Park JS, et al. - Researchers performed a prospective single-center observational study enrolling 36 post-cardiac arrest patients treated with target temperature management (TTM) from April 2018 to March 2019 to determine the optimal timing of optic nerve sheath diameter (ONSD) measurement to predict neurologic outcome in these patients. They used ultrasonography to measure ONSD initially after return of spontaneous circulation (ROSC) (ONSD_initial), at 24 h (ONSD₂₄), 48 h (ONSD₄₈), and 72 h (ONSD₇₂). The values were compared for predicting neurologic outcomes using the receiver operating characteristic (ROC) curves and DeLong method. Outcomes establish the significance of ONSD₂₄ as a tool to predict the neurologic outcome in these patients. Hence, they made a recommendation for measuring ONSD using ultrasonography at 24 h after ROSC, rather than immediately after ROSC, to predict neurologic outcome in post-cardiac arrest patients treated with TTM.