Optic Nerve Sheath Diameter for Assessing Prognosis after Out-of-Hospital Cardiac Arrest

Area of Science:

• Neurology
• Radiology
• Critical Care Medicine

Background:

• Out-of-hospital cardiac arrest (CA) presents a significant challenge in predicting patient outcomes.
• Accurate prognostic biomarkers are crucial for guiding clinical decision-making and resource allocation post-resuscitation.

Purpose of the Study:

• To evaluate the prognostic significance of optic nerve sheath diameter (ONSD) and optic nerve pial diameter (ONPD) measured via sonography and computed tomography (CT) after CA.
• To compare the predictive value of these imaging biomarkers with other established laboratory markers like neuron-specific enolase (NSE) and lactate levels.

Main Methods:

• A prospective observational study included patients resuscitated from CA between December 2017 and August 2021.
• Optic nerve sheath and pial diameters were measured using both sonography and CT.
• CT also assessed grey-to-white matter ratio (GWR) in basal ganglia (GWR_BG) and cerebrum (GWR_CBR).
• Blood levels of lactate and NSE were measured as laboratory biomarkers.

Main Results:

• Sonographic measurements of ONSD and ONPD showed no significant difference between survivors and non-survivors (p ≥0.4).
• CT-assessed ONSD, GWR_BG, GWR_CBR, and NSE levels significantly differed between survival groups (p ≤0.005) and neurological outcome groups (p ≤0.04).
• GWR_BG, GWR_CBR, and NSE were excellent predictors of survival, with NSE demonstrating the highest accuracy for predicting good neurological outcomes.

Conclusions:

• CT-derived grey-to-white ratio (GWR_BG, GWR_CBR) and serum NSE levels are highly effective biomarkers for predicting outcomes after cardiac arrest.
• Sonographic measurements of optic nerve sheath and pial diameters are not recommended for prognostic decision-making in the post-CA setting.
• CT imaging and NSE levels provide valuable prognostic information, aiding in patient management and prognostication.