Impact of country income level on outcomes in acute brain injured patients requiring invasive mechanical ventilation: a secondary analysis of the ENIO study

Abstract

BACKGROUND/OBJECTIVES: Invasive mechanical ventilation (IMV) can present complex challenges for patients with acute brain injury (ABI) in middle income countries (MICs). We characterized the impact of country income level on weaning strategies and outcomes in neurocritical care patients. METHODS: A secondary analysis was performed on a registry of neurocritical care patients admitted to 73 intensive care units (ICUs) in 18 countries from 2018-2020. Patients were classified as high (HIC) or middle income country (MIC). The primary outcome was ICU mortality. Secondary outcomes were days to first extubation, tracheostomy, extubation failure, ICU length of stay, and hospital mortality. Multivariable analyses were adjusted for clinically pre-selected covariates such as age, sex, body mass index, neurological severity, comorbidities, and ICU management. Extubation and tracheostomy outcomes were also adjusted for arterial blood gas values and extubation day ventilatory settings. RESULTS: Of 1,512 patients (median age=54 years, 66% male), 1,170 (77%) were from HICs, and 342 (23%) were from MICs. Median age was significantly lower in MICs (35 (26-52) vs 58 (45-68) years in HICs). Neurosurgical procedures (47.7% vs 38.2%) and decompressive craniectomy (30.7% vs 15.9%) were more common in MICs, while intracranial pressure monitoring (12.0% vs 51.5%) and external ventricular drain (7.6% vs 35.6%) were less common. Compared to HICs, patients from MICs had 2.27 times the odds of ICU mortality (p=0.009, 95% CI=1.22, 4.21). Frequency of extubation failure was lower in MICs but not significant after adjustment. Patients from MICs had 3.38 times the odds of tracheostomy (p=<0.001, 95%CI=2.28-5.01), 5.59 days shorter mean ICU stay (p<0.001, 95%CI=-7.82, -3.36), and 1.96 times the odds of hospital mortality (p=0.011, 95%CI=1.17, 3.30). CONCLUSIONS: In an international registry of patients with ABI requiring IMV, MICs had higher odds of ICU mortality, tracheostomy, and hospital mortality compared to HICS, likely due to differences in neurocritical care resources and decision-making.