Prediction of poor prognosis using the peak systolic velocity and early diastolic velocity of the central retinal artery in patients with post-cardiac arrest syndrome

IntroductionMonitoring intracranial pressure (ICP) in patients with post-cardiac arrest syndrome (PCAS) is crucial for effective management and prognosis assessment. However, continuous ICP monitoring is rarely practiced. Increased ICP is often associated with the impairment of brain autoregulation. This study investigated whether central retinal artery (CRA) flow velocity, autoregulation status according to mean arterial pressure (MAP), and the optic nerve sheath diameter (ONSD)/eyeball transverse diameter (ETD) ratio could predict poor prognosis related to increased ICP in PCAS patients.MethodsIn this multicenter prospective observational study, transocular ultrasonography of the optic nerve sheath was performed on 38 PCAS patients treated with targeted temperature management from December 2021 to November 2022. CRA peak systolic velocity (PSV), early diastolic velocity (eDV), MAP, CRA-PSV changes following MAP changes (autoregulation), and ONSD/ETD ratio were measured repeatedly from days 0 to 4 post-admission.ResultsUnivariable analysis indicated that CRA-PSV, nonpositive or flat CRA-eDV, and disrupted autoregulation correlated with a poor prognosis (Cerebral Performance Category 4 or 5). In multivariable analysis, nonpositive CRA-eDV or disrupted autoregulation was the most significant predictor of poor prognosis (odds ratio, 40.576; p = 0.002), with an area under the curve of 0.774. The ONSD/ETD ratio did not show a significant correlation.ConclusionsNonpositive CRA-eDV, CRA-PSV and disrupted autoregulation can predict poor prognosis in PCAS patients. Transocular Doppler ultrasonography of the CRA and autoregulation assessment may aid in ICP monitoring and management in PCAS patients.