Serum netrin-1 levels at presentation and delayed neurological sequelae in unintentional carbon monoxide poisoning

Objectives: The early identification of patients with a high risk of developing delayed neurological sequelae (DNS) can improve the quality of care in carbon monoxide (CO) poisoning cases. The aim of this study is to investigate whether the serum netrin-1 levels measured at presentation to the emergency department (ED) predicted the development of DNS after acute CO intoxication. Methods: This prospective observational study was conducted between 1 August 2018 and 31 July 2019 in a single tertiary hospital. The patients with acute CO intoxication and serum netrin-1 levels measured at the time of ED presentation were included in the study. All patients were followed up for six weeks regarding the development of DNS. The patients were divided into two groups, including those who developed DNS (DNS group) and those who did not (non-DNS group). Results: A total of 183 patients were included in the study, and 54 (29.5%) developed DNS. The median serum netrin-1 level at ED presentation was significantly lower in the DNS group (391.5 pg/mL [263.0-550.5]) than in the non-DNS group (626.0 pg/mL [505.9-755.6]) (p < .001). Multivariate analysis revealed that a low serum netrin-1 level (adjusted odds ratio [AOR]: 8.02, 95% CI: 2.45-26.20), low Glasgow coma scale (GCS) score at ED presentation (AOR: 0.81, 95% CI: 0.68-0.97), long CO exposure time (AOR: 1.96, 95% CI: 1.49-2.56), and the presence of acute brain lesions (AOR: 8.24, 95% CI: 2.37-28.58) on diffusion-weighted imaging were independent predictors of DNS. Serum netrin-1 levels less than 432 pg/mL predicted the development of DNS with a sensitivity of 68.5% (95% CI: 54.4%-80.5%) and a specificity of 86.0% (95% CI: 78.8%-91.5%). Conclusions: Low serum netrin-1 levels were significantly associated with the development of DNS. Therefore, serum netrin-1 at ED presentation can help identify patients at risk of developing DNS following discharge.