Balancing the Potential Risks and Benefits of Out-of-Hospital Intubation in Traumatic Brain Injury: The Intubation/Hyperventilation Effect

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.

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.

Prehospital Airway Management: A Systematic Review

Objective: To assess comparative benefits and harms across three airway management approaches (bag valve mask [BVM], supraglottic airway [SGA], and endotracheal intubation [ETI]) used by prehospital emergency medical services (EMS) to treat patients with trauma, cardiac arrest, or medical emergencies, and how they differ based on techniques and devices, EMS personnel and patient characteristics. Data sources: We searched electronic citation databases (Ovid® MEDLINE®, CINAHL®, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, and Scopus®) from 1990 to September 2020. Review methods: We followed Agency for Healthcare Research and Quality Effective Health Care Program Methods guidance. Outcomes included mortality, neurological function, return of spontaneous circulation (ROSC), and successful advanced airway insertion. Meta-analyses using profile-likelihood random effects models were conducted, with analyses stratified by study design, emergency type, and age. Results: We included 99 studies involving 630,397 patients. We found few differences in primary outcomes across airway management approaches. For survival, there was no difference for BVM versus ETI or SGA in adult and pediatric patients with cardiac arrest or trauma. For neurological function, there was no difference for BVM versus ETI and SGA versus ETI in pediatric patients with cardiac arrest. There was no difference in BVM versus ETI in adults with cardiac arrest, but improved neurological function with BVM or ETI versus SGA. There was no difference in ROSC for patients with cardiac arrest for BVM versus ETI or SGA in adults and pediatrics, or SGA versus ETI in pediatrics. There was higher frequency of ROSC in adults with SGA versus ETI. For successful advanced airway insertion, there was higher first-pass success with SGA versus ETI for all patients except adult medical patients (no difference), and no difference in overall success using SGA versus ETI in adults. Conclusions: The currently available evidence does not indicate benefits of more invasive airway approaches based on survival, neurological function, ROSC, or successful airway insertion. Strength of evidence was low or moderate; most included studies were observational. This supports the need for high-quality randomized controlled trials to advance clinical practice and EMS education and policy, and improve patient-centered outcomes.

A systematic review of the timing of intubation in patients with traumatic brain injury: pre-hospital versus in-hospital intubation

PURPOSE

The objective of this systematic review was to examine current evidence on the risks versus benefit of pre-hospital intubation when compared with in-hospital intubation in adult patients with traumatic brain injuries.

METHODS

We conducted electronic searches of PubMed, Medline, Embase, CIANHL and the Cochrane library up to March 2021. Data extracted compared mortality, length of hospital and intensive care stay, pneumonia and functional outcomes in traumatic brain injured patients undergoing pre-hospital intubation versus in-hospital intubation. The risk of bias was assessed using the Grading of Recommendations Assessment, Development and Evaluation.

RESULTS

Ten studies including 25,766 patients were analysed. Seven were retrospective studies, two prospective cohort studies and one randomised control study. The mean mortality rate in patients who underwent pre-hospital intubation was 44.5% and 31.98% for in-hospital intubation. The odds ratio for an effect of pre-hospital intubation on mortality ranged from 0.31 (favouring in-hospital intubation) to 3.99 (favouring pre-hospital). The overall quality of evidence is low; however, the only randomised control study showed an improved functional outcome for pre-hospital intubation at 6 months.

CONCLUSIONS

The existing evidence does not support widespread pre-hospital intubation in all traumatic brain injured patients. This does not, however, contradict the need for the intervention when there is severe airway compromise; instead, it must be assessed by experienced personnel if a time critical transfer to hospital is more advantageous. Favourable neurological outcomes highlighted by the randomised control trial favours pre-hospital intubation, but further research is required in this field.

Prehospital Manual Ventilation: An NAEMSP Position Statement and Resource Document

Manual ventilation using a self-inflating bag device paired with a facemask (bag-valve-mask, or BVM ventilation) or invasive airway (bag-valve-device, or BVD ventilation) is a fundamental airway management skill for all Emergency Medical Services (EMS) clinicians. Delivery of manual ventilations is challenging. Several strategies and adjunct technologies can increase the effectiveness of manual ventilation. NAEMSP recommends:All EMS clinicians must be proficient in bag-valve-mask ventilation.BVM ventilation should be performed using a two-person technique whenever feasible.EMS clinicians should use available techniques and adjuncts to achieve optimal mask seal, improve airway patency, optimize delivery of the correct rate, tidal volume, and pressure during manual ventilation, and allow continual assessment of manual ventilation effectiveness.

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.

Tracheal intubation in traumatic brain injury: a multicentre prospective observational study

BACKGROUND

We aimed to study the associations between pre- and in-hospital tracheal intubation and outcomes in traumatic brain injury (TBI), and whether the association varied according to injury severity.

METHODS

Data from the international prospective pan-European cohort study, Collaborative European NeuroTrauma Effectiveness Research for TBI (CENTER-TBI), were used (n=4509). For prehospital intubation, we excluded self-presenters. For in-hospital intubation, patients whose tracheas were intubated on-scene were excluded. The association between intubation and outcome was analysed with ordinal regression with adjustment for the International Mission for Prognosis and Analysis of Clinical Trials in TBI variables and extracranial injury. We assessed whether the effect of intubation varied by injury severity by testing the added value of an interaction term with likelihood ratio tests.

RESULTS

In the prehospital analysis, 890/3736 (24%) patients had their tracheas intubated at scene. In the in-hospital analysis, 460/2930 (16%) patients had their tracheas intubated in the emergency department. There was no adjusted overall effect on functional outcome of prehospital intubation (odds ratio=1.01; 95% confidence interval, 0.79-1.28; P=0.96), and the adjusted overall effect of in-hospital intubation was not significant (odds ratio=0.86; 95% confidence interval, 0.65-1.13; P=0.28). However, prehospital intubation was associated with better functional outcome in patients with higher thorax and abdominal Abbreviated Injury Scale scores (P=0.009 and P=0.02, respectively), whereas in-hospital intubation was associated with better outcome in patients with lower Glasgow Coma Scale scores (P=0.01): in-hospital intubation was associated with better functional outcome in patients with Glasgow Coma Scale scores of 10 or lower.

CONCLUSION

The benefits and harms of tracheal intubation should be carefully evaluated in patients with TBI to optimise benefit. This study suggests that extracranial injury should influence the decision in the prehospital setting, and level of consciousness in the in-hospital setting.

CLINICAL TRIAL REGISTRATION

NCT02210221.

Optimal Airway Management in Cardiac Arrest

Airway management during cardiac arrest has undergone several advancements. Endotracheal intubation (ETI) often is considered the gold standard for airway management in cardiac arrest; however, other options exist. Recent prospective randomized trials have compared outcomes in bag-valve mask ventilation and supraglottic airways to ETI in out-of-hospital cardiac arrest. ETI, if performed early in resuscitation, is associated with worse patient outcomes and has been de-emphasized so as not to interfere with other aspects of the resuscitation. Hyperventilation has multiple theoretic harms during cardiac arrest, and methods, such as compression-adjusted ventilation, may be utilized to help reduce the incidence of hyperventilation.

Association of Statewide Implementation of the Prehospital Traumatic Brain Injury Treatment Guidelines With Patient Survival Following Traumatic Brain Injury: The Excellence in Prehospital Injury Care (EPIC) Study

Importance

Traumatic brain injury (TBI) is a massive public health problem. While evidence-based guidelines directing the prehospital treatment of TBI have been promulgated, to our knowledge, no studies have assessed their association with survival.

Objective

To evaluate the association of implementing the nationally vetted, evidence-based, prehospital treatment guidelines with outcomes in moderate, severe, and critical TBI.

Design, Setting, and Participants

The Excellence in Prehospital Injury Care (EPIC) Study included more than 130 emergency medical services systems/agencies throughout Arizona. This was a statewide, multisystem, intention-to-treat study using a before/after controlled design with patients with moderate to critically severe TBI (US Centers for Disease Control and Prevention Barell Matrix-Type 1 and/or Abbreviated Injury Scale Head region severity ≥3) transported to trauma centers between January 1, 2007, and June 30, 2015. Data were analyzed between October 25, 2017, and February 22, 2019.

Interventions

Implementation of the prehospital TBI guidelines emphasizing avoidance/treatment of hypoxia, prevention/correction of hyperventilation, and avoidance/treatment of hypotension.

Main Outcomes and Measures

Primary: survival to hospital discharge; secondary: survival to hospital admission.

Results

Of the included patients, the median age was 45 years, 14 666 (67.1%) were men, 7181 (32.9%) were women; 16 408 (75.1% ) were white, 1400 (6.4%) were Native American, 743 (3.4% ) were Black, 237 (1.1%) were Asian, and 2791 (12.8%) were other race/ethnicity. Of the included patients, 21 852 met inclusion criteria for analysis (preimplementation phase [P1]: 15 228; postimplementation [P3]: 6624). The primary analysis (P3 vs P1) revealed an adjusted odds ratio (aOR) of 1.06 (95% CI, 0.93-1.21; P = .40) for survival to hospital discharge. The aOR was 1.70 (95% CI, 1.38-2.09; P < .001) for survival to hospital admission. Among the severe injury cohorts (but not moderate or critical), guideline implementation was significantly associated with survival to discharge (Regional Severity Score-Head 3-4: aOR, 2.03; 95% CI, 1.52-2.72; P < .001; Injury Severity Score 16-24: aOR, 1.61; 95% CI, 1.07-2.48; P = .02). This was also true for survival to discharge among the severe, intubated subgroups (Regional Severity Score-Head 3-4: aOR, 3.14; 95% CI, 1.65-5.98; P < .001; Injury Severity Score 16-24: aOR, 3.28; 95% CI, 1.19-11.34; P = .02).

Conclusions and Relevance

Statewide implementation of the prehospital TBI guidelines was not associated with significant improvement in overall survival to hospital discharge (across the entire, combined moderate to critical injury spectrum). However, adjusted survival doubled among patients with severe TBI and tripled in the severe, intubated cohort. Furthermore, guideline implementation was significantly associated with survival to hospital admission. These findings support the widespread implementation of the prehospital TBI treatment guidelines.

Trial Registration

ClinicalTrials.gov identifier: NCT01339702.

To intubate or not: ventilation is the question. A manikin-based observational study

INTRODUCTION

There is a continuous debate concerning the superiority of endotracheal intubation on bag-valve-mask (BVM) ventilation in patients with cardiac arrest. In this manikin-based observational study, we evaluate and compare the performance of manual ventilation through a facemask (BVM) and an endotracheal tube (ETT).

METHODS

One hundred and forty healthcare providers were instructed to manually ventilate a manikin as they would do for a 75 kg adult patient in respiratory arrest. Each one was ventilating both through a facemask and an ETT for a 5 min period in a random order. Ventilatory parameters were measured by the ASL 5000 lung simulator and ventilation performance was analysed using a sliding window method published in a previous study to assess accurately ventilation efficiency.

RESULTS

The mean ventilation rate was high whatever the technique used (24 bpm). A weak relationship between manual ventilation performance and the type of interface used was observed (p=0.0484). The overall rate of adequate ventilation was low even if we noticed a slight improvement when ventilating through an ETT (13.21% vs 7.5% of adequate ventilation). However, the rate of hyperventilation did not differ between mask and tube (79% vs 77%). A significant relationship is observed between professional category, the size of the hand squeezing the bag and manual ventilation performance (p<0.05).

CONCLUSION

Whatever the interface used, healthcare professionals are still struggling to perform manual ventilation efficiently according to international guidelines. Ventilation with an ETT does not prove to be significantly more efficient than with a facemask. It would be therefore important to recentre the debate on controlling ventilatory parameters with current devices. Focusing on training may maximise manual ventilation efficiency and minimise the loss of time during cardiopulmonary resuscitation.

Prehospital Intubation is Associated with Favorable Outcomes and Lower Mortality in ProTECT III

OBJECTIVE

Traumatic brain injury (TBI) causes more than 2.5 million emergency department visits, hospitalizations, or deaths annually. Prehospital endotracheal intubation has been associated with poor outcomes in patients with TBI in several retrospective observational studies. We evaluated the relationship between prehospital intubation, functional outcomes, and mortality using high quality data on clinical practice collected prospectively during a randomized multicenter clinical trial.

METHODS

ProTECT III was a multicenter randomized, double-blind, placebo-controlled trial of early administration of progesterone in 882 patients with acute moderate to severe nonpenetrating TBI. Patients were excluded if they had an index GCS of 3 and nonreactive pupils, those with withdrawal of life support on arrival, and if they had documented prolonged hypotension and/or hypoxia. Prehospital intubation was performed as per local clinical protocol in each participating EMS system. Models for favorable outcome and mortality included prehospital intubation, method of transport, index GCS, age, race, and ethnicity as independent variables. Significance was set at α = 0.05. Favorable outcome was defined by a stratified dichotomy of the GOS-E scores in which the definition of favorable outcome depended on the severity of the initial injury.

RESULTS

Favorable outcome was more frequent in the 349 subjects with prehospital intubation (57.3%) than in the other 533 patients (46.0%, p = 0.003). Mortality was also lower in the prehospital intubation group (13.8% v. 19.5%, p = 0.03). Logistic regression analysis of prehospital intubation and mortality, adjusted for index GCS, showed that odds of dying for those with prehospital intubation were 47% lower than for those that were not intubated (OR = 0.53, 95% CI = 0.36-0.78). 279 patients with prehospital intubation were transported by air. Modeling transport method and mortality, adjusted for index GCS, showed increased odds of dying in those transported by ground compared to those transported by air (OR = 2.10, 95% CI = 1.40-3.15). Decreased odds of dying trended among those with prehospital intubation adjusted for transport method, index GCS score at randomization, age, and race/ethnicity (OR = 0.70, 95% CI = 0.37-1.31).

CONCLUSIONS

In this study that excluded moribund patients, prehospital intubation was performed primarily in patients transported by air. Prehospital intubation and air medical transport together were associated with favorable outcomes and lower mortality. Prehospital intubation was not associated with increased morbidity or mortality regardless of transport method or severity of injury.

Body Temperature after EMS Transport: Association with Traumatic Brain Injury Outcomes

INTRODUCTION

Low body temperatures following prehospital transport are associated with poor outcomes in patients with traumatic brain injury (TBI). However, a minimal amount is known about potential associations across a range of temperatures obtained immediately after prehospital transport. Furthermore, a minimal amount is known about the influence of body temperature on non-mortality outcomes. The purpose of this study was to assess the correlation between temperatures obtained immediately following prehospital transport and TBI outcomes across the entire range of temperatures.

METHODS

This retrospective observational study included all moderate/severe TBI cases (CDC Barell Matrix Type 1) in the pre-implementation cohort of the Excellence in Prehospital Injury Care (EPIC) TBI Study (NIH/NINDS: 1R01NS071049). Cases were compared across four cohorts of initial trauma center temperature (ITCT): <35.0°C [Very Low Temperature (VLT)]; 35.0-35.9°C [Low Temperature (LT)]; 36.0-37.9°C [Normal Temperature (NT)]; and ≥38.0°C [Elevated Temperature (ET)]. Multivariable analysis was performed adjusting for injury severity score, age, sex, race, ethnicity, blunt/penetrating trauma, and payment source. Adjusted odds ratios (aORs) with 95% confidence intervals (CI) for mortality were calculated. To evaluate non-mortality outcomes, deaths were excluded and the adjusted median increase in hospital length of stay (LOS), ICU LOS and total hospital charges were calculated for each ITCT group and compared to the NT group.

RESULTS

22,925 cases were identified and cases with interfacility transfer (7361, 32%), no EMS transport (1213, 5%), missing ITCT (2083, 9%), or missing demographic data (391, 2%) were excluded. Within this study cohort the aORs for death (compared to the NT group) were 2.41 (CI: 1.83-3.17) for VLT, 1.62 (CI: 1.37-1.93) for LT, and 1.86 (CI: 1.52-3.00) for ET. Similarly, trauma center (TC) LOS, ICU LOS, and total TC charges increased in all temperature groups when compared to NT.

CONCLUSION

In this large, statewide study of major TBI, both ETs and LTs immediately following prehospital transport were independently associated with higher mortality and with increased TC LOS, ICU LOS, and total TC charges. Further study is needed to identify the causes of abnormal body temperature during the prehospital interval and if in-field measures to prevent temperature variations might improve outcomes.

Environmental Hyperthermia in Prehospital Patients with Major Traumatic Brain Injury

BACKGROUND

Traumatic brain injury (TBI) results in an estimated 1.7 million emergency department visits each year in the United States. These injuries frequently occur outside, leaving injured individuals exposed to environmental temperature extremes before they are transported to a hospital.

OBJECTIVE

Evaluate the existing literature for evidence that exposure to high temperatures immediately after TBI could result in elevated body temperatures (EBTs), and whether or not EBTs affect patient outcomes.

DISCUSSION

It has been clear since the early 1980s that after brain injury, exposure to environmental temperatures can cause hypothermia, and that this represents a significant contributor to increased morbidity and mortality. Less is known about elevated body temperature. Early evidence from the Iraq and Afghanistan wars indicated that exposure to elevated environmental temperatures in the prehospital setting may result in significant EBTs, however, it is unclear what impact these EBTs might have on outcomes in TBI patients. In the hospital, EBT, or neurogenic fever, is thought to be due to the acute-phase reaction that follows critical injury, and these high body temperatures are associated with poor outcomes after TBI.

CONCLUSION

Hospital data suggest that EBTs are associated with poor outcomes, and some preliminary reports suggest that early EBTs are common after TBI in the prehospital setting. However, it remains unclear whether patients with TBI have an increased risk of EBTs after exposure to high environmental temperatures, or if this very early "hyperthermia" might cause secondary injury after TBI.

Mechanisms linking advanced airway management and cardiac arrest outcomes

Advanced airway management--such as endotracheal intubation (ETI) or supraglottic airway (SGA) insertion--is one of the most prominent interventions in out-of-hospital cardiac arrest (OHCA) resuscitation. While randomized controlled trials are currently in progress to identify the best advanced airway technique in OHCA, the mechanisms by which airway management may influence OHCA outcomes remain unknown. We provide a conceptual model describing potential mechanisms linking advanced airway management with OHCA outcomes.