Dutch Prospective Observational Study on Prehospital Treatment of Severe Traumatic Brain Injury: The BRAIN-PROTECT Study Protocol

Effect of Daytime versus Nighttime on Prehospital Care and Outcomes after Severe Traumatic Brain Injury

Background/Objectives: Severe traumatic brain injury (TBI) is a frequent cause of morbidity and mortality worldwide. In the Netherlands, suspected TBI is a criterion for the dispatch of the physician-staffed helicopter emergency medical services (HEMS) which are operational 24 h per day. It is unknown if patient outcome is influenced by the time of day during which the incident occurs. Therefore, we investigated the association between the time of day of the prehospital treatment of severe TBI and 30-day mortality. Methods: A retrospective analysis of prospectively collected data from the BRAIN-PROTECT study was performed. Patients with severe TBI treated by one of the four Dutch helicopter emergency medical services were included and followed up to one year. The association between prehospital treatment during day- versus nighttime, according to the universal daylight period, and 30-day mortality was analyzed with multivariable logistic regression. A planned subgroup analysis was performed in patients with TBI with or without any other injury. Results: A total of 1794 patients were included in the analysis, of which 1142 (63.7%) were categorized as daytime and 652 (36.3%) as nighttime. Univariable analysis showed a lower 30-day mortality in patients with severe TBI treated during nighttime (OR 0.74, 95% CI 0.60-0.91, p = 0.004); this association was no longer present in the multivariable model (OR 0.82, 95% CI 0.59-1.16, p = 0.262). In a subgroup analysis, no association was found between mortality rates and the time of prehospital treatment in patients with combined injuries (TBI and any other injury). Patients with isolated TBI had a lower mortality rate when treated during nighttime than when treated during daytime (OR 0.51, 95% CI 0.34-0.76, p = 0.001). Within the whole cohort, daytime versus nighttime treatments were not associated with differences in functional outcome defined by the Glasgow Outcome Scale. Conclusions: In the overall study population, no difference was found in 30-day mortality between patients with severe TBI treated during day or night in the multivariable model. Patients with isolated severe TBI had lower mortality rates at 30 days when treated at nighttime.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

EDITOR’S PERSPECTIVE

Association between prehospital end-tidal carbon dioxide levels and mortality in patients with suspected severe traumatic brain injury

PURPOSE

Severe traumatic brain injury is a leading cause of mortality and morbidity, and these patients are frequently intubated in the prehospital setting. Cerebral perfusion and intracranial pressure are influenced by the arterial partial pressure of CO₂ and derangements might induce further brain damage. We investigated which lower and upper limits of prehospital end-tidal CO₂ levels are associated with increased mortality in patients with severe traumatic brain injury.

METHODS

The BRAIN-PROTECT study is an observational multicenter study. Patients with severe traumatic brain injury, treated by Dutch Helicopter Emergency Medical Services between February 2012 and December 2017, were included. Follow-up continued for 1 year after inclusion. End-tidal CO₂ levels were measured during prehospital care and their association with 30-day mortality was analyzed with multivariable logistic regression.

RESULTS

A total of 1776 patients were eligible for analysis. An L-shaped association between end-tidal CO₂ levels and 30-day mortality was observed (p = 0.01), with a sharp increase in mortality with values below 35 mmHg. End-tidal CO₂ values between 35 and 45 mmHg were associated with better survival rates compared to < 35 mmHg. No association between hypercapnia and mortality was observed. The odds ratio for the association between hypocapnia (< 35 mmHg) and mortality was 1.89 (95% CI 1.53-2.34, p < 0.001) and for hypercapnia (≥ 45 mmHg) 0.83 (0.62-1.11, p = 0.212).

CONCLUSION

A safe zone of 35-45 mmHg for end-tidal CO₂ guidance seems reasonable during prehospital care. Particularly, end-tidal partial pressures of less than 35 mmHg were associated with a significantly increased mortality.

Intravenous lidocaine attenuates distention of the optical nerve sheath, a correlate of intracranial pressure, during endotracheal intubation

BACKGROUND

By preventing hypoxia and hypercapnia, advanced airway management can save lives among patients with traumatic brain injury. During endotracheal intubation (ETI), tracheal stimulation causes an increase in intracranial pressure (ICP), which may impair brain perfusion. It has been suggested that intravenous lidocaine might attenuate this ICP response. We hypothesized that adding lidocaine to the standard induction medication for general anesthesia might reduce the ICP response to ETI. Here, we measured the optical nerve sheath diameter (ONSD) as a correlate of ICP and evaluated the effect of intravenous lidocaine on ONSD during and after ETI in patients undergoing anesthesia.

METHODS

This double-blinded, randomized placebo-controlled trial included 60 patients with American Society of Anesthesiologists I or II physical status that were scheduled for elective surgery under general anesthesia. In addition to the standard anesthesia medication, 30 subjects received 1.5 mg/kg 1% lidocaine (0.15 mL/kg, ONSD lidocaine) and 30 received 0.15 mL/kg 0.9% NaCl (ONSD placebo). ONSDs were measured with ultrasound on the left eye, before (T0), during (T1), and 4 times after ETI (T2-5 at 5-min intervals).

RESULTS

Compared to placebo, lidocaine did not significantly affect the baseline ONSD after anesthesia induction measured at T0. During ETI, the ONSD lidocaine was significantly smaller (β=-0.24 mm P=0.022) than the ONSD placebo. At T4 and T5, the ONSD placebo increased steadily, up to 20 min after ETI, but the ONSD lidocaine tended to return to baseline levels.

CONCLUSIONS

We found that the ONSD was distended during and after ETI in anesthetized patients, and intravenous lidocaine attenuated this effect.

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

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

Indications for prehospital intubation among severely injured children and the prevalence of significant traumatic brain injury among those intubated due to impaired level of consciousness

BACKGROUND

Prehospital endotracheal intubation (PEI) of head injured children with impaired level of consciousness (LOC) aims to minimize secondary brain injury. However, PEI is controversial in otherwise stable children. We aimed to investigate the indications for PEI among pediatric trauma patients and the prevalence of clinically significant traumatic brain injury (csTBI) among those intubated solely due to impaired consciousness.

METHODS

This is a multicenter retrospective cohort study of children who underwent PEI in northern Israel between January 2014 and December 2020 by six EMS agencies and were transported to two trauma centers in the area. We extracted data from EMS records and trauma registries.

RESULTS

PEI was attempted in 179/986 (18.2%) patients and was successful in 92.2% of cases. Common indications for PEI were hypoxemia not corrected by supplemental oxygen (n = 30), traumatic cardiac arrest (n = 16), and facial injury compromising the airway (n = 13). 112 patients (62.6%) were intubated solely due to impaired or deteriorating LOC. Among these patients, 68 (62.4%) suffered csTBI. The prevalence of csTBI among those with field Glasgow Coma Scale (GCS) of 3, 4-8, and > 8 was 81.4%, 55.8%, and 28.6%, respectively (p < 0.001). Among children ≤ 10 years old intubated due to impaired LOC, 50% had csTBI.

CONCLUSION

Impaired LOC is a major indication for PEI. However, a significant proportion of these patients do not suffer csTBI. Older age and lower pre-intubation GCS are associated with more accurate field classification. Our data indicate that further investigation and better characterization of patients who may benefit from PEI is necessary.

Face-to-Face Versus Telephonic Extended Glasgow Outcome Score Testing After Traumatic Brain Injury

OBJECTIVE

The Extended Glasgow Outcome Scale (GOS-E) is used for objective assessment of functional outcome in traumatic brain injury (TBI). In situations where face-to-face contact is not feasible, telephonic assessment of the GOS-E might be desirable. The aim of this study is to assess the level of agreement between face-to-face and telephonic assessment of the GOS-E.

SETTING

Multicenter study in 2 Dutch University Medical Centers. Inclusion was performed in the outpatient clinic (face-to-face assessment, by experienced neurologist), followed by assessment via telephone of the GOS-E after ±2 weeks (by trained researcher).

PARTICIPANTS

Patients ±6 months after TBI.

DESIGN

Prospective validation study.

MAIN MEASURES

Interrater agreement of the GOS-E was assessed with Cohen's weighted κ.

RESULTS

From May 2014 until March 2018, 50 patients were enrolled; 54% were male (mean age 49.1 years). Median time between trauma and in-person GOS-E examination was 158 days and median time between face-to-face and telephonic GOS-E was 15 days. The quadratic weighted κ was 0.79. Sensitivity analysis revealed a quadratic weighted κ of 0.77, 0.78, and 0.70 for moderate-severe, complicated mild, and uncomplicated mild TBI, respectively.

CONCLUSION

No disagreements of more than 1 point on the GOS-E were observed, with the κ value representing good or substantial agreement. Assessment of the GOS-E via telephone is a valid alternative to the face-to-face interview when in-person contact is not feasible.

Association Between Prehospital Tranexamic Acid Administration and Outcomes of Severe Traumatic Brain Injury

Importance

The development and expansion of intracranial hematoma are associated with adverse outcomes. Use of tranexamic acid might limit intracranial hematoma formation, but its association with outcomes of severe traumatic brain injury (TBI) is unclear.

Objective

To assess whether prehospital administration of tranexamic acid is associated with mortality and functional outcomes in a group of patients with severe TBI.

Design, Setting, and Participants

This multicenter cohort study is an analysis of prospectively collected observational data from the Brain Injury: Prehospital Registry of Outcome, Treatments and Epidemiology of Cerebral Trauma (BRAIN-PROTECT) study in the Netherlands. Patients treated for suspected severe TBI by the Dutch Helicopter Emergency Medical Services between February 2012 and December 2017 were included. Patients were followed up for 1 year after inclusion. Data were analyzed from January 10, 2020, to September 10, 2020.

Exposures

Administration of tranexamic acid during prehospital treatment.

Main Outcomes and Measures

The primary outcome was 30-day mortality. Secondary outcomes included mortality at 1 year, functional neurological recovery at discharge (measured by Glasgow Outcome Scale), and length of hospital stay. Data were also collected on demographic factors, preinjury medical condition, injury characteristics, operational characteristics, and prehospital vital parameters.

Results

A total of 1827 patients were analyzed, of whom 1283 (70%) were male individuals and the median (interquartile range) age was 45 (23-65) years. In the unadjusted analysis, higher 30-day mortality was observed in patients who received prehospital tranexamic acid (odds ratio [OR], 1.34; 95% CI, 1.16-1.55; P < .001), compared with patients who did not receive prehospital tranexamic acid. After adjustment for confounders, no association between prehospital administration of tranexamic acid and mortality was found across the entire cohort of patients. However, a substantial increase in the odds of 30-day mortality persisted in patients with severe isolated TBI who received prehospital tranexamic acid (OR, 4.49; 95% CI, 1.57-12.87; P = .005) and after multiple imputations (OR, 2.05; 95% CI, 1.22-3.45; P = .007).

Conclusions and Relevance

This study found that prehospital tranexamic acid administration was associated with increased mortality in patients with isolated severe TBI, suggesting the judicious use of the drug when no evidence for extracranial hemorrhage is present.

Operational experience of the Dutch helicopter emergency medical services (HEMS) during the initial phase of the COVID-19 pandemic: jeopardy on the prehospital care system?

Purpose

The SARS-CoV-2 virus has disrupted global and local medical supply chains. To combat the spread of the virus and prevent an uncontrolled outbreak with limited resources, national lockdown protocols have taken effect in the Netherlands since March 13^th, 2020. The aim of this study was to describe the incidence, type and characteristics of HEMS and HEMS-ambulance ‘Lifeliner 1’ dispatches during the initial phase of the COVID-19 pandemic compared to the same period one year prior.

Methods

A retrospective review of all HEMS and HEMS-ambulance ‘Lifeliner 1’ dispatches was performed from the start of Dutch nationwide lockdown orders from March 13th until May 13th, 2020 and the corresponding period one year prior. Dispatch-, operational-, patient-, injury-, and on-site treatment characteristics were extracted for analysis. In addition, the rate of COVID-19 positively tested HEMS personnel and the time physicians were unable to take call was described.

Results

During the initial phase of the COVID-19 pandemic, the HEMS and HEMS-ambulance was requested in 528 cases. One year prior, a total of 620 requests were received. The HEMS (helicopter and ambulance) was cancelled after deployment in 56.4% of the COVID-19 cohort and 50.7% of the historical cohort (P = 0.05). Incident location type did not differ between the two cohorts, specifically, there was no significant difference in the number of injuries that occurred at home in pandemic versus non-pandemic circumstances. Besides a decrease in the number of falls, the distribution of mechanisms of injury remained similar during the COVID-19 study period. There was no difference in self-inflicted injuries observed. Prehospital interventions remained similar during the COVID-19 pandemic compared to one year prior. Specifically, prehospital intubation did not differ between the two cohorts. The rate of COVID-19 positively tested HEMS personnel was 23.1%. Physicians who tested positive were unable to take call for a mean of 25 days (range 8–53).

Conclusion

A decrease in the number of deployments and increase in the number of cancelled missions was observed during the COVID-19 study period. No major differences in operational- and injury characteristics were found for HEMS and HEMS-ambulance dispatches between the initial phase of the COVID-19 pandemic in the Netherlands and the same period one year prior. These findings highlight the importance of continued operability of the HEMS, even during pandemic circumstances.

Level of evidence

III, retrospective comparative study.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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