortality, intensive care unit length of stay [LOS], hospital LOS and ventilator days) were compared to a historical cohort of pediatric trauma patients who received uncrossmatched red blood cells (RBC) and conventional room temperature platelets.

RESULTS

Twenty-two children were included in the study; 14 in the component cohort versus 8 in the WB cohort. Neither posttransfusion platelet count (129 × 109/L vs. 135 × 109/L) nor function (thromboelastography maximum amplitude, 59.5 mm vs. 60.2 mm) differed significantly between children receiving cold-stored platelets within the WB unit versus children who received conventional warm platelets. Median (interquartile range) weight-adjusted platelet transfusion volume in the historical cohort was 4.6 (2.5-7.7) mL/kg vs. 2.4 (1.3-4.0) mL/kg in the WB cohort (p = 0.03). There was no difference between groups in age, race, mechanism of injury, Injury Severity Score, vital signs, and severe traumatic brain injury (TBI). Outcomes, including mortality, intensive care unit LOS, hospital LOS, and ventilator days, were not significantly different between groups.

CONCLUSION

No difference was seen in posttransfusion platelet number or function in severely injured children receiving cold-stored WB platelets as compared to those receiving conventional room temperature-stored platelets. Larger cohorts are required to confirm these findings.

LEVEL OF EVIDENCE

Therapeutic, level IV.

Evaluating emergency-release blood transfusion of newborn infants at the Intermountain Healthcare hospitals

BACKGROUND

An emergency-release blood transfusion (ERBT) protocol (uncrossmatched type O-negative red blood cells, AB plasma, AB platelets) is critical for neonatology practice. However, few reports of emergency transfusions are available. We conducted an ERBT quality improvement project as a basis for progress.

STUDY DESIGN AND METHODS

For each ERBT in the past 8 years, we logged indications, products, locations and timing of the transfusions, and outcomes.

RESULTS

One hundred forty-nine ERBTs were administered; 42% involved a single blood product, and 58% involved two or more. The incidence was 6.25 ERBT per 10,000 live births, with a higher rate (9.52 ERBT/10,000) in hospitals with a Level 3 neonatal intensive care unit (NICU) (p < 0.001). Seventy percent of ERBTs were administered in a NICU and 30% in a delivery room, operating room, or emergency department. Indications were abruption/previa (32.2%), congenital anemia (i.e., fetomaternal hemorrhage; 15.4%), umbilical cord accident (i.e., velamentous insertion; 15.0%), and bleeding/coagulopathy (12.8%). Fifty-eight percent of those with hemorrhage before birth did not have a hemoglobin value reported on the umbilical cord gas; thus, anemia was not recognized initially. None of the 149 ERBTs were administered using a blood warmer. The mortality rate of recipients was 35%.

CONCLUSION

Based on our findings, we recommend including a hemoglobin value with every cord blood gas after emergency delivery to rapidly identify fetal anemia. We also discuss two potential improvements for future testing: 1) the use of a warming device for massive transfusion of neonates and 2) the use of low-titer group O cold-stored whole blood for massive hemorrhage in neonates.