Admission to specialised neurocritical units and association with clinical outcomes

Globally, managing critically ill adults with acute brain injuries (ABIs) in specialised neurocritical units (NCCUs) is associated with improved survival, but this has not been assessed in Australia. This study aims to determine in adults with an ABI if admission to a general intensive care unit (ICU) or a NCCU was associated with a difference in outcomes.

Australian ICUs were surveyed regarding NCCU capabilities via the Australian and New Zealand Intensive Care Society (ANZICS). Linked patient-level outcomes were extracted from the ANZICS Adult Patient Database for a retrospective observational cohort study. Adults with an ABI (intracerebral haemorrhage, acute ischaemic stroke, subarachnoid haemorrhage or traumatic brain injury) admitted to ICU between January 2016 and December 2022 were included. Readmissions within the same hospital, transfers from another ICU and admissions for end-of-life care or organ donation were excluded. The primary outcome was in-hospital mortality. Secondary outcomes were ICU mortality, ICU length of stay (LOS), hospital LOS and discharge destination other than home.

Responses were received from 78 out of 192 surveyed ICUs. Amongst these, 41 reported routinely caring for ABI patients, of which 8 were specialist NCCUs. There were 14,740 index admissions to participating ICUs over the study period, with 7,402 NCCU and 7,338 general ICU admissions respectively. Crude in-hospital mortality was 18% (1,356/7,402) in NCCUs and 21% (1,514/7,338) in general ICUs. The adjusted odds ratio (OR) for in-hospital mortality was 0.88 (95% confidence interval [CI] 0.81-0.96, p-value 0.003), favouring those cared for in a NCCU. In survivors, those admitted to NCCUs were more likely to remain in hospital longer (relative change in geometric mean = 20.5%, 95% CI 16.2-25.1, p-value < 0.001) and less likely to be discharged home (OR = 2.01, 95% CI 1.83-2.21).

In Australian adult ABI patients admitted to ICU, admission to a NCCU was independently associated with lower hospital mortality. However, in survivors, this was associated with a lower likelihood of being discharged home and a longer stay in hospital. Variable intensive care capabilities for neurocritical care may impact key patient-centred outcomes. Future research is required to assess long-term functional outcomes.