Keep an Eye on the Intracranial Pressure, Thanks to the Optic Nerve Sheath Diameter

Neurological examination on sedated patients is challenging and no gold standard monitoring is currently available. We report the case of a patient deeply sedated for the management of acute respiratory distress syndrome secondary to pneumonia. Delay in awakening led to cerebral exploration by transcranial Doppler (TCD) and measurement of optic nerve sheath diameter (ONSD). Abnormal values of ONSD prompted immediate brain computed tomography scan that confirmed high intracranial pressure (ICP) due to multiple deep parenchymal hematomas. Despite raised ICP, values obtained by TCD were normal, thanks to the persistence of cerebral autoregulation. This case highlights the interest of combining noninvasive techniques for neurological examination, especially for sedated patients.