Resuscitation and transfusion principles for traumatic hemorrhagic shock

Fresh whole blood: A feasible alternative in disasters and mass casualty incidents? a systematic review and meta-analysis

INTRODUCTION

While balanced blood component therapy (BCT) is pivotal in trauma patient damage control resuscitation in well-resourced settings, disasters, and mass casualty incidents (MCIs) pose significant challenges, especially in securing sufficient access to blood products. This systematic review and meta-analysis aim to explore the utilization of fresh whole blood (FWB) transfusion as a potential alternative to BCT, informing future research and clinical strategies.

METHODS

We searched Pubmed, MEDLINE, Embase, CINAHL, the Cochrane Library and grey literature for articles identifying FWB transfusions, limited to those published in English or French. We evaluated the outcomes of post-FWB transfusion and conducted a meta-analysis comparing overall mortality in patients receiving FWB in addition to BCT during damage control resuscitation with those receiving BCT or single blood components alone.

RESULTS

Of the 4830 studies identified, only 74 articles met all the eligibility criteria; the majority of them were conducted in military contexts. Mortality was lower among the FWB group compared to the BCT alone group, with a pooled OR of 0.61 (95% CI: 0.38-0.98) overall, and a pooled OR of 0.47 (95% CI: 0.25-0.87) among studies adjusting for confounders. FWB transfusion related complications rarely occurred.

CONCLUSIONS

While FWB shows potential as an alternative to BCT for managing severe haemorrhagic shock in disasters and MCIs, additional research is essential to validate FWB's efficacy before considering it as a standard approach in civilian scenarios. Further studies focusing on the feasibility of implementing FWB in civilian contexts are also warranted.

Effect of access to the integrated treatment model for patients with multiple severe injuries in the Chinese population

AIMS

The aim of this study was to enhance the effectiveness of an integrated treatment model for patients with severe multiple injuries in China.

METHODS

In this study, we conducted a retrospective analysis of data from 110 patients with multiple severe injuries. These patients were divided into two groups based on the treatment model they received. The first group, called the MDTM group, received the integrated treatment model, which involved a multidisciplinary team-based approach. The second group, designated the TSM group, received the traditional specialist-based treatment model. The primary outcome measure was the survival rate of patients after treatment. Secondary outcomes included the time spent on hospital emergency treatment, the length of hospital stay, the mortality rate, and family satisfaction.

RESULTS

The survival rate of patients after treatment in the MDTM group (83.93%) was significantly greater than that in the TSM group (70.37%). Consequently, the mortality of patients after treatment in the MDTM group (16.07%) was significantly lower than that in the TSM group (29.63%). Furthermore, the MDTM group demonstrated significantly shorter durations of rescue efforts and shorter hospital stays. Additionally, family satisfaction was significantly greater in the MDTM group.

CONCLUSION

The integrated treatment model shows potential for optimizing outcomes for patients with multiple severe injuries and generating higher levels of family satisfaction. This model holds practical applicability in the context of China and may help alleviate the strained relationship between physicians and patients.

What's new in whole blood resuscitation? In the trauma bay and beyond

PURPOSE OF REVIEW

Transfusion therapy commonly supports patient care during life-threatening injury and critical illness. Herein we examine the recent resurgence of whole blood (WB) resuscitation for patients in hemorrhagic shock following trauma and other causes of severe bleeding.

RECENT FINDINGS

A growing body of literature supports the use of various forms of WB for hemostatic resuscitation in military and civilian trauma practice. Different types of WB include warm fresh whole blood (FWB) principally used in the military and low titer O cold stored whole blood (LTOWB) used in a variety of military and civilian settings. Incorporating WB initial resuscitation alongside subsequent component therapy reduces aggregate blood product utilization and improves early mortality without adversely impacting intensive care unit length of stay or infection rate. Applications outside the trauma bay include prehospital WB and use in patients with nontraumatic hemorrhagic shock.

SUMMARY

Whole blood may be transfused as FWB or LTOWB to support a hemostatic approach to hemorrhagic shock management. Although the bulk of WB resuscitation literature has appropriately focused on hemorrhagic shock following injury, extension to other etiologies of severe hemorrhage will benefit from focused inquiry to address cost, efficacy, approach, and patient-centered outcomes.

Development of a machine learning model to predict intraoperative transfusion and guide type and screen ordering

STUDY OBJECTIVE

To develop an algorithm to predict intraoperative Red Blood Cell (RBC) transfusion from preoperative variables contained in the electronic medical record of our institution, with the goal of guiding type and screen ordering.

DESIGN

Machine Learning model development on retrospective single-center hospital data.

SETTING

Preoperative period and operating room.

PATIENTS

The study included patients ≥18 years old who underwent surgery during 2019-2022 and excluded those who refused transfusion, underwent emergency surgery, or surgery for organ donation after cardiac or brain death.

INTERVENTION

Prediction of intraoperative transfusion vs. no intraoperative transfusion.

MEASUREMENTS

The outcome variable was intraoperative transfusion of RBCs. Predictive variables were surgery, surgeon, anesthesiologist, age, sex, body mass index, race or ethnicity, preoperative hemoglobin (g/dL), partial thromboplastin time (s), platelet count x 109 per liter, and prothrombin time. We compared the performances of seven machine learning algorithms. After training and optimization on the 2019-2021 dataset, model thresholds were set to the current institutional performance level of sensitivity (93%). To qualify for comparison, models had to maintain clinically relevant sensitivity (>90%) when predicting on 2022 data; overall accuracy was the comparative metric.

MAIN RESULTS

Out of 100,813 cases that met study criteria from 2019 to 2021, intraoperative transfusion occurred in 5488 (5.4%) of cases. The LightGBM model was the highest performing algorithm in external temporal validity experiments, with overall accuracy of (76.1%) [95% confidence interval (CI), 75.6-76.5], while maintaining clinically relevant sensitivity of (91.2%) [95% CI, 89.8-92.5]. If type and screens were ordered based upon the LightGBM model, the predicted type and screen to transfusion ratio would improve from 8.4 to 5.1.

CONCLUSIONS

Machine learning approaches are feasible in predicting intraoperative transfusion from preoperative variables and may improve preoperative type and screen ordering practices when incorporated into the electronic health record.

Effect of restrictive fluid resuscitation on the coagulation function and hemodynamic parameters in patients with hemorrhagic traumatic shock

OBJECTIVES

To investigate the changes in the coagulation function and hemodynamic parameters in patients with Hemorrhagic Traumatic Shock (HTS) after restrictive fluid resuscitation.

METHODS

A total of 139 patients with HTS admitted to our hospital were enrolled, among which 69 HTS patients were divided into the control group and the remaining 70 HTS patients as the observation group. Patients in the control group underwent regular fluid resuscitation, while those in the observation group underwent restrictive fluid resuscitation.

RESULTS

During treatment, 70 patients in the observation group had a lower bleeding amount, infusion amount, and blood transfusion volume than those in the control group (p < 0.05). After treatment, patients in the observation group had better hemodynamic parameters and blood coagulation than those in the control group (p < 0.05), and the incidence rate in the observation group was only 12.9%, which was significantly lower than 60.87% in the control group, while the cure rate in the observation group was 100%, which was significantly higher than that in the control group (p < 0.05).

CONCLUSIONS

Restrictive fluid resuscitation could remarkably increase the cure rate and reduce the bleeding amount during HTS treatment, thereby benefiting the recovery of the patient's blood coagulation.

Comparison of Pediatric Trauma Scoring Tools That Incorporate Neurological Status for Trauma Team Activation

BACKGROUND

Two novel pediatric trauma scoring tools, SIPAB+ (defined as elevated SIPA with Glasgow Coma Scale ≤8) and rSIG (reverse Shock Index multiplied by Glasgow Coma Scale and defined as abnormal using cutoffs for early outcomes), which combine neurological status with Pediatric Age-Adjusted Shock Index (SIPA), have been shown to predict early trauma outcomes better than SIPA alone. We sought to determine if one more accurately identifies children in need of trauma team activation.

METHODS

Patients 1 to 18 years old from the 2014-2018 Pediatric Trauma Quality Improvement Program database were included. Sensitivity and specificity for SIPAB+ and rSIG were calculated for components of pediatric trauma team activation, based on criteria standard definitions.

RESULTS

There were 11,426 patients (1.9%) classified as SIPAB+ and 235,672 (39.0%) as having an abnormal rSIG. SIPAB+ was consistently more specific, with specificities exceeding 98%, but its sensitivity was poor (<30%) for all outcomes. In comparison, rSIG was a more sensitive tool, with sensitivities exceeding 60%, and specificity values exceeded 60% for all outcomes.

CONCLUSIONS

Trauma systems must determine their priorities to decide how best to incorporate SIPAB+ and rSIG into practice, although rSIG may be preferred as it balances both sensitivity and specificity.

LEVEL OF EVIDENCE

Level III.

Trauma in Pregnancy

Trauma is the leading cause of nonobstetric maternal death. Pregnant patients have a similar spectrum of traumatic injuries with a noted increase in interpersonal violence. A structured approach to trauma evaluation and management is recommended with several guidelines expanding on ATLS principles; however, evidence is limited. Optimal management requires understanding of physiologic changes in pregnancy, a team-based approach, and preparation for interventions that may including neonatal resuscitation. The principles of trauma management are the same in pregnancy with a systematic approach and initial maternal focused resuscitation..

Cryoprecipitate for the treatment of life-threatening hemorrhage in children

BACKGROUND

Hypofibrinogenemia is an important risk factor for poor outcomes in children with severe bleeding. There is a paucity of data on the impact of cryoprecipitate transfusion on outcomes in pediatric patients with life-threatening hemorrhage (LTH).

STUDY DESIGN AND METHODS

This secondary analysis of a multicenter prospective observational study of children with LTH investigated subjects who were categorized by receipt of cryoprecipitate during their resuscitation and according to the etiology of their bleeding: trauma, operative, and medical. Bivariate analysis was performed to identify variables associated with 6-h, 24-h, and 28-day mortality. Cox Hazard regression models were generated to adjust for potential confounders.

RESULTS

Cryoprecipitate was transfused to 33.9% (152/449) of children during LTH. The median (Interquartile range) time to cryoprecipitate administration was 108 (47-212) minutes. Children in the cryoprecipitate group were younger, more often female, with higher BMI and pre-LTH PRISM score and lower platelet counts. After adjusting for PRISM score, bleeding etiology, age, sex, RBC volume, platelet volume, antifibrinolytic use and cardiac arrest, cryoprecipitate administration was independently associated with lower 6-h mortality, Hazard Ratio (95% CI), 0.41 (0.19-0.89), (p = 0.02) and 24-h mortality, Hazard Ratio (95% CI), 0.46 (0.24-0.89), (p = 0.02).

CONCLUSION

Cryoprecipitate transfusion to children with LTH was associated with reduced early mortality. A prospective randomized trial is needed to determine if cryoprecipitate can improve outcomes in children with LTH.

Severe Trauma-Induced Coagulopathy: Molecular Mechanisms Underlying Critical Illness

Trauma remains one of the leading causes of death in adults despite the implementation of preventive measures and innovations in trauma systems. The etiology of coagulopathy in trauma patients is multifactorial and related to the kind of injury and nature of resuscitation. Trauma-induced coagulopathy (TIC) is a biochemical response involving dysregulated coagulation, altered fibrinolysis, systemic endothelial dysfunction, platelet dysfunction, and inflammatory responses due to trauma. The aim of this review is to report the pathophysiology, early diagnosis and treatment of TIC. A literature search was performed using different databases to identify relevant studies in indexed scientific journals. We reviewed the main pathophysiological mechanisms involved in the early development of TIC. Diagnostic methods have also been reported which allow early targeted therapy with pharmaceutical hemostatic agents such as TEG-based goal-directed resuscitation and fibrinolysis management. TIC is a result of a complex interaction between different pathophysiological processes. New evidence in the field of trauma immunology can, in part, help explain the intricacy of the processes that occur after trauma. However, although our knowledge of TIC has grown, improving outcomes for trauma patients, many questions still need to be answered by ongoing studies.

Pediatric Age-Adjusted Shock Index as a Predictor of Mortality by Sex Disparity in Pediatric Trauma: A Pan-Asian Trauma Outcome Study

PURPOSE

There has been no report of sex-specific, pediatric age-adjusted shock index (PASI) for pediatric trauma patients in previous studies. We aimed to determine the association between the PASI and in-hospital mortality of pediatric trauma patients and whether this association differs depending on sex.

MATERIALS AND METHODS

This is a prospective, multinational, and multicenter cohort study using the Pan-Asian Trauma Outcome Study (PATOS) registry in the Asia-Pacific region, conducted in pediatric patients who visited the participating hospitals. The main exposure of our study was abnormal (elevated) PASI measured in an emergency department. The main outcome was in-hospital mortality. We performed a multivariable logistic regression analysis to estimate the association between abnormal PASI and study outcomes after adjusting for potential confounders. An interaction analysis between PASI and sex was also conducted.

RESULTS

Of 6280 pediatric trauma patients, 10.9% (686) of the patients had abnormal PASI. In multivariable logistic regression analysis, abnormal PASI was significantly associated with increased in-hospital mortality [adjusted odds ratios (aOR), 1.74; 95% confidence interval (CI), 1.13-2.47]. Abnormal PASI had interaction effects with sex for in-hospital mortality (aOR, 1.86; 95% CI, 1.19-2.91 and aOR, 1.38; 95% CI, 0.58-2.99 for male and female, respectively) (p<0.01).

CONCLUSION

Abnormal PASI is associated with increased in-hospital mortality in pediatric trauma patients. The prediction power of PASI for in-hospital mortality was maintained only in male patients.

Outcomes in Pediatric Trauma Patients Who Receive Blood Transfusion

INTRODUCTION

Increased blood volumes, due to massive transfusion (MT), are known to be associated with both infectious and noninfectious adverse outcomes. The aim of this study was to assess the association between MT and outcomes in pediatric trauma patients, and, secondarily, determine if these outcomes are differential by age once MT is reached.

METHODS

Pediatric patients (ages 1-18 y old) in the ACS pediatric Trauma Quality Improvement Program (TQIP) database (2015-2018) who received blood were included. Patients were stratified by MT status, which was defined as blood product volume of 40 mL/kg within 24 h of admission (MT+) and compared to children who received blood products but did not meet the MT threshold (MT-). Defined MT + patients were matched 1:1 to MT-patients via propensity score matching of characteristics before comparisons. Adjusted logistic regression was performed on univariably significant outcomes of interest.

RESULTS

There were 2318 patients in the analytic cohort. Patients who received MT had higher rates of deep venous thrombosis (DVT) (2.5% versus 1.0%, P < 0.001), acute kidney injury (AKI) (1.5% versus 0.0%, P = 0.022), CLABSI (4.0% versus 2.0% P = 0.008), and severe sepsis (2.3% versus. 1.1%, P = 0.02). On logistic regression MT was an independent risk factor for these outcomes. There was no differential effect of MT on these outcomes based on age.

CONCLUSIONS

Outcomes associated with blood transfusion in pediatric trauma patients are low overall, but rates of DVT, AKI, CLABSI, and sepsis are higher in those who receive MT+ with no differences based on age.

The role of point of care thromboelastography (TEG) and thromboelastometry (ROTEM) in management of Primary postpartum haemorrhage: A meta-analysis and systematic review

Background

The utility of instantaneous evaluation of coagulation during primary postpartum haemorrhage (PPH) is paramount in the context of empirical blood product transfusion-related risk of dilutional and consumptive coagulopathy and circulatory overload.

Methods

A profound screening of electronic databases till August 15, 2022 was carried out after being enlisted in PROSPERO (CRD42021275514). Randomized control studies, comparative cohort studies, and cross-sectional studies comparing point-of-care viscoelastic test guided blood product transfusion with empirical transfusion in patients with PPH were included.

Results

We retrieved five studies, with a total of 1914 parturient with PPH. Patients receiving transfusion based upon point of care viscoelastic tests had lesser risk of having emergency hysterectomy (Odds ratio (OR) = 0.55, 95% CI 0.32-0.95, I2 = 7%), transfusion-associated circulatory overload (TACO) (OR = 0.03, 95% CI 0.00-0.50), reduced transfusion of fresh frozen plasma (OR = 0.07, 95% CI 0.04-0.14, I2 = 89%), platelets (OR = 0.51, 95% CI 0.28-0.91, I2 = 89%), packed red blood cell transfusion (OR = 0.70, 95% CI 0.55-0.88, I2 = 89%), and had better cost-effective treatment [Mean difference (MD) = -357.5, 95% CI - 567.75 to -147.25, I2 = 93%] than patient received empirical transfusion. However, there was no significant difference in the requirement of ICU admissions (OR = 0.77, 95% CI = 0.46-1.29, I2 = 82%). No mortality was detected across the studies.

Conclusions

Point of care viscoelastic assessment guided transfusion in PPH confederates with reduced morbidity. Nevertheless, more studies on the triggering values for transfusion, long-term survival, and cost-benefit in patients with PPH are warranted to establish its utility.

Utility of viscoelastic hemostatic assay to guide hemostatic resuscitation in trauma patients: a systematic review

Objective

Viscoelastic hemostatic assay (VHA) provides a graphical representation of a clot’s lifespan and reflects the real time of coagulation. It has been used to guide trauma resuscitation; however, evidence of the effectiveness of VHAs is still limited. This systematic review aims to summarize the published evidence to evaluate the VHA-guided strategy in resuscitating trauma patients.

Methods

The PubMed, Embase, and Web of Science databases were searched from their inception to December 13, 2021. Randomized controlled trials (RCTs) or observational studies comparing VHA-guided transfusion to controls in resuscitating trauma patients were included in this systematic review.

Results

Of the 7743 records screened, ten studies, including two RCTs and eight observational studies, met the inclusion criteria. There was great heterogeneity concerning study design, enrollment criterion, VHA device, VHA-guided strategy, and control strategy. Thrombelastography (TEG) was used as a guiding tool for transfusion in eight studies, and rotational thromboelastometry (ROTEM), and TEG or ROTEM were used in the other two studies. The overall risk of bias assessment was severe or mild in RCTs and was severe or moderate in observational studies. The main outcomes reported from the included studies were blood transfusion (n = 10), mortality (n = 10), hospital length of stay (LOS) (n = 7), intensive care unit LOS (n = 7), and cost (n = 4). The effect of the VHA-guided strategy was not always superior to the control. Most of the studies did not find significant differences in the transfusion amount of red blood cells (n = 7), plasma (n = 5), platelet (n = 7), cryoprecipitate/fibrinogen (n = 7), and mortality (n = 8) between the VHA-guided group and control group. Notable, two RCTs showed that the VHA-guided strategy was superior or equal to the conventional coagulation test-guided strategy in reducing mortality, respectively.

Conclusion

Although some studies demonstrated VHA-guided strategy probable benefit in reducing the need for blood transfusion and mortality when resuscitating trauma patients, the evidence is still not robust. The quality of evidence was primarily downgraded by the limited number of included studies and great heterogeneity and severe risk of bias in these. Further studies are strongly recommended.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13017-022-00454-8.

The U.S. Armed Services Blood Program support to U.S. Central Command 2014-2021: Transformation of combat trauma resuscitation through blood product innovation and expansion of blood availability far forward

BACKGROUND

The United States Armed Services Blood Program (ASBP) faced complex blood supply challenges during two decades of military operations in the U.S. Central Command (CENTCOM) and through an adaptive, responsive, and agile system, gained valuable insights on blood product usage in combat casualty care.

STUDY DESIGN AND METHODS

A retrospective review of blood product introduction and utilization trends was compiled from ASBP data collected during CENTCOM operations from 2014 through 2021.

RESULTS

During the study period, several blood products were introduced to the CENTCOM area of operations including Low Titer O Whole Blood (LTOWB), Cold-Stored Platelets (CSP), Liquid Plasma (LP), and French Freeze Dried Plasma (FDP) manufactured from U.S. sourced donor plasma, all while expanding Walking Blood Bank capabilities. There was a gradual substitution of component therapy for whole blood; blood utilization peaked in 2017. Transfusion of Fresh Whole Blood (FWB) from Walking Blood Banks decreased as fully pre-tested LTOWB was supplied by the ASBP. LTOWB was initially supplied in citrate-phosphate-dextrose (CPD) anticoagulant (21-day shelf life) but was largely replaced with LTOWB in citrate-phosphate-dextrose-adenine (CPDA-1) anticoagulant (35-day shelf life) by 2019. Implementation of prehospital transfusion and expansion of surgical and resuscitation teams led to an increase in the number of sites receiving blood.

DISCUSSION

ASBP introduced new products to its inventory in order to meet changing blood product demands driven by changes in the Joint Trauma System Clinical Practice Guidelines and operational demands. These products were adopted into clinical practice with a resultant evolution in transfusion strategies.

Fifteen-minute consultation: A guide to the paediatric primary survey

It's 21:00 and you receive a stand-by call from the local ambulance service. Peter, a 9-year-old boy, was riding an electric scooter and has collided with a car. He has reduced consciousness, signs of shock and is hypoxic. How will you prepare your team? What are the possible injuries? Who will perform the primary survey? Injury is the leading cause of morbidity and mortality in the paediatric population accounting for approximately half of all attendances to paediatric emergency departments in the UK and Ireland. Major trauma can be distressing for patients, parents and physicians. Managing major trauma is challenging and it is vital to have a clear and organised approach. In this 15-minute guide we describe a structured approach to the primary survey that includes how to prepare before the child's arrival, the suggested roles of team members and the key components of the primary survey. We discuss life-threatening injuries, the life-saving bundle and the principles of resuscitation, and the role of imaging in the initial assessment of the injured child.

Determining Resuscitation Outcomes in Combat Casualties: Design of the Deployed Hemostatic Emergency Resuscitation Of Traumatic Exsanguinating Shock (Deployed HEROES) Study

BACKGROUND

During the course of the recent conflicts, the recommendations for resuscitation practices have evolved, but there has been no comprehensive comparative effectiveness study of these resuscitation strategies. The objective of this study was to describe the development and study design of the Deployed Hemostatic Emergency Resuscitation Of Traumatic Exsanguinating Shock (Deployed HEROES) Study- the first comprehensive analysis of military resuscitation practices in the deployed environment from October 2001 to October 2019.

METHODS

This retrospective cohort study uses the DoD Trauma Registry, Armed Services Blood Program database, and Military Trauma Mortality Review, while abstractors will use Theater Medical Data Store and Web Interface Patient Records to collect transfusion timing data. This study includes patients, who received blood products or died before receiving blood, treated at US military medical treatment facilities. The primary endpoints are survival at 6 hours, 24 hours, and 30 days post-injury. Secondary outcomes include infection, renal dysfunction, pulmonary dysfunction, and thromboembolic event. Exposure will be defined by blood product transfusion. Study groups will be frequency-matched. Cox proportional hazards will compare patients who received WFWB, LTOWB, or only component therapy, while using adjustment for type of blood product transfused as a time-dependent covariate. Multilevel mixed-effects logistic regression will determine the effect of incompatible plasma in LTOWB.

RESULTS

An analysis plan for the Deployed HEROES study was developed with the aim of minimizing bias.

CONCLUSIONS

This study will inform the optimal resuscitation strategies, which will potentially have a substantial impact on combat mortality. If whole blood is found to be the optimal transfusion strategy, this finding will be crucial in future operating environments involving dispersed medical assets. These results will provide critical information necessary for combat casualty care guidelines.

LEVEL OF EVIDENCE

Level III.

Massive transfusion in pediatric trauma-does more blood predict mortality?

BACKGROUND

Treatment of severe hemorrhage focuses on the control of bleeding and intravascular volume expansion through massive transfusion (MT). This study aimed to determine if transfusion volumes in pediatric trauma patients who receive MT is associated with increased risk of death, and to establish if there is a threshold above which further resuscitation with blood products is futile.

METHODS

Pediatric patients (2-18 years old) in the 2014-2017 Trauma Quality Improvement Program (TQIP) database with complete age and blood transfusion data who met the MT definition of 40 mL/kg/24 h were included in analysis. Data elements were cleaned to eliminate discrepancies in reporting blood volumes and erroneous values were excluded. Early mortality was defined as death within 24 h. Late mortality was defined as death more than 24 h after hospital admission. Area under the curve (AUC) was calculated from receiver operating characteristic (ROC) curve analyses to determine upper volume thresholds to predict early versus late mortality.

RESULTS

There were 633 patients who met the MT definition of 40 mL/kg/24 h. The overall mortality rate was 21.6%. Volume of blood had poor predicting early and late mortality with an AUC of 0.50 [95% CI (0.42, 0.59)] and 0.50 [95% CI (0.43,0.57)], respectively. Regardless of mechanism, no transfusion volume was associated with a predictably high rate of mortality.

CONCLUSIONS

There is no upper transfusion volume threshold to predict mortality in pediatric trauma patients who are massively transfused, regardless of mechanism. Severely injured children can tolerate massive amounts of blood products and still survive.

LEVEL OF EVIDENCE

III.

Estimating the risks of prehospital transfusion of D-positive whole blood to trauma patients who are bleeding in England

Background and Objectives

D‐negative red cells are transfused to D‐negative females of childbearing potential (CBP) to prevent haemolytic disease of the foetus and newborn (HDFN). Transfusion of low‐titre group O whole blood (LTOWB) prehospital is gaining interest, to potentially improve clinical outcomes and for logistical benefits compared to standard of care. Enhanced donor selection requirements and reduced shelf‐life of LTOWB compared to red cells makes the provision of this product challenging.

Materials and Methods

A universal policy change to the use of D‐positive LTOWB across England was modelled in terms of risk of three specific harms occurring: risk of haemolytic transfusion reaction now or in the future, and the risk of HDFN in future pregnancies for all recipients or D‐negative females of CBP.

Results

The risk of any of the three harms occurring for all recipients was 1:14 × 10³ transfusions (credibility interval [CI] 56 × 10²–42 × 10³) while for females of CBP it was 1:520 transfusions (CI 250–1700). The latter was dominated by HDFN risk, which would be expected to occur once every 5.7 years (CI 2.6–22.5). We estimated that a survival benefit of ≥1% using LTOWB would result in more life‐years gained than lost if D‐positive units were transfused exclusively. These risks would be lower, if D‐positive blood were only transfused when D‐negative units are unavailable.

Conclusion

These data suggest that the risk of transfusing RhD‐positive blood is low in the prehospital setting and must be balanced against its potential benefits.

Pediatric age-adjusted shock index as a tool for predicting outcomes in children with or without traumatic brain injury

BACKGROUND

The pediatric age-adjusted shock index (SIPA) accurately identifies severely injured children following trauma without accounting for neurological status. Understanding how the presence of traumatic brain injury (TBI) affects the generalizability of SIPA as a bedside triage tool is important given high rates of TBI in the pediatric trauma population. We hypothesized that SIPA combined with TBI (SIPAB+) would more accurately identify severely injured children.

METHODS

Patients (1-18 years old) in the American College of Surgeons Pediatric Trauma Quality Improvement Program database (2014-2017) with an elevated SIPA upon arrival to a pediatric trauma center were included. Pediatric age-adjusted shock index combined with TBI was defined as elevated SIPA with Glasgow Coma Scale score of ≤8. Pediatric age-adjusted shock index without TBI (SIPAB-) was defined as elevated SIPA with Glasgow Coma Scale score of >9. Patients were stratified into SIPAB+ and SIPAB-. A subanalysis of patients with isolated brain injury and those with brain injury and multisystem injuries was also performed. Data were compared through univariate models and three separate logistic regression models.

RESULTS

Overall, 25,068 had an elevated SIPA, with 12.3% classified as SIPAB+ and the remainder SIPAB-. Patients classified as SIPAB+ received more blood transfusions within 4 hours of injury and had higher mortality rates. On logistic regression, SIPAB+ patients had significantly higher odds of early blood transfusion and a combination of both. Mortality and early blood transfusion were also higher in SIPAB+ patients on subanalysis for patients with isolated TBI and those with multisystem injuries.

CONCLUSION

The use of SIPAB+ as a bedside triage tool accurately identifies traumatically injured children at high risk for early blood transfusion and/or death while incorporating the presence of neurological injury. This is true for patients with isolated TBI and those with multisystem injury, indicating its utility in predicting outcomes for TBI patients with elevated SIPA regardless of presence of concomitant injuries. Incorporation of this as a triage tool should be considered to better predict resources in this population.

LEVEL OF EVIDENCE

Prognostic, level III.

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.

Cold-stored leukoreduced whole blood: Extending the time between donation and filtration has minimal impact on in vitro quality

BACKGROUND

Leukoreduced whole blood (LR-WB) has received renewed attention as alternative to component-based transfusion in trauma. According to the manufacturer's instructions, leukoreduction should be carried out within 8 h after collection. This study assessed impact of (1) WB collection bag, (2) LR filtration, and (3) timing of filtration on in vitro quality.

STUDY DESIGN AND METHODS

WB collected into different vendor bags was held at room temperature for <8 h or >16 h but <24 h prior to LR. In vitro quality was assessed before and after filtration, and throughout 3 weeks of storage at 4°C. Cell count and hemoglobin levels were determined by hematology analyzer, platelet activation, and responsiveness to ADP by surface expression of P-selectin by flow cytometry, hemolysis by HemoCue, and metabolic parameters by blood gas analyzer. Hemostatic properties were assessed by rotational thromboelastometry. Plasma protein activities and clotting times were determined by automated coagulation analyzer or quantitative immunoblotting.

RESULTS

Bag type had no impact on WB in vitro quality. LR by filtration had some impact, but is aligned with data in the literature. The time between donation and filtration resulted in some statistically significant differences in metabolic activity, platelet yield, platelet activation, and factor protein activity initially; however, these differences in in vitro quality attributes decreased throughout 21-day cold storage.

CONCLUSION

WB hold time showed only a minor impact on WB in vitro quality, so it may be possible for blood processing facilities to explore extended hold times prior to filtration in order to provide greater operational flexibility.

Identification of Fibrinogen as a Key Anti-Apoptotic Factor in Human Fresh Frozen Plasma for Protecting Endothelial Cells In Vitro

Resuscitation with human fresh frozen plasma (FFP) in hemorrhagic shock (HS) patients is associated with improved clinical outcomes. Our group has demonstrated that the beneficial effect of FFP is due to its blockade on endothelial hyperpermeability, thereby improving vascular barrier function. The current study aimed to investigate HS-induced endothelial cell apoptosis, a potential major contributor to the endothelial hyperpermeability, and to determine the effect and the key components/factors of FFP on protecting endothelial cells from apoptosis. We first measured and demonstrated an increase in apoptotic endothelial microparticles (CD146AnnexinV) in patients in shock compared to normal subjects, indicating the induction of endothelial cell activation and apoptosis in shock patients. We then transfused HS rats with FFP and showed that FFP blocked HS-induced endothelial cell apoptosis in gut tissue. To identify the anti-apoptotic factors in FFP, we utilized high-performance liquid chromatography, fractionated FFP, and screened the fractions in vitro for the anti-apoptotic effects. We selected the most effective fractions, performed mass spectrometry, and identified fibrinogen as a potent anti-apoptotic factor. Taken together, our findings suggest that HS-induced endothelial apoptosis may constitute a major mechanism underlying the vascular hyperpermeability. Furthermore, the identified anti-apoptotic factor fibrinogen may contribute to the beneficial effects of FFP resuscitation, and therefore, may have therapeutic potential for HS.

Life-Threatening Bleeding in Children: A Prospective Observational Study

OBJECTIVES

The purpose of our study was to describe children with life-threatening bleeding.

DESIGN

We conducted a prospective observational study of children with life-threatening bleeding events.

SETTING

Twenty-four childrens hospitals in the United States, Canada, and Italy participated.

SUBJECTS

Children 0-17 years old who received greater than 40 mL/kg total blood products over 6 hours or were transfused under massive transfusion protocol were included.

INTERVENTIONS

Children were compared according bleeding etiology: trauma, operative, or medical.

MEASUREMENTS AND MAIN RESULTS

Patient characteristics, therapies administered, and clinical outcomes were analyzed. Among 449 enrolled children, 55.0% were male, and the median age was 7.3 years. Bleeding etiology was 46.1% trauma, 34.1% operative, and 19.8% medical. Prior to the life-threatening bleeding event, most had age-adjusted hypotension (61.2%), and 25% were hypothermic. Children with medical bleeding had higher median Pediatric Risk of Mortality scores (18) compared with children with trauma (11) and operative bleeding (12). Median Glasgow Coma Scale scores were lower for children with trauma (3) compared with operative (14) or medical bleeding (10.5). Median time from bleeding onset to first transfusion was 8 minutes for RBCs, 34 minutes for plasma, and 42 minutes for platelets. Postevent acute respiratory distress syndrome (20.3%) and acute kidney injury (18.5%) were common. Twenty-eight-day mortality was 37.5% and higher among children with medical bleeding (65.2%) compared with trauma (36.1%) and operative (23.8%). There were 82 hemorrhage deaths; 65.8% occurred by 6 hours and 86.5% by 24 hours.

CONCLUSIONS

Patient characteristics and outcomes among children with life-threatening bleeding varied by cause of bleeding. Mortality was high, and death from hemorrhage in this population occurred rapidly.

Major Prehospital Trauma and In-Hospital Emergencies: Massive Transfusion Triggers

BACKGROUND

Massive transfusion (MT) in trauma is initiated on the basis of factors of different natures and depending on protocols and scales used both in prehospital and in-hospital care areas.

OBJECTIVE

The main goal was to analyze and relate factors and predictive variables for MT requirements considering both health care areas.

METHOD

This was a retrospective cohort study that included patients who were treated either at the emergency department of a large hospital or through prehospital care before arrival at the hospital. The patients included were adults who received MT, defined as a blood bank request of 10 or more units of red cells in the first 24 hours or 5 or more within 4 hours of trauma, from January 1, 2009, to January 1, 2017. The variables included were individual characteristics and those associated with the trauma, clinical-analytical assessment, resuscitation, timing, and survival.

RESULTS

A total of 52 patients who received MT were included. The average age of the patients was 41.23 ± 16.06 years, a mean of 19.56 ± 12.77 units was administered, and the mortality rate was 21.2%.

DISCUSSION

Injury mechanism, clinical-analytical variables, and resuscitation strategies have a significant influence on the need for MT; therefore, early identification is fundamental for performing quality management and addressing avoidable factors during MT processes.

Is fresh, leucodepleted, whole blood transfusion superior to blood component transfusion in pediatric patients undergoing spinal deformity surgeries? A prospective, randomized study analyzing postoperative serological parameters and clinical recovery

Purpose

To compare the effectiveness of fresh whole blood (FWB) and blood component transfusion in improving clinical outcome and serological parameters in the early postoperative period following spinal deformity surgery.

Methods

Patients undergoing major spinal deformity surgeries involving ≥ 6 levels of fusion and expected blood loss ≥ 750 ml between September 2017 and August 2018 were included in the study. The patients were randomized into two groups: FWBG and CG, receiving fresh whole blood and component transfusions, respectively.

Results

A total of 65 patients with spinal deformities of different etiologies were included. The mean age was 14.0 and 14.9 years in FWB and CG, respectively. All other preoperative parameters were comparable. The mean fusion levels and surgical time were 11.1 and 221.20 min in FWB, as compared with 10.70 and 208.74minutes in CG, respectively. Intraoperative blood losses were 929 ml (FWBG) and 847 ml(CG), and the mean volumes of transfusion were 1.90 (FWBG) and 1.65 units (CG). FWBG was significantly superior to CG in the following clinical and laboratory parameters: duration of oxygen dependence [36.43 (FWBG) vs. 43.45 h (CG); P = 0.0256], mean arterial pH [7.442 (FWBG) vs. 7.394 (CG); p < 0.001], interleukin-6 [30.04 (FWBG) vs. 35.10 (CG); p < 0.019], mean duration of HDU stay [40.6 hours (FWBG) vs 46.51 hours (CG); p = 0.0234] and postoperative facial puffiness [7/30 in FWBG vs. 18/35 (CG) (P < 0.02)].

Conclusion

FWB transfusion can potentially improve the immediate postoperative outcome in patients undergoing major spinal deformity surgeries by reducing the duration of intensive care unit stay and oxygen dependence. The other potential benefits of this practice, based on our study, include a reduced inflammatory response (reduced lactate and IL-6) and postoperative facial puffiness. However, further large-scale validation studies in future are necessary to precisely determine the role of FWB in spine surgeries.

Level of evidence II

Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Bicarbonate Ringer's solution for early resuscitation in hemorrhagic shock rabbits

Background

Fluid resuscitation is important for correcting hypovolemia. Isotonic crystalloids are the preferred solution for the initial clinical management of patients with multiple traumas. Bicarbonated Ringer’s solution (BRS), offering physiological levels of bicarbonate ions and electrolyte ions, can be used for supplementing missing extracellular fluid and correcting metabolic acidosis. We here investigated the effects of BRS on the resuscitation of hemorrhagic shock models and compared the resuscitation performance of three crystalloids, including BRS, acetated Ringer’s solution (ARS), and normal saline.

Methods

Thirty adult male New Zealand rabbits were randomly divided into five groups (n=6): a sham operation group (Sham group), an operation without fluid therapy group (Shock group), a BRS group, an ARS group, and a normal saline group (Saline group). The New Zealand rabbits experienced rapid bloodletting to shock status and maintained for 20 minutes except Sham group. The status of shock was maintained in the Shock group. The fluid was infused at a rate of 60 mL/kg per hour for 1.5 hours in three fluid therapy group. Measurement of vital signs, arterial blood gas tests, blood biochemistry, hematoxylin and eosin (HE) staining of lung tissue, TUNEL staining of the liver and kidney tissues, and analysis of intestinal flora were performed.

Results

The reduction in both base excess (BE) and bicarbonate ion (HCO₃^-) caused by acidosis in rabbits with hemorrhagic shock was significantly improved in the BRS group when compared with the Saline group at infusion for 30 minutes (T3) and 30 minutes after infusion (T5) (BRS group vs. Saline group, BE: at T3, −4.83±3.60 vs. −12.50±3.27 mmol/L, P<0.01; at T5, −3.67±4.37 vs. −11.00±2.76 mmol/L, P<0.01; HCO₃^-: at T3, 22.15±2.63 vs. 15.42±3.03 mmol/L, P<0.01; at T5, 23.15±2.9 vs. 16.23±3.07 mmol/L, P<0.01). Compared with Shock group, liver cell apoptosis due to hemorrhagic shock was relieved in both the BRS group and ARS group (BRS group vs. Shock group: 19.1±3.3 vs. 28.1±6.1, P<0.05; ARS group vs. Shock group: 19.8±5.4 vs. 28.1±6.1, P<0.05).

Conclusions

During resuscitation of hemorrhagic shock, BRS, a novel perioperative balanced crystalloid, is more effective than normal saline in maintaining acid-base balance and in protecting tissues and organs.

Pulse Arrival Time Is Associated With Hemorrhagic Volume in a Porcine Model: A Pilot Study

BACKGROUND

Hemorrhage is a major cause of preventable death worldwide, and early identification can be lifesaving. Pulse wave contour analysis has previously been used to infer hemodynamic variables in a variety of settings. We hypothesized that pulse arrival time (PAT), a form of pulse wave contour analysis which is assessed via electrocardiography (ECG) and photoplethysmography (PPG), is associated with hemorrhage volume.

METHODS

Yorkshire-Cross swine were randomized to hemorrhage (30 mL/kg over 20 minutes) vs. control. Continuous ECG and PPG waveforms were recorded with a novel monitoring device, and algorithms were developed to calculate PAT and PAT variability throughout the respiratory cycle, termed "PAT index" or "PAT_I." Mixed effects models were used to determine associations between blood loss and PAT and between blood loss and PAT_I to account for clustering within subjects and investigate inter-subject variability in these relationships.

RESULTS

PAT and PAT_I data were determined for ∼150 distinct intervals from five subjects. PAT and PAT_I were strongly associated with blood loss. Mixed effects modeling with PAT alone was substantially better than PAT_I alone (R2 0.93 vs. 0.57 and Akaike information criterion (AIC) 421.1 vs. 475.5, respectively). Modeling blood loss with PAT and PAT_I together resulted in slightly improved fit compared to PAT alone (R2 0.96, AIC 419.1). Mixed effects models demonstrated significant inter-subject variability in the relationships between blood loss and PAT.

CONCLUSIONS

Findings from this pilot study suggest that PAT and PAT_I may be used to detect blood loss. Because of the simple design of a single-lead ECG and PPG, the technology could be packaged into a very small form factor device for use in austere or resource-constrained environments. Significant inter-subject variability in the relationship between blood loss and PAT highlights the importance of individualized hemodynamic monitoring.

Physiology of Human Hemorrhage and Compensation

Hemorrhage is a leading cause of death following traumatic injuries in the United States. Much of the previous work in assessing the physiology and pathophysiology underlying blood loss has focused on descriptive measures of hemodynamic responses such as blood pressure, cardiac output, stroke volume, heart rate, and vascular resistance as indicators of changes in organ perfusion. More recent work has shifted the focus toward understanding mechanisms of compensation for reduced systemic delivery and cellular utilization of oxygen as a more comprehensive approach to understanding the complex physiologic changes that occur following and during blood loss. In this article, we begin with applying dimensional analysis for comparison of animal models, and progress to descriptions of various physiological consequences of hemorrhage. We then introduce the complementary side of compensation by detailing the complexity and integration of various compensatory mechanisms that are activated from the initiation of hemorrhage and serve to maintain adequate vital organ perfusion and hemodynamic stability in the scenario of reduced systemic delivery of oxygen until the onset of hemodynamic decompensation. New data are introduced that challenge legacy concepts related to mechanisms that underlie baroreflex functions and provide novel insights into the measurement of the integrated response of compensation to central hypovolemia known as the compensatory reserve. The impact of demographic and environmental factors on tolerance to hemorrhage is also reviewed. Finally, we describe how understanding the physiology of compensation can be translated to applications for early assessment of the clinical status and accurate triage of hypovolemic and hypotensive patients. © 2021 American Physiological Society. Compr Physiol 11:1531-1574, 2021.

Age of thawed plasma does not affect clinical outcomes or biomarker expression in patients receiving prehospital thawed plasma: a PAMPer secondary analysis

Background

Prehospital plasma administration during air medical transport reduces the endotheliopathy of trauma, circulating pro-inflammatory cytokines, and 30-day mortality among traumatically injured patients at risk of hemorrhagic shock. No clinical data currently exists evaluating the age of thawed plasma and its association with clinical outcomes and biomarker expression post-injury.

Methods

We performed a secondary analysis from the prehospital plasma administration randomized controlled trial, PAMPer. We dichotomized the age of thawed plasma creating three groups: standard-care, YOUNG (day 0-1) plasma, and OLD (day 2-5) plasma. We generated HRs and 95% CIs for mortality. Among all patients randomized to plasma, we compared predicted biomarker values at hospital admission (T0) and 24 hours later (T24) controlling for key difference between groups with a multivariable linear regression. Analyses were repeated in a severely injured subgroup.

Results

Two hundred and seventy-one patients were randomized to standard-care and 230 to plasma (40% YOUNG, 60% OLD). There were no clinically or statistically significant differences in demographics, injury, admission vital signs, or laboratory values including thromboelastography between YOUNG and OLD. Compared with standard-care, YOUNG (HR 0.66 (95% CI 0.41 to 1.07), p=0.09) and OLD (HR 0.64 (95% CI 0.42 to 0.96), p=0.03) plasma demonstrated reduced 30-day mortality. Among those randomized to plasma, plasma age did not affect mortality (HR 1.04 (95% CI 0.60 to 1.82), p=0.90) and/or adjusted serum markers by plasma age at T0 or T24 (p>0.05). However, among the severely injured subgroup, OLD plasma was significantly associated with increased adjusted inflammatory and decreased adjusted endothelial biomarkers at T0.

Discussion

Age of thawed plasma does not result in clinical outcome or biomarker expression differences in the overall PAMPer study cohort. There were biomarker expression differences in those patients with severe injury. Definitive investigation is needed to determine if the age of thawed plasma is associated with biomarker expression and outcome differences following traumatic injury.

Level of evidence

II.

Thoracic, Peripheral, and Cerebral Volume, Circulatory and Pressure Responses To PEEP During Simulated Hemorrhage in a Pig Model: a Case Study

Positive end-expiratory pressure (PEEP) is a respiratory/ventilation procedure that is used to maintain or improve breathing in clinical and experimental cases that exhibit impaired lung function. Body fluid shift movement is not monitored during PEEP application in intensive care units (ICU), which would be interesting specifically in hypotensive patients. Brain injured and hypotensive patients are known to have compromised cerebral blood flow (CBF) autoregulation (AR) but currently, there is no non-invasive way to assess the risk of implementing a hypotensive resuscitation strategy and PEEP use in these patients. The advantage of electrical bioimpedance measurement is that it is noninvasive, continuous, and convenient. Since it has good time resolution, it is ideal for monitoring in intensive care units (ICU). The basis of its future use is to establish physiological correlates. In this study, we demonstrate the use of electrical bioimpedance measurement during bleeding and the use of PEEP in pig measurement. In an anesthetized pig, we performed multimodal recording on the torso and head involving electrical bioimpedance spectroscopy (EIS), fixed frequency impedance plethysmography (IPG), and bipolar (rheoencephalography - REG) measurements and processed data offline. Challenges (n=16) were PEEP, bleeding, change of SAP, and CO2 inhalation. The total measurement time was 4.12 hours. Systemic circulatory results: Bleeding caused a continuous decrease of SAP, cardiac output (CO), and increase of heart rate, temperature, shock index (SI), vegetative - Kerdo index (KI). Pulse pressure (PP) decreased only after second bleeding which coincided with loss of CBF AR. Pulmonary arterial pressure (PAP) increased during PEEP challenges as a function of time and bleeding. EIS/IPG results: Body fluid shift change was characterized by EIS-related variables. Electrical Impedance Spectroscopy was used to quantify the intravascular, interstitial, and intracellular volume changes during the application of PEEP and simulated hemorrhage. The intravascular fluid compartment was the primary source of blood during hemorrhage. PEEP produced a large fluid shift out of the intravascular compartment during the first bleeding period and continued to lose more blood following the second and third bleeding. Fixed frequency IPG was used to quantify the circulatory responses of the calf during PEEP and simulated hemorrhage. PEEP reduced the arterial blood flow into the calf and venous outflow from the calf. Head results: CBF AR was evaluated as a function of SAP change. Before bleeding, and after moderate bleeding, intracranial pressure (ICP), REG, and carotid flow pulse amplitudes (CFa) increased. This change reflected vasodilatation and active CBF AR. After additional hemorrhaging during PEEP, SAP, ICP, REG, CFa signal amplitudes decreased, indicating passive CBF AR. 1) The indicators of active AR status by modalities was the following: REG (n=9, 56 %), CFa (n=7, 44 %), and ICP (n=6, 38 %); 2) CBF reactivity was better for REG than ICP; 3) REG and ICP correlation coefficient were high (R2 = 0.81) during CBF AR active status; 4) PRx and REGx reflected active CBF AR status. CBF AR monitoring with REG offers safety for patients by preventing decreased CBF and secondary brain injury. We used different types of bioimpedance instrumentation to identify physiologic responses in the different parts of the body (that have not been discussed before) and how the peripheral responses ultimately lead to decreased cardiac output and changes in the head. These bioimpedance methods can improve ICU monitoring, increase the adequacy of therapy, and decrease mortality and morbidity.

Massive Transfusion in Pediatric Patients

Massive transfusion in pediatric patients is infrequent but associated with much higher mortality than in adults. Blood transfusion and hematology has conceptualized ideas such as blood failure and the interplay of the blood-endothelium interface to understand coagulopathy in the context of hemorrhagic shock. Researchers are still searching for an appropriate definition of what constitutes a pediatric massive transfusion. There is no universally accepted protocol for massive transfusion and how to address the many complications that can arise. Pharmacologic adjuncts to resuscitation may prove beneficial in reducing coagulopathy during pediatric massive transfusion, but high-quality evidence has not yet emerged.

"TEG talk": expanding clinical roles for thromboelastography and rotational thromboelastometry

Viscoelastic assays (VEAs) that include thromboelastography and rotational thromboelastometry add value to the investigation of coagulopathies and goal-directed management of bleeding by providing a complete picture of clot formation, strength, and lysis in whole blood that includes the contribution of platelets, fibrinogen, and coagulation factors. Conventional coagulation assays have several limitations, such as their lack of correlation with bleeding and hypercoagulability; their inability to reflect the contribution of platelets, factor XIII, and plasmin during clot formation and lysis; and their slow turnaround times. VEA-guided transfusion algorithms may reduce allogeneic blood exposure during and after cardiac surgery and in the emergency management of trauma-induced coagulopathy and hemorrhage. However, the popularity of VEAs for other indications is driven largely by extrapolation of evidence from cardiac surgery, by the drawbacks of conventional coagulation assays, and by institution-specific preferences. Robust diagnostic studies validating and standardizing diagnostic cutoffs for VEA parameters and randomized trials comparing VEA-guided algorithms with standard care on clinical outcomes are urgently needed. Lack of such studies represents the biggest barrier to defining the role and impact of VEA in clinical care.

Targeted cryoprecipitate transfusion in severe traumatic haemorrhage

BACKGROUND

Severe traumatic haemorrhage is the leading cause of death in young adults. Trauma Induced Coagulopathy is a complex and multifactorial phenomenon associated with severe traumatic haemorrhage. Fibrinogen is one of the first coagulation factors to become depleted in TIC and evidence suggests that severely injured trauma patients with hypofibrinogenaemia have poor outcomes. It is postulated that early fibrinogen replacement can improve clinical outcomes. This study investigated cryoprecipitate transfusion in hyopfibrinogeneamic trauma patients.

METHODS

This retrospective, single center, observational study investigated the use of cryoprecipitate in severely injured trauma patients admitted to an Australian Level I Trauma Centre. The primary outcome was time to administration of cryoprecipitate after identification of hypofibrinogenaemia using ROTEM (FIBTEM A5). Data collected included demographics, ISS, laboratory values of coagulation and blood product usage.

RESULTS

71 patients received cryoprecipitate with a median time of 61 minutes [IQR 37-93] from FIBTEM A5 result to initial cryoprecipitate administration. At 24 hours following admission to ED, Clauss Fibrinogen levels increased by 1.30g/L [IQR 0.45-1.85] and FIBTEM A5 assay increased by 8mm [IQR 3.0-11.3]. Changes in both variables were highly significant (p<0.001) and Clauss Fibrinogen versus FIBTEM A5 values showed moderate to strong correlation (R=0.75-0.80).

CONCLUSION

This study demonstrated that early administration of cryoprecipitate was both feasible and efficacious in fibrinogen replacement in severe traumatic haemorrhage. High-level evidence supporting cryoprecipitate or fibrinogen concentrate replacement with regards to efficacy and feasibility is required to guide future clinical practice. This study provided baseline data to inform the design of further clinical trials investigating fibrinogen replacement in traumatic haemorrhage.

Comparison of the trometamol-balanced solution with two other crystalloid solutions for fluid resuscitation of a rat hemorrhagic model

Currently, the optimal resuscitation fluid remains debatable. Therefore, in the present study, we designed a trometamol-balanced solution (TBS) for use as a resuscitation fluid for hemorrhagic shock. Hemorrhagic shock was induced in 18 male Wistar-Kyoto rats, which were assigned to normal saline (NS), Ringer's solution (RS), and TBS groups. During the hemorrhagic state, their hemodynamic parameters were recorded using an Abbott i-STAT analyzer with the CG4+ cartridge (for pH, pressure of carbon dioxide, pressure of oxygen, total carbon dioxide, bicarbonate, base excess, oxygen saturation, and lactate), the CG6+ cartridge (for sodium, potassium, chloride, blood glucose, blood urea nitrogen, hematocrit, and hemoglobin), and enzyme-linked immunosorbent assay kits (calcium, magnesium, creatinine, aspartate aminotransferase, alanine aminotransferase, bilirubin, and albumin). Similar trends were found for the parameters of biochemistries, electrolytes, and blood gas, and they revealed no significant changes after blood withdrawal-induced hemorrhagic shock. However, the TBS group showed more effective ability to correct metabolic acidosis than the NS and RS groups. TBS was a feasible and safe resuscitation solution in this study and may be an alternative to NS and RS for resuscitation in hemorrhagic shock patients without liver damage.

Damage Control Laparotomy: High-Volume Centers Display Similar Mortality Rates Despite Differences in Country Income Level

BACKGROUND

Comprehensive analysis of trauma care between high-, middle-, and low-income countries (HIC/MIC/LIC) is needed to improve global health. Comparison of HIC and MIC outcomes after damage control laparotomy (DCL) for patients is unknown. We evaluated DCL utilization among patients treated at high-volume trauma centers in the USA and South Africa, an MIC, hypothesizing similar mortality outcomes despite differences in resources and setting.

METHODS

Post hoc analysis of prospectively collected trauma databases from participating centers was performed. Injury severity, physiologic, operative data and post-operative outcomes were abstracted. Univariate and multivariable analyses were performed to assess differences between HIC/MIC for the primary outcome of mortality.

RESULTS

There were 967 HIC and 602 MIC patients who underwent laparotomy. DCL occurred in 144 MIC patients (25%) and 241 HIC (24%) patients. Most sustained (58%) penetrating trauma with higher rates in the MIC compared to the HIC (71 vs. 32%, p = 0.001). Between groups, no differences were found for admission physiology, coagulopathy, or markers of shock except for increased presence of hypotension among patients in the HIC. Crystalloid infusion volumes were greater among MIC patients, and MIC patients received fewer blood products than those in the HIC. Overall mortality was 30% with similar rates between groups (29 in HIC vs. 33% in MIC, p = 0.4). On regression, base excess and penetrating injury were independent predictors of mortality but not patient residential status.

CONCLUSION

Use and survival of DCL for patients with severe abdominal trauma was similar between trauma centers in HIC and MIC settings despite increased penetrating trauma and less transfusion in the MIC center. While the results overall suggest no gap in care for patients requiring DCL in this MIC, it highlights improvements that can be made in damage control resuscitation.

Innate coagulability changes with age in stored packed red blood cells

BACKGROUND

Packed red blood cell (pRBC) units administered during resuscitation from hemorrhagic shock are of varied storage ages. We have previously shown that RBC-derived microparticles' impact on thrombogenesis. However, the impact of storage age on pRBC coagulability is unknown. Therefore, we sought to investigate the effect of storage age on innate coagulability and aggregability of stored pRBCs.

METHODS

pRBCs prepared from male C57BL/6J mice were stored in Additive Solution-3 according to our standardized murine blood banking protocols for 14 days. Rotational thromboelastometry (ROTEM) was used to assess the innate coagulation status of fresh and 14-day old pRBCs. Viscoelastic coagulation parameters of clotting time (CT), clot formation time (CFT), alpha angle, and maximum clot firmness (MCF) were analyzed to determine coagulability. Plasma was added to the fresh pRBCs and 15-day old pRBCs to determine if the storage-associated coagulopathy was reversible with plasma. Statistical analyses were conducted with a Student's t-test.

RESULTS

Fifteen-day old pRBCs demonstrated a significant reduction in MCF (10.3 vs. 24.4 mm, P-value <0.001) and alpha angle (6.0 vs. 27.2 degrees, P-value <0.001) as well as significant prolongation of CFT and CT (1126.5 vs. 571.4 s, P-value <0.001) compared to fresh pRBCs. FFP addition to 15-day old and fresh pRBCs, demonstrated a significant reduction in MCF and persistent prolongation of CFT. This suggests that pRBCs lost coagulability as they aged and this deficit was not completely corrected by plasma administration.

CONCLUSIONS

Storage duration may be an important factor in coagulation potential of pRBCs. Transfusion with older pRBCs may contribute to coagulopathy in massively transfused patients.

Tranexamic Acid Use in Pediatric Hemorrhagic Shock From Farm-Related Trauma: A Case Report

This case describes the use of tranexamic acid as an adjunctive treatment in the management of a pediatric patient in hemorrhagic shock. The case also highlights other components of current best practices for hemorrhagic shock in children, including bleeding source control and prompt resuscitation with blood products. A 20-month old male suffered an agricultural accident with significant injury to the right upper extremity. This led to subsequent extremity hemorrhage and clinical evidence of hemorrhagic shock. As a result of interventions performed by emergency medical services as well as the helicopter emergency medical services team, including the application of a tourniquet, prehospital blood product administration, and tranexamic acid administration, the patient had hemodynamically stabilized by arrival at the level 1 pediatric trauma center and was neurologically intact when discharged from the hospital.

Use of Specialized Pro-Resolving Mediators to Alleviate Cold Platelet Storage Lesion

BACKGROUND

Cold-stored platelets are an attractive option for treatment of actively bleeding patients due to a reduced risk of septic complications and preserved hemostatic function compared to conventional room temperature-stored platelets. However, refrigeration causes increased platelet activation and aggregate formation. Specialized pro-resolving mediators (SPMs), cell signaling mediators biosynthesized from essential fatty acids, have been shown to modulate platelet function and activation. In this study, we sought to determine if SPMs could be used to inhibit cold-stored platelet activation.

METHODS

Platelets were collected from healthy donors (n = 4-7) and treated with SPMs (resolvin E1 [RvE1], maresin 1 [MaR1], and resolvin D2 [RvD2]) or vehicle (VEH; 0.1% EtOH). Platelets were stored without agitation in the cold and assayed on Days 0 and 7 of storage for platelet activation levels using flow cytometry, platelet count, aggregation response using impedance aggregometry, and nucleotide content using mass spectrometry.

RESULTS

Compared to VEH, SPM treatment inhibited GPIb shedding (all compounds), significantly reduced both PS exposure and activation of GPIIb/IIIa receptor (RvD2, MaR1), and preserved aggregation response to TRAP (RvD2, MaR1) after 7 days of storage. Similar to untreated cold-stored platelets, SPM-treated samples did not preserve platelet counts or block the release of P-Selectin. Nucleotide content was unaffected by SPM treatment in cold-stored platelets.

CONCLUSIONS

SPM treatment, particularly Mar1 and RvD2, led to reduced platelet activation and preserved platelet function after 7 days of storage in the cold. Future work is warranted to better elucidate the mechanism of action of SPMs on cold platelet function and activation.

A child in shock: carotid blowout syndrome

Paediatricians commonly encounter neck lumps during their routine clinical practice; vascular abnormalities, such as (pseudo)aneurysms, are a rare cause of these. Pseudoaneurysms of the carotid artery in children are usually the result of blunt or penetrating trauma, infection or vasculitis/connective tissue disorders. They can present with a variety of symptoms including neck pain, as a pulsatile neck mass or with compressive symptoms (for example, cranial nerve palsies or dyspnoea). Pseudoaneurysms carry a risk of rupture in which case they are fatal, unless immediate treatment is provided.We report a 17-month-old male child with idiopathic carotid artery blowout syndrome presenting with acute oropharyngeal haemorrhage leading to asystolic cardiac arrest. He was successfully resuscitated and emergency embolisation controlled the bleeding. Despite extensive left hemispheric infarct, he has survived.Carotid artery blowout syndrome needs to be recognised as a potential cause of major haemorrhage in childhood. The purpose of this case report is to remind readers of the differential diagnosis and work-up of a child presenting with a neck lump, to highlight important aspects of the acute management of major haemorrhage and massive blood transfusion in paediatrics, to describe the aetiology, presentation and management of carotid artery pseudoaneurysm in children and to discuss long term rehabilitation in patients with consequent neurological sequelae (including the need for input from multiple specialty teams).

Fresh frozen plasma-to-red blood cell ratio is an independent predictor of blood loss in patients with neuromuscular scoliosis undergoing posterior spinal fusion

PURPOSE

In major trauma with massive blood loss, higher fresh frozen plasma (FFP)-to-red blood cell (RBC) ratios have been associated with improved morbidity and mortality. Our population of patients with neuromuscular scoliosis undergoing posterior spinal fusion (PSF) often lose volumes of blood considered massive, that is, half a blood volume in 3 hours. In this retrospective cohort study, we examined the association of FFP ratio with blood loss in this elective surgical population.

METHODS

Patients with neuromuscular scoliosis undergoing PSF with unit rod fixation were identified from our anesthesia cases database. The patients were divided into two groups: the low FFP group received FFP-to-RBC≤0.5, and the high FFP group received FFP-to-RBC>0.5. After controlling for a false discovery rate in the univariate analysis, a logistic and linear regression was performed to understand the contribution of the significant factors associated with increased blood loss.

RESULTS

Risk estimation showed that patients in the low FFP group were more likely to lose >120% blood volume (odds ratio, 3.87; 95% confidence interval, 2.03-7.38). Linear regression revealed that each unit of increase in FFP-to-RBC ratio was associated with a 27.5% (95% confidence interval, -43.12-11.89) mean reduction in blood volume loss.

CONCLUSIONS

In our retrospective study, we found that FFP-to-RBC ratio was significant independent predictor of blood loss in this group of complex spine patients undergoing PSF. Thus, in patients with neuromuscular scoliosis undergoing posterior spine fusion, use of higher ratio of FFP to RBC may decrease blood loss.

Prediction of perioperative transfusions using an artificial neural network

BACKGROUND

Accurate prediction of operative transfusions is essential for resource allocation and identifying patients at risk of postoperative adverse events. This research examines the efficacy of using artificial neural networks (ANNs) to predict transfusions for all inpatient operations.

METHODS

Over 1.6 million surgical cases over a two year period from the NSQIP-PUF database are used. Data from 2014 (750937 records) are used for model development and data from 2015 (885502 records) are used for model validation. ANN and regression models are developed to predict perioperative transfusions for surgical patients.

RESULTS

Various ANN models and logistic regression, using four variable sets, are compared. The best performing ANN models with respect to both sensitivity and area under the receiver operator characteristic curve outperformed all of the regression models (p < .001) and achieved a performance of 70-80% specificity with a corresponding 75-62% sensitivity.

CONCLUSION

ANNs can predict >75% of the patients who will require transfusion and 70% of those who will not. Increasing specificity to 80% still enables a sensitivity of almost 67%. The unique contribution of this research is the utilization of a single ANN model to predict transfusions across a broad range of surgical procedures.

Tranexamic Acid for Acute Hemorrhage: A Narrative Review of Landmark Studies and a Critical Reappraisal of Its Use Over the Last Decade

The publication of the Clinical Randomization of an Antifibrinolytic in Significant Hemorrhage-2 (CRASH-2) study and its intense dissemination prompted a renaissance for the use of the antifibrinolytic agent tranexamic acid (TXA) in acute trauma hemorrhage. Subsequent studies led to its widespread use as a therapeutic as well as prophylactic agent across different clinical scenarios involving bleeding, such as trauma, postpartum, and orthopedic surgery. However, results from the existing studies are confounded by methodological and statistical ambiguities and are open to varied interpretations. Substantial knowledge gaps remain on dosing, pharmacokinetics, mechanism of action, and clinical applications for TXA. The risk for potential thromboembolic complications with the use of TXA must be balanced against its clinical benefits. The present article aims to provide a critical reappraisal of TXA use over the last decade and a "thought exercise" in the potential downsides of TXA. A more selective and individualized use of TXA, guided by extended and functional coagulation assays, is advocated in the context of the evolving concept of precision medicine.

The association between the initial lactate level and need for massive transfusion in severe trauma patients with and without traumatic brain injury

Background

Exsanguination is a major cause of death in severe trauma patients. The purpose of this study was to analyze the prognostic impact of the initial lactate level for massive transfusion (MT) in severe trauma. We divided patients according to subgroups of traumatic brain injury (TBI) and non-TBI.

Methods

This single-institution retrospective study was conducted on patients who were admitted to hospital for severe trauma between January 2016 and December 2017. TBI was defined by a head Abbreviated Injury Scale ≥3. Receiver operating characteristic analysis was used to analyze the prognostic impact of the lactate level. Multivariate analyses were performed to evaluate the relationship between the MT and lactate level. The primary outcome was MT.

Results

Of the 553 patients, MT was performed in 62 patients (11.2%). The area under the curve (AUC) for the lactate level for predicting MT was 0.779 (95% confidence interval [CI], 0.742 to 0.813). The AUCs for lactate level in the TBI and non-TBI patients were 0.690 (95% CI, 0.627 to 0.747) and 0.842 (95% CI, 0.796 to 0.881), respectively. In multivariate analyses, the lactate level was independently associated with the MT (odds ratio [OR], 1.179; 95% CI, 1.070 to 1.299). The lactate level was independently associated with MT in non-TBI patients (OR, 1.469; 95% CI, 1.262 to 1.710), but not in TBI patients.

Conclusions

The initial lactate level may be a possible prognostic factor for MT in severe trauma. In TBI patients, however, the initial lactate level was not suitable for predicting MT.

Evaluation of prolonged 'Permissive Hypotension': results from a 6-hour hemorrhage protocol in swine

Background

Tactical Combat Casualty Care guidelines for hemorrhage recommend resuscitation to systolic blood pressure (SBP) of 85±5 mm Hg during prehospital care. Success depends on transport to definitive care within the ‘golden hour’. As future conflicts may demand longer prehospital/transport times, we sought to determine safety of prolonged permissive hypotension (PH).

Methods

Adult male swine were randomized into three experimental groups. Non-shock (NS)/normotensive underwent anesthesia only. NS/PH was bled to SBP of 85±5 mm Hg for 6 hours of prolonged field care (PFC) with SBP maintained via crystalloid, then recovered. Experimental group underwent controlled hemorrhage to mean arterial pressure 30 mm Hg until decompensation (Decomp/PH), followed by 6 hours of PFC. Hemorrhaged animals were then resuscitated with whole blood and observed for 24 hours. Physiologic variables, blood, tissue samples, and neurologic scores were collected.

Results

Survival of all groups was 100%. Fluid volumes to maintain targeted SBP in PFC were significantly higher in the hemorrhage group than sham groups. After 24 hours’ recovery, no significant differences were observed in neurologic scores or cerebrospinal fluid markers of brain injury. No significant changes in organ function related to treatment were observed during PFC through recovery, as assessed by serum chemistry and histological analysis.

Conclusions

After 6 hours, a prolonged PH strategy showed no detrimental effect on survival or neurologic outcome despite the increased ischemic burden of hemorrhage. Significant fluid volume was required to maintain SBP—a potential logistic burden for prehospital care. Further work to define maximum allowable time of PH is needed.

Study type

Translational animal model.

Level of evidence

N/A.

Fresh Low Titer O Whole Blood Transfusion in the Austere Medical Environment

Massive hemorrhage is an immediate threat to life. The military developed the Tactical Combat Casualty Care guidelines to address the management of acute trauma, including administration of blood products. The guidelines have been expanded to include low titer O whole blood, which is in limited use by the military. This proposal describes how the transfusion of fresh whole blood might be applied to the remote civilian environment. In doing so, this life-saving intervention may be brought to the austere medical environment, allowing critically hemorrhaging patients to survive to reach definitive medical care.