Optic Nerve Sheath Diameter for Prediction of Sepsis Associated Encephalopathy

Ocular ultrasonography will be performed by single skilled examiner with patients placed in supine position with closed eyes. A layer of ultrasound gel will be applied over the closed upper eyelid and the liner high frequency probe 7 - 12 MHz of SonoSite M-Turbo ultrasound machine is placed on temporal area of eyelid with the hand holding it resting on forehead of patient. ONSD is measured 3mm behind the globe in the transverse plane perpendicular to the optic nerve. For each eye one measurement will be made and the reported ONSD corresponds to the mean of the two values obtained for each patient. An average ONSD greater than 5 mm is considered abnormal and elevated intracranial pressure should be suspected. all enrolled subjects will be eligible for ONSD measurements, SOFA score calculation, as well as GCS assessment on daily basis for up to 10 consecutive days, until ICU discharge or death.