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.