Predictive value of optic nerve sheath diameters on cerebral performance category scale in patients with impaired consciousness in the emergency department: a prospective pilot study.

BACKGROUND: The value of optic nerve sheath diameter (ONSD) in emergency departments remains unclear. The aim of this study is to investigate the predictive value of ONSD in discharge cerebral performance category (CPC) in emergency department patients with impaired consciousness. METHODS: This is a prospective pilot study. Emergency department patients with impaired consciousness were prospectively included in a tertiary hospital in China in January 2025. Demographical data, medical data, and ONSD were prospectively collected by two researchers. Patients were divided into the good CPC group and the poor CPC group according to the CPC scale at discharge. Logistic regression was conducted to investigate the predictive value of ONSD in discharge CPC. RESULTS: A total of 58 patients were included in this study. 20(33.9%) patients in the good CPC group. The ONSD was significantly different between groups (good CPC group: 5.44 ± 0.46 vs. poor CPC group: 5.89 ± 0.73, P = 0.016). After adjustment for blood glucose and sodium, ONSD remained a significant predictor of discharge CPC, with consistent associations observed across per 1 mm, per 0.5 mm, and per 0.1 mm scaling (OR: 3.065, 95%CI: 1.042–9.014, P = 0.042; OR: 1.751, 95%CI: 1.021–3.002, P = 0.042; OR: 1.119, 95%CI: 1.004–1.246, P = 0.042). Receiver operating characteristic (ROC) analysis further demonstrated a moderate discriminative ability of ONSD for poor neurological outcome, with an area under the curve (AUC) of 0.704 (95% CI: 0.571–0.837). The optimal cut-off value of ONSD was 5.67 mm. CONCLUSION: ONSD is a predictive factor for discharge neurological function in emergency department patients with impaired consciousness. Further studies are needed to clarify the predictive value of ONSD.