Role of serial ultrasonic optic nerve sheath diameter monitoring in head injury

Aim: To establish a local nomogram of Computed Tomographic measurement of Optic Nerve Sheath Diameter and determine the values that can objectively predict raised intracranial pressure. Study design: observational retrospective study Place and duration of study: Department of Radiology of University of Abuja teaching hospital, Abuja from March 2016 to February 2020. Methodology: We included images of 356 patients referred to the Radiology department for brain CT. Data was grouped into three:(A) 200 non head injury patients as control,(B) head injury patients without radioclinical signs of raised ICP ,(C) head injury patients with at least one radiologic sign of raised ICP.ONSD obtained in axial scans at 3mm retrobulbar region at constant window width and level of 250/50 were analysed using SAS software version 9.3 and statistical level of significance set at 0.05. Result: Mean ONSD of 200 normal patients was 4.4mm± 0.5 with no significant correlation with age and side. Mean ONSD of 118 head injury patients with CT signs of raised ICP was 6.0mm±0.7 while mean ONSD of 38 head injury patients without CT signs of raised ICP was 4.3mm±0.7. ONSD was slightly higher in patients with significant midline shift compared with patients without shift but no correlation with degree of shift. The ONSD value above which raised ICP can be predicted with the highest sensitivity and specificity was >5.2mm with Receiver Operating Characteristic curve (ROC) demonstrating an area under the curve of 0.9796 (p-value < 0.0001) with specificity of 93.5% and sensitivity of 90.7%. Conclusion: There is a positive correlation between ONSD measurement on CT and intracranial pressure. This measurement is therefore recommended as an additional indirect radiological marker of raised ICP. Normal mean ONSD in a North-Central Nigerian population is 4.4mm± 0.5 with 5.2mm proposed as the upper limit of normal.

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Ultrasonic Assessment of Optic Nerve Sheath Diameter in Patients at Risk of Sepsis-Associated Brain Dysfunction: A Preliminary Report

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17103656 ◽

2020 ◽

Vol 17 (10) ◽

pp. 3656 ◽

Cited By ~ 2

Author(s):

Piotr F. Czempik ◽

Jakub Gąsiorek ◽

Aleksandra Bąk ◽

Łukasz J. Krzych

Keyword(s):

Optic Nerve ◽

Sequential Organ Failure Assessment ◽

Organ Failure ◽

Optic Nerve Sheath Diameter ◽

Brain Dysfunction ◽

Optic Nerve Sheath ◽

Non Invasive ◽

Nerve Sheath ◽

Failure Assessment

Sepsis-associated brain dysfunction (SABD) with increased intracranial pressure (ICP) is a complex pathology that can lead to unfavorable outcome. Ultrasonographic measurement of optic nerve sheath diameter (ONSD) is used for non-invasive assessment of ICP. We aimed to assess the role of ONSD as a SABD screening tool. This prospective preliminary study covered 10 septic shock patients (5 men; aged 65, IQR 50–78 years). ONSD was measured bilaterally from day 1 to 10 (n = 1), until discharge (n = 3) or death (n = 6). The upper limit for ONSD was set at 5.7 mm. Sequential organ failure assessment score was calculated on a daily basis as a surrogate formulti-organ failure due to sepsis in the study population. On day 1, the medians of right and left ONSD were 5.56 (IQR 5.35–6.30) mm and 5.68 (IQR 5.50–6.10) mm, respectively, and four subjects had bilaterally elevated ONSD. Forty-nine out of 80 total measurements performed (61%) exceeded 5.7 mm during the study period. We found no correlations between ONSD and sequential organ failure assessment (SOFA) during the study period (right: R = −0.13–0.63; left R = −0.24–0.63). ONSD measurement should be applied for screening of SABD cautiously. Further research is needed to investigate the exact role of this non-invasive method in the assessment of brain dysfunction in these patients.

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