The Effect of Combined Out-of-Hospital Hypotension and Hypoxia on Mortality in Major Traumatic Brain Injury

Evaluation of a portable, lightweight modular system to deliver high inspired oxygen to trauma casualties without the use of pressurised cylinders

INTRODUCTION

Administering supplemental oxygen is a standard of care for trauma casualties to minimise the deleterious effects of hypoxaemia. Forward deployment of oxygen using pressurised cylinders is challenging, for example, logistics (weight and finite resource) and environmental risk (fire and explosion). Oxygen concentrators may overcome these challenges. Although previous studies successfully demonstrated fractional inspired oxygen (FiO2) >0.8 using oxygen concentrators and ventilators, the systems did not fulfil the size, weight and power requirements of agile military medical units. This study evaluated whether a modular system of commercially available clinical devices could supply high FiO2 to either ventilated or spontaneously breathing casualties.

METHODS

As a proof of principle, we configured an Inogen One G5 oxygen concentrator, Ventway Sparrow ventilator and Wenoll rebreather system to ventilate a simulated lung (tidal volume 500 mL). Casualty oxygen consumption (gas withdrawal inspiratory limb) and carbon dioxide (CO2) production (CO2 added expiratory limb) were simulated (respiratory quotient of 0.7-0.8). Three circuit configurations were evaluated: open (supplementary oxygen introduced into air inlet of ventilator); semiclosed (ventilator replaces rebreather bag of Wenoll, oxygen connected to either ventilator or Wenoll); and semiclosed with reservoir tubing (addition of 'deadspace' tube between ventilator patient circuit and Wenoll). Data presented as mean and 95% reference range.

RESULTS

There were modest increases in FiO2 with increasing Inogen settings in 'open' configuration 0.23 (0.23-0.24) and 0.30 (0.28-0.32) (Inogen output 420 and 1260 mL/min, respectively). With the 'semiclosed' configuration and oxygen added directly into rebreather circuit, FiO2 increased to 0.36 (0.36-0.37). The addition of the 'reservoir tubing' elevated FiO2 to 0.78 (0.71-0.85). FiO2 remained stable over a 4-hour evaluation period. Fractional inspired carbon dioxide CO2 increased over time, reaching 0.005 after 170 (157-182) min.

CONCLUSION

Combining existing lightweight devices can deliver high (>0.8) FiO2 and offers a potential solution for the forward deployment of oxygen without needing pressurised cylinders.

A standard operating procedure for prehospital anaesthesia and its effect on mortality-An observational study

BACKGROUND

Prehospital anaesthesia is a complex intervention performed for critically ill patients. To minimise complications, a standard operating procedure (SOP) outlining the process is considered valuable. We investigated the implementation of an SOP for prehospital anaesthesia in helicopter emergency medical services (HEMS).

METHODS

We performed a retrospective observational study of patients receiving prehospital anaesthesia by Finnish HEMS from January 2012 to August 2019. The intervention studied was the implementation of an SOP at two of the five bases during 2015-2016. Patients were stratified according to whether they were anaesthetised before, during or after implementation and the primary outcomes were 1- and 30-day mortality. Secondary outcomes included anaesthesia quality indicators. Confounding factors was assessed via logistic regression.

RESULTS

A total of 3902 tracheal intubations were performed without an SOP, 430 during implementation and 1525 after implementation. The SOP had a significant effect on 1-day mortality during implementation with an odds ratio (OR) of 0.56, 95% confidence interval (95% CI) 0.37-0.81 and a further trend towards benefit after implementation (OR 0.84, 95% CI 0.68-1.04), but no difference in 30-day mortality (OR after implementation 1.10, 95% CI 0.92-1.30). Implementation of an SOP improved first-pass success rate from 87.3% to 96.5%, p < 0.001.

CONCLUSION

Implementation of an SOP for prehospital anaesthesia was associated with a trend towards lower 1-day mortality and an improved first-pass success but did not affect 30-day mortality. Despite this, we advocate prehospital systems to consider implementation of a prehospital anaesthesia SOP as immediate performance markers improved significantly.

Association between out-of-hospital cardiac arrest quality indicator and prehospital management and clinical outcomes for major trauma

INTRODUCTION

It is unclear whether emergency medical service (EMS) agencies with good out-of-hospital cardiac arrest (OHCA) quality indicators also perform well in treating other emergency conditions. We aimed to evaluate the association of an EMS agency's non-traumatic OHCA quality indicators with prehospital management processes and clinical outcomes of major trauma.

METHODS

This retrospective cross-sectional study analyzed data from registers of nationwide, population-based OHCA (adult EMS-treated non-traumatic OHCA patients from 2017 to 2018) and major trauma (adult, EMS-treated, and injury severity score ≥16 trauma patients in 2018) in South Korea. We developed a prehospital ROSC prediction model to categorize EMS agencies into quartiles (Q1-Q4) based on the observed-to-expected (O/E) ROSC ratio for each EMS agency. We evaluated the national EMS protocol compliance of on-scene management according to O/E ROSC ratio quartile. The association between O/E ROSC ratio quartiles and trauma-related early mortality was determined in a multi-level logistic regression model by adjusted odds ratios (OR) and 95 % confidence intervals (95 % CI).

RESULTS

Among 30,034 severe trauma patients, 4,836 were analyzed. Patients in Q4 showed the lowest early mortality rate (5.6 %, 5.5 %, 4.8 %, and 3.4 % in Q1, Q2, Q3, and Q4, respectively). In groups Q1 to Q4, increasing compliance with the national EMS on-scene management protocol (trauma center transport, basic airway management for patients with altered mentality, spinal motion restriction for patients with spinal injury, and intravenous access for patients with hypotension) was observed (p for trend <0.05). Multivariable multi-level logistic regression analysis showed significantly lower early mortality in Q4 than in Q1 (adjusted OR [95 % CI] 0.56 [0.35-0.91]).

CONCLUSION

Major trauma patients managed by EMS agencies with high success rates in achieving prehospital ROSC in non-traumatic OHCA were more likely to receive protocol-based care and exhibited lower early 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.

Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR), Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) Guideline for difficult airway management. Part II

The Airway Management section of the Spanish Society of Anesthesiology, Resuscitation, and Pain Therapy (SEDAR), the Spanish Society of Emergency Medicine (SEMES), and the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC) present the Guide for the comprehensive management of difficult airway in adult patients. Its principles are focused on the human factors, cognitive processes for decision-making in critical situations, and optimization in the progression of strategies application to preserve adequate alveolar oxygenation in order to enhance safety and the quality of care. The document provides evidence-based recommendations, theoretical-educational tools, and implementation tools, mainly cognitive aids, applicable to airway management in the fields of anesthesiology, critical care, emergencies, and prehospital medicine. For this purpose, an extensive literature search was conducted following PRISMA-R guidelines and was analyzed using the GRADE methodology. Recommendations were formulated according to the GRADE methodology. Recommendations for sections with low-quality evidence were based on expert opinion through consensus reached via a Delphi questionnaire.

Early systemic insults following traumatic brain injury: association with biomarker profiles, therapy for intracranial hypertension, and neurological outcomes-an analysis of CENTER-TBI data

PURPOSE

We analysed the impact of early systemic insults (hypoxemia and hypotension, SIs) on brain injury biomarker profiles, acute care requirements during intensive care unit (ICU) stay, and 6-month outcomes in patients with traumatic brain injury (TBI).

METHODS

From patients recruited to the Collaborative European neurotrauma effectiveness research in TBI (CENTER-TBI) study, we documented the prevalence and risk factors for SIs and analysed their effect on the levels of brain injury biomarkers [S100 calcium-binding protein B (S100B), neuron-specific enolase (NSE), neurofilament light (NfL), glial fibrillary acidic protein (GFAP), ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), and protein Tau], critical care needs, and 6-month outcomes [Glasgow Outcome Scale Extended (GOSE)].

RESULTS

Among 1695 TBI patients, 24.5% had SIs: 16.1% had hypoxemia, 15.2% had hypotension, and 6.8% had both. Biomarkers differed by SI category, with higher S100B, Tau, UCH-L1, NSE and NfL values in patients with hypotension or both SIs. The ratio of neural to glial injury (quantified as UCH-L1/GFAP and Tau/GFAP ratios) was higher in patients with hypotension than in those with no SIs or hypoxia alone. At 6 months, 380 patients died (22%), and 759 (45%) had GOSE ≤ 4. Patients who experienced at least one SI had higher mortality than those who did not (31.8% vs. 19%, p < 0.001).

CONCLUSION

Though less frequent than previously described, SIs in TBI patients are associated with higher release of neuronal than glial injury biomarkers and with increased requirements for ICU therapies aimed at reducing intracranial hypertension. Hypotension or combined SIs are significantly associated with adverse 6-month outcomes. Current criteria for hypotension may lead to higher biomarker levels and more negative outcomes than those for hypoxemia suggesting a need to revisit pressure targets in the prehospital settings.

Haemodynamic response to pre-hospital emergency anaesthesia in trauma patients within an urban helicopter emergency medical service

PURPOSE

Pre-hospital emergency anaesthesia is routinely used in the care of severely injured patients by pre-hospital critical care services. Anaesthesia, intubation, and positive pressure ventilation may lead to haemodynamic instability. The aim of this study was to identify the frequency of new-onset haemodynamic instability after induction in trauma patients with a standardised drug regime.

METHODS

A retrospective database analysis was undertaken of all adult patients treated by a physician-led urban pre-hospital care service over a 6-year period. The primary outcome measure was the frequency of new haemodynamic instability following pre-hospital emergency anaesthesia. The association of patient characteristics and drug regimes with new haemodynamic instability was also analysed.

RESULTS

A total of 1624 patients were included. New haemodynamic instability occurred in 231 patients (17.4%). Patients where a full-dose regime was administered were less likely to experience new haemodynamic instability than those who received a modified dose regime (9.7% vs 24.8%, p < 0.001). The use of modified drug regimes became more common over the study period (p < 0.001) but there was no change in the rates of pre-existing (p = 0.22), peri-/post-anaesthetic (p = 0.36), or new haemodynamic instability (p = 0.32).

CONCLUSION

New haemodynamic instability within the first 30 min following pre-hospital emergency anaesthesia in trauma patients is common despite reduction of sedative drug doses to minimise their haemodynamic impact. It is important to identify non-drug factors that may improve cardiovascular stability in this group to optimise the care received by these patients.

Post-Traumatic Cerebral Infarction: A Narrative Review of Pathophysiology, Diagnosis, and Treatment

Traumatic brain injury (TBI) is a common diagnosis requiring acute hospitalization. Long-term, TBI is a significant source of health and socioeconomic impact in the United States and globally. The goal of clinicians who manage TBI is to prevent secondary brain injury. In this population, post-traumatic cerebral infarction (PTCI) acutely after TBI is an important but under-recognized complication that is associated with negative functional outcomes. In this comprehensive review, we describe the incidence and pathophysiology of PTCI. We then discuss the diagnostic and treatment approaches for the most common etiologies of isolated PTCI, including brain herniation syndromes, cervical artery dissection, venous thrombosis, and post-traumatic vasospasm. In addition to these mechanisms, hypercoagulability and microcirculatory failure can also exacerbate ischemia. We aim to highlight the importance of this condition and future clinical research needs with the goal of improving patient outcomes after TBI.

Prehospital Time Following Traumatic Injury Is Independently Associated With the Need for In-Hospital Blood and Early Mortality for Specific Injury Types

OBJECTIVE

Treating traumatic hemorrhage is time sensitive. Prehospital care and transport modes (eg, helicopter and ground) may influence in-hospital events. We hypothesized that prehospital time (on-scene time [OST] and total prehospital time [TPT]) and transport mode are associated with same-day transfusion and mortality. Furthermore, we sought to identify regions of anatomic injury that modify the relationship between prehospital time and outcomes in strata corresponding to transport types.

METHODS

We obtained prehospital, in-hospital, and trauma registry data from an 8-center cohort of adult nonburn trauma patients from 2017 to 2022 directly transported from the scene to the hospital and having an Injury Severity Score (ISS) > 9 for the Task Order 1 project of the Linking Investigators in Trauma and Emergency Services research network. We excluded patients missing prehospital times, patients < 18 years of age, patients from interfacility transfers, and recipients of prehospital blood. Our same-day outcomes were in-hospital transfusions within 4 hours and 24-hour mortality. Each outcome was adjusted using multivariable logistic regression for covariates of prehospital phases (OST and TPT), mode of transport (helicopter and ground), age, sex, ISS, Glasgow Coma Scale motor subscale score < 6, and field hypotension (systolic blood pressure < 90 mm Hg). We evaluated the association of prehospital time on outcomes for scene missions by transport mode across severe injury patterns defined by Abbreviated Injury Scale > 2 body regions.

RESULTS

Of 78,198 subjects, 34,504 were eligible for the study with a mean age of 47.6 ± 20.3 years, ISS of 18 ± 11, OST of 15.9 ± 9.5 minutes, and TPT of 48.7 ± 20.3 minutes. Adjusted for injury severity and demographic factors, transport type significantly modified the relationship between prehospital time and outcomes. The association of OST and TPT with the odds of 4-hour transfusion was absent for the ground emergency medical services (GEMS) cohort and present for the helicopter emergency medical services (HEMS) ambulance cohort, whereas these times were associated with decreased 24-hour mortality for both transport types. When stratifying by injury to most anatomic regions, OST and TPT were associated with a decreased need for 4-hour transfusions in the GEMS cohort. However, OST was associated with increased early transfusion only among patients with severe injuries of the thorax, and this association persisted after adjusting additionally for injury type (odds ratio [OR] = 1.03; 95% confidence interval [CI], 1.00-1.05; P = .02). The presence of polytrauma supported an association between prehospital time and decreased 24-hour mortality for the GEMS cohort (OST: OR = 0.97; 95% CI, 0.95-0.99; P < .01; TPT: OR = 0.99; 95% CI, 0.98-0.99; P = .02), whereas no injuries showed significant association of helicopter prehospital time on mortality after adjustment.

CONCLUSION

We determined that transport type affects the relationship between prehospital time and hospital outcomes (4-hour transfusion: positive relationship for HEMS and negative for GEMS, 24-hour mortality: negative for both transport types). Furthermore, we identified regions of anatomic injury that modify the relationship between prehospital time and outcomes in strata corresponding to transport types. Of these regions, most notable were severe isolated injuries to the thorax that supported a positive relationship between HEMS OST and 4-hour transfusions and polytrauma that showed a negative relationship between GEMS OST or TPT and 24-hour mortality after adjustment.

Evidence-Based Guideline for Prehospital Airway Management

Airway management is a cornerstone of emergency medical care. This project aimed to create evidence-based guidelines based on the systematic review recently conducted by the Agency for Healthcare Research and Quality (AHRQ). A technical expert panel was assembled to review the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. The panel made specific recommendations on the different PICO (population, intervention, comparison, outcome) questions reviewed in the AHRQ review and created good practice statements that summarize and operationalize these recommendations. The recommendations address the use of ventilation with bag-valve mask ventilation alone vs. supraglottic airways vs. endotracheal intubation for adults and children with cardiac arrest, medical emergencies, and trauma. Additional recommendations address the use of video laryngoscopy and drug-assisted airway management. These recommendations, and the associated good practice statements, offer EMS agencies and clinicians an opportunity to review the available evidence and incorporate it into their airway management strategies.

Critical hypertension in trauma patients following prehospital emergency anaesthesia: a multi-centre retrospective observational study

BACKGROUND

Critical hypertension in major trauma patients is associated with increased mortality. Prehospital emergency anaesthesia (PHEA) is performed for 10% of the most seriously injured patients. Optimising oxygenation, ventilation, and cerebral perfusion, whilst avoiding extreme haemodynamic fluctuations are the cornerstones of reducing secondary brain injury. The aim of this study was to report the differential determinants of post-PHEA critical hypertension in a large regional dataset of trauma patients across three Helicopter Emergency Medical Service (HEMS) organisations.

METHODS

A multi-centre retrospective observational study of consecutive adult trauma patients undergoing PHEA across three HEMS in the United Kingdom; 2015-2022. Critical hypertension was defined as a new systolic blood pressure (SBP) > 180mmHg within 10 min of induction of anaesthesia, or > 10% increase if the baseline SBP was > 180mmHg prior to induction. Purposeful logistical regression was used to explore variables associated with post-PHEA critical hypertension in a multivariable model. Data are reported as number (percentage), and odds ratio (OR) with 95% confidence interval (95%CI).

RESULTS

30,744 patients were attended by HEMS during the study period; 2161 received PHEA and 1355 patients were included in the final analysis. 161 (11.9%) patients had one or more new episode(s) of critical hypertension ≤ 10 min post-PHEA. Increasing age (compared with 16-34 years): 35-54 years (OR 1.76, 95%CI 1.03-3.06); 55-74 years (OR 2.00, 95%CI 1.19-3.44); ≥75 years (OR 2.38, 95%CI 1.31-4.35), pre-PHEA Glasgow Coma Scale (GCS) motor score four (OR 2.17, 95%CI 1.19-4.01) and five (OR 2.82, 95%CI 1.60-7.09), patients with a pre-PHEA SBP > 140mmHg (OR 6.72, 95%CI 4.38-10.54), and more than one intubation attempt (OR 1.75, 95%CI 1.01-2.96) were associated with post-PHEA critical hypertension.

CONCLUSION

Delivery of PHEA to seriously injured trauma patients risks haemodynamic fluctuation. In adult trauma patients undergoing PHEA, 11.9% of patients experienced post-PHEA critical hypertension. Increasing age, pre-PHEA GCS motor score four and five, patients with a pre-PHEA SBP > 140mmHg, and more than intubation attempt were independently associated with post-PHEA critical hypertension.

Patients with both traumatic brain injury and hemorrhagic shock benefit from resuscitation with whole blood

BACKGROUND

Hemorrhagic shock in the setting of traumatic brain injury (TBI) reduces cerebral blood flow and doubles mortality. The optimal resuscitation strategy for hemorrhage in the setting of TBI is unknown. We hypothesized that, among patients presenting with concomitant hemorrhagic shock and TBI, resuscitation including whole blood (WB) is associated with decreased overall and TBI-related mortality when compared with patients receiving component (COMP) therapy alone.

METHODS

An a priori subgroup of prospective, observational cohort study of injured patients receiving emergency-release blood products for hemorrhagic shock is reported. Adult trauma patients presenting November 2017 to September 2020 with TBI, defined as a Head Abbreviated Injury Scale of ≥3, were included. Whole blood group patients received any cold-store low-titer Group O WB units. The COMP group received fractionated blood components alone. Overall and TBI-related 30-day mortality, favorable discharge disposition (home or rehabilitation), and 24-hour blood product utilization were assessed. Univariate and inverse probabilities of treatment-weighted multivariable analyses were performed.

RESULTS

Of 564 eligible patients, 341 received WB. Patients who received WB had a higher injury severity score (median, 34 vs. 29), lower scene blood pressure (104 vs. 118), and higher arrival lactate (4.3 vs. 3.6, all p < 0.05). Univariate analysis noted similar overall mortality between WB and COMP; however, weighted multivariable analyses found WB was associated with decreased overall mortality and TBI-related mortality. There were no differences in discharge disposition between the WB group and COMP group.

CONCLUSION

In patients with concomitant hemorrhagic shock and TBI, WB transfusion was associated with decreased overall mortality and TBI-related mortality. Whole blood should be considered a first-line therapy for hemorrhage in the setting of TBI.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

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.

The Association of Combined Prehospital Hypotension and Hypoxia with Outcomes following Out-of-Hospital Cardiac Arrest Resuscitation

BACKGROUND

Prehospital post-resuscitation hypotension and hypoxia have been associated with adverse outcomes in the context of out-of-hospital cardiac arrest (OHCA). We aimed to investigate the association between clinical outcomes and post-resuscitation hypoxia alone, hypotension alone, and combined hypoxia and hypotension.

METHODS

We used the 2018-2021 ESO annual datasets to conduct this study. All EMS-treated non-traumatic OHCA patients who had a documented prehospital return of spontaneous circulation (ROSC) and two or more SpO2 readings and systolic blood pressures recorded were evaluated for inclusion. Patients who were less than 18 years of age, pregnant, had a do-not-resuscitate order or similar, achieved ROSC after bystander CPR only, or had an EMS-witnessed cardiac arrest were excluded. Multivariable logistic regression adjusted for standard Utstein factors and highest prehospital Glasgow Coma Scale (GCS) score was used to investigate the association between hypoxia, hypotension, and outcomes.

RESULTS

We analyzed data for 17,943 patients, of whom 3,979 had hospital disposition data. Hypotension and hypoxia were not documented in 1,343 (33.8%) patients, 1,144 (28.8%) had only hypoxia documented, 507 (12.7%) had only hypotension documented, and 985 (24.8%) had both hypoxia and hypotension documented. In comparison to patients who did not have documented hypotension or hypoxia, patients who had documented hypoxia (aOR: 1.76 [1.38, 2.24]), documented hypotension (aOR: 3.00 [2.15, 4.18]), and documented hypoxia and hypotension combined (aOR: 4.87 [3.63, 6.53]) had significantly increased mortality. The relationship between mortality and vital sign abnormalities (hypoxia and hypotension > hypotension > hypoxia) was observed in every evaluated subgroup.

CONCLUSIONS

In this large dataset, hypotension and hypoxia were independently associated with mortality both alone and in combination. Compared to patients without documented hypotension and hypoxia, patients with documented hypotension and hypoxia had nearly five-fold greater odds of mortality.

Ultrasound, photoacoustic, and magnetic resonance imaging to study hyperacute pathophysiology of traumatic and vascular brain injury

BACKGROUND AND PURPOSE

Cerebrovascular dynamics and pathomechanisms that evolve in the minutes and hours following traumatic vascular injury in the brain remain largely unknown. We investigated the pathophysiology evolution in mice within the first 3 hours after closed-head traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH), two significant traumatic vascular injuries.

METHODS

We took a multimodal imaging approach using photoacoustic imaging, color Doppler ultrasound, and MRI to track injury outcomes using a variety of metrics.

RESULTS

Brain oxygenation and velocity-weighted volume of blood flow (VVF) values significantly decreased from baseline to 15 minutes after both TBI and SAH. TBI resulted in 19.2% and 41.0% ipsilateral oxygenation and VVF reductions 15 minutes postinjury, while SAH resulted in 43.9% and 85.0% ipsilateral oxygenation and VVF reduction (p < .001). We found partial recovery of oxygenation from 15 minutes to 3 hours after injury for TBI but not SAH. Hemorrhage, edema, reduced perfusion, and altered diffusivity were evident from MRI scans acquired 90-150 minutes after injury in both injury models, although the spatial distribution was mostly focal for TBI and diffuse for SAH.

CONCLUSIONS

The results reveal that the cerebral oxygenation deficits immediately following injuries are reversible for TBI and irreversible for SAH. Our findings can inform future studies on mitigating these early responses to improve long-term recovery.

Rapid Sequence Intubation Using the SEADUC Manual Suction Unit in a Contaminated Airway

The case presented here highlights the utility/feasibility of the SEADUC (EM Innovations, Galloway, OH) manual suction unit in clearing a contaminated airway during rapid sequence intubation. The case also highlights the importance of intubation in a patient with declining mental status in the prehospital environment. A 75-year-old woman suffered a head injury, and a helicopter emergency medical service team staffed with a physician and nurse was tasked with retrieval and transfer back to the tertiary care center. As the flight team rendezvoused with ground emergency medical services and the patient, a decision to intubate was made because of the patient's declining mental status and inability to protect her own airway. While in preparation for intubation, it was noted that the ambulance's electrical suction system was not working, and the flight crew had to resort to a SEADUC manual suction unit to clear the patient's airway of contaminants. The patient's airway was cleared, and she was successfully intubated and transported to a tertiary care center where the patient underwent an emergent neurosurgery procedure/decompression and was discharged home a few weeks later.

Predictors of post-intubation hypotension in trauma patients following prehospital emergency anaesthesia: a multi-centre observational study

BACKGROUND

Post-intubation hypotension (PIH) after prehospital emergency anaesthesia (PHEA) is prevalent and associated with increased mortality in trauma patients. The objective of this study was to compare the differential determinants of PIH in adult trauma patients undergoing PHEA.

METHODS

This multi-centre retrospective observational study was performed across three Helicopter Emergency Medical Services (HEMS) in the UK. Consecutive sampling of trauma patients who underwent PHEA using a fentanyl, ketamine, rocuronium drug regime were included, 2015-2020. Hypotension was defined as a new systolic blood pressure (SBP) < 90 mmHg within 10 min of induction, or > 10% reduction if SBP was < 90 mmHg before induction. A purposeful selection logistic regression model was used to determine pre-PHEA variables associated with PIH.

RESULTS

During the study period 21,848 patients were attended, and 1,583 trauma patients underwent PHEA. The final analysis included 998 patients. 218 (21.8%) patients had one or more episode(s) of hypotension ≤ 10 min of induction. Patients > 55 years old; pre-PHEA tachycardia; multi-system injuries; and intravenous crystalloid administration before arrival of the HEMS team were the variables significantly associated with PIH. Induction drug regimes in which fentanyl was omitted (0:1:1 and 0:0:1 (rocuronium-only)) were the determinants with the largest effect sizes associated with hypotension.

CONCLUSION

The variables significantly associated with PIH only account for a small proportion of the observed outcome. Clinician gestalt and provider intuition is likely to be the strongest predictor of PIH, suggested by the choice of a reduced dose induction and/or the omission of fentanyl during the anaesthetic for patients perceived to be at highest risk.

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.

Effect of Different Early Oxygenation Levels on Clinical Outcomes of Patients Presenting in the Emergency Department With Severe Traumatic Brain Injury

STUDY OBJECTIVE

Despite the almost universal administration of supplemental oxygen in patients presenting in the emergency department (ED) with severe traumatic brain injury, optimal early oxygenation levels are unknown. Therefore, we aimed to examine the effect of different early oxygenation levels on the clinical outcomes of patients presenting in the emergency department with severe traumatic brain injury.

METHODS

We performed a secondary analysis of the Resuscitation Outcomes Consortium Traumatic Brain Injury Hypertonic Saline randomized controlled trial by including patients with Glasgow Coma Scale ≤8. Early oxygenation levels were assessed by the worst value of arterial partial pressure of oxygen (PaO₂) during the first 4 hours of presentation in the emergency department. The primary outcome was 6-month neurologic status, as assessed by the Extended Glasgow Outcome Scale. A binary logistic regression was utilized, and an odds ratio (OR) with 95% (95% confidence intervals) was calculated.

RESULTS

A total of 910 patients were included. In unadjusted (crude) analysis, a PaO₂ of 101 to 250 mmHg (OR, 0.59 [0.38 to 0.91]), or 251 to 400 mmHg (OR, 0.53 [0.34 to 0.83]) or ≥401 mmHg (OR, 0.31 [0.20 to 0.49]) was less likely to be associated with poor neurologic status when compared with a PaO₂ of ≤100 mmHg. This was also the case for adjusted analyses (including age, pupillary reactivity, and Revised Trauma Score).

CONCLUSION

High oxygenation levels as early as the first 4 hours of presentation in the emergency department may not be adversely associated with the long-term neurologic status of patients with severe traumatic brain injury. Therefore, during the early phase of trauma, clinicians may focus on stabilizing patients while giving low priority to the titration of oxygenation levels.

Immunomodulatory Effect of Electromagnetic Field in the Treatment of Traumatic Brain Injury

A review was performed utilizing PubMed and GoogleScholar to highlight the future directions of EMF research in the setting of brain pathology, specifically in ischemic and traumatic brain injury. Additionally, a critical review of the current state-of-the art of EMF use in treating brain pathology has been conducted. The authors have added to this large body of research their own experimental studies, including a description of the on-going studies. The field of EMF utilization in the diagnosis and treatment of brain injury is highly promising and warrant careful studies in clinically relevant experimental models followed by human trials in TBI.

Intubation first-pass success in a high performing pre-hospital critical care system is not associated with 30-day mortality: a registry study of 4496 intubation attempts

BACKGROUND

Lower intubation first-pass success (FPS) rate is associated with physiological deterioration, and FPS is widely used as a quality indicator of the airway management of a critically ill patient. However, data on FPS's association with survival is limited. We aimed to investigate if the FPS rate is associated with 30-day mortality or physiological complications in a pre-hospital setting. Furthermore, we wanted to describe the FPS rate in Finnish helicopter emergency medical services.

METHODS

This was a retrospective observational study. Data on drug-facilitated intubation attempts by helicopter emergency medical services were gathered from a national database and analysed. Multivariate logistic regression, including known prognostic factors, was performed to assess the association between FPS and 30-day mortality, collected from population registry data.

RESULTS

Of 4496 intubation attempts, 4082 (91%) succeeded on the first attempt. The mortality rates in FPS and non-FPS patients were 34% and 38% (P = 0.21), respectively. The adjusted odds ratio of FPS for 30-day mortality was 0.88 (95% CI 0.66-1.16). Hypoxia after intubation and at the time of handover was more frequent in the non-FPS group (12% vs. 5%, P < 0.001, and 5% vs. 3%, P = 0.01, respectively), but no significant differences were observed regarding other complications.

CONCLUSION

FPS is not associated with 30-day mortality in pre-hospital critical care delivered by advanced providers. It should therefore be seen more as a process quality indicator instead of a risk factor of poor outcome, at least considering the current limitations of the parameter.

Association of prehospital hypotension depth and dose with survival following out-of-hospital cardiac arrest

INTRODUCTION

Hypotension following resuscitation from out-of-hospital cardiac arrest (OHCA) may cause harm by exacerbating secondary brain injury; however, limited research has explored this relationship. Our objective was to examine the association between duration and depth of prehospital post return of spontaneous circulation (ROSC) hypotension and survival.

METHODS

We utilized the 2019 and 2020 ESO Data Collaborative public use research data sets for this study (ESO, Austin, TX). Hypotension dose (mmHg*min.), average prehospital systolic blood pressure (SBP), and lowest recorded prehospital SBP were calculated. The association of these measures with survival to home (STH) and rearrest were explored using multivariable logistic regression. Time to hypotension resolution analyses by hypotension management strategy (push dose vasopressors, vasopressor infusion, or fluid only) were conducted using adjusted Cox proportional hazards models.

RESULTS

17,280 OHCA patients met inclusion criteria, of which 3,345 had associated hospital outcome data. Over one-third (37.8%; 6,526/17,280) of all patients had at least one recorded SBP below 90 mmHg. When modeled continuously, average prehospital SBP (1.19 [1.15, 1.23] per 10 mmHg), lowest prehospital SBP (1.20 [1.17, 1.24] per 10 mmHg), and hypotension dose (0.995 [0.993, 0.996] per mmHg*min.) were independently associated with STH. Differences in hypotension management were not associated with differences in survival or time to hypotension resolution.

CONCLUSION

Severity and duration of hypotension were significantly associated with worse outcomes in this dataset. Defining a threshold for hypotension requiring treatment above the classical SBP threshold of 90 mmHg may be warranted in the setting of prehospital post-resuscitation care.

The Prehospital Emergency Anaesthetic in 2022

Prehospital emergency anesthesia (PHEA) is a commonly performed prehospital procedure with inherent risks. The processes and drug regimens behind PHEA are continually updated by prehospital teams across the country as part of their governance structure. Essex & Herts Air Ambulance has recently updated this practice by reviewing the entire process of performing PHEA. Through experiential learning in a high-volume service, audit, and a contemporary literature review, a new standard operating procedure has been developed to combat common problems, such as hypotension, associated with the more traditional methods of performing PHEA. The aim of this article was to summarize the literature behind this new standard operating procedure, systematically breaking down the core components of performing a PHEA and the rationale behind them. The key components identified in the review are indications for PHEA, airway assessment, peri-intubation oxygenation, preparation for PHEA, drug dosing, special circumstances, and failed intubation. One significant change is the drug dosage regimen; 1 μg/kg fentanyl, 2 mg/kg ketamine, and 2 mg/kg rocuronium is recommended as the main drug dosing regimen for both medical and trauma patients. Other changes include preoxygenation with a nasal cannula in addition to the nonrebreather mask, optimizing patients in the preparation phase by considering inopressors or fluid bolus and ensuring a "sterile cockpit" to control the surrounding environment to ensure the first intubation attempt is the best attempt.

Design and Implementation of Airway Response Teams to Improve the Practice of Emergency Airway Management

Emergency airway management (EAM) is a commonly performed procedure in the critical care setting. Despite clinical advances that help practitioners identify patients at risk for having a difficult airway, improved airway management tools, and algorithms that guide clinical decision-making, the practice of EAM is associated with significant morbidity and mortality. Evidence suggests that a dedicated airway response team (ART) can help mitigate the risks associated with EAM and provide a framework for airway management in acute settings. We review the risks and challenges related to EAM and describe strategies to improve patient care and outcomes via implementation of an ART.

The Relationship Between Trauma Scoring Systems and Outcomes in Patients With Severe Traumatic Brain Injury

OBJECTIVE

This study investigated the relationship between trauma scoring systems and outcomes in patients with severe traumatic brain injury (TBI).

METHODS

From January 2018 to June 2021, 1,122 patients with severe TBI were registered in the Korean Neuro-Trauma Data Bank System. Among them, 697 patients with data on trauma scoring systems were included in the study. According to the Glasgow Outcome Scale-Extended score, the patients were divided into unfavorable and favorable outcome groups. The abbreviated injury scale (AIS), injury severity score (ISS), revised trauma score (RTS), and trauma and injury severity score (TRISS) were evaluated.

RESULTS

The AIS head score was higher in the unfavorable outcome group than in the favorable outcome group (4.39 vs. 4.06, p<0.001). ISS was also higher in the unfavorable outcome group (27.27 vs. 24.22, p=0.001). The RTS and TRISS were higher in the favorable outcome group (RTS, 4.74 vs. 5.45, p<0.001; TRISS, 48.05 vs. 71.02, p<0.001). In comparing the survival and death groups, the ISS was lower in the survival group (25.76 vs. 27.29, p=0.036). Furthermore, RTS was higher in the survival group (5.26 vs. 4.54, p<0.001), as was TRISS (62.11 vs. 44.91, p<0.001).

CONCLUSION

Trauma scoring systems, including ISS, RTS, and TRISS, provide tools for quantifying posttraumatic risk and can be used to predict prognosis. Among these, TRISS is an indicator of the predicted survival rate and is considered a clinically useful tool for predicting unfavorable and favorable outcomes in patients with severe TBI.

Tracheostomy without mechanical ventilation in patients with traumatic brain injury at a tertiary referral hospital in Malawi: a cross sectional study

Background

Tracheostomy alone, without mechanical ventilation, has been advocated to maintain a free airway in patients with traumatic brain injury in low-income settings with minimal critical care capacity. However, no reports exist on the outcomes of this strategy. We examine the results of this practice at a central hospital in Malawi.

Methods

This is a retrospective review of medical records and prospectively gathered trauma surveillance data of patients admitted to Kamuzu Central Hospital, with traumatic brain injury from January 2010 to December 2015. In-hospital mortality rates were examined according to registered traumatic brain injury severity and airway management.

Results

In our analysis, 1875 of 2051 registered traumatic brain injury patients were included; 83.3% were male, mean age 32.6 (SD 12.9) years. 14.2% (n=267) of the patients had invasive airway management (endotracheal tube or tracheostomy) with or without mechanical ventilation. Mortality in severe traumatic brain injury treated with tracheostomy without mechanical ventilation was 42% (10/24) compared to 21% (14/68) in patients treated without intubation or tracheostomy (p= 0.043). Tracheostomies had an overall complication rate of 11%.

Conclusion

Tracheostomy without mechanical ventilation in severe traumatic brain injury did not improve survival outcomes in our setting. Tracheostomy for severe traumatic brain injury cannot be recommended when mechanical ventilation is not available unless there are sufficient specialized human resources for follow up in the ward. Efforts to improve critical care facilities and human resource capacity to allow proper use of mechanical ventilation in severe traumatic brain injury should be a high priority in low-income countries where the burden of trauma is high.

A retrospective descriptive analysis of non-physician-performed prehospital endotracheal intubation practices and performance in South Africa

Introduction

Prehospital advanced airway management, including endotracheal intubation (ETI), is one of the most commonly performed advanced life support skills. In South Africa, prehospital ETI is performed by non-physician prehospital providers. This practice has recently come under scrutiny due to lower first pass (FPS) and overall success rates, a high incidence of adverse events (AEs), and limited evidence regarding the impact of ETI on mortality. The aim of this study was to describe non-physician ETI in a South African national sample in terms of patient demographics, indications for intubation, means of intubation and success rates. A secondary aim was to determine what factors were predictive of first pass success.

Methods

This study was a retrospective chart review of prehospital ETIs performed by non-physician prehospital providers, between 01 January 2017 and 31 December 2017. Two national private Emergency Medical Services (EMS) and one provincial public EMS were sampled. Data were analysed descriptively and summarised. Logistic regression was performed to evaluate factors that affect the likelihood of FPS.

Results

A total of 926 cases were included. The majority of cases were adults (n = 781, 84.3%) and male (n = 553, 57.6%). The most common pathologies requiring emergency treatment were head injury, including traumatic brain injury (n = 328, 35.4%), followed by cardiac arrest (n = 204, 22.0%). The mean time on scene was 46 minutes (SD = 28.3). The most cited indication for intubation was decreased level of consciousness (n = 515, 55.6%), followed by cardiac arrest (n = 242, 26.9%) and ineffective ventilation (n = 96, 10.4%). Rapid sequence intubation (RSI, n = 344, 37.2%) was the most common approach. The FPS rate was 75.3%, with an overall success rate of 95.7%. Intubation failed in 33 (3.6%) patients. The need for ventilation was inversely associated with FPS (OR = 0.42, 95% CI: 0.20–0.88, p = 0.02); while deep sedation (OR = 0.56, 95% CI: 0.36–0.88, p = 0.13) and no drugs (OR = 0.47, 95% CI: 0.25–0.90, p = 0.02) compared to RSI was less likely to result in FPS. Increased scene time (OR = 0.99, 95% CI: 0.985–0.997, p < 0.01) was inversely associated FPS.

Conclusion

This is one of the first and largest studies evaluating prehospital ETI in Africa. In this sample of ground-based EMS non-physician ETI, we found success rates similar to those reported in the literature. More research is needed to determine AE rates and the impact of ETI on patient outcome. There is an urgent need to standardise prehospital ETI reporting in South Africa to facilitate future research.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-022-00688-4.

Mortality and Risk Factors in Isolated Traumatic Brain Injury Patients: A Prospective Cohort Study

INTRODUCTION

Outcomes in patients with isolated traumatic brain injury (iTBI) have not been evaluated comprehensively in low-income and middle-income countries. We aimed to study the in-hospital iTBI mortality and its associated risk factors in a prospective multicenter Indian trauma registry.

METHODS

Patients with iTBI (head and neck Abbreviated Injury Score ≥2 and other region Abbreviated Injury Score ≤2) were included. Study variables comprised age, gender, mechanism of injury, systolic blood pressure (SBP) at arrival, Glasgow Coma Scale (GCS) score - classified as mild (13-15), moderate (9-12), and severe (3-8), transfer status, and time to presentation at any participating hospital. A multivariable logistic regression was performed to assess the impact of these factors on 24-h and 30-d mortality following iTBI.

RESULTS

Among 5042 included patients, 24-h and 30-d in-hospital mortalities were 5.9% and 22.4%. On a regression analysis, 30-d mortality was associated with age ≥45 y (odds ratio [OR] = 2.1 [1.6-2.7]), railway injury mechanisms (OR = 2.1 [1.3-3.5]), SBP <90 mmHg (OR = 2.6 [1.6-4.1]), and moderate (OR = 3.8 [3.0-5.0]) to severe (OR = 21.1 [16.8-26.7]) iTBI based on GCS scores. 24-h mortality showed similar trends. Patients transferred to the participating hospitals from other centers had higher odds of 30-d mortality (OR = 1.4 [1.2-1.8]) compared to those arriving directly. Those who received neurosurgical intervention had lower odds of 24-h mortality (0.3 [0.2-0.4]).

CONCLUSIONS

Age ≥45 y, GCS score ≤12, and SBP <90 mmHg at arrival increased the risk of in-hospital mortality from iTBI.

Fluoxetine reduces organ injury and improves motor function after traumatic brain injury in mice

BACKGROUND

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality in trauma patients worldwide. Brain injury is associated with significant inflammation, both within the brain and in the peripheral organs. This inflammatory response in TBI leads to a secondary injury, worsening the effects of the original brain injury. Serotonin is also linked to inflammation in the intestine and inflammatory bowel disease, but its role in the gut-brain axis is not known. We hypothesized that using fluoxetine to block serotonin reuptake would reduce organ inflammation and improve outcomes after TBI.

METHODS

C57/B6 mice were given a severe TBI using a controlled cortical impact. To measure intestinal permeability, a piece of terminal ileum was resected, the lumen was filled with 4-kDa fluorescein isothiocyanate (FITC)-dextran, and the ends were tied. The intestinal segment was submerged in buffer and fluorescence in the buffer measured over time. To measure lung permeability, 70-kDa FITC-dextran is injected retro-orbitally. Thirty minutes later, the left lung was homogenized and the fluorescence was measured. To measure performance on the rota-rod, mice were placed on a spinning rod, and the time to fall off was measured. Those treated with fluoxetine received a single dose of 5 mg/kg via intraperitoneal injection immediately after injury.

RESULTS

Traumatic brain injury was associated with an increase in intestinal permeability to FITC-dextran, increased lung vascular permeability, and worse performance on the rota-rod. Fluoxetine significantly reduced lung and intestinal permeability after TBI and improved performance on the rota-rod after TBI.

CONCLUSION

Use of fluoxetine has the potential to reduce lung injury and improve motor coordination in severe TBI patients. Further study will be needed to elucidate the mechanism behind this effect.

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.

Prehospital Plasma Transfusion: What Does the Literature Show?

Background

Early initiation of blood products transfusion after injury has been associated with improved patient outcomes following traumatic injury. The ability to transfuse patients' plasma in the prehospital setting provides a prime opportunity to begin resuscitation with blood products earlier and with a more balanced plasma: RBC ratio than what has traditionally been done. Published studies on the use of prehospital plasma show a complex relationship between its use and improved survival.

Summary

Examination of the literature shows that there may be a mortality benefit from the use of prehospital plasma, but that it may be limited to certain subgroups of trauma patients. The likelihood of realizing these survival benefits appears to be predicted by several factors including the type of injury, length of transport time, presence of traumatic brain injury, and total number of blood products transfused, whether the patient required only a few products or a massive transfusion. When taken as a whole the evidence appears to show that prehospital plasma may have a mortality benefit that is most clearly demonstrated in patients with blunt injuries, moderate transfusion requirements, traumatic brain injury, and/or transport time greater than 20 min, as well as those who demonstrate a certain cytokine expression profile.

Key Messages

The evidence suggests that a targeted use of prehospital plasma will most likely maximize the benefits from the use of this limited resource. It is also possible that prehospital plasma may best be provided through whole blood as survival benefits were greatest in patients who received both prehospital plasma and RBCs.

Prehospital Trauma Airway Management: An NAEMSP Position Statement and Resource Document

Definitive management of trauma is not possible in the out-of-hospital environment. Rapid treatment and transport of trauma casualties to a trauma center are vital to improve survival and outcomes. Prioritization and management of airway, oxygenation, ventilation, protection from gross aspiration, and physiologic optimization must be balanced against timely patient delivery to definitive care. The optimal prehospital airway management strategy for trauma has not been clearly defined; the best choice should be patient-specific. NAEMSP recommends:The approach to airway management and the choice of airway interventions in a trauma patient requires an iterative, individualized assessment that considers patient, clinician, and environmental factors.Optimal trauma airway management should focus on meeting the goals of adequate oxygenation and ventilation rather than on specific interventions. Emergency medical services (EMS) clinicians should perform frequent reassessments to determine if there is a need to escalate from basic to advanced airway interventions.Management of immediately life-threatening injuries should take priority over advanced airway insertion.Drug-assisted airway management should be considered within a comprehensive algorithm incorporating failed airway options and balanced management of pain, agitation, and delirium.EMS medical directors must be highly engaged in assuring clinician competence in trauma airway assessment, management, and interventions.

Optimizing Physiology During Prehospital Airway Management: An NAEMSP Position Statement and Resource Document

Airway management is a critical component of resuscitation but also carries the potential to disrupt perfusion, oxygenation, and ventilation as a consequence of airway insertion efforts, the use of medications, and the conversion to positive-pressure ventilation. NAEMSP recommends:Airway management should be approached as an organized system of care, incorporating principles of teamwork and operational awareness.EMS clinicians should prevent or correct hypoxemia and hypotension prior to advanced airway insertion attempts.Continuous physiological monitoring must be used during airway management to guide the timing of, limit the duration of, and inform decision making during advanced airway insertion attempts.Initial and ongoing confirmation of advanced airway placement must be performed using waveform capnography. Airway devices must be secured using a reliable method.Perfusion, oxygenation, and ventilation should be optimized before, during, and after advanced airway insertion.To mitigate aspiration after advanced airway insertion, EMS clinicians should consider placing a patient in a semi-upright position.When appropriate, patients undergoing advanced airway placement should receive suitable pharmacologic anxiolysis, amnesia, and analgesia. In select cases, the use of neuromuscular blocking agents may be appropriate.

Controversies and evidence gaps in the early management of severe traumatic brain injury: back to the ABCs

Traumatic brain injury (TBI) accounts for around 30% of all trauma-related deaths. Over the past 40 years, TBI has remained a major cause of mortality after trauma. The primary injury caused by the injurious mechanical force leads to irreversible damage to brain tissue. The potentially preventable secondary injury can be accentuated by addressing systemic insults. Early recognition and prompt intervention are integral to achieve better outcomes. Consequently, surgeons still need to be aware of the basic yet integral emergency management strategies for severe TBI (sTBI). In this narrative review, we outlined some of the controversies in the early care of sTBI that have not been settled by the publication of the Brain Trauma Foundation’s 4th edition guidelines in 2017. The topics covered included the following: mode of prehospital transport, maintaining airway patency while securing the cervical spine, achieving adequate ventilation, and optimizing circulatory physiology. We discuss fluid resuscitation and blood product transfusion as components of improving circulatory mechanics and oxygen delivery to injured brain tissue. An outline of evidence-based antiplatelet and anticoagulant reversal strategies is discussed in the review. In addition, the current evidence as well as the evidence gaps for using tranexamic acid in sTBI are briefly reviewed. A brief note on the controversial emergency surgical interventions for sTBI is included. Clinicians should be aware of the latest evidence for sTBI. Periods between different editions of guidelines can have an abundance of new literature that can influence patient care. The recent advances included in this review should be considered both for formulating future guidelines for the management of sTBI and for designing future clinical studies in domains with clinical equipoise.

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.

Trauma Indicators in Spinal Cord Injury Rehabilitation Outcomes: A Retrospective Cohort Analysis of the National Trauma Data Bank and National Spinal Cord Injury Database

OBJECTIVE

To investigate whether initial emergency room physiologic measures and metrics of trauma severity predict functional outcomes and neurologic recovery in traumatic spinal cord injury.

DESIGN

Retrospective analysis of a clinical database.

SETTING

Merged multi-center data from the Spinal Cord Injury Model Systems (SCIMS) database and National Trauma Data Bank (NTDB) from six academic medical centers across the United States.

PARTICIPANTS

319 patients admitted to SCIMS rehabilitation centers within one-year of injury. The majority of patients were male (76.2%), with a mean age of 44 (SD 19). At rehabilitation admission, the most common neurologic level of injury was low cervical (C5-C8, 39.5%) and ASIA impairment scale (AIS) was A (34.4%).

MAIN OUTCOME MEASURES(S)

Primary outcomes were (1) Functional Independence Measure (FIM) motor score at discharge from inpatient rehabilitation and (2) change in FIM motor score between inpatient rehabilitation admission and discharge. We hypothesized that derangements in emergency room physiologic measures, such as decreased blood pressure and oxygen saturation, as well as increased severity of trauma burden, would predict poorer functional outcomes.

RESULTS

Linear regression analysis showed that neurologic level of injury and AIS predicted discharge FIM motor score. Systolic blood pressure, heart rate, oxygen saturation, need for assisted respiration, and presence of penetrating injury did not predict discharge motor FIM or FIM motor score improvement.

CONCLUSIONS

Initial emergency room physiologic parameters did not prognosticate functional outcomes in this cohort.

Association of Flow Rate of Prehospital Oxygen Administration and Clinical Outcomes in Severe Traumatic Brain Injury

The goal of this study was to investigate the association of prehospital oxygen administration flow with clinical outcome in severe traumatic brain injury (TBI) patients. This was a cross-sectional observational study using an emergency medical services-assessed severe trauma database in South Korea. The sample included adult patients with severe blunt TBI without hypoxia who were treated by EMS providers in 2013 and 2015. Main exposure was prehospital oxygen administration flow rate (no oxygen, low-flow 1~5, mid-flow 6~14, high-flow 15 L/min). Primary outcome was in-hospital mortality. A total of 1842 patients with severe TBI were included. The number of patients with no oxygen, low-flow oxygen, mid-flow oxygen, high-flow oxygen was 244, 573, 607, and 418, respectively. Mortality of each group was 34.8%, 32.3%, 39.9%, and 41.1%, respectively. Compared with the no-oxygen group, adjusted odds (95% CI) for mortality in the low-, mid-, and high-flow oxygen groups were 0.86 (0.62–1.20), 1.15 (0.83–1.60), and 1.21 (0.83–1.73), respectively. In the interaction analysis, low-flow oxygen showed lower mortality when prehospital saturation was 94–98% (adjusted odds ratio (AOR): 0.80 (0.67–0.95)) and ≥99% (AOR: 0.69 (0.53–0.91)). High-flow oxygen showed higher mortality when prehospital oxygen saturation was ≥99% (AOR: 1.33 (1.01~1.74)). Prehospital low-flow oxygen administration was associated with lower in-hospital mortality compared with the no-oxygen group. High-flow administration showed higher mortality.

Predictors of first pass success without hypoxemia in trauma patients requiring emergent rapid sequence intubation

Objective

The predictors of first pass success (FPS) without hypoxemia among trauma patients requiring rapid sequence intubation (RSI) in the emergent setting are unknown.

Methods

Retrospective study of adult trauma patients requiring RSI during a 5-year period comparing the trauma patients achieving FPS without hypoxemia to those who did not. The primary outcome was FPS without hypoxemia evaluated by multivariate logistic regression adjusting for the neuromuscular blocking agent used (succinylcholine or rocuronium), hypoxemia prior to RSI, Glasgow Coma Scale (GCS) scores, the presence of head or facial trauma, and intubating operator level of training.

Results

246 patients met our inclusion criteria. The overall FPS rate was 89%, and there was no statistical difference between those receiving either paralytic agent. 167 (69%) patients achieved FPS without hypoxemia. The two groups (those achieving FPS without hypoxemia and those who did not) had similar mean GCS, mean Injury Severity Scores, presence of head or facial trauma, the presence of penetrating trauma, intubating operator-level training, use of direct laryngoscopy, hypoxemia prior to RSI, heart rate per minute, mean systolic blood pressure, and respiratory rate. In the multivariate regression analysis, the use of succinylcholine and GCS score of 13–15 were found to have adjusted ORs of 2.1 (95% CI 1.2 to 3.8) and 2.0 (95% CI 1.0 to 3.3) for FPS without hypoxemia, respectively.

Conclusion

Trauma patients requiring emergency department RSI with high GCS score and those who received succinylcholine had higher odds of achieving FPS without hypoxemia, a patient safety goal requiring more study.

Level of evidence

IV.

Study type

Prognostic.

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.

Trauma centre admissions for traumatic brain injury in France: One-year epidemiological analysis of prospectively collected data

INTRODUCTION

In France, there is a lack of recent data on Traumatic brain injury (TBI), remaining a major global health challenge in terms of morbidity and mortality. The present study reports the epidemiology and the factors associated with mortality of patients with TBI admitted to 9 French trauma centres.

METHOD

Patients ≥ 15 years old admitted, between the 1^st of January and the 31^st of December 2017, following TBI (Abbreviated Injury Scale head ≥ 2) were included. Descriptive analyses were carried out and a logistic regression was used in order to identify in-hospital mortality predictors.

RESULTS

1,177 patients (889 males (76%), median age 42 [26-59]) were admitted following TBI. Road traffic accidents were the primary mechanism of TBI. Mechanisms leading to TBI were highly correlated with age. The in-hospital mortality was 23%. In-hospital mortality increased with age, from 15% in 15-24-year-olds to 71% among patients aged 85 years and older. Age, relevant past medical history, Glasgow coma scale motor score, subdural haematoma, systolic arterial blood pressure < 110 mmHg, pupillary abnormality and haemoglobin level were significantly associated with in-hospital mortality.

CONCLUSIONS

TBI is still a major public health concern affecting mostly young patients, victims of road traffic accidents and elderly patients, victims of falls. These findings could help clinicians adjusting medical approaches, targeting prevention measures and planning new research projects according to these French TBI population characteristics.

Severe traumatic brain injury management in Tanzania: analysis of a prospective cohort

OBJECTIVE

Given the high burden of neurotrauma in low- and middle-income countries (LMICs), in this observational study, the authors evaluated the treatment and outcomes of patients with severe traumatic brain injury (TBI) accessing care at the national neurosurgical institute in Tanzania.

METHODS

A neurotrauma registry was established at Muhimbili Orthopaedic Institute, Dar-es-Salaam, and patients with severe TBI admitted within 24 hours of injury were included. Detailed emergency department and subsequent medical and surgical management of patients was recorded. Two-week mortality was measured and compared with estimates of predicted mortality computed with admission clinical variables using the Corticoid Randomisation After Significant Head Injury (CRASH) core model.

RESULTS

In total, 462 patients (mean age 33.9 years) with severe TBI were enrolled over 4.5 years; 89% of patients were male. The mean time to arrival to the hospital after injury was 8 hours; 48.7% of patients had advanced airway management in the emergency department, 55% underwent cranial CT scanning, and 19.9% underwent surgical intervention. Tiered medical therapies for intracranial hypertension were used in less than 50% of patients. The observed 2-week mortality was 67%, which was 24% higher than expected based on the CRASH core model.

CONCLUSIONS

The 2-week mortality from severe TBI at a tertiary referral center in Tanzania was 67%, which was significantly higher than the predicted estimates. The higher mortality was related to gaps in the continuum of care of patients with severe TBI, including cardiorespiratory monitoring, resuscitation, neuroimaging, and surgical rates, along with lower rates of utilization of available medical therapies. In ongoing work, the authors are attempting to identify reasons associated with the gaps in care to implement programmatic improvements. Capacity building by twinning provides an avenue for acquiring data to accurately estimate local needs and direct programmatic education and interventions to reduce excess in-hospital mortality from TBI.

Early Trauma Indicators and Rehabilitation Outcomes in Traumatic Spinal Cord Injury

Objectives

To investigate the relationship between early trauma indicators and neurologic recovery after traumatic SCI using standardized outcome measures from the ISNCSCI examination and standardized functional outcome measures for rehabilitation populations.

Methods

This is a retrospective review of merged, prospectively collected, multicenter data from the Spinal Cord Injury Model Systems (SCIMS) database and institutional trauma databases from five academic medical centers across the United States. Functional status at inpatient rehabilitation discharge and change in severity and level of injury from initial SCI to inpatient rehabilitation discharge were analyzed to assess neurologic recovery for patients with traumatic SCI. Linear and logistic regression with multiple imputation were used for the analyses.

Results

A total of 209 patients were identified. Mean age at injury was 47.2 ± 18.9 years, 72.4% were male, 22.4% of patients had complete injuries at presentation to the emergency department (ED), and most patients were admitted with cervical SCI. Mean systolic blood pressure (SBP) was 124.1 ± 29.6 mm Hg, mean ED heart rate was 83.7 ± 19.9 bpm, mean O2 saturation was 96.8% ± 4.0%, and mean Glasgow Coma Scale (GCS) score was 13.3 ± 3.9. The average Injury Severity Score (ISS) in this population was 22.4. Linear regression analyses showed that rehabilitation discharge motor FIM was predicted by motor FIM on admission and ISS. Requiring ventilatory support on ED presentation was negatively associated with improvement of ASIA Impairment Scale (AIS) grade at rehabilitation discharge compared with AIS grade after initial injury. Emergency room physiologic measures (SBP, pulse, oxygen saturation) did not predict discharge motor FIM or improvement in AIS grade or neurological level of injury.

Conclusion

Our study showed a positive association between discharge FIM and ISS and a negative association between ventilatory support at ED presentation and AIS improvement. The absence of any significant association between other physiologic or clinical variables at ED presentation with rehabilitation outcomes suggests important areas for future clinical research.

The Association Between Arterial Oxygen Level and Outcome in Neurocritically Ill Patients is not Affected by Blood Pressure

Background

In neurocritically ill patients, one early mechanism behind secondary brain injury is low systemic blood pressure resulting in inadequate cerebral perfusion and consequent hypoxia. Intuitively, higher partial pressures of arterial oxygen (PaO₂) could be protective in case of inadequate cerebral circulation related to hemodynamic instability.

Study purpose

We examined whether the association between PaO₂ and mortality is different in patients with low compared to normal and high mean arterial pressure (MAP) in patients after various types of brain injury.

Methods

We screened the Finnish Intensive Care Consortium database for mechanically ventilated adult (≥ 18) brain injury patients treated in several tertiary intensive care units (ICUs) between 2003 and 2013. Admission diagnoses included traumatic brain injury, cardiac arrest, subarachnoid and intracranial hemorrhage, and acute ischemic stroke. The primary exposures of interest were PaO₂ (recorded in connection with the lowest measured PaO₂/fraction of inspired oxygen ratio) and the lowest MAP, recorded during the first 24 h in the ICU. PaO₂ was grouped as follows: hypoxemia (< 8.2 kPa, the lowest 10th percentile), normoxemia (8.2–18.3 kPa), and hyperoxemia (> 18.3 kPa, the highest 10th percentile), and MAP was divided into equally sized tertiles (< 60, 60–68, and > 68 mmHg). The primary outcome was 1-year mortality. We tested the association between hyperoxemia, MAP, and mortality with a multivariable logistic regression model, including the PaO₂, MAP, and interaction of PaO₂*MAP, adjusting for age, admission diagnosis, premorbid physical performance, vasoactive use, intracranial pressure monitoring use, and disease severity. The relationship between predicted 1-year mortality and PaO₂ was visualized with locally weighted scatterplot smoothing curves (Loess) for different MAP levels.

Results

From a total of 8290 patients, 3912 (47%) were dead at 1 year. PaO₂ was not an independent predictor of mortality: the odds ratio (OR) for hyperoxemia was 1.16 (95% CI 0.85–1.59) and for hypoxemia 1.24 (95% CI 0.96–1.61) compared to normoxemia. Higher MAP predicted lower mortality: OR for MAP 60–68 mmHg was 0.73 (95% CI 0.64–0.84) and for MAP > 68 mmHg 0.80 (95% CI 0.69–0.92) compared to MAP < 60 mmHg. The interaction term PaO₂*MAP was nonsignificant. In Loess visualization, the relationship between PaO₂ and predicted mortality appeared similar in all MAP tertiles.

Conclusions

During the first 24 h of ICU treatment in mechanically ventilated brain injured patients, the association between PaO₂ and mortality was not different in patients with low compared to normal MAP.

Supplementary Information

The online version of this article (10.1007/s12028-020-01178-w) contains supplementary material, which is available to authorized users.

A Review of "Prehospital Hypotension as a Valid Indicator of Trauma Team Activation" (2000)

Prehospital hypotension has been utilized for decades as a surrogate marker of injury severity. Several studies have discussed the correlation between injury and hypotension both in the field as well as in the emergency department. Increases have been noted in injury severity score and mortality. Resource utilization is higher in this patient population. This study revisits our original work from 2000 and reviews the current literature regarding hypotension and injury severity. We also examine the role of prehospital hypotension as an indicator of trauma team activation and resource allocation. This review serves as a part of a Literary Festschrift in honor of Dr J David Richardson's role as the Editor-in-Chief of The American Surgeon.

Impact of nursing education and a monitoring tool on outcomes in traumatic brain injury

Introduction

Throughout the world, traumatic brain injury (TBI) is one of the leading causes of morbidity and mortality. Low-and middle-income countries experience an especially high burden of TBI. While guidelines for TBI management exist in high income countries, little is known about the optimal management of TBI in low resource settings. Prevention of secondary injuries is feasible in these settings and has potential to improve mortality.

Methods

A pragmatic quasi-experimental study was conducted in the emergency centre (EC) of Mulago National Referral Hospital to evaluate the impact of TBI nursing education and use of a monitoring tool on mortality. Over 24 months, data was collected on 541 patients with moderate (GCS9-13) to severe (GCS≤8) TBI. The primary outcome was in-hospital mortality and secondary outcomes included time to imaging, time to surgical intervention, time to advanced airway, length of stay and number of vital signs recorded.

Results

Data were collected on 286 patients before the intervention and 255 after. Unadjusted mortality was higher in the post-intervention group but appeared to be related to severity of TBI, not the intervention itself. Apart from number of vital signs, secondary outcomes did not differ significantly between groups. In the post-intervention group, vital signs were recorded an average of 2.85 times compared to 0.49 in the pre-intervention group (95% CI 2.08-2.62, p ≤ 0.001). The median time interval between vital signs in the post-intervention group was 4.5 h (IQR 2.1-10.6).

Conclusion

Monitoring of vital signs in the EC improved with nursing education and use of a monitoring tool, however, there was no detectable impact on mortality. The high mortality among patients with TBI underscores the need for treatment strategies that can be implemented in low resource settings. Promising approaches include improved monitoring, organized trauma systems and protocols with an emphasis on early aggressive care and primary prevention.