Impact of Country Income Level on Outcomes in Patients with Acute Brain Injury Requiring Invasive Mechanical Ventilation: A Secondary Analysis of the ENIO Study

Abstract

Background: Invasive mechanical ventilation 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 patients with ABI. Methods: A secondary analysis was performed on a registry of critically ill patients with ABI admitted to 73 intensive care units (ICUs) in 18 countries from 2018 to 2020. Patients were classified as high-income country (HIC) or 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 preselected 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 ventilatory settings. Results: Of 1512 patients (median age = 54 years, 66% male), 1170 (77%) were from HICs, and 342 (23%) were from MICs. Median age was significantly lower in MICs [35 (range 26–52) vs. 58 (range 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, whereas intracranial pressure monitoring (12.0% vs. 51.5%) and external ventricular drain (7.6% vs. 35.6%) were less common. Compared with HICs, patients from MICs had 2.27 times the odds of ICU mortality [p = 0.009, 95% confidence interval (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 to − 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 invasive mechanical ventilation, MICs had higher odds of ICU mortality, tracheostomy placement, and hospital mortality compared with HICs, which may be due to difference in neurocritical care resources and management.