Characteristics, management and outcomes of patients with severe traumatic brain injury in Victoria, Australia compared to United Kingdom and Europe: A comparison between two harmonised prospective cohort studies

Evaluation of severe traumatic brain injury referrals to the National Tertiary Neurosurgical Centre in the Republic of Ireland

BACKGROUND

Transfer of all severe TBI patients to a neurosurgical unit (NSU) has been advocated irrespective of levels of complexity and prognostic factors. Previous publications have suggested that only 50% of severe TBI patients in Ireland were managed in NSUs.

AIMS

This study aims to audit severe TBI referrals to the National Neurosurgical Centre, to evaluate reasons for nonacceptance, assess for differences in the transferred and not transferred cohorts and to analyse observed and expected mortality rates.

METHODS

Data on all patients with TBI referred in 2021 were prospectively collected using an electronic referral system. Patients with severe TBI (GCS ≤ 8 and AIS ≥ 3) were included and dichotomised into transferred and not transferred cohorts.

RESULTS

Of 118 patients referred with severe TBI, 45 patients (38.1%) were transferred to the neurosurgical centre. Patients in the transferred cohort were significantly younger (p < 0.001), had a higher GCS score (p < 0.001) and a lower proportion of bilaterally unreactive pupils (p < 0.001) compared to the not transferred cohort. 93% (68/73) of those not transferred were either >65 years old, or had bilaterally unreactive pupils, or both. Based on the IMPACT model, the observed to expected mortality ratios in the transferred and not transferred cohorts were 0.65 (95% CI 0.25-1.05) and 0.88 (95% CI 0.65-1.11) respectively.

CONCLUSION

The observed mortality rate for severe TBI in Ireland was similar to or better than expected mortality rates when adjusted for important prognostic factors. 93% of severe TBI patients not transferred to a neurosurgical centre were either elderly or had bilaterally unreactive pupils or both. These patients have an extremely poor prognosis and recommendation for transfer cannot be made based on current available evidence.

Improvement in Functional Outcome from 6 to 12 Months After Moderate and Severe Traumatic Brain Injury Is Frequent, But May Not Be Detected With the Glasgow Outcome Scale Extended

The aims of this study were (1) to report outcome and change in outcome in patients with moderate and severe traumatic brain injury (mo/sTBI) between 6 and 12 months post-injury as measured by the Glasgow Outcome Scale Extended (GOSE), (2) to explore if demographic/injury-related variables can predict improvement in GOSE score, and (3) to investigate rate of improvement in Disability Rating Scale (DRS) score, in patients with a stable GOSE. All surviving patients ≥16 years of age who were admitted with mo/sTBI (Glasgow Coma Scale [GCS] score ≤13) to the regional trauma center in Central Norway between 2004 and 2019 were prospectively included (n = 439 out of 503 eligible). GOSE and DRS were used to assess outcome. Twelve-months post-injury, 13% with moTBI had severe disability (GOSE 2-4) versus 27% in sTBI, 26% had moderate disability (GOSE 5-6) versus 41% in sTBI and 62% had good recovery (GOSE 7-8) versus 31% in sTBI. From 6 to 12 months post-injury, 27% with moTBI and 32% with sTBI had an improvement, whereas 6% with moTBI and 6% with sTBI had a deterioration in GOSE score. Younger age and higher GCS score were associated with improved GOSE score. Improvement was least frequent for patients with a GOSE score of 3 at 6 months. In patients with a stable GOSE score of 3, an improvement in DRS score was observed in 22 (46%) patients. In conclusion, two thirds and one third of patients with mo/sTBI, respectively, had a good recovery. Importantly, change, mostly improvement, in GOSE score between 6 and 12 months was frequent and argues against the use of 6 months outcome as a time end-point in research. The GOSE does, however, not seem to be sensitive to actual change in function in the lower categories and a combination of outcome measures may be needed to describe the consequences after TBI.

ABO blood type and functional neurological outcome in patients with severe traumatic brain injury

BACKGROUND

The ABO blood system has been involved in the pathogenesis of several diseases, including coagulopathy and bleeding complications. In trauma patients, blood type A has been associated with acute respiratory distress syndrome, and recently, blood type O has been associated with all-cause mortality. The purpose of this study was to assess the association between ABO blood types and long-term functional outcomes in critically ill patients with severe traumatic brain injury (TBI).

METHODS

We conducted a single-center, retrospective, observational study including all patients admitted to the intensive care unit with severe TBI (defined as a Glasgow Coma Scale score of ≤8) between January 2007 and December 2018. Patient characteristics and outcomes were extracted from a prospective registry of all intubated patients admitted to the intensive care unit for TBI. ABO blood types were retrospectively retrieved from patient medical records. The association between ABO blood type (A, B, AB, and O) and unfavorable functional outcome (defined by a Glasgow Outcome Scale score between 1 and 3) 6 months after injury was assessed in univariate and multivariate analysis.

RESULTS

A total of 333 patients meeting the inclusion criteria were included. There were 151 type O (46%), 131 type A (39%), 37 type B (11%), and 12 type AB patients (4%). No significant differences in baseline demographic, clinical, or biological characteristics were observed between blood types. The prevalence of unfavorable outcome was significantly different between the four groups. After adjustment for confounders, blood type O was significantly associated with unfavorable outcome at 6 months (odds ratio, 1.97; confidence interval [1.03-3.80]; p = 0.042). The prevalence of coagulopathy or progressive hemorrhagic injury was not statistically different between blood types ( p = 0.575 and p = 0.813, respectively).

CONCLUSION

Blood type O appears to be associated with unfavorable long-term functional outcome in critically ill patients with severe TBI. Further studies are needed to detail the mechanism underlying this relationship.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level IV.

Functional Connectivity in the Mouse Brainstem Represents Signs of Recovery from Concussion

Mild traumatic brain injury (mTBI) is one of the most frequent neurological disorders. Diagnostic criteria for mTBI are based on cognitive or neurological symptoms without fully understanding the neuropathological basis for explaining behaviors. From the neuropathological perspective of mTBI, recent neuroimaging studies have focused on structural or functional differences in motor-related cortical regions but did not compare topological network properties between the post-concussion days in the brainstem. We investigated temporal changes in functional connectivity and evaluated network properties of functional networks in the mouse brainstem. We observed a significantly decreased functional connectivity and global and local network properties on post-concussion day 7, which normalized on post-concussion day 14. Functional connectivity and local network properties on post-concussion day 2 were also significantly decreased compared with those on post-concussion day 14, but there were no significant group differences in global network properties between days 2 and 14. We also observed that the local efficiency and clustering coefficient of the brainstem network were significantly correlated with anxiety-like behaviors on post-concussion days 7 and 14. This study suggests that functional connectivity in the mouse brainstem provides vital recovery signs from concussion through functional reorganization.

A retrospective review of patients who sustained traumatic brain injury in Ireland 2014-2019

INTRODUCTION

Traumatic brain injury (TBI) is the most significant cause of death and disability resulting from major trauma. The aim of this study is to describe the demographics of TBI patients, the current pathways of care and outcomes in the Republic of Ireland from 2014 to 2019.

METHODS

We performed a retrospective review of all TBI patients meeting inclusion criteria in Ireland's Major Trauma Audit (MTA) from 2014 to 2019. Severe TBI was defined as an abbreviated injury scale (AIS) ≥3 and GCS ≤8.

RESULTS

During the study period, 30,891 patients sustained major trauma meeting inclusion criteria for MTA, of which 7,393 (23.9%) patients met the inclusion criteria for TBI; 1,025 (13.9%) were classified as severe. The median age was 60.6 years (IQR 36.9-78.0), 54.3 years (32.8-73.4) for males and 71.7 years (50.0-83.0) for females (p<0.001). Of patients with severe TBI, 185 (18.0%) were brought direct to a neurosurgical centre, 389 (37.9%) were transferred to a neurosurgical centre and 321 (31.3%) had a neurosurgical intervention performed. In patients sustaining severe TBI, older patients (Adjusted OR, 0.96,95% CI 0.95-0.97) and patients requiring another surgery (OR 0.31, 95%CI 0.18-0.53) were less likely to be secondarily transferred to a neurosurgical centre. There were 47 (4.6%) patients with severe TBI discharged to rehabilitation. The 30-day mortality in Ireland was 11.6% in all TBI patients and 45.5% in severe TBI patients. Older patients and patients with higher ISS had a higher chance of death. Male patients, patients treated in neurosurgical centre, patients who had neurosurgery or non-neurosurgical surgery had a higher chance of survival.

CONCLUSION

This population-based study bench marks the 'as is' for patients with TBI in Ireland. We found that presently in Ireland, the mortality rate from severe TBI appears to be higher than that reported in international literature, and only a minority of severe TBI patients are brought directly from the incident to a neurosurgical centre. The new major trauma system should focus on providing effective and efficient access to neurosurgical, neuro-critical and neuro-rehabilitative care for patients who sustain TBI.

Decompressive craniectomy practice following traumatic brain injury, in comparison with randomized trials

High quality evidence shows decompressive craniectomy (DC) following traumatic brain injury (TBI) may improve survival but increase the number of severely disabled survivors. Contemporary international practice is unknown. We sought to describe international use of DC, and the alignment with evidence and clinical practice guidelines, by analyzing the harmonized CENTER-TBI and OzENTER-TBI Core study datasets. These include patients admitted to ICUs in Europe, the United Kingdom and Australia between 2015 and 2017. Outcomes of interest were treatment with DC relative to clinical trial evidence and the Brain Trauma Foundation guidelines. Of 2336 people admitted to ICUs following TBI, DC was performed in 320 (13.7%): in 64/1422 (4.5%) patients with diffuse TBI, and 195/640 (30.5%) patients with traumatic mass lesions. Secondary DC (for treatment of intracranial hypertension) was used infrequently in patients who met enrolment criteria of the two randomised clinical trials informing the guidelines: in 11/124 (8.9%) of those matching DECRA enrolment, and in 30/224 (13.4%) of those matching RESCUEicp. Of patients who underwent DC 258/320 (80.6%) were ineligible for either trial: 149/320 (46.6%) underwent primary DC, 62/320 (19.4%) were outside the trials' age criteria, and 126/320 (39.4%) did not develop intracranial hypertension refractory to non-operative therapies prior to DC. Secondary DC was used infrequently in patients in whom it had been shown to be potentially harmful, indicating alignment between contemporaneous evidence and practice. However, most patients who underwent DC were ineligible for the key trials; whether they benefitted from DC remains unknown.

Incidence, Mechanisms of Injury and Mortality of Severe Traumatic Brain Injury: An Observational Population-Based Cohort Study from New Zealand and Norway

BACKGROUND

Comparing trauma registry data from different countries can help to identify possible differences in epidemiology, which may help to improve the care of trauma patients.

METHODS

This study directly compares the incidence, mechanisms of injuries and mortality of severe TBI based on population-based data from the two national trauma registries from New Zealand and Norway. All patients prospectively registered with severe TBI in either of the national registries for the 4-year study period were included. Patient and injury variables were described and age-adjusted incidence and mortality rates were calculated.

RESULTS

A total of 1378 trauma patients were identified of whom 751 (54.5%) from New Zealand and 627 (45.5%) from Norway. The patient cohort from New Zealand was significantly younger (median 32 versus 53 years; p < 0.001) and more patients from New Zealand were injured in road traffic crashes (37% versus 13%; p < 0.001). The age-adjusted incidence rate of severe TBI was 3.8 per 100,000 in New Zealand and 2.9 per 100,000 in Norway. The age-adjusted mortality rates were 1.5 per 100,000 in New Zealand and 1.2 per 100,000 in Norway. The fatality rates were 38.5% in New Zealand and 34.2% in Norway (p = 0.112).

CONCLUSIONS

Road traffic crashes in younger patients were more common in New Zealand whereas falls in elderly patients were the main cause for severe TBI in Norway. The age-adjusted incidence and mortality rates of severe TBI among trauma patients are similar in New Zealand and Norway. The fatality rates of severe TBI are still considerable with more than one third of patients dying.