Guidelines for prehospital management of traumatic brain injury 2nd edition

Should We Keep or Transfer Our Severely Injured Geriatric Patients to Higher Levels of Care?

INTRODUCTION

Interfacility transfer to higher levels of care is becoming increasingly common. This study aims to evaluate the association between transfer to higher levels of care and prolonged transfer times with outcomes of severely injured geriatric trauma patients compared to those who are managed definitively at lower-level trauma centers.

METHODS

Severely injured (Injury Severity Score >15) geriatric (≥60 y) trauma patients in the 2017-2018 American College of Surgeons Trauma Quality Improvement Program database managing at an American College of Surgeons/State Level III trauma center or transferring to a level I or II trauma center were included. Outcome measures were 24-h and in-hospital mortality and major complications.

RESULTS

Forty thousand seven hundred nineteen patients were identified. Mean age was 75 ± 8 y, 54% were male, 98% had a blunt mechanism of injury, and the median Injury Severity Score was 17 [16-21]. Median transfer time was 112 [79-154] min, and the most common transport mode was ground ambulance (82.3%). Transfer to higher levels of care within 90 min was associated with lower 24-h mortality (adjusted odds ratio [aOR]: 0.493, P < 0.001) and similar odds of in-hospital mortality as those managed at level III centers. However, every 30-min delay in transfer time beyond 90 min was progressively associated with increased odds of 24-h (aOR: 1.058, P < 0.001) and in-hospital (aOR: 1.114, P < 0.001) mortality and major complications (aOR: 1.127, P < 0.001).

CONCLUSIONS

Every 30-min delay in interfacility transfer time beyond 90 min is associated with 6% and 11% higher risk-adjusted odds of 24-h and in-hospital mortality, respectively. Estimated interfacility transfer time should be considered while deciding about transferring severely injured geriatric trauma patients to a higher level of care.

Patients suffering traumatic brain injury: patient characteristics, prehospital triage, primary referral and mortality - A population-based follow-up study

BACKGROUND

Traumatic brain injury (TBI) is a potential high-risk condition, but appropriate care pathways, including prehospital triage and primary referral to a specialised neurosurgical centre, can improve neurological outcome and survival. The care pathway starts with layman triage, wherein the patient or bystander decides whether to contact a general practitioner (GP) or emergency services (1-1-2 call) as an entryway into the health care system. The GP or 112-health care professional then decides on the level of urgency and dispatches emergency medical services (EMS) when needed. Finally, a decision is made regarding referral of the TBI patient to a specialised neurotrauma centre or a local hospital. Recent studies have shown that injuries are generally more severe in patients entering the health care system through EMS (112-calls) than through GPs; however, no information exists on whether mortality and morbidity outcomes differ depending on the referral choice. The aim of this study was to examine triage pathways, including the method of entry into the health care system, as well as patient characteristics and place of primary referral, to determine the associated 30-day and 1-year mortality rates in TBI patients with confirmed intracranial lesions.

METHODS

This retrospective observational population-based follow-up study was conducted in the Central Denmark Region from 1 February 2017 to 31 January 2019. We included all adult patients who contacted hospitals and were ascribed a predefined TBI ICD-10 diagnosis code in the Danish National Patient Register. The obtained TBI cohort was merged with prehospital data from the Prehospital Emergency Medical Services, Central Denmark Region, and vital status from the Danish Civil Registration System. Binary logistic regression analysis of mortality was conducted. In all patients with TBI (including concussions), the primary outcome was primary referral to a specialised centre based on mode of entry ('GP/HCP', '112-call' or 'Unreferred') into the health care system. In the subgroup of patients with confirmed intracranial lesions, the secondary outcomes were the relative risk of death at day 30 and 1 year based on the place of primary referral.

RESULTS

Of 5,257 first TBI hospital contacts of adult patients included in the cohort, 1,430 (27.2%) entered the health care system via 1-1-2 emergency medical calls. TBI patients triaged by 112-calls were more likely to receive the highest level of emergency response (15.6% vs. 50.3%; p < 0.001) and second-tier resources and were more frequently referred directly to a specialised centre than were patients entering through GPs or other health care personnel. In the subgroup of 1188/5257 (22.4%) patients with confirmed intracranial lesions, we found no difference in the risk ratio of 30 day (RR 1.04 (95%CI 0.65-1.63)) or 1 year (RR 0.96 (95%CI 0.72-1.25)) all-cause mortality between patients primarily referred to a regional hospital or to a specialised centre when adjusting for age, sex, comorbidities, antiplatelet/anticoagulant treatment and type of intracranial lesions.

CONCLUSION

TBI patients mainly enter the health system by contact with GPs or other health care professionals. However, patients entering through 112-calls are more frequently triaged directly to specialised centres. We were unable to demonstrate any significant difference in the adjusted 30-day and 1-year mortality based on e primary referral to a specialised centre. The inability to demonstrate an effect on mortality based on primary referral to a specialised centre may reflect a lack of clinical data in the registries used. Considerable differences may exist in nondocumented baseline characteristics (i.e., GCS, blood pressure and injury severity) between the groups and may limit conclusions about differences in mortality. Further research providing high-quality evidence on the effect of primary referral is needed to secure early neurosurgical interventions in TBI patients.

Analysis of risk factors for acute kidney injury in children with severe wasp stings

BACKGROUND

Acute kidney injury (AKI) is common in children with sepsis, chronic kidney disease, poisoning or other conditions. Wasp stings are recognized as an important etiology. Several retrospective studies have investigated AKI after wasp stings in adults, but research on children remains limited.

METHODS

The study included 48 children with multiple organ dysfunction syndrome after wasp stings. Demographic data, clinical manifestations, laboratory findings, management and clinical outcomes were collected, and analyzed to identify early indicators or risk factors for AKI.

RESULTS

20 children (41.7%) developed AKI, and 28 (58.3%) did not. Serum creatine levels elevated mostly within 24 h from stings in children with AKI (16/20, 80%). Compared with non-AKI group, AKI group exhibited more cases with cola-colored urine, jaundice, and had higher sting numbers/body surface area (BSA) and higher revised sequential organ failure assessment scores (rSOFA) as well as higher levels of C-reactive protein (CRP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), lactate dehydrogenase (LDH), troponin (cTnI), creatine kinase (CK), and longer prothrombin time (PT). Both univariable and multivariable logistic regression analysis identified cola-colored urine as a potential early risk factor for AKI.

CONCLUSIONS

The AKI group exhibited higher sting numbers/BSA, higher levels of CRP, ALT, AST, TBIL, LDH, cTnI, and CK, as well as longer PT (p < 0.05). Our findings also suggest that cola-colored urine may serve as an early indicator or potential risk factor for AKI after wasp stings in children, which is very easy to identify for first aiders or pediatricians.

Correlation between early computed tomography findings and neurological outcome in pediatric traumatic brain injury patients

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality in children. Head computed tomography (CT) is frequently utilized for evaluating trauma-related characteristics, selecting treatment options, and monitoring complications in the early stages. This study assessed the relationship between cranial CT findings and early and late neurological outcomes in pediatric TBI patients admitted to the pediatric intensive care unit (PICU). The study included children aged 1 month to 18 years who were admitted to the PICU due to TBI between 2014 and 2020. Sociodemographic data, clinical characteristics, and cranial CT findings were analyzed. Patients were categorized based on their Glasgow Coma Scale (GCS) score. Of the 129 patients, 83 (64%) were male, and 46 (36%) were female, with a mean age of 6.8 years. Falls (n = 51, 39.5%) and in-vehicle traffic accidents (n = 35, 27.1%) were the most common trauma types observed. Normal brain imaging findings were found in 62.7% of the patients, while 37.3% exhibited intracranial pathology. Hemorrhage was the most frequent CT finding. Severe TBI (n = 26, p = 0.032) and mortality (n = 9, p = 0.017) were more prevalent in traffic accidents. The overall mortality rate in the study population was 10.1%. In children with TBI, cranial CT imaging serves as an essential initial method for patients with neurological manifestations. Particularly, a GCS score of ≤ 8, multiple hemorrhages, diffuse cerebral edema, and intraventricular bleeding are associated with sequelae and mortality.

EMS Treatment Guidelines in Major Traumatic Brain Injury With Positive Pressure Ventilation

Importance

The Excellence in Prehospital Injury Care (EPIC) study demonstrated improved survival in patients with severe traumatic brain injury (TBI) following implementation of the prehospital treatment guidelines. The impact of implementing these guidelines in the subgroup of patients who received positive pressure ventilation (PPV) is unknown.

Objective

To evaluate the association of implementation of prehospital TBI evidence-based guidelines with survival among patients with prehospital PPV.

Design, Setting, and Participants

The EPIC study was a multisystem, intention-to-treat study using a before/after controlled design. Evidence-based guidelines were implemented by emergency medical service agencies across Arizona. This subanalysis was planned a priori and included participants who received prehospital PPV. Outcomes were compared between the preimplementation and postimplementation cohorts using logistic regression, stratified by predetermined TBI severity categories (moderate, severe, or critical). Data were collected from January 2007 to June 2017, and data were analyzed from January to February 2023.

Exposure

Implementation of the evidence-based guidelines for the prehospital care of patient with TBI.

Main Outcomes and Measures

The primary outcome was survival to hospital discharge, and the secondary outcome was survival to admission.

Results

Among the 21 852 participants in the main study, 5022 received prehospital PPV (preimplementation, 3531 participants; postimplementation, 1491 participants). Of 5022 included participants, 3720 (74.1%) were male, and the median (IQR) age was 36 (22-54) years. Across all severities combined, survival to admission improved (adjusted odds ratio [aOR], 1.59; 95% CI, 1.28-1.97), while survival to discharge did not (aOR, 0.94; 95% CI, 0.78-1.13). Within the cohort with severe TBI but not in the moderate or critical subgroups, survival to hospital admission increased (aOR, 6.44; 95% CI, 2.39-22.00), as did survival to discharge (aOR, 3.52; 95% CI, 1.96-6.34).

Conclusions and Relevance

Among patients with severe TBI who received active airway interventions in the field, guideline implementation was independently associated with improved survival to hospital admission and discharge. This was true whether they received basic airway interventions or advanced airways. These findings support the current guideline recommendations for aggressive prevention/correction of hypoxia and hyperventilation in patients with severe TBI, regardless of which airway type is used.

Etomidate versus Ketamine as Prehospital Induction Agent in Patients with Suspected Severe Traumatic Brain Injury

BACKGROUND

Severe traumatic brain injury is a leading cause of morbidity and mortality among young people around the world. Prehospital care focuses on the prevention and treatment of secondary brain injury and commonly includes tracheal intubation after induction of general anesthesia. The choice of induction agent in this setting is controversial. This study therefore investigated the association between the chosen induction medication etomidate versus S(+)-ketamine and the 30-day mortality in patients with severe traumatic brain injury who received prehospital airway management in the Netherlands.

METHODS

This study is a retrospective analysis of the prospectively collected observational data of the Brain Injury: Prehospital Registry of Outcomes, Treatments and Epidemiology of Cerebral Trauma (BRAIN-PROTECT) cohort study. Patients with suspected severe traumatic brain injury who were transported to a participating trauma center and who received etomidate or S(+)-ketamine for prehospital induction of anesthesia for advanced airway management were included. Statistical analyses were performed with multivariable logistic regression and inverse probability of treatment weighting analysis.

RESULTS

In total, 1,457 patients were eligible for analysis. No significant association between the administered induction medication and 30-day mortality was observed in unadjusted analyses (32.9% mortality for etomidate versus 33.8% mortality for S(+)-ketamine; P = 0.716; odds ratio, 1.04; 95% CI, 0.83 to 1.32; P = 0.711), as well as after adjustment for potential confounders (odds ratio, 1.08; 95% CI, 0.67 to 1.73; P = 0.765; and risk difference 0.017; 95% CI, -0.051 to 0.084; P = 0.686). Likewise, in planned subgroup analyses for patients with confirmed traumatic brain injury and patients with isolated traumatic brain injury, no significant differences were found. Consistent results were found after multiple imputations of missing data.

CONCLUSIONS

The analysis found no evidence for an association between the use of etomidate or S(+)-ketamine as an anesthetic agent for intubation in patients with traumatic brain injury and mortality after 30 days in the prehospital setting, suggesting that the choice of induction agent may not influence the patient mortality rate in this population.

EDITOR’S PERSPECTIVE

Assessing the impact of pre-hospital airway management on severe traumatic Brain injury: A systematic review and Meta-analysis

OBJECTIVE

This study aimed to assess the impact of establishing a pre-hospital definitive airway on mortality and morbidity compared with no prehospital airway in cases of severe traumatic brain injury (TBI).

BACKGROUND

Traumatic brain injury (TBI) is a global health concern that is associated with substantial morbidity and mortality. Prehospital intubation (PHI) has been proposed as a potential life-saving intervention for patients with severe TBI to mitigate secondary insults, such as hypoxemia and hypercapnia. However, their impact on patient outcomes remains controversial.

METHODS

A systematic review and meta-analysis were conducted to assess the effects of prehospital intubation versus no prehospital intubation on morbidity and mortality in patients with severe TBI, adhering to the PRISMA guidelines.

RESULTS

24 studies, comprising 56,543 patients, indicated no significant difference in mortality between pre-hospital and In-hospital Intubation (OR 0.89, 95% CI 0.65-1.23, p = 0.48), although substantial heterogeneity was noted. Morbidity analysis also showed no significant difference (OR 0.83, 95% CI 0.43-1.63, p = 0.59). These findings underscore the need for cautious interpretation due to heterogeneity and the influence of specific studies on the results.

CONCLUSION

In summary, an initial assessment did not reveal any apparent disparity in mortality rates between individuals who received prehospital intubation and those who did not. However, subsequent analyses and randomized controlled trials (RCTs) demonstrated that patients who underwent prehospital intubation had a reduced risk of death and morbidity. The dependence on biased observational studies and the need for further replicated RCTs to validate these findings are evident. Despite the intricacy of the matter, it is crucial to intervene during severe airway impairment.

Racial and ethnic differences in the association between mild traumatic brain injury and work duty limitations in the US military

OBJECTIVE

This study examined racial and ethnic differences in the association between mild traumatic brain injury (mTBI) and work duty limitations in active-duty service members (ADSMs).

METHODS

This study used retrospective and cross-sectional data from the 2019-2021 Military Health System Data Repository on 910,700 ADSMs who were 18-64 years old and were grouped into racial and ethnic categories of White, non-Hispanic; Black, non-Hispanic; Hispanic/Latino; and Asian or Pacific Islander, non-Hispanic.

RESULTS

Descriptive statistics showed that Black, Hispanic/Latino, and Asian or Pacific Islander patients had a lower proportion of having a diagnosis of mTBI compared to White patients (ps < 0.001). Further, the proportion of history of deployment varied by racial and ethnic group and deployment location. Multivariate logistic regression results showed odds of 1.52 (p < 0.001) for White patients with mTBI, odds of 1.61 (p < 0.001) for Black patients with mTBI, odds of 1.57 (p < 0.001) for Hispanic/Latino patients with mTBI, and odds of 1.99 (p < 0.001) for Asian or Pacific Islander patients with mTBI for being placed on work duty limitations.

DISCUSSION

These results advance our understanding of the work duty limitations for racial/ethnic minority patients with mTBI in the Military Health System.

Temporal changes in the prehospital management of trauma patients: 2014-2021

INTRODUCTION

Aggressive prehospital interventions (PHI) in trauma may not improve outcomes compared to prioritizing rapid transport. The aim of this study was to quantify temporal changes in the frequency of PHI performed by EMS.

METHODS

Retrospective chart review of adult patients transported by EMS to our trauma center from January 1, 2014 to 12/31/2021. PHI were recorded and annual changes in their frequency were assessed via year-by-year trend analysis and multivariate regression.

RESULTS

Between the first and last year of the study period, the frequency of thoracostomy (6% vs. 9%, p ​= ​0.001), TXA administration (0.3% vs. 33%, p ​< ​0.001), and whole blood administration (0% vs. 20%, p ​< ​0.001) increased. Advanced airway procedures (21% vs. 12%, p ​< ​0.001) and IV fluid administration (57% vs. 36%, p ​< ​0.001) decreased. ED mortality decreased from 8% to 5% (p ​= ​0.001) over the study period. On multivariate regression, no PHI were independently associated with increased or decreased ED mortality.

CONCLUSION

PHI have changed significantly over the past eight years. However, no PHI were independently associated with increased or decreased ED mortality.

Guidelines for Prehospital Management of Traumatic Brain Injury 3rd Edition: Executive Summary

Prehospital care markedly influences outcome from traumatic brain injury, yet it remains highly variable. The Brain Trauma Foundation's guidelines informing prehospital care, first published in 2002, have sought to identify and disseminate best practices. Many of its recommendations relate to the management of airway, breathing and circulation, and infrastructure for this care. Compliance with the second edition of these guidelines has been associated with significantly improved survival. A working group developed evidence-based recommendations informing assessment, treatment, and transport decision-making relevant to the prehospital care of brain injured patients. A literature search spanning May 2005 to January 2022 supplemented data contained in the 2nd edition. Identified studies were assessed for quality and used to inform evidence-based recommendations. A total of 122 published articles formed the evidentiary base for this guideline update including 5 providing Class I evidence, 35 providing Class II evidence, and 98 providing Class III evidence for the various topics. Forty evidence-based recommendations were generated, 30 of which were strong and 10 of which were weak. In many cases, new evidence allowed guidelines from the 2nd edition to be strengthened. Development of guidelines on some new topics was possible including the prehospital administration of tranexamic acid. A management algorithm is also presented. These guidelines help to identify best practices for prehospital traumatic brain injury care, and they also identify gaps in knowledge which we hope will be addressed before the next edition.

Pre-hospital endotracheal intubation in severe traumatic brain injury: ventilation targets and mortality-a retrospective analysis of 308 patients

BACKGROUND

Traumatic brain injury (TBI) remains one of the main causes of mortality and long-term disability worldwide. Maintaining physiology of brain tissue to the greatest extent possible through optimal management of blood pressure, airway, ventilation, and oxygenation, improves patient outcome. We studied the quality of prehospital care in severe TBI patients by analyzing adherence to recommended target ranges for ventilation and blood pressure, prehospital time expenditure, and their effect on mortality, as well as quality of prehospital ventilation assessed by arterial partial pressure of CO2 (PaCO2) at hospital admission.

METHODS

This is a retrospective cohort study of all TBI patients requiring tracheal intubation on scene who were transported to one of two major level 1 trauma centers in Switzerland between January 2014 and December 2019 by Swiss Air Rescue (Rega). We assessed systolic blood pressure (SBP), end-tidal partial pressure of CO2 (PetCO2), and PaCO2 at hospital admission as well as prehospital and on-scene time. Quality markers of prehospital care (PetCO2, SBP, prehospital times) and prehospital ventilation (PaCO2) are presented as descriptive analysis. Effect on mortality was calculated by multivariable regression analysis and a logistic general additive model.

RESULTS

Of 557 patients after exclusions, 308 were analyzed. Adherence to blood pressure recommendations was 89%. According to PetCO2, 45% were normoventilated, and 29% had a SBP ≥ 90 mm Hg and were normoventilated. Due to the poor correlation between PaCO2 and PetCO2, only 33% were normocapnic at hospital admission. Normocapnia at hospital admission was strongly associated with reduced probability of mortality. Prehospital and on-scene times had no impact on mortality.

CONCLUSIONS

PaCO2 at hospital admission is strongly associated with mortality risk, but normocapnia is achieved only in a minority of patients. Therefore, the time required for placement of an arterial cannula and prehospital blood gas analysis may be warranted in severe TBI patients requiring on-scene tracheal intubation.

Effect of prehospital intubation on mortality rates in patients with traumatic brain injury: A systematic review and meta-analysis

OBJECTIVE

It is unclear if prehospital intubation improves survival in patients with traumatic brain injury. We performed a systematic review and meta-analysis to assess the impact of prehospital intubation on mortality rates of traumatic brain injury.

METHODS

PubMed, CENTRAL, Web of Science, and Embase databases were searched without any language restriction up to 20 June 2022 for all types of comparative studies reporting survival of traumatic brain injury patients based on prehospital intubation.

RESULTS

In total, 18 studies with 41,185 patients were eligible for inclusion. Meta-analysis showed that traumatic brain injury patients receiving prehospital intubation had higher odds of mortality as compared to those not receiving prehospital intubation. Meta-analysis of adjusted data also indicated that prehospital intubation was associated with increased odds of mortality in traumatic brain injury patients. The results did not change on sensitivity analysis. Subgroup analysis based on study type, the severity of traumatic brain injury, inclusion of isolated traumatic brain injury, emergency department intubation in the control group, and prehospital intubation group sample size demonstrated variable results.

CONCLUSION

Heterogeneous data from mostly observational studies demonstrates higher mortality rates among traumatic brain injury patients receiving prehospital intubation. The efficacy of prehospital intubation is difficult to judge without taking into account multiple confounding factors.

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.

Correlation between prehospital and in-hospital hypotension and outcomes after traumatic brain injury

BACKGROUND AND OBJECTIVE

Hypotension has a powerful effect on patient outcome after traumatic brain injury (TBI). The relative impact of hypotension occurring in the field versus during early hospital resuscitation is unknown. We evaluated the association between hypotension and mortality and non-mortality outcomes in four cohorts defined by where the hypotension occurred [neither prehospital nor hospital, prehospital only, hospital only, both prehospital and hospital].

METHODS

Subjects ≥10 years with major TBI were included. Standard statistics were used for unadjusted analyses. We used logistic regression, controlling for significant confounders, to determine the adjusted odds (aOR) for outcomes in each of the three cohorts.

RESULTS

Included were 12,582 subjects (69.8% male; median age 44 (IQR 26-61). Mortality by hypotension status: No hypotension: 9.2% (95%CI: 8.7-9.8%); EMS hypotension only: 27.8% (24.6-31.2%); hospital hypotension only: 45.6% (39.1-52.1%); combined EMS/hospital hypotension 57.6% (50.0-65.0%); (p < 0.0001). The aOR for death reflected the same progression: 1.0 (reference-no hypotension), 1.8 (1.39-2.33), 2.61 (1.73-3.94), and 4.36 (2.78-6.84), respectively. The proportion of subjects having hospital hypotension was 19.0% (16.5-21.7%) in those with EMS hypotension compared to 2.0% (1.8-2.3%) for those without (p < 0.0001). Additionally, the proportion of patients with TC hypotension was increased even with EMS "near hypotension" up to an SBP of 120 mmHg [(aOR 3.78 (2.97, 4.82)].

CONCLUSION

While patients with hypotension in the field or on arrival at the trauma center had markedly increased risk of death compared to those with no hypotension, those with prehospital hypotension that was not resolved before hospital arrival had, by far, the highest odds of death. Furthermore, TBI patients who had prehospital hypotension were five times more likely to arrive hypotensive at the trauma center than those who did not. Finally, even "near-hypotension" in the field was strongly and independently associated the risk of a hypotensive hospital arrival (<90 mmHg). These findings are supportive of the prehospital guidelines that recommend aggressive prevention and treatment of hypotension in major TBI.

Development of Traumatic Brain Injury Associated Intracranial Hypertension Prediction Algorithms: A Narrative Review

Traumatic intracranial hypertension (tIH) is a common and potentially lethal complication of moderate to severe traumatic brain injury (m-sTBI). It often develops with little warning and is managed reactively with the tiered application of intracranial pressure (ICP)-lowering interventions administered in response to an ICP rising above a set threshold. For over 45 years, a variety of research groups have worked toward the development of technology to allow for the preemptive management of tIH in the hope of improving patient outcomes. In 2022, the first operationalizable tIH prediction system became a reality. With such a system, ICP lowering interventions could be administered prior to the rise in ICP, thus protecting the patient from potentially damaging tIH episodes and limiting the overall ICP burden experienced. In this review, we discuss related approaches to ICP forecasting and IH prediction algorithms, which collectively provide the foundation for the successful development of an operational tIH prediction system. We also discuss operationalization and the statistical assessment of tIH algorithms. This review will be of relevance to clinicians and researchers interested in development of this technology as well as those with a general interest in the bedside application of machine learning (ML) technology.

Treatment of pediatric patients with traumatic brain injury by Dutch Helicopter Emergency Medical Services (HEMS)

BACKGROUND

Sparse data are available on prehospital care by Helicopter Emergency Medical Service (HEMS) for pediatric patients with traumatic brain injury (TBI). This study focusses on prehospital interventions, neurosurgical interventions and mortality in this group.

METHODS

We performed a retrospective analysis of pediatric (0-18 years of age) patients with TBI treated by Rotterdam HEMS.

RESULTS

From January 2012 to December 2017 415 pediatric (<18 years of age) patients with TBI were included. Intubation was required in in 92 of 111 patients with GCS ≤ 8, 92 (82.9%), compared to 12 of 77 (15.6%) with GCS 9-12, and 7 of 199 (3.5%) with GCS 13-15. Hyperosmolar therapy (HSS) was started in 73 patients, 10 with a GCS ≤8. Decompressive surgery was required in 16 (5.8%), nine patients (56.3%) of these received HSS from HEMS. Follow-up data was available in 277 patients. A total of 107 (38.6%) patients were admitted to a (P)ICU. Overall mortality rate was 6.3%(n = 25) all with GCS ≤8, 15 (60.0%) died within 24 hours and 24 (96.0%) within a week. Patients with neurosurgical interventions (N = 16) showed a higher mortality rate (18.0%).

CONCLUSIONS

The Dutch HEMS provides essential emergency care for pediatric TBI patients, by performing medical procedures outside of regular EMS protocol. Mortality was highest in patients with severe TBI (n = 111) (GCS≤8) and in those who required neurosurgical interventions. Despite a relatively good initial GCS (>8) score, there were patients who required prehospital intubation and HSS. This group will require further investigation to optimize care in the future.

Epidural and subdural hematoma following spinal anesthesia in infants rat model

The aim of this study was to assess the epidural and subdural hematoma following spinal anesthesia in infants’ rat model. We investigated during 10, 15, and 20 days’ rats in group 1: intrathecal injection of bupivacaine 3.75 mg/kg (n = 7); group 2: received 37.5 μl midazolam 0.1% intrathecal with 37.5μl fentanyl 0.005% (no=7); injected into group 3 methylene blue 1 mg/ml (No. 7). Rats were exposed to spinal anesthesia in infancy and rotarod in motor function in adulthood. Histological evaluation and tissue extraction were also performed after the treatment and magnetic resonance imaging (MRI) of the head. MRI of the head of all rat pups that showed similar symptoms were performed. 4 rat pups showed the symptoms of hematoma Group1: small acute subdural hematoma at the left posterior temporal-parietal junction (PTPJ) and group 2 (one: right temporal epidural hematoma, two: Small acute subdural hematoma in the right temporomandibular area, and three: frontal-temporal-parietal-occipital hematoma). the rat pup that had epidural hematoma died 6 hours later. Finally, in the first group, one rat and the second group three rats showed hematoma symptoms. For these three rats, a histopathologic study was performed and indicate the presence of small acute subdural hematoma at the left posterior temporal-parietal junction, right temporal epidural hematoma, and frontal-temporal-parietal-occipital hematoma. In summary, because subdural or epidural hematoma of the skull can have serious consequences, differential diagnosis is very important for pain after spinal anesthesia.

Traumatic Brain Injury in Different Age Groups

Traumatic Brain Injury (TBI) is a global health burden [...].

Traumatic brain injury: progress and challenges in prevention, clinical care, and research

Traumatic brain injury (TBI) has the highest incidence of all common neurological disorders, and poses a substantial public health burden. TBI is increasingly documented not only as an acute condition but also as a chronic disease with long-term consequences, including an increased risk of late-onset neurodegeneration. The first Lancet Neurology Commission on TBI, published in 2017, called for a concerted effort to tackle the global health problem posed by TBI. Since then, funding agencies have supported research both in high-income countries (HICs) and in low-income and middle-income countries (LMICs). In November 2020, the World Health Assembly, the decision-making body of WHO, passed resolution WHA73.10 for global actions on epilepsy and other neurological disorders, and WHO launched the Decade for Action on Road Safety plan in 2021. New knowledge has been generated by large observational studies, including those conducted under the umbrella of the International Traumatic Brain Injury Research (InTBIR) initiative, established as a collaboration of funding agencies in 2011. InTBIR has also provided a huge stimulus to collaborative research in TBI and has facilitated participation of global partners. The return on investment has been high, but many needs of patients with TBI remain unaddressed. This update to the 2017 Commission presents advances and discusses persisting and new challenges in prevention, clinical care, and research.

In LMICs, the occurrence of TBI is driven by road traffic incidents, often involving vulnerable road users such as motorcyclists and pedestrians. In HICs, most TBI is caused by falls, particularly in older people (aged ≥65 years), who often have comorbidities. Risk factors such as frailty and alcohol misuse provide opportunities for targeted prevention actions. Little evidence exists to inform treatment of older patients, who have been commonly excluded from past clinical trials—consequently, appropriate evidence is urgently required. Although increasing age is associated with worse outcomes from TBI, age should not dictate limitations in therapy. However, patients injured by low-energy falls (who are mostly older people) are about 50% less likely to receive critical care or emergency interventions, compared with those injured by high-energy mechanisms, such as road traffic incidents.

Mild TBI, defined as a Glasgow Coma sum score of 13–15, comprises most of the TBI cases (over 90%) presenting to hospital. Around 50% of adult patients with mild TBI presenting to hospital do not recover to pre-TBI levels of health by 6 months after their injury. Fewer than 10% of patients discharged after presenting to an emergency department for TBI in Europe currently receive follow-up. Structured follow-up after mild TBI should be considered good practice, and urgent research is needed to identify which patients with mild TBI are at risk for incomplete recovery.

The selection of patients for CT is an important triage decision in mild TBI since it allows early identification of lesions that can trigger hospital admission or life-saving surgery. Current decision making for deciding on CT is inefficient, with 90–95% of scanned patients showing no intracranial injury but being subjected to radiation risks. InTBIR studies have shown that measurement of blood-based biomarkers adds value to previously proposed clinical decision rules, holding the potential to improve efficiency while reducing radiation exposure. Increased concentrations of biomarkers in the blood of patients with a normal presentation CT scan suggest structural brain damage, which is seen on MR scanning in up to 30% of patients with mild TBI. Advanced MRI, including diffusion tensor imaging and volumetric analyses, can identify additional injuries not detectable by visual inspection of standard clinical MR images. Thus, the absence of CT abnormalities does not exclude structural damage—an observation relevant to litigation procedures, to management of mild TBI, and when CT scans are insufficient to explain the severity of the clinical condition.

Although blood-based protein biomarkers have been shown to have important roles in the evaluation of TBI, most available assays are for research use only. To date, there is only one vendor of such assays with regulatory clearance in Europe and the USA with an indication to rule out the need for CT imaging for patients with suspected TBI. Regulatory clearance is provided for a combination of biomarkers, although evidence is accumulating that a single biomarker can perform as well as a combination. Additional biomarkers and more clinical-use platforms are on the horizon, but cross-platform harmonisation of results is needed. Health-care efficiency would benefit from diversity in providers.

In the intensive care setting, automated analysis of blood pressure and intracranial pressure with calculation of derived parameters can help individualise management of TBI. Interest in the identification of subgroups of patients who might benefit more from some specific therapeutic approaches than others represents a welcome shift towards precision medicine. Comparative-effectiveness research to identify best practice has delivered on expectations for providing evidence in support of best practices, both in adult and paediatric patients with TBI.

Progress has also been made in improving outcome assessment after TBI. Key instruments have been translated into up to 20 languages and linguistically validated, and are now internationally available for clinical and research use. TBI affects multiple domains of functioning, and outcomes are affected by personal characteristics and life-course events, consistent with a multifactorial bio-psycho-socio-ecological model of TBI, as presented in the US National Academies of Sciences, Engineering, and Medicine (NASEM) 2022 report. Multidimensional assessment is desirable and might be best based on measurement of global functional impairment. More work is required to develop and implement recommendations for multidimensional assessment. Prediction of outcome is relevant to patients and their families, and can facilitate the benchmarking of quality of care. InTBIR studies have identified new building blocks (eg, blood biomarkers and quantitative CT analysis) to refine existing prognostic models. Further improvement in prognostication could come from MRI, genetics, and the integration of dynamic changes in patient status after presentation.

Neurotrauma researchers traditionally seek translation of their research findings through publications, clinical guidelines, and industry collaborations. However, to effectively impact clinical care and outcome, interactions are also needed with research funders, regulators, and policy makers, and partnership with patient organisations. Such interactions are increasingly taking place, with exemplars including interactions with the All Party Parliamentary Group on Acquired Brain Injury in the UK, the production of the NASEM report in the USA, and interactions with the US Food and Drug Administration. More interactions should be encouraged, and future discussions with regulators should include debates around consent from patients with acute mental incapacity and data sharing. Data sharing is strongly advocated by funding agencies. From January 2023, the US National Institutes of Health will require upload of research data into public repositories, but the EU requires data controllers to safeguard data security and privacy regulation. The tension between open data-sharing and adherence to privacy regulation could be resolved by cross-dataset analyses on federated platforms, with the data remaining at their original safe location. Tools already exist for conventional statistical analyses on federated platforms, however federated machine learning requires further development. Support for further development of federated platforms, and neuroinformatics more generally, should be a priority.

This update to the 2017 Commission presents new insights and challenges across a range of topics around TBI: epidemiology and prevention (section 1 ); system of care (section 2 ); clinical management (section 3 ); characterisation of TBI (section 4 ); outcome assessment (section 5 ); prognosis (Section 6 ); and new directions for acquiring and implementing evidence (section 7 ). Table 1 summarises key messages from this Commission and proposes recommendations for the way forward to advance research and clinical management of TBI.

Prehospital Intubation of Patients with Severe Traumatic Brain Injury: A Dutch Nationwide Trauma Registry Analysis

ObjectivePatients with severe traumatic brain injury (TBI) are commonly intubated during prehospital treatment despite a lack of evidence that this is beneficial. Accumulating evidence even suggests that prehospital intubation may be hazardous, in particular when performed by inexperienced EMS clinicians. To expand the limited knowledge base, we studied the relationship between prehospital intubation and hospital mortality in patients with severe TBI in a large Dutch trauma database. We specifically hypothesized that the relationship differs depending on whether a physician-based emergency medical service (EMS) was involved in the treatment, as opposed to intubation by paramedics.MethodsA retrospective analysis was performed using the Dutch Nationwide Trauma Registry that includes all trauma patients in the Netherlands who are admitted to any hospital with an emergency department. All patients treated for severe TBI (Head Abbreviated Injury Scale score ≥4) between January 2015 and December 2019 were selected. Multivariable logistic regression was used to assess the relationship between prehospital intubation and mortality while adjusting for potential confounders. An interaction term between prehospital intubation and the involvement of physician-based EMS was added to the model. Complete case analysis as well as multiple imputation were performed.Results8946 patients (62% male, median age 63 years) were analyzed. The hospital mortality was 26.4%. Overall, a relationship between prehospital intubation and higher mortality was observed (complete case: OR 1.86, 95%CI 1.35-2.57, P < 0.001; multiple imputation: OR 1.92, 95%CI 1.56-2.36, P < 0.001). Adding the interaction revealed that the relationship of prehospital intubation may depend on whether physician-based EMS is involved in the treatment (complete case: P = 0.044; multiple imputation: P = 0.062). Physician-based EMS involvement attenuated but did not completely remove the detrimental association between prehospital intubation and mortality.ConclusionThe data do not support the common practice of prehospital intubation. The effect of prehospital intubation on mortality might depend on EMS clinician experience, and it seems prudent to involve prehospital personnel well proficient in prehospital intubation whenever intubation is potentially required. The decision to perform prehospital intubation should not merely be based on the largely unsupported dogma that it is generally needed in severe TBI, but should rather individually weigh potential benefits and harms.

Rationale and Methods for Updated Guidelines for the Management of Penetrating Traumatic Brain Injury

Penetrating traumatic brain injury (pTBI) affects civilian and military populations resulting in significant morbidity, mortality, and healthcare costs. No up-to-date and evidence-based guidelines exist to assist modern medical and surgical management of these complex injuries. A preliminary literature search revealed a need for updated guidelines, supported by the Brain Trauma Foundation. Methodologists experienced in TBI guidelines were recruited to support project development alongside two cochairs and a diverse steering committee. An expert multi-disciplinary workgroup was established and vetted to inform key clinical questions, to perform an evidence review and the development of recommendations relevant to pTBI. The methodological approach for the project was finalized. The development of up-to-date evidence- and consensus-based clinical care guidelines and algorithms for pTBI will provide critical guidance to care providers in the pre-hospital and emergent, medical, and surgical settings.

Effect of time intervals in critical care provided by helicopter emergency medical services on 30-day survival after trauma

BACKGROUND

Trauma is the leading cause of death especially in children and young adults. Prehospital care following trauma emphasizes swift transport to a hospital following initial care. Previous studies have shown conflicting results regarding the effect of time on the survival following major trauma. In our study we investigated the effect of prehospital time-intervals on 30-day mortality on trauma patients that received prehospital critical care.

METHODS

We performed a retrospective study on all trauma patients encountered by helicopter emergency medical services in Finland from 2012 to 2018. Patients discharge diagnoses were classed into (1) trauma without traumatic brain injury, (2) isolated traumatic brain injury and (3) trauma with traumatic brain injury. Emergency medical services response time, helicopter emergency medical services response time, on-scene time and transport time were used as time-intervals and age, Glasgow coma scale, hypotension, need for prehospital airway intervention and ICD-10 based Injury Severity Score were used as variables in logistic regression analysis.

RESULTS

Mortality data was available for 4,803 trauma cases. The combined 30-day mortality was 12.1% (582/4,803). Patients with trauma without a traumatic brain injury had the lowest mortality, at 4.3% (111/2,605), whereas isolated traumatic brain injury had the highest, at 22.9% (435/1,903). Patients with both trauma and a traumatic brain injury had a mortality of 12.2% (36/295). Following adjustments, no association was observed between time intervals and 30-day mortality.

DISCUSSION

Our study revealed no significant association between different timespans and mortality following severe trauma in general. Trends in odds ratios can be interpreted to favor more expedited care, however, no statistical significance was observed. As trauma forms a heterogenous patient group, specific subgroups might require different approaches regarding the prehospital timeframes.

STUDY TYPE

prognostic/therapeutic/diagnostic test.

Standardised data collection in prehospital critical care: a comparison of medical problem categories and discharge diagnoses

Background

Prehospital medical problem reporting is essential in the management of helicopter emergency medical services (HEMS) operations. The consensus-based template for reporting and documenting in physician-staffed prehospital services exists and the classification of medical problems presented in the template is widely used in research and quality improvement. However, validation of the reported prehospital medical problem is lacking. This study aimed to describe the in-hospital diagnoses, patient characteristics and medical interventions in different categories of medical problems.

Methods

This retrospective, observational registry study examined the 10 most common in-hospital International Statistical Classification of Disease (ICD-10) diagnoseswithin different prehospital medical problem categories, defined by the HEMS physician/paramedic immediately after the mission was completed. Data were gathered from a national HEMS quality registry and a national hospital discharge registry. Patient characteristics and medical interventions related to different medical problem categories are also described.

Results

A total of 33,844 patients were included in the analyses. All the medical problem categories included a broad spectrum of ICD-10 diagnoses (the number of diagnosis classes per medical problem category ranged from 73 to 403). The most frequent diagnoses were mainly consistent with the reported medical problems. Overlapping of ICD-10 diagnoses was mostly seen in two medical problem categories: stroke and acute neurology excluding stroke. Additionally, typical patient characteristics and disturbances in vital signs were related to adequate medical problem categories.

Conclusions

Medical problems reported by HEMS personnel have adequate correspondence to hospital discharge diagnoses. However, the classification of cerebrovascular accidents remains challenging.

Optimal Out-of-Hospital Blood Pressure in Major Traumatic Brain Injury: A Challenge to the Current Understanding of Hypotension

STUDY OBJECTIVE

Little is known about the out-of-hospital blood pressure ranges associated with optimal outcomes in traumatic brain injuries (TBI). Our objective was to evaluate the associations between out-of-hospital systolic blood pressure (SBP) and multiple hospital outcomes without assuming any predefined thresholds for hypotension, normotension, or hypertension.

METHODS

This was a preplanned secondary analysis from the Excellence in Prehospital Injury Care (EPIC) TBI study. Among patients (age ≥10 years) with major TBIs (Barell Matrix type 1 and/or Abbreviated Injury Scale-head severity ≥3) and lowest out-of-hospital SBPs of 40 to 299 mmHg, we utilized generalized additive models to summarize the distributions of various outcomes as smoothed functions of SBP, adjusting for important and significant confounders. The subjects who were enrolled in the study phase after the out-of-hospital TBI guideline implementation were used to validate the models developed from the preimplementation cohort.

RESULTS

Among 12,169 included cases, the mortality model revealed 3 distinct ranges: (1) a monotonically decreasing relationship between SBP and the adjusted probability of death from 40 to 130 mmHg, (2) lowest adjusted mortality from 130 to 180 mmHg, and (3) rapidly increasing mortality above 180 mmHg. A subanalysis of the cohorts with isolated TBIs and multisystem injuries with TBIs revealed SBP mortality patterns that were similar to each other and to that of the main analysis. While the specific SBP ranges varied somewhat for the nonmortality outcomes (hospital length of stay, ICU length of stay, discharge to skilled nursing/inpatient rehabilitation, and hospital charges), the patterns were very similar to that of mortality. In each model, validation was confirmed utilizing the postimplementation cohort.

CONCLUSION

Optimal adjusted mortality was associated with a surprisingly high SBP range (130 to 180 mmHg). Below this level, there was no point or range of inflection that would indicate a physiologically meaningful threshold for defining hypotension. Nonmortality outcomes showed very similar patterns. These findings highlight how sensitive the injured brain is to compromised perfusion at SBP levels that, heretofore, have been considered adequate or even normal. While the study design does did not allow us to conclude that the currently recommended treatment threshold (<90 mmHg) should be increased, the findings imply that the definition of hypotension in the setting of TBI is too low. Randomized trials evaluating treatment levels significantly higher than 90 mmHg are needed.

Long-term outcome after severe traumatic brain injury: a systematic literature review

BACKGROUND

Expectation of long-term outcome is an important factor in treatment decision-making after severe traumatic brain injury (sTBI). Conclusive long-term outcome data substantiating these decisions is nowadays lacking. This systematic review aimed to provide an overview of the scientific literature on long-term outcome after sTBI.

METHODS

A systematic search was conducted using PubMed from 2008 to 2020. Studies were included when reporting long-term outcome ≥ 2 years after sTBI (GCS 3-8 or AIS head score ≥ 4), using standardized outcome measures. Study quality and risk of bias were assessed using the QUIPS tool.

RESULTS

Twenty observational studies were included. Studies showed substantial variation in study objectives and study methodology. GOS-E (n = 12) and GOS (n = 8) were the most frequently used outcome measures. Mortality was reported in 46% of patients (range 18-75%). Unfavourable outcome rates ranged from 29 to 100% and full recovery was seen in 21-27% of patients. Most surviving patients reported SF-36 scores lower than the general population.

CONCLUSION

Literature on long-term outcome after sTBI was limited and heterogeneous. Mortality and unfavourable outcome rates were high and persisting sequelae on multiple domains common. Nonetheless, a considerable proportion of survivors achieved favourable outcome. Future studies should incorporate standardized multidimensional and temporal long-term outcome measures to strengthen the evidence-base for acute and subacute decision-making.

HIGHLIGHTS

1. Expectation of long-term outcome is an important factor in treatment decision-making for patients with severe traumatic brain injury (sTBI). 2. Favourable outcome and full recovery after sTBI are possible, but mortality and unfavourable outcome rates are high. 3. sTBI survivors are likely to suffer from a wide range of long-term consequences, underscoring the need for long-term and multi-modality outcome assessment in future studies. 4. The quality of the scientific literature on long-term outcome after sTBI can and should be improved to advance treatment decision-making.

Association between case volume and mortality in pre-hospital anaesthesia management: a retrospective observational cohort

BACKGROUND

Pre-hospital anaesthesia is a core competency of helicopter emergency medical services (HEMS). Whether physician pre-hospital anaesthesia case volume affects outcomes is unknown in this setting. We aimed to investigate whether physician case volume was associated with differences in mortality or medical management.

METHODS

We conducted a registry-based cohort study of patients undergoing drug-facilitated intubation by HEMS physician from January 1, 2013 to August 31, 2019. The primary outcome was 30-day mortality, analysed using multivariate logistic regression controlling for patient-dependent variables. Case volume for each patient was determined by the number of pre-hospital anaesthetics the attending physician had managed in the previous 12 months. The explanatory variable was physician case volume grouped by low (0-12), intermediate (13-36), and high (≥37) case volume. Secondary outcomes were characteristics of medical management, including the incidence of hypoxaemia and hypotension.

RESULTS

In 4818 patients, the physician case volume was 511, 2033, and 2274 patients in low-, intermediate-, and high-case-volume groups, respectively. Higher physician case volume was associated with lower 30-day mortality (odds ratio 0.79 per logarithmic number of cases [95% confidence interval: 0.64-0.98]). High-volume physician providers had shorter on-scene times (median 28 [25th-75th percentile: 22-38], compared with intermediate 32 [23-42] and lowest 32 [23-43] case-volume groups; P<0.001) and a higher first-pass success rate for tracheal intubation (98%, compared with 93% and 90%, respectively; P<0.001). The incidence of hypoxaemia and hypotension was similar between groups.

CONCLUSIONS

Mortality appears to be lower after pre-hospital anaesthesia when delivered by physician providers with higher case volumes.

Development and validation of a prehospital-stage prediction tool for traumatic brain injury: a multicentre retrospective cohort study in Korea

OBJECTIVES

Predicting diagnosis and prognosis of traumatic brain injury (TBI) at the prehospital stage is challenging; however, using comprehensive prehospital information and machine learning may improve the performance of the predictive model. We developed and tested predictive models for TBI that use machine learning algorithms using information that can be obtained in the prehospital stage.

DESIGN

This was a multicentre retrospective study.

SETTING AND PARTICIPANTS

This study was conducted at three tertiary academic emergency departments (EDs) located in an urban area of South Korea. The data from adult patients with severe trauma who were assessed by emergency medical service providers and transported to three participating hospitals between 2014 to 2018 were analysed.

RESULTS

We developed and tested five machine learning algorithms-logistic regression analyses, extreme gradient boosting, support vector machine, random forest and elastic net (EN)-to predict TBI, TBI with intracranial haemorrhage or injury (TBI-I), TBI with ED or admission result of admission or transferred (TBI with non-discharge (TBI-ND)) and TBI with ED or admission result of death (TBI-D). A total of 1169 patients were included in the final analysis, and the proportions of TBI, TBI-I, TBI-ND and TBI-D were 24.0%, 21.5%, 21.3% and 3.7%, respectively. The EN model yielded an area under receiver-operator curve of 0.799 for TBI, 0.844 for TBI-I, 0.811 for TBI-ND and 0.871 for TBI-D. The EN model also yielded the highest specificity and significant reclassification improvement. Variables related to loss of consciousness, Glasgow Coma Scale and light reflex were the three most important variables to predict all outcomes.

CONCLUSION

Our results inform the diagnosis and prognosis of TBI. Machine learning models resulted in significant performance improvement over that with logistic regression analyses, and the best performing model was EN.

Incidence of emergency neurosurgical TBI procedures: a population-based study

BACKGROUND

The rates of emergency neurosurgery in traumatic brain injury (TBI) patients vary between populations and trauma centers. In planning acute TBI treatment, knowledge about rates and incidence of emergency neurosurgery at the population level is of importance for organization and planning of specialized health care services. This study aimed to present incidence rates and patient characteristics for the most common TBI-related emergency neurosurgical procedures.

METHODS

Oslo University Hospital is the only trauma center with neurosurgical services in Southeast Norway, which has a population of 3 million. We extracted prospectively collected registry data from the Oslo TBI Registry - Neurosurgery over a five-year period (2015-2019). Incidence was calculated in person-pears (crude) and age-adjusted for standard population. We conducted multivariate multivariable logistic regression models to assess variables associated with emergency neurosurgical procedures.

RESULTS

A total of 2151 patients with pathological head CT scans were included. One or more emergency neurosurgical procedure was performed in 27% of patients. The crude incidence was 3.9/100,000 person-years. The age-adjusted incidences in the standard population for Europe and the world were 4.0/100,000 and 3.3/100,000, respectively. The most frequent emergency neurosurgical procedure was the insertion of an intracranial pressure monitor, followed by evacuation of the mass lesion. Male sex, road traffic accidents, severe injury (low Glasgow coma score) and CT characteristics such as midline shift and compressed/absent basal cisterns were significantly associated with an increased probability of emergency neurosurgery, while older age was associated with a decreased probability.

CONCLUSIONS

The incidence of emergency neurosurgery in the general population is low and reflects neurosurgery procedures performed in patients with severe injuries. Hence, emergency neurosurgery for TBIs should be centralized to major trauma centers.

Pediatric traumatic brain injury prehospital guidelines: a systematic review and appraisal

BACKGROUND

Traumatic brain injury (TBI) disproportionately affects children within low- and middle-income countries (LMICs). Prehospital emergency care can mitigate secondary brain injury and improve outcomes. Here, we systematically review clinical practice guidelines (CPGs) for pediatric TBI with the goal to inform LMICs prehospital care.

METHODS

A systematic search was conducted in PubMed/Medline, Embase, and Web of Science databases. We appraised evidence-based CPGs addressing prehospital management of pediatric TBI using the Appraisal of Guidelines for Research & Evaluation (AGREE) tool. CPGs were rated as high-quality if ≥ 5 (out of 6) AGREE domains scored > 60%.

RESULTS

Of the 326 articles identified, 10 CPGs were included in analysis. All 10 were developed in HICs, and 4 were rated as high-quality. A total of 154 pediatric prehospital recommendations were grouped into three subcategories, initial assessment (35.7%), prehospital treatment (38.3%), and triage (26.0%). Of these, 79 (51.3%) were evidence-based with grading, and 31 (20.1%) were consensus-based without direct evidence.

CONCLUSION

Currently available CPGs for prehospital pediatric TBI management were all developed in HICs. Four CPGs have high-quality, and recommendations from these can serve as frameworks for LMICs or resource-limited settings. Context-specific evaluation and implementation of evidence-based recommendations allow LMIC settings to respond to the public health crisis of pediatric TBI and address gaps in trauma care systems.

Perioperative Management of Polytrauma Patients with Severe Traumatic Brain Injury Undergoing Emergency Extracranial Surgery: A Narrative Review

Managing the acute phase after a severe traumatic brain injury (TBI) with polytrauma represents a challenging situation for every trauma team member. A worldwide variability in the management of these complex patients has been reported in recent studies. Moreover, limited evidence regarding this topic is available, mainly due to the lack of well-designed studies. Anesthesiologists, as trauma team members, should be familiar with all the issues related to the management of these patients. In this narrative review, we summarize the available evidence in this setting, focusing on perioperative brain protection, cardiorespiratory optimization, and preservation of the coagulative function. An overview on simultaneous multisystem surgery (SMS) is also presented.

Prevalence of significant traumatic brain injury among patients intubated in the field due to impaired level of consciousness

OBJECTIVE

Current guidelines advocate prehospital endotracheal intubation (ETI) in patients with suspected severe head injury and impaired level of consciousness. However, the ability to identify patients with traumatic brain injury (TBI) in the prehospital setting is limited and prehospital ETI carries a high complication rate. We investigated the prevalence of significant TBI among patients intubated in the field for that reason.

METHODS

Data were retrospectively collected from emergency medical services and hospital records of trauma patients for whom prehospital ETI was attempted and who were transferred to Rambam Health Care Campus, Israel. The indication for ETI was extracted. The primary outcome was significant TBI (clinical or radiographic) among patients intubated due to suspected severe head trauma.

RESULTS

In 57.3% (379/662) of the trauma patients, ETI was attempted due to impaired consciousness. 349 patients were included in the final analysis: 82.8% were male, the median age was 34 years (IQR 23.0-57.3), and 95.7% suffered blunt trauma. 253 patients (72.5%) had significant TBI. In a multivariable analysis, Glasgow Coma Scale>8 and alcohol intoxication were associated with a lower risk of TBI with OR of 0.26 (95% CI 0.13-0.51, p < 0.001) and 0.16 (95% CI 0.06-0.46, p < 0.001), respectively.

CONCLUSION

Altered mental status in the setting of trauma is a major reason for prehospital ETI. Although most of these patients had TBI, one in four of them did not suffer a significant TBI. Patients with a higher field GCS and those suffering from intoxication have a higher risk of misdiagnosis. Future studies should explore better tools for prehospital assessment of TBI and ways to better define and characterize patients who may benefit from early ETI.

Do neurosurgeons follow the guidelines? A world-based survey on severe traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) is going to be the third-leading cause of death worldwide, according to the WHO. Two European surveys suggested that adherence to brain trauma guidelines is poor. No study has compared compliance between low- (LMICs) and high-income (UHICs) countries. Hence, this study aimed to investigate differences in the management of severe TBI patients, comparing low- and high-income, and adherence to the BTF guidelines.

METHODS

A web-based survey was spread through the Global Neuro Foundation, different neurosurgical societies, and social media.

RESULTS

A total of 803 neurosurgeons participated: 70.4 from UHICs and 29.6% from LMICs. Hypertonic was administered as an early measure by the 73% and 65% of the responders in LMICs and UHICs, respectively (P=0.016). An invasive intracranial pressure monitoring was recommended by the 66% and 58% of the neurosurgeons in LMICs and UHICs, respectively (P<0.001). Antiseizure drugs (P<0.001) were given most frequently in LMICs as, against recommendations, steroids (87% vs. 61% and 86% vs. 81%, respectively). In the LMICs both the evacuation of the contusion and decompressive craniectomy were performed earlier than in UHICs (30% vs. 17% with P<0.001 and 44% vs. 28% with P=0.006, respectively). In the LMICs, the head CT control was performed mostly between 12 and 24 hours from the first imaging (38% vs. 23%, P<0.001).

CONCLUSIONS

The current Guidelines on TBI do not always fit to both the resources and circumstances in different countries. Future research and clinical practice guidelines should reflect the greater relevance of TBI in low resource settings.

Evolution and Impact of the Brain Trauma Foundation Guidelines

The Brain Trauma Foundation (BTF) Guidelines for the Management of Severe Head Injury were the first clinical practice guidelines published by any surgical specialty. These guidelines have earned a reputation for rigor and have been widely adopted around the world. Implementation of these guidelines has been associated with a 50% reduction in mortality and reduced costs of patient care. Over their 25-yr history the traumatic brain injury (TBI) guidelines have been expanded, refined, and made increasingly more rigorous in conjunction with new clinical evidence and evolving methodologic standards. Here, we discuss the history and accomplishments of BTF guidelines for TBI as well as their limitations. We also discuss planned changes to future TBI guidelines intended to increase their utility and positive impact in an evolving medical landscape. Perhaps the greatest limitation of TBI guidelines now is the lack of high-quality clinical research as well as novel diagnostics and treatments with which to generate substantially new recommendations.

Primary versus early secondary referral to a specialized neurotrauma center in patients with moderate/severe traumatic brain injury: a CENTER TBI study

Background

Prehospital care for patients with traumatic brain injury (TBI) varies with some emergency medical systems recommending direct transport of patients with moderate to severe TBI to hospitals with specialist neurotrauma care (SNCs). The aim of this study is to assess variation in levels of early secondary referral within European SNCs and to compare the outcomes of directly admitted and secondarily transferred patients.

Methods

Patients with moderate and severe TBI (Glasgow Coma Scale < 13) from the prospective European CENTER-TBI study were included in this study. All participating hospitals were specialist neuroscience centers. First, adjusted between-country differences were analysed using random effects logistic regression where early secondary referral was the dependent variable, and a random intercept for country was included. Second, the adjusted effect of early secondary referral on survival to hospital discharge and functional outcome [6 months Glasgow Outcome Scale Extended (GOSE)] was estimated using logistic and ordinal mixed effects models, respectively.

Results

A total of 1347 moderate/severe TBI patients from 53 SNCs in 18 European countries were included. Of these 1347 patients, 195 (14.5%) were admitted after early secondary referral. Secondarily referred moderate/severe TBI patients presented more often with a CT abnormality: mass lesion (52% vs. 34%), midline shift (54% vs. 36%) and acute subdural hematoma (77% vs. 65%). After adjusting for case-mix, there was a large European variation in early secondary referral, with a median OR of 1.69 between countries. Early secondary referral was not associated with functional outcome (adjusted OR 1.07, 95% CI 0.78–1.69), nor with survival at discharge (1.05, 0.58–1.90).

Conclusions

Across Europe, substantial practice variation exists in the proportion of secondarily referred TBI patients at SNCs that is not explained by case mix. Within SNCs early secondary referral does not seem to impact functional outcome and survival after stabilisation in a non-specialised hospital. Future research should identify which patients with TBI truly benefit from direct transportation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00930-1.

Common Symptoms of Mild Traumatic Brain Injury and Work Functioning of Active-Duty Service Members with a History of Deployment

This study used data from the Military Health System Data Repository to examine the association between mild traumatic brain injuries (mTBI) and work functioning such as work duty limitations, hospital emergency room visits and inpatient admissions for active-duty service members (ADSMs). Further, this study assessed the role that common symptoms of mTBI play in work functioning. Multivariate results showed that having a mTBI diagnosis is not a major factor that results in being "released with work duty limitations". However, findings from these regression models also showed that the interaction of mTBI with cognitive and linguistic symptoms resulted in odds of 3.63 (CI: 1.40-9.36, p < 0.01) for being "released with work duty limitations" and odds of 4.98 (CI: 1.16-21.39, p < 0.05) for having any emergency department visits compared to those with no diagnosis of mTBI and none of these symptoms. Additionally, the interaction of mTBI with sleep disturbance and chronic pain showed odds of 2.72 (CI: 1.31-5.65, p < 0.01) and odds of 11.56 (CI: 2.65-50.44, p < 0.01) for being "released with work duty limitations" compared to those with no diagnosis of TBI and none of these symptoms, respectively. Further research is needed to investigate the association between mTBI and duration of time off work to provide a comprehensive understanding of the effect of mTBI on work functioning in the Military Health System.

Ambulance deceleration causes increased intra cranial pressure in supine position: a prospective observational prove of principle study

BACKGROUND

Ambulance drivers in the Netherlands are trained to drive as fluent as possible when transporting a head injured patient to the hospital. Acceleration and deceleration have the potential to create pressure changes in the head that may worsen outcome. Although the idea of fluid shift during braking causing intra cranial pressure (ICP) to rise is widely accepted, it lacks any scientific evidence. In this study we evaluated the effects of driving and deceleration during ambulance transportation on the intra cranial pressure in supine position and 30° upright position.

METHODS

Participants were placed on the ambulance gurney in supine position. During driving and braking the optical nerve sheath diameter (ONSD) was measured with ultrasound. Because cerebro spinal fluid percolates in the optical nerve sheath when ICP rises, the diameter of this sheath will distend if ICP rises during braking of the ambulance. The same measurements were taken with the headrest in 30° upright position.

RESULTS

Mean ONSD in 20 subjects in supine position increased from 4.80 (IQR 4.80-5.00) mm during normal transportation to 6.00 (IQR 5.75-6.40) mm (p < 0.001) during braking. ONSD's increased in all subjects in supine position. After raising the headrest of the gurney 30° mean ONSD increased from 4.80 (IQR 4.67-5.02) mm during normal transportation to 4.90 (IQR 4.80-5.02) mm (p = 0.022) during braking. In 15 subjects (75%) there was no change in ONSD at all.

CONCLUSIONS

ONSD and thereby ICP increases during deceleration of a transporting vehicle in participants in supine position. Raising the headrest of the gurney to 30 degrees reduces the effect of breaking on ICP.

Fibrinolysis in Traumatic Brain Injury: Diagnosis, Management, and Clinical Considerations

Posttraumatic coagulopathy involves disruption of both the coagulation and fibrinolytic pathways secondary to tissue damage, hypotension, and inflammatory upregulation. This phenomenon contributes to delayed complications after traumatic brain injury (TBI), including intracranial hemorrhage progression and systemic disseminated intravascular coagulopathy. Development of an early hyperfibrinolytic state may result in uncontrolled bleeding and is associated with increased mortality in patients with TBI. Although fibrinolytic assays are not routinely performed in the assessment of posttraumatic coagulopathy, circulating biomarkers such as D-dimer and fibrin degradation products have demonstrated potential utility in outcome prediction. Unfortunately, the relatively delayed nature of these tests limits their clinical utility. In contrast, viscoelastic tests are able to provide a rapid global assessment of coagulopathy, although their ability to reliably identify disruptions in the fibrinolytic cascade remains unclear. Limited evidence supports the use of hypertonic saline, cryoprecipitate, and plasma to correct fibrinolytic disruption; however, some studies suggest more harm than benefit. Recently, early use of tranexamic acid in patients with TBI and confirmed hyperfibrinolysis has been proposed as a strategy to further improve clinical outcomes. Moving forward, further delineation of TBI phenotypes and the clinical implications of fibrinolysis based on phenotypic variation is needed. In this review, we summarize the clinical aspects of fibrinolysis in TBI, including diagnosis, treatment, and clinical correlates, with identification of targeted areas for future research efforts.

Prehospital Impact on Family Members of Road Traffic Accident

Background  Prehospital care is nonexistent in most rural and semiurban areas. The implementation of golden hour care is still unachieved. The psychosocial problems of family members who accompany the traumatic brain injury (TBI) survivors after road traffic accidents (RTA) are not given attention during prehospital care. Therefore, the current study was aimed to understand the prehospital psychosocial impact on family members.

Methodology  A cross-sectional study was conducted at the Emergency and Trauma Care Centre at National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru between July 2017 to April 2018. Forty-five ( n = 45) referred family members providing care for trauma survivors were purposively recruited in the study. Structured checklists were administered to measure the psychological reactions and psychosocial problems experienced by the family members during prehospital care. Data analysis was analyzed using the R software 3.0.1 version.

Results  TBI survivor's mean age was found to be 33 years (33.09 ± 13.20), of which males were 23 (51.1%) and females were 22 (48.9%), respectively. The result depicted first aid was provided by unskilled people after an average of 41 minutes (41 ± 30). The results further showed that family members had experienced agitation (100%), shock (82.2%), fatigue and headache (75.6%), depression (66.7%), feeling of hopelessness (55.6%) helplessness, and lack of support from family and financial constraints (48.9%) during prehospital care.

Conclusion  Psychosocial interventions need to be provided during prehospital care by trained medical and psychiatric social work professionals to address the need of family members during the crisis.

Arterial and end-tidal carbon dioxide partial pressure difference during prehospital anaesthesia in critically ill patients

BACKGROUND

Normoventilation is crucial for many critically ill patients. Ventilation is routinely guided by end-tidal capnography during prehospital anaesthesia, based on the assumption of the gap between arterial partial pressure of carbon dioxide (PaCO2 ) and end-tidal carbon dioxide partial pressure (PetCO2 ) of approximately 0.5 kPa (3.8 mmHg).

METHODS

We retrospectively analysed the airway registry and patient chart data of patients who had been anaesthetised and intubated endotracheally by the prehospital critical care team and had their prehospital arterial blood gases analysed. Bland-Altman analysis was used to estimate the bias and limits of agreement.

RESULTS

Altogether 502 patients were included in the study, with a median age of 58 years. The most common patient groups were post-resuscitation (155, 31%), neurological emergencies (96, 19%), intoxication (75, 15%) and trauma (68, 14%). The median of the gap between PaCO2 and PetCO2 was 1.3 kPa (interquartile range 0.7 to 2.2) (9.8 (5.3-16.5) mmHg). Mean bias of PetCO2 was -1.6 kPa/12.0 mmHg (standard deviation 1.7 kPa/12.8 mmHg) with 95% confidence limits of agreement -4.9 to 1.9 kPa (-36.8 to 14.3 mmHg). The gap was ≥ 1.0 kPa (>7.5 mmHg) in 297 (66%, 95% confidence interval 55 to 63) patients.

CONCLUSION

Our results suggest that end-tidal capnography alone might not be an adequate method to achieve normoventilation for critically ill patients intubated and mechanically ventilated in prehospital setting. Thus, an arterial blood gas analysis might be useful to recognize patients with an increased gap between PaCO2 and PetCO2 .

Acceptable Blood Pressure Levels in the Prehospital Setting for Patients with Traumatic Brain Injury: A Multicenter Observational Study

BACKGROUND

Safe blood pressure levels in the prehospital setting for patients with traumatic brain injury (TBI) remain unclear. We aimed to investigate the association between prehospital blood pressure and the outcomes of patients with TBI to determine optimal threshold for hypotension that could be considered in the prehospital setting.

METHODS

Using data from the Japan Trauma Data Bank, we identified adult patients (aged ≥18 years) who experienced severe TBI (maximum head Abbreviated Injury Severity score ≥3) and were transported directly from the scene of the blunt trauma occurrence to the hospital, between 2004 and 2019. We excluded patients with prehospital systolic blood pressure (SBP) levels of <60 and ≥160 mm Hg. Using mixed effects logistic regression models, we investigated the association between prehospital SBP and in-hospital mortality, considering the hospital ID as a random effect variable. In addition, we also conducted a stratified analysis based on age (<60 vs. ≥60 years).

RESULTS

A total of 34,175 patients (16,114 aged <60 years and 18,061 aged ≥60 years) were eligible for the analyses. Plotting the adjusted odds ratios for in-hospital mortality as a function of SBP produced J-shaped curves. An SBP <110 mm Hg was significantly associated with in-hospital mortality, with an adjusted odds ratio of 1.52 (95% confidence interval: 1.39-1.65). Stratified analyses revealed that the threshold did not differ between the age groups.

CONCLUSIONS

An SBP <110 mm Hg in the prehospital setting is significantly associated with higher in-hospital mortality.

Effect of Implementing the Out-of-Hospital Traumatic Brain Injury Treatment Guidelines: The Excellence in Prehospital Injury Care for Children Study (EPIC4Kids)

STUDY OBJECTIVE

We evaluate the effect of implementing the out-of-hospital pediatric traumatic brain injury guidelines on outcomes in children with major traumatic brain injury.

METHODS

The Excellence in Prehospital Injury Care for Children study is the preplanned secondary analysis of the Excellence in Prehospital Injury Care study, a multisystem, intention-to-treat study using a before-after controlled design. This subanalysis included children younger than 18 years who were transported to Level I trauma centers by participating out-of-hospital agencies between January 1, 2007, and June 30, 2015, throughout Arizona. The primary and secondary outcomes were survival to hospital discharge or admission for children with major traumatic brain injury and in 3 subgroups, defined a priori as those with moderate, severe, and critical traumatic brain injury. Outcomes in the preimplementation and postimplementation cohorts were compared with logistic regression, adjusting for risk factors and confounders.

RESULTS

There were 2,801 subjects, 2,041 in preimplementation and 760 in postimplementation. The primary analysis (postimplementation versus preimplementation) yielded an adjusted odds ratio of 1.16 (95% confidence interval 0.70 to 1.92) for survival to hospital discharge and 2.41 (95% confidence interval 1.17 to 5.21) for survival to hospital admission. In the severe traumatic brain injury cohort (Regional Severity Score-Head 3 or 4), but not the moderate or critical subgroups, survival to discharge significantly improved after guideline implementation (adjusted odds ratio = 8.42; 95% confidence interval 1.01 to 100+). The improvement in survival to discharge among patients with severe traumatic brain injury who received positive-pressure ventilation did not reach significance (adjusted odds ratio = 9.13; 95% confidence interval 0.79 to 100+).

CONCLUSION

Implementation of the pediatric out-of-hospital traumatic brain injury guidelines was not associated with improved survival when the entire spectrum of severity was analyzed as a whole (moderate, severe, and critical). However, both adjusted survival to hospital admission and discharge improved in children with severe traumatic brain injury, indicating a potential severity-based interventional opportunity for guideline effectiveness. These findings support the widespread implementation of the out-of-hospital pediatric traumatic brain injury guidelines.

Addressing Key Clinical Care and Clinical Research Needs in Severe Pediatric Traumatic Brain Injury: Perspectives From a Focused International Conference

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality in children and adolescents. Survivors of severe TBI are more prone to functional deficits, resulting in poorer school performance, poor health-related quality of life (HRQoL), and increased risk of mental health problems. Critical gaps in knowledge of pathophysiological differences between children and adults concerning TBI outcomes, the paucity of pediatric trials and prognostic models and the uncertain extrapolation of adult data to pediatrics pose significant challenges and demand global efforts. Here, we explore the clinical and research unmet needs focusing on severe pediatric TBI to identify best practices in pathways of care and optimize both inpatient and outpatient management of children following TBI.

Epidemiology, Prehospital Characteristics and Outcomes of Severe Traumatic Brain Injury in The Netherlands: The BRAIN-PROTECT Study

OBJECTIVE

A thorough understanding of the epidemiology, patient characteristics, trauma mechanisms, and current outcomes among patients with severe traumatic brain injury (TBI) is important as it may inform potential strategies to improve prehospital emergency care. The aim of this study is to describe the prehospital epidemiology, characteristics and outcome of (suspected) severe TBI in the Netherlands.

METHODS

The BRAIN-PROTECT study is a prospective observational study on prehospital management of patients with severe TBI in the Netherlands. The study population comprised all consecutive patients with clinical suspicion of TBI and a prehospital GCS score ≤ 8, who were managed by one of the 4 Helicopter Emergency Medical Services (HEMS). Patients were followed-up in 9 trauma centers until 1 year after injury. Planned sub-analyses were performed for patients with "confirmed" and "isolated" TBI.

RESULTS

Data from 2,589 patients, of whom 2,117 (81.8%) were transferred to a participating trauma center, were analyzed. The incidence rate of prehospitally suspected and confirmed severe TBI were 3.2 (95% CI: 3.1;3.4) and 2.7 (95% CI: 2.5;2.8) per 100,000 inhabitants per year, respectively. Median patient age was 46 years, 58.4% were involved in traffic crashes, of which 37.4% were bicycle related. 47.6% presented with an initial GCS of 3. The median time from HEMS dispatch to hospital arrival was 54 minutes. The overall 30-day mortality was 39.0% (95% CI: 36.8;41.2).

CONCLUSION

This article summarizes the prehospital epidemiology, characteristics and outcome of severe TBI in the Netherlands, and highlights areas in which primary prevention and prehospital care can be improved.

Survey of resources available to implement severe pediatric traumatic brain injury management guidelines in low and middle-income countries

PURPOSE

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide, with a disproportionately high burden in low-middle income countries. Guideline implementation has been associated with mortality reduction in high-income countries (HIC), but it is not known if hospitals in low and middle-income countries possess the resources to implement the pre-hospital TBI guidelines and the guidelines for the management of severe pediatric traumatic brain injury.

METHOD

An anonymous online survey was undertaken by a range of health care professionals currently managing children with severe TBI in low to middle-income countries. A variety of international and national pediatric, intensive care, and neurological societies assisted in the survey distribution. Thirty-eight questions were included to evaluate patient care and the provider's perceptions of their resources available to implement the pre-hospital specific TBI and current pediatric severe TBI guidelines.

RESULTS

Two hundred and forty-seven hospitals were represented from 68 countries. Fifty percent of LMIC hospitals that responded had the resources to implement 13 of 15 guidelines for the pediatric component of pre-hospital management for TBI and all baseline care recommendations. First tier therapies including the intracranial pressure (ICP) and cerebral perfusion pathways (CPP), however, demonstrated low capacity for uptake with 21.5% and 38.5% of surveyed hospitals possessing sufficient resources to follow the recommended pathways.

CONCLUSION

Pediatric TBI ICP/CPP management guidelines require numerous resources not widely sourced in LMIC. The creation of international guidelines that outline recommendations of care for LMIC may benefit patient care and outcomes in these settings.

End-tidal and arterial carbon dioxide gradient in serious traumatic brain injury after prehospital emergency anaesthesia: a retrospective observational study

OBJECTIVES

In the UK, 20% of patients with severe traumatic brain injury (TBI) receive prehospital emergency anaesthesia (PHEA). Current guidance recommends an end-tidal carbon dioxide (ETCO2) of 4.0-4.5 kPa (30.0-33.8 mm Hg) to achieve a low-normal arterial partial pressure of CO2 (PaCO2), and reduce secondary brain injury. This recommendation assumes a 0.5 kPa (3.8 mm Hg) ETCO2-PaCO2 gradient. However, the gradient in the acute phase of TBI is unknown. The primary aim was to report the ETCO2-PaCO2 gradient of TBI patients at hospital arrival.

METHODS

A retrospective cohort study of adult patients with serious TBI, who received a PHEA by a prehospital critical care team in the East of England between 1 April 2015 and 31 December 2017. Linear regression was performed to test for correlation and reported as R-squared (R2). A Bland-Altman plot was used to test for paired ETCO2 and PaCO2 agreement and reported with 95% CI. ETCO2-PaCO2 gradient data were compared with a two-tailed, unpaired, t-test.

RESULTS

107 patients were eligible for inclusion. Sixty-seven patients did not receive a PaCO2 sample within 30 min of hospital arrival and were therefore excluded. Forty patients had complete data and were included in the final analysis; per protocol. The mean ETCO2-PaCO2 gradient was 1.7 (±1.0) kPa (12.8 mm Hg), with moderate correlation (R2=0.23, p=0.002). The Bland-Altman bias was 1.7 (95% CI 1.4 to 2.0) kPa with upper and lower limits of agreement of 3.6 (95% CI 3.0 to 4.1) kPa and -0.2 (95% CI -0.8 to 0.3) kPa, respectively. There was no evidence of a larger gradient in more severe TBI (p=0.29). There was no significant gradient correlation in patients with a coexisting serious thoracic injury (R2=0.13, p=0.10), and this cohort had a larger ETCO2-PaCO2 gradient, 2.0 (±1.1) kPa (15.1 mm Hg), p=0.01. Patients who underwent prehospital arterial blood sampling had an arrival PaCO2 of 4.7 (±0.2) kPa (35.1 mm Hg).

CONCLUSION

There is only moderate correlation of ETCO2 and PaCO2 at hospital arrival in patients with serious TBI. The mean ETCO2-PaCO2 gradient was 1.7 (±1.0) kPa (12.8 mm Hg). Lower ETCO2 targets than previously recommended may be safe and appropriate, and there may be a role for prehospital PaCO2 measurement.