Ultrasonographic Measurement of Optic Nerve Sheath Diameter for Detection of Increased Intracranial Pressure in Patients Scheduled for Elective Tumor Craniotomy

Abstract

Background: Elevated intracranial pressure (EICP) is a serious neurological condition. The diameter of the optic nerve sheath can be determined by means of ultrasonography as a non-invasive method of detecting EICP. Objective: The aim of the current work was to evaluate the accuracy of bedside optic nerve sheath diameter (ONSD) by ultrasound (US) as a non-invasive method of detecting increased intracranial pressure (ICP) in patients underwent elective tumor craniotomy in comparison to clinical and radiological computed tomography (CT) findings of EICP. Patients and Methods: From January 2020 to May 2020, this prospective observational study was conducted on seventy-one patients underwent elective tumor craniotomy at Zagazig University Hospitals. ONSD measurements were done and compared with clinical and radiographic features on CT brain suggesting increase in ICP pre and post-operatively. Results: There were good relation between ONSD and clinical signs of EICP. it was found that there were increase in preoperative mean ONSD among cases had nausea (4.94±0.57 mm), vomiting (4.97±0.55) mm and headache (4.87±0.6 mm), disturbed conscious level (4.9±0.62 mm) and visual field affection (5±0.46 mm). also, there was increase in postoperative mean ONSD among cases with nausea (4.81±0.67 mm), vomiting (4.81±0.62 mm), headache (4.83±0.63 mm). The cut-off value of ONSD for diagnosing increased ICP was >4.8 mm with sensitivity 78.9%, specificity 63.6% and accuracy 71.8%. Conclusion: It could be concluded that bedside ultrasonographic measurement of ONSD is a reliable technique for prediction of elevated intracranial pressure.