Optic Nerve Sheath Diameter In Children Research Articles

Optic nerve sheath diameter in children with acute liver failure: A prospective observational pilot study.

Early detection of raised intracranial pressure (ICP) improves outcome in acute liver failure (ALF). We evaluated the feasibility of bedside, ultrasound-guided measurement of optic nerve sheath diameter (ONSD) in normal and ALF children and correlation of ONSD with grade of hepatic encephalopathy (HE), international normalized ratio (INR) and blood ammonia (BA). Forty-one ALF and 47 healthy children (5-18years) were prospectively enrolled and 12 hourly clinical evaluation was done. Laboratory parameters including INR and BA were recorded. ONSD was measured at admission, change in HE grade and at recovery in ALF, and once in controls. One hundred and twenty-one ONSD measurements (ALF-74, controls-47) were taken without complications. ONSD was 4.2 (3.9-4.3), 4.4 (4.0-4.6), 5.2 (4.8-5.8) and 3.9 (3.3-4.1) mm in controls, ALF without HE, with HE and at recovery respectively. ONSD was significantly higher in ALF with HE than those without HE. ALF without HE and at recovery had ONSD similar to controls. ONSD was higher in ALF with the clinical signs of raised ICP than those without (5.4 [4.9-5.7] vs 4.6 [4.1-5.3] mm; P=.01). ONSD of 4.6mm differentiated ALF with HE vs without HE and 5.1mm between poor vs good non-transplant outcome with ≥80% sensitivity and specificity. ONSD positively correlated with INR (r=.53, P<.001) and BA (r=.42, P=.002). ONSD can be safely and easily measured in ALF children and correlates with HE grade, INR and BA. Normal ONSD in children (>4years) is <4.5mm and value of >5.1mm in ALF requires urgent attention.

Advances in the clinical application of ultrasonic measurement in optic nerve sheath diameter

Due to the special anatomic structure of optic nerve, the optic nerve sheath diameter(ONSD) increases along with the elevated intracranial pressure(ICP). The normal value or cut-off point of ONSD has not been unified in adults and children.The change of ONSD in children is different from that of adults as the children are at the stage of growth.With the deep understanding of ONSD, ultrasonic measurement of ONSD has a wide range of applications in adults and children. Key words: Intracranial pressure; Optic nerve sheath diameter; Ultrasound examination

Effect of caudal block using different volumes of local anaesthetic on optic nerve sheath diameter in children: a prospective, randomized trial

Background:Caudal block is commonly administered for postoperative analgesia in children. Although caudal block with 1.5 ml kg−1 local anaesthetic has been reported to reduce cerebral oxygenation in infants, the effect of caudal block on intracranial pressure (ICP) in children has not been well investigated. Optic nerve sheath diameter (ONSD) correlates with degree of ICP. This study aimed to estimate the effects of caudal block on ICP according to volume of local anaesthetic using ultrasonographic measurement of ONSD in children. Methods:Eighty patients, 6- to 48-months-old, were randomly allocated to the high-volume (HV) or low-volume (LV) groups for caudal block with ropivacaine 0.15%, 1.5 ml kg−1 or 1.0 ml kg−1, respectively. Measurement of ONSD was performed before (T0), immediately after (T1), and 10 min (T2) and 30 min (T3) after caudal block. Results:The two groups exhibited significant differences in ONSD according to time (PGroup x Time=0.003). The HV group exhibited significantly greater changes in ONSD from T0 to T2 and T3 than the LV group. However, in both groups, ONSDs at T1, T2 and T3 were significantly greater compared with those at T0, with the highest values at T2. Conclusions:Caudal block with a high volume of local anaesthetic can cause a greater increase in ICP than caudal block with a low volume of local anaesthetic. However, caudal block with 1.0 ml kg−1 of local anaesthetic can also result in a significant increase in ICP. Clinical trial registrationNCT02768493.

High resolution transbulbar sonography in children with suspicion of increased intracranial pressure.

To evaluate the accuracy of high resolution transbulbar sonography for the estimation of intracranial pressure (ICP) in children. In children and adolescents with acute neurologic symptoms of various origin, transbulbar sonography was performed. Besides measurement of the optic nerve sheath diameter (ONSD), the ultrastructure of the subarachnoid space of the optic nerve sheath was evaluated. The results of transbulbar sonography were correlated with clinical data based on cross-sectional imaging, ICP measurement, and ophthalmologic examination. Eighty-one patients (age 3-17.8 years, mean 11.7 years) were included. In 25 children, cross-sectional imaging and ICP measurement revealed increased intracranial pressure. The mean ONSD was 6.85 ± 0.81 mm. Twenty patients (20/25, 80 %) had a microcystic appearance of the subarachnoid space of the optic nerve. In 56 children without evidence of increased intracranial pressure, the mean ONSD was 5.77 ± 0.48 mm. Forty-nine patients (49/56, 87.5 %) had a normal homogenous appearance of the subarachnoid space. The ONSD in children with increased intracranial pressure was significantly higher than in patients without (p < 0.001). High resolution transbulbar sonography of the optic nerve is a useful technique for the rapid and non-invasive estimation of intracranial pressure in children. Besides measurement of the optic nerve sheath diameter, evaluation of the ultrastructure of the subarachnoid space of the optic nerve is a helpful parameter.

Normal values for transbulbar sonography and magnetic resonance imaging of the optic nerve sheath diameter (ONSD) in children and adolescents.

To establish normal values of the optic nerve sheath diameter (ONSD) in children and adolescents for transbulbar sonography and magnetic resonance imaging. In 99 children and adolescents (age: 5.6 - 18.6 years, mean: 12 years) without neurologic or ophthalmologic disease, measurements of the ONSD with transbulbar sonography were performed. For comparison 59 children and adolescents (age: 5.1 - 17.4 years, mean 12.3 years) with a normal MR examination of the brain had measurements of the ONSD on a T2-weighted thin section sequence of the orbit. Besides establishing modality-related normal values, age dependency, accuracy and reproducibility of measurements were assessed. Overall the mean ONSD was 5.75 ± 0.52 mm for transbulbar sonography and 5.69 ± 0.31 mm for MRI. There was no statistical significance between the 95 % percentiles and age for both transbulbar sonography (p = 0.332) and MRI (p = 0.336). As a parameter for the reproducibility of measurements, the repeatability coefficient (RC) was between 0.34 mm and 0.46 mm. The concordance correlation coefficient (CCC) values revealed a high agreement between readers both for transbulbar sonography (0.868) and MRI (0.796). Normal values for ONSD in children and adolescents found in this study are significantly higher than assumed. The values found for transbulbar sonography are confirmed by comparable results for MR measurements. A precise sonographic measurement technique and the consideration of normal values found hereby are essential for correct interpretation of ONSD measurements in children and adolescents.

Measurement of the Optic Nerve Sheath Diameter in Children: Comparison Between Transbulbar Sonography and Magnetic Resonance Imaging

To evaluate the accuracy of measurements of the optic nerve sheath diameter (ONSD) in children by comparing transbulbar sonography with magnetic resonance imaging (MRI). 65 children (age: 3 mo- 17y; mean age: 11.3y) underwent MR imaging of the brain including a heavily T 2-w sequence of the orbit and transbulbar sonography using a 17 MHz linear array transducer. Measurements of the ONSD were performed retrospectively by two experienced readers and all images were evaluated regarding the image quality. Bland-Altman Plots were produced to assess the accuracy of measurements. The correlation between readers and between MR imaging and transbulbar sonography was calculated by the concordance correlation coefficient (CCC). Overall the mean values of the ONSD for MRI (5.86 ± 0.66 mm) and transbulbar sonography (5.86 ± 0.71 mm) were identical. There was a high correlation between readers for measurements of the ONSD both for transbulbar sonography (CCC = 0.93) as well as for MRI (CCC = 0.9). Comparing the measurement values between transbulbar sonography and MRI, the correlation of ONSD values was good to moderate with a high dependency on image quality (CCC [0.31, 0.68]). We were able to demonstrate that the ONSD values of transbulbar sonography in children correlate well with MRI if the relevant anatomic structures are depicted and the measuring points are set correctly. Based on the findings of our study, it seems necessary to define normal and cut-off values for the ONSD in children again to finally assess the clinical relevance of the ONSD as a noninvasive parameter for the evaluation of intracranial pressure.