Retrospective Evaluation of Optic Nerve Sheath Diameters of Patients Diagnosed With Brain Death

Abstract

Introduction: Aim of the study is to investigate whether there is a correlation between causes of brain death, blood gas parameters before and after the apnea test and optic nerve sheath diameter (ONSD).
 Method: The records of 92 patients with brain death diagnosis were retrospectively analyzed for ONSD measurements of the right and left eyes, partial carbon dioxide pressure (pCO2), blood gas parameters before and after the apnea test. 
 Results: Subarachnoidal hemorrhage and intracerebral hemorrhage were the two most common brain death etiology. Mean ONSD for right eye was 6.37±1.03 mm. Mean ONSD for left eye was 6.43±1.02 mm. Only 8 patients had ONSD below 5.00 mm. There was no statistically significant correlation between the percent change of pCO2 and ONSD change (p>0.05).
 Conclusion: The present study shows that ONSD values are very high regardless of the partial pressure of carbon dioxide in patients with brain death diagnosis. We can suggest that ONSD can find itself a place for evaluating comatose patients for brain death diagnosis.