 The investigators hypothesize that bedside ultrasound measurement of the ONSD is a simple screening test for increased intracranial pressure and can be used to rapidly and efficiently identify patients in the ICU who have coma due to an increase in intracranial pressure. The investigators propose to carry out an observational trial to determine the predictive ability of the Optic Nerve Sheath Diameter for cerebral edema increased intracranial pressure and to compare it with the results of neuroimaging CT andor MRI. 