New Optic Nerve Sonography Quality Criteria in the Diagnostic Evaluation of Traumatic Brain Injury.

Ibrahim Soliman,Nasir Nasim Mahmood,Dimitrios Karakitsos,Lawrence M Gillman,Waleed Tharwat Aletreby,Christos Lazaridis,Abdulrahman Alharthy,Abdullah Balhamar,Fahad Faqihi,Garrett G R J Johnson,Frederick A Zeiler,Shahzad Ahmad Mumtaz

doi:10.1155/2018/3589762

Abstract

Background New sonographic quality criteria to optimize optic nerve sheath diameter (ONSD) measurements were suggested. The latter were correlated to elevated intracranial pressure (ICP) in traumatic brain injury (TBI). Aim We investigated whether ONSD measurements were correlated to simultaneous ICP measurements in severe TBI. Methods Forty patients with severe TBI (Marshall Scale ≥II and GCS ≤8) participated in the study. All patients had an intraparenchymal ICP catheter inserted, while ONSD was measured bilaterally, upon admission and over the next 48 hours, based on the new sonographic criteria. A total of 400 ONSD measurements were performed, while mean ONSD values of both eyes were used in the analysis. Results ONSD measurements were strongly correlated to ICP values (r=0.74, p < 0.0001). Receiver operator curve (ROC) analysis revealed that the ONSD cutoff value for predicting elevated ICP was 6.4 mm when using the mean of both eyes (AUC = 0.88, 95% CI = 0.80 to 0.95; sensitivity = 85.3%, specificity = 82.6%). Linear regression analysis nested models revealed that sex (p=0.006) and height (p=0.04) were significant predictors of ONSD values. Conclusion When applying the new sonographic quality criteria, ONSD is strongly correlated to ICP in severe TBI. Whether to use such criteria to monitor ONSD as a proxy for ICP trend in TBI remains to be further explored.

Highlights

Traumatic brain injury (TBI) is frequently complicated by elevated intracranial pressure (ICP)
All patients were examined in the supine position as previously described [17,18,19,20,21,22], the exam takes less than a minute, and the patient’s head immediately repositioned to 30 degrees head up position as per TBI protocol. e optic nerve sheath diameter (ONSD) was measured according to the new quality criteria as detailed elsewhere (Table 1) [21]. e ONSD was recorded for both eyes in all cases, while the mean value of all measurements which were electronically stored and reviewed by expert sonographers was used in the statistical analysis
Previous studies have shown a strong correlation between ICP and ONSD; there has been a substantial variability in the literature around the ideal ONSD cuto value that corresponds to elevated ICP [7, 8, 10]

Summary

Introduction

Traumatic brain injury (TBI) is frequently complicated by elevated intracranial pressure (ICP). Secondary brain injury due to elevated ICP and decreased perfusion pressure to the brain is an important cause of morbidity and mortality in those patients. In order to treat this complication, elevated ICP must be diagnosed quickly and accurately [1,2,3]. Due to the invasive nature of these procedures and associated risks, intracranial monitoring is usually not employed until after elevated ICP is already suspected based on clinical picture and noninvasive testing such as computed tomography [5]. Invasive monitoring may not always be possible due to coagulopathy, thrombocytopenia, or lack of relevant procedural expertise and tools [6]. E latter were correlated to elevated intracranial pressure (ICP) in traumatic brain injury (TBI).

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Conclusion