Blood component transfusion increases the risk of death in children with traumatic brain injury

Need for Blood Transfusion Volume Is Associated With Increased Mortality in Severe Traumatic Brain Injury

INTRODUCTION

Many patients suffering from isolated severe traumatic brain injury (sTBI) receive blood transfusion on hospital arrival due to hypotension. We hypothesized that increasing blood transfusions in isolated sTBI patients would be associated with an increase in mortality.

METHODS

We performed a trauma quality improvement program (TQIP) (2017-2019) and single-center (2013-2021) database review filtering for patients with isolated sTBI (Abbreviated Injury Scale head ≥3 and all other areas ≤2). Age, initial Glasgow Coma Score (GCS), Injury Severity Score (ISS), initial systolic blood pressure (SBP), mechanism (blunt/penetrating), packed red blood cells (pRBCs) and fresh frozen plasma (FFP) transfusion volume (units) within the first 4 h, FFP/pRBC ratio (4h), and in-hospital mortality were obtained from the TQIP Public User Files.

RESULTS

In the TQIP database, 9257 patients had isolated sTBI and received pRBC transfusion within the first 4 h. The mortality rate within this group was 47.3%. The increase in mortality associated with the first unit of pRBCs was 20%, then increasing approximately 4% per unit transfused to a maximum mortality of 74% for 11 or more units. When adjusted for age, initial GCS, ISS, initial SBP, and mechanism, pRBC volume (1.09 [1.08-1.10], FFP volume (1.08 [1.07-1.09]), and FFP/pRBC ratio (1.18 [1.08-1.28]) were associated with in-hospital mortality. Our single-center study yielded 138 patients with isolated sTBI who received pRBC transfusion. These patients experienced a 60.1% in-hospital mortality rate. Logistic regression corrected for age, initial GCS, ISS, initial SBP, and mechanism demonstrated no significant association between pRBC transfusion volume (1.14 [0.81-1.61]), FFP transfusion volume (1.29 [0.91-1.82]), or FFP/pRBC ratio (6.42 [0.25-164.89]) and in-hospital mortality.

CONCLUSIONS

Patients suffering from isolated sTBI have a higher rate of mortality with increasing amount of pRBC or FFP transfusion within the first 4 h of arrival.

Blood Transfusion is Associated With Adverse Outcomes in Pediatric Solid Tumor Oncology Patients Following Tumor Resection

BACKGROUND

Packed red blood cell (PRBC) transfusion is a lifesaving intervention that also has proinflammatory and immunosuppressive effects. Adults with a malignancy who receive PRBC transfusion have increased rates of infection, tumor recurrence, and decreased survival. The effect of PRBC transfusion among children with solid tumors is unknown.

METHODS

We performed a retrospective review of all children who underwent operative resection of a solid tumor malignancy. Data collected included demographic information, location of operation, nadir hemoglobin, and any PRBC transfusion within 30 days of tumor resection.

RESULTS

Three hundred sixty children underwent tumor resection at our institution between 2002 and 2013; 194 (54%) received a perioperative blood transfusion. After adjusting for stage at diagnosis, tumor location, preoperative chemotherapy and nadir hemoglobin, blood transfusion was associated with a higher rate of postoperative infectious complications, shorter disease-free interval, and a higher rate of tumor recurrence. Each additional transfused unit increased the risk of postoperative infection (odds ratio 3.83; 95% confidence interval 1.21, 14.22, P =0.031).

CONCLUSIONS

Among children with solid tumor malignancies, PRBC transfusion within 30 days of operation is associated with higher rates of postoperative infection. If transfusion becomes necessary, single unit increments should be transfused.

LEVEL OF EVIDENCE

Level III.

Pediatric traumatic hemorrhagic shock consensus conference research priorities

BACKGROUND

Traumatic injury is the leading cause of death in children and adolescents. Hemorrhagic shock remains a common and preventable cause of death in the pediatric trauma patients. A paucity of high-quality evidence is available to guide specific aspects of hemorrhage control in this population. We sought to identify high-priority research topics for the care of pediatric trauma patients in hemorrhagic shock.

METHODS

A panel of 16 consensus multidisciplinary committee members from the Pediatric Traumatic Hemorrhagic Shock Consensus Conference developed research priorities for addressing knowledge gaps in the care of injured children and adolescents in hemorrhagic shock. These ideas were informed by a systematic review of topics in this area and a discussion of these areas in the consensus conference. Research priorities were synthesized along themes and prioritized by anonymous voting.

RESULTS

Eleven research priorities that warrant additional investigation were identified by the consensus committee. Areas of proposed study included well-designed clinical trials and evaluations, including increasing the speed and accuracy of identifying and treating hemorrhagic shock, defining the role of whole blood and tranexamic acid use, and assessment of the utility and appropriate use of viscoelastic techniques during early resuscitation. The committee recommended the need to standardize essential definitions, data elements, and data collection to facilitate research in this area.

CONCLUSION

Research gaps remain in many areas related to the care of hemorrhagic shock after pediatric injury. Addressing these gaps is needed to develop improved evidence-based recommendations for the care of pediatric trauma patients in hemorrhagic shock.

The need for blood transfusion therapy is associated with increased mortality in children with traumatic brain injury

OBJECTIVE

Blood transfusion therapy (BTT) is widely used in trauma patients. However, the adverse effects of BTT in pediatric trauma patients with traumatic brain injury (TBI) were poorly studied. The objective of this study is to evaluate the effect of BTT on mortality in children with severe TBI.

METHODS

In this retrospective cohort analysis, we analyzed 2012 and 2016 Kids' Inpatient Databases and used a weighted sample to obtain national outcome estimates. We included children aged 1 month to 21 years with TBI who were mechanically ventilated, considered severe TBI; we then compared the demographics, comorbidities, and mortality rates of those patients who had undergone BTT to those who did not. Statistical analysis was performed using the chi-squared test and regression models. In addition, in a correlative propensity score matched analysis, cases (BTT) were matched 1:1 with controls (non-BTT) based on age, gender, hospital region, income quartiles, race, and All Patients Refined Diagnosis Related Groups (APRDRG) severity of illness scores to minimize the effect of confounding variables between the groups.

RESULTS

Out of 87,980 children with a diagnosis of TBI, 17,199 (19.5%) with severe TBI were included in the analysis. BTT was documented in 3184 (18.5%) children. Among BTT group, the mortality was higher compared to non-BTT group [31.6% (29.7-33.5%) vs. 14.4 (13.7-15.1%), (OR 2.2, 95% CI 1.9-2.6; p<0.05)]. In the BTT group, infants and adolescents, white race, APRDRG severity of illness, cardiac arrest, platelet, and coagulation factor transfusions were associated with higher mortality. In a propensity-matched analysis, BTT associated with a higher risk of mortality (32.1% [30.1-34.2] vs. 17.4% [15.8-19.1], p<0.05; OR: 2.2, 95% CI: 1.9-2.6).

CONCLUSION

In children with severe TBI, blood transfusion therapy is associated with higher mortality.

Predictors of In-Hospital Mortality for Road Traffic Accident-Related Severe Traumatic Brain Injury

(1) Background: Road traffic accidents (RTAs) are the leading cause of pediatric traumatic brain injury (TBI) and are associated with high mortality. Few studies have focused on RTA-related pediatric TBI. We conducted this study to analyze the clinical characteristics of RTA-related TBI in children and to identify early predictors of in-hospital mortality in children with severe TBI. (2) Methods: In this 15-year observational cohort study, a total of 618 children with RTA-related TBI were enrolled. We collected the patients' clinical characteristics at the initial presentations in the emergency department (ED), including gender, age, types of road user, the motor components of the Glasgow Coma Scale (mGCS) score, body temperature, blood pressure, blood glucose level, initial prothrombin time, and the intracranial computed tomography (CT) Rotterdam score, as potential mortality predictors. (3) Results: Compared with children exhibiting mild/moderate RTA-related TBI, those with severe RTA-related TBI were older and had a higher mortality rate (p < 0.001). The in-hospital mortality rate for severe RTA-related TBI children was 15.6%. Compared to children who survived, those who died in hospital had a higher incidence of presenting with hypothermia (p = 0.011), a lower mGCS score (p < 0.001), a longer initial prothrombin time (p < 0.013), hyperglycemia (p = 0.017), and a higher Rotterdam CT score (p < 0.001). Multivariate analyses showed that the mGCS score (adjusted odds ratio (OR): 2.00, 95% CI: 1.28-3.14, p = 0.002) and the Rotterdam CT score (adjusted OR: 2.58, 95% CI: 1.31-5.06, p = 0.006) were independent predictors of in-hospital mortality. (4) Conclusions: Children with RTA-related severe TBI had a high mortality rate. Patients who initially presented with hypothermia, a lower mGCS score, a prolonged prothrombin time, hyperglycemia, and a higher Rotterdam CT score in brain CT analyses were associated with in-hospital mortality. The mGCS and the Rotterdam CT scores were predictive of in-hospital mortality independently.

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.

Evaluating abusive head trauma in children <5 years old: Risk factors and the importance of the social history

BACKGROUND

Abusive head trauma (AHT) is the leading cause traumatic death in children ≤5 years of age. AHT remains seriously under-surveilled, increasing the risk of subsequent injury and death. This study assesses the clinical and social risks associated with fatal and non-fatal AHT.

METHODS

A single-institution, retrospective review of suspected AHT patients ≤5 years of age between 2010 and 2016 using a prospective hospital forensic registry data yielded demographic, clinical, family, psycho-social and other follow-up information. Descriptive statistics were used to look for differences between patients with AHT and accidental head trauma. Logistic regression estimated the adjusted odds ratios (AOR) for AHT. A receiver operating characteristic (ROC) curve was created to calculate model sensitivity and specificity.

RESULTS

Forensic evaluations of 783 children age ≤5 years with head trauma met the inclusion criteria; 25 were fatal with median[IQR] age 23[4.5-39.0] months. Of 758 non-fatal patients, age was 7[3.0-11.0] months; 59.5% male; 435 patients (57.4%) presented with a skull fracture, 403 (53.2%) with intracranial hemorrhage. Ultimately 242 (31.9%) were adjudicated AHT, 335(44.2%) were accidental, 181 (23.9%) were undetermined. Clinical factors increasing the risk of AHT included multiple fractures (Exp(β) = 9.9[p = 0.001]), bruising (Expβ = 5.7[p < 0.001]), subdural blood (Exp(β) = 5.3[p = 0.001]), seizures (Exp(β) = 4.9[p = 0.02]), lethargy/unresponsiveness (Exp(β) = 2.24[p = 0.02]), loss of consciousness (Exp(β) = 4.69[p = 0.001]), and unknown mechanism of injury (Exp(β) = 3.9[p = 0.001]); skull fracture reduced the risk of AHT by half (Exp(β) = 0.5[p = 0.011]). Social risks factors included prior police involvement (Exp(β) = 5.9[p = 0.001]), substance abuse (Exp(β) = 5.7[p = .001]), unknown number of adults in the home (Exp(β) = 4.1[p = 0.001]) and intimate partner violence (Exp(β) = 2.3[p = 0.02]). ROC area under the curve (AUC) = 0.90([95% CI = 0.86-0.93] p = .001) provides 73% sensitivity; 91% specificity.

CONCLUSIONS

To improve surveillance of AHT, interviews should include and consider social factors including caregiver/household substance abuse, intimate partner violence, prior police involvement and household size. An unknown number of adults in home is associated with an increased risk of AHT.

STUDY TYPE/LEVEL OF EVIDENCE

Prognostic, Level III.

Predictors of In-Hospital Mortality for School-Aged Children with Severe Traumatic Brain Injury

Traumatic brain injury (TBI) is the leading cause of mortality in children. There are few studies focused on school-aged children with TBI. We conducted this study to identify the early predictors of in-hospital mortality in school-aged children with severe TBI. In this 10 year observational cohort study, a total of 550 children aged 7-18 years with TBI were enrolled. Compared with mild/moderate TBI, children with severe TBI were older; more commonly had injury mechanisms of traffic accidents; and more neuroimage findings of subarachnoid hemorrhage (SAH), subdural hemorrhage (SDH), parenchymal hemorrhage, cerebral edema, and less epidural hemorrhage (EDH). The in-hospital mortality rate of children with severe TBI in our study was 23%. Multivariate analysis showed that falls, being struck by objects, motor component of Glasgow coma scale (mGCS), early coagulopathy, and SAH were independent predictors of in-hospital mortality. We concluded that school-aged children with severe TBI had a high mortality rate. Clinical characteristics including injury mechanisms of falls and being struck, a lower initial mGCS, early coagulopathy, and SAH are predictive of in-hospital mortality.

Infections after a traumatic brain injury: The complex interplay between the immune and neurological systems

Traumatic brain injury (TBI) is a serious global health issue, being the leading cause of death and disability for individuals under the age of 45, and one of the largest causes of global neurological disability. In addition to the brain injury itself, it is increasingly appreciated that a TBI may also alter the systemic immune response in a way that renders TBI patients more vulnerable to infections in the acute post-injury period. Such infections pose an additional challenge to the patient, increasing rates of mortality and morbidity, and worsening neurological outcomes. Hospitalization, surgical interventions, and a state of immunosuppression induced by injury to the central nervous system (CNS), may all contribute to the high rate of infections seen in the population with TBI. Ongoing research to better understand the immunomodulators that underlie TBI-induced immunosuppression may aid in the development of effective therapeutic strategies to improve the recovery trajectory for patients. This review first describes the clinical scenario, posing the question of whether TBI patients are more susceptible to infections such as pneumonia, and if so, why? We then consider how cross-talk between the injured brain and the systemic immune system occurs, and further, how the additional immune challenge of an acquired infection can contribute to ongoing neuroinflammation and neurodegeneration after a TBI. Experimental models combining TBI with infection are discussed, as well as current treatment options available for this double-barreled insult. The aims of this review are to summarize current understanding of the bidirectional relationship between the CNS and the immune system when faced with a mechanical trauma combined with a concomitant infection, and to highlight key outstanding questions that remain in the field.

Transfusion practices in traumatic brain injury

Purpose of review

The aim of this review is to summarize the recent studies looking at the effects of anemia and red blood cell transfusion in critically-ill patients with traumatic brain injury (TBI), describe the transfusion practice variations observed worldwide, and outline the ongoing trials evaluating restrictive versus liberal transfusion strategies for TBI.

Recent findings

Anemia is common among critically-ill patients with TBI, it is also thought to exacerbate secondary brain injury, and is associated with an increased risk of poor outcome. Conversely, allogenic red blood cell transfusion carries its own risks and complications, and has been associated with worse outcomes. Globally, there are large reported differences in the hemoglobin threshold used for transfusion after TBI. Observational studies have shown differential results for improvements in cerebral oxygenation and metabolism after red blood cell transfusion in TBI.

Summary

Currently, there is insufficient evidence to make strong recommendations regarding which hemoglobin threshold to use as a transfusion trigger in critically-ill patients with TBI. There is also uncertainty whether the restrictive transfusion strategy used in general critical care can be extrapolated to acutely brain injured patients. Ultimately, the consequences of anemia-induced cerebral injury need to be weighed up against the risks and complications associated with red blood cell transfusion.

Recommendations on RBC Transfusion in General Critically Ill Children Based on Hemoglobin and/or Physiologic Thresholds From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the consensus recommendations and supporting literature for RBC transfusions in general critically ill children from the Pediatric Critical Care Transfusion and Anemia Expertise Initiative.

DESIGN

Consensus conference series of international, multidisciplinary experts in RBC transfusion management of critically ill children.

METHODS

The panel of 38 experts developed evidence-based and, when evidence was lacking, expert-based recommendations and research priorities regarding RBC transfusions in critically ill children. The subgroup on RBC transfusion in general critically ill children included six experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 30, 2017, using a combination of keywords to define concepts of RBC transfusion and critically ill children. Recommendation consensus was obtained using the Research and Development/UCLA Appropriateness Method. The results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method.

RESULTS

Three adjudicators reviewed 4,399 abstracts; 71 papers were read, and 17 were retained. Three papers were added manually. The general Transfusion and Anemia Expertise Initiative subgroup developed, and all Transfusion and Anemia Expertise Initiative members voted on two good practice statements, six recommendations, and 11 research questions; in all instances, agreement was reached (> 80%). The good practice statements suggest a framework for RBC transfusion in PICU patients. The good practice statements and recommendations focus on hemoglobin as a threshold and/or target. The research questions focus on hemoglobin and physiologic thresholds for RBC transfusion, alternatives, and risk/benefit ratio of transfusion.

CONCLUSIONS

Transfusion and Anemia Expertise Initiative developed pediatric-specific good practice statements and recommendations regarding RBC transfusion management in the general PICU population, as well as recommendations to guide future research priorities. Clinical recommendations emphasized relevant hemoglobin thresholds, and research recommendations emphasized a need for further understanding of physiologic thresholds, alternatives to RBC transfusion, and hemoglobin thresholds in populations with limited pediatric literature.

Iron-mediated oxidative cell death is a potential contributor to neuronal dysfunction induced by neonatal hemolytic hyperbilirubinemia

The review article discusses current knowledge of iron-mediated oxidative cell death (ferroptosis) and its potential role in the pathogenesis of neuronal dysfunction induced by neonatal hemolytic hyperbilirubinemia. The connection between metabolic conditions related to hemolysis (iron and bilirubin overload) and iron-induced lipid peroxidation is highlighted. Neurotoxicity of iron and bilirubin is associated with their release from destructed erythrocytes in response to hemolytic disease. Iron overload initiates lipid peroxidation through the reactive oxygen species production resulting to oxidative damage to cells. Excessive loading of immature brain cells by iron-induced formation of reactive oxygen species contributes to the development of various neurodevelopmental disorders. The causal relationship between iron overload and susceptibility of brain cells to oxidative damage by ferroptosis appears to be associated not only with the amount of redox-active iron involved in oxidative cell damage but also with the degree of maturity of the neonatal brain. Neuronal dysfunction induced by neonatal hemolytic disease can represent a specific model of ferroptosis. The mechanism by which iron overload triggers ferroptosis is not completely explained. However, hemolysis of neonatal red blood cells appears to be a determining factor. Potential therapeutic strategy with iron-chelating agents to inhibit ferroptosis has a promising future in postnatal care.

Anatomical and Physiological Differences between Children and Adults Relevant to Traumatic Brain Injury and the Implications for Clinical Assessment and Care

General and central nervous system anatomy and physiology in children is different to that of adults and this is relevant to traumatic brain injury (TBI) and spinal cord injury. The controversies and uncertainties in adult neurotrauma are magnified by these differences, the lack of normative data for children, the scarcity of pediatric studies, and inappropriate generalization from adult studies. Cerebral metabolism develops rapidly in the early years, driven by cortical development, synaptogenesis, and rapid myelination, followed by equally dramatic changes in baseline and stimulated cerebral blood flow. Therefore, adult values for cerebral hemodynamics do not apply to children, and children cannot be easily approached as a homogenous group, especially given the marked changes between birth and age 8. Their cranial and spinal anatomy undergoes many changes, from the presence and disappearance of the fontanels, the presence and closure of cranial sutures, the thickness and pliability of the cranium, anatomy of the vertebra, and the maturity of the cervical ligaments and muscles. Moreover, their systemic anatomy changes over time. The head is relatively large in young children, the airway is easily compromised, the chest is poorly protected, the abdominal organs are large. Physiology changes—blood volume is small by comparison, hypothermia develops easily, intracranial pressure (ICP) is lower, and blood pressure normograms are considerably different at different ages, with potentially important implications for cerebral perfusion pressure (CPP) thresholds. Mechanisms and pathologies also differ—diffuse injuries are common in accidental injury, and growing fractures, non-accidental injury and spinal cord injury without radiographic abnormality are unique to the pediatric population. Despite these clear differences and the vulnerability of children, the amount of pediatric-specific data in TBI is surprisingly weak. There are no robust guidelines for even basics aspects of care in children, such as ICP and CPP management. This is particularly alarming given that TBI is a leading cause of death in children. To address this, there is an urgent need for pediatric-specific clinical research. If this goal is to be achieved, any clinician or researcher interested in pediatric neurotrauma must be familiar with its unique pathophysiological characteristics.

Targeted treatment in severe traumatic brain injury in the age of precision medicine

In recent years, much progress has been made in our understanding of traumatic brain injury (TBI). Clinical outcomes have progressively improved, but evidence-based guidelines for how we manage patients remain surprisingly weak. The problem is that the many interventions and strategies that have been investigated in randomized controlled trials have all disappointed. These include many concepts that had become standard care in TBI. And that is just for adult TBI; in children, the situation is even worse. Not only is pediatric care more difficult than adult care because physiological norms change with age, but also there is less evidence for clinical practice. In this article, we discuss the heterogeneity inherent in TBI and why so many clinical trials have failed. We submit that a key goal for the future is to appreciate important clinical differences between patients in their pathophysiology and their responses to treatment. The challenge that faces us is how to rationally apply therapies based on the specific needs of an individual patient. In doing so, we may be able to apply the principles of precision medicine approaches to the patients we treat.

Comparison of the impact of applications of Targeted Transfusion Protocol and Massive Transfusion Protocol in trauma patients

Background

The current study assessed a recently developed resuscitation protocol for bleeding trauma patients called the Targeted Transfusion Protocol (TTP) and compared its results with those of the standard Massive Transfusion Protocol (MTP).

Methods

Per capita utilization of blood products such as packed red blood cells (RBCs), fresh frozen plasma (FFP), and platelet concentrates was compared along with mortality rates during two 6-month periods, one in 2011 (when the standard MTP was followed) and another in 2014 (when the TTP was used). In the TTP, patients were categorized into three groups based on the presence of head injuries, long bone fractures, or penetrating injuries involving the trunk, extremities, or neck who were resuscitated according to separate algorithms. All cases had experienced motor vehicle accidents and had injury severity scores over 16.

Results

No statistically significant differences were observed between the study groups at hospital admission. Per capita utilization of RBC (4.76 ± 0.92 vs. 3.37 ± 0.55; P = 0.037), FFP (3.71 ± 1.00 vs. 2.40 ± 0.52; P = 0.025), and platelet concentrate (1.18 ± 0.30 vs. 0.55 ± 0.18; P = 0.006) blood products were significantly lower in the TTP epoch. Mortality rates were similar between the two study periods (P = 0.74).

Conclusions

Introduction of the TTP reduced the requirements for RBCs, FFP, and platelet concentrates in severely injured trauma patients.

Blood transfusion indications in neurosurgical patients: A systematic review

Neurosurgical procedures can be complicated by significant blood losses that have the potential to decrease tissue perfusion to critical brain tissue. Red blood cell transfusion is used in a variety of capacities both inside, and outside, of the operating room to prevent untoward neurologic damage. However, evidence-based guidelines concerning thresholds and indications for transfusion in neurosurgery remain limited. Consequently, transfusion practices in neurosurgical patients are highly variable and based on institutional experiences. Recently, a paradigm shift has occurred in neurocritical intensive care units, whereby restrictive transfusion is increasingly favored over liberal transfusion but the ideal strategy remains in clinical equipoise. The authors of this study perform a systematic review of the literature with the objective of capturing the changing landscape of blood transfusion indications in neurosurgical patients.

The effects of anaemia and transfusion on patients with traumatic brain injury: A review

BACKGROUND

Anaemia in traumatic brain injury (TBI) is frequently encountered. Neurosurgical texts continue to recommend transfusion for hematocrit below 30%, despite clear evidence to do so. Transfusion should increase oxygen delivery to the brain, but it may also increase morbidity and mortality.

METHODS

This study reviewed the relevant literature to better understand the risks of anaemia and benefits of correction of anaemia by transfusion.

RESULTS

Of the 21 studies reviewed, eight found that anaemia was harmful to patients with TBI; five found no significant outcome; seven found transfusion was associated with higher rates of morbidity and mortality; two found that transfusion lowered mortality and increased brain tissue oxygen levels; and ten found no correlation between transfusion and outcome. However, the levels of anaemia severity and the outcome measurements varied widely and the majority of outcomes focused on crude measurements rather than detailed functional assessments.

CONCLUSIONS

No division of response based on gender difference or impact of anaemia in the post-hospital treatment setting was observed. A randomized control trial is recommended to determine the impact of anaemia and transfusion on detailed outcome assessment in comparison of transfusion thresholds ranging from ≤ 7 g dL^-1 to ≤ 9 g dL^-1 in patients with moderate-to-severe TBI.

A pediatric specific shock index in combination with GMS identifies children with life threatening or severe traumatic brain injury

PURPOSE

We have previously demonstrated that a shock index, pediatric age adjusted (SIPA) accurately identifies severely blunt injured children. We aimed to determine if SIPA could more accurately identify children with severe traumatic brain injury (TBI) than hypotension alone.

METHODS

We performed subset analysis of those children with TBI among a cohort of children age 4-16 years with blunt trauma and injury severity score ≥15 from 1/07 to 6/13. We evaluated the ability of four markers to identify the most severely brain injured children. Markers included hypotension, elevated SIPA, abnormal GCS motor score (GMS), and elevated SIPA or abnormal GMS. We aimed to determine which of these four markers had the highest sensitivity in identifying severely injured children.

RESULTS

Three hundred and ninety-two (392) children were included. Hypotension was present in 24 patients (6%); elevated SIPA in 106 (27 %), abnormal GMS in 172 (44%), and elevated SIPA or abnormal GMS in 206 (53%). All markers were able to accurately identify severely injured children with TBI. Elevated SIPA or abnormal GMS identified a greater percentage of patients with each of seven complications with higher sensitivity than each of the three other markers.

CONCLUSION

Among blunt injured children with TBI, elevated SIPA or abnormal GMS identifies severely brain injured children.

Red blood cell transfusion in neurosurgical patients

PURPOSE OF REVIEW

Anemia is common in neurosurgical patients, and is associated with secondary brain injury. Although recent studies in critically ill patients have shifted practice toward more restrictive red blood cell (RBC) transfusion strategies, the evidence for restrictive versus liberal transfusion strategies in neurosurgical patients has been controversial. In this article, we review recent studies that highlight issues in RBC transfusion in neurosurgical patients.

RECENT FINDINGS

Recent observational, retrospective studies in patients with traumatic brain injury, subarachnoid hemorrhage, and intracranial hemorrhage have demonstrated that prolonged anemia and RBC transfusions were associated with worsened outcomes. Anemia in patients with ischemic stroke was associated with increased ICU length of stay and longer mechanical ventilation requirements, but mortality and functional outcomes did not improve with RBC transfusion. In elective craniotomy, perioperative anemia was associated with increased hospital length of stay but no difference in 30-day morbidity or mortality.

SUMMARY

There is a lack of definitive evidence to guide RBC transfusion practices in neurosurgical patients. Large randomized control trials are needed to better assess when and how aggressively to transfuse RBCs in neurosurgical patients.

Injured children are resistant to the adverse effects of early high volume crystalloid resuscitation

INTRODUCTION

Excessive crystalloid resuscitation of blunt injured adults is deleterious. We hypothesize that children, unlike adults, are resistant to the adverse effects of high volume resuscitation.

METHODS

We reviewed the trauma databases at two level-one trauma centers, including all children age 4-16years admitted following blunt trauma with an injury severity score (ISS) ≥15 to determine the relationship between crystalloid volume received and clinical outcomes.

RESULTS

A total of 384 children were included. After controlling for age, sex, AIS head, ISS, GCS on presentation, hemoglobin, blood transfusion, and surgical procedures in the first 24hours, crystalloid volume greater than 60ml/kg in the first 24hours was associated with increased length of stay (LOS) and need for mechanical ventilation. On univariate analysis, initial crystalloid volume of >60ml/kg was associated with anemia and thrombocytopenia. Volume of resuscitation was not associated with ARDS, ACS, MOF, urinary tract infection, or blood stream infection. However, these complications were exceedingly rare, with no children developing MOF.

CONCLUSIONS

Excessive crystalloid resuscitation was associated with increased hospital LOS and need for mechanical ventilation. Increased rates of other complications including ARDS, ACS, and MOF were not observed. Injured children appear relatively resistant to some of the adverse effects of early high volume fluid resuscitation.

Red blood cell transfusion and immune function in critically ill children: a prospective observational study

BACKGROUND

Our previous in vitro work showed that stored red blood cells (RBCs) increasingly suppress markers of innate immune function with increased storage time. This multicenter prospective observational study tests the hypothesis that a single RBC transfusion in critically ill children is associated with immune suppression as a function of storage time.

STUDY DESIGN AND METHODS

Blood samples were taken immediately before and 24 (±6) hours after a single RBC transfusion ordered as part of routine care. Innate and adaptive immune function was assessed by ex vivo whole blood stimulation with lipopolysaccharide (LPS) and phytohemagglutinin, respectively. Monocyte HLA-DR expression, regulatory T cells, plasma interleukin (IL)-6, and IL-8 levels were also measured.

RESULTS

Thirty-one transfused critically ill children and eight healthy controls were studied. Critically ill subjects had lower pretransfusion LPS-induced tumor necrosis factor-α production capacity compared to healthy controls, indicating innate immune suppression (p < 0.0002). Those who received RBCs stored for not more than 21 days demonstrated recovery of innate immune function (p = 0.02) and decreased plasma IL-6 levels (p = 0.002) over time compared to children transfused with older blood, who showed persistence of systemic inflammation and innate immune suppression. RBC storage time was not associated with changes in adaptive immune function.

CONCLUSION

In this pilot cohort of critically ill children, transfusion with older prestorage leukoreduced RBCs was associated with persistence of innate immune suppression and systemic inflammation. This was not seen with fresher RBCs. RBC transfusion had no short-term association with adaptive immune function. Further studies are warranted to confirm these findings in a larger cohort of patients.