Bedside Ultrasonography of the Optic Nerve Sheath in Brain Death

Abstract

Increased intracranial pressure has successfully been detected by using bedside optic nerve sheath diameter (ONSD) ultrasonography. ONSD ultrasonography has become one of the current methods used to detect potential brain death in recent years. In this study, we carried out ONSD ultrasonography for patients who were diagnosed with brain death and in comatose state. Mean ONSD values obtained from the patients with brain death were compared with ONSD values of patients in a comatose state. There was no significant difference between the mean ONSD values of the right and left eye and no significant difference in transverse and sagittal plane measurements in all groups. Mean ONSD values of Group BD were significantly higher than both Group CT (P < .05) and Group CM values (P < .05). Some of the patients with a history of intracranial hemorrhage, subdural hematoma, or traumatic brain injuries who remain in a comatose state in intensive care units may ultimately result in brain death. Therefore, it may be kept in mind that intermittent ONSD measurements of patients in deep comas might have an important role for diagnosing brain death early for purposes of cadaveric organ donation. In conclusion, transorbital ONSD measurement using bedside ultrasonography, an inexpensive, comfortable, and noninvasive test for patients in deep comas, may be helpful in determining potential brain death.