Evaluation of ultrasonographic optic nerve sheath diameter and central retinal artery Doppler indices by point-of-care ultrasound in pediatric patients with increased intracranial pressure

Abstract

Background. Measurement of the optic nerve sheath diameter (ONSD) with point-of-care ultrasound (POCUS) is a non-invasive and radiation-free technique that can be used to assess increased intracranial pressure (ICP). Ophthalmic artery and central retinal artery Doppler indices can be used like transcranial Doppler to evaluate increased ICP. This study aims to examine the diagnostic value of ONSD measurements and central retinal artery Doppler indices in the evaluation of pediatric patients with increased ICP. Methods. This was a prospective, case-controlled single center study. The study group was comprised of a total of 38 pediatric patients with increased ICP and the control group included 19 healthy children. Ophthalmic ultrasound was performed and ONSD and central retinal artery Doppler indices were measured. Results. The mean age of the study group was 80.84 ± 65.12 months. The mean ONSD was 5.9 ± 0.8 (3.6-8.1) mm in the study group and the mean resistive index (RI) was 0.71 ± 0.08 (min:0,55-max:1) and was significantly greater than the control group (p < 0.001 and p < 0.001, respectively). In terms of predicting increased ICP, the ONSD measurement was the strongest parameter, with its area under the curve: 0.767 (95 percent confidence interval: 0.68-0.85). In the study group, the cut-off value for ONSD was 5.8 mm (66 percent sensitivity, 100 percent specificity) and the cut-off value for RI was 0.68 (63 percent sensitivity, 83 percent specificity). Conclusions. Point-of-care ultrasound is a noninvasive and important tool in pediatric intensive care units. Our study is significant as one of the few pediatric studies where central retinal artery Doppler indices are evaluated in addition to OSND, in patients with increased ICP.

The Incremental Role of Multiorgan Point-of-Care Ultrasounds in the Emergency Setting

“…The ONS diameter (ONSD) can be assessed through the transorbital window using a 2 MHz frequency ultrasound probe. The ONSD is measured behind the globe, using the optic disc as a reference point together with the central retinal artery color Doppler technique, which helps to identify the optic nerve [126]. Moreover, the blood flow velocities in the main cerebral arteries, measured through the transcranial Doppler (TCD) technique, help to identify intracranial hypertension by identifying an elevation in both the pulsatility index (PI) and the resistive index (RI) ( [127,128].…”

Noninvasive methods to monitor intracranial pressure

“…A number of recent studies have shown a good correlation between ONSD and invasively obtained ICP [84,87,91,[94][95][96][97]. For example, a recent study showed that measurement of the ONSD 3 mm posterior to the globe in patients with IIH predicted elevated ICP with good sensitivity and specificity (97% sensitivity and 100% specificity) [98].…”

“…Several parameters of transcranial Doppler (TCD) ultrasound, such as cerebral blood flow velocity (CBV), pulsatility index, and the ability to measure the diameter of the optic nerve sheath (discussed in a later section), have been studied as noninvasive biomarkers of ICP [84][85][86]. Although several early studies and a few recent studies have shown a strong correlation between TCD and ICP [87], a number of studies have shown varying correlations between TCD-determined ICP and invasively obtained ICP or have failed to show a correlation [84,[88][89][90][91].…”