Evaluation of near-infrared spectroscopy, transcranial Doppler, and ophthalmic ultrasound measurements in critically Ill pediatric patients with increased intracranial pressure

BackgroundThe increased intracranial pressure (ICP) syndrome may emerge depending on many different neurological factors and the early diagnosis and treatment are important for the prevention of neurologic damage and related mortality. In recent years, the follow-up of increased ICP with non-invasive methods has been rising. In this study, our objective was to determine the significance and any possible correlation between Optic Nerve Sheath Diameter (ONSD) and Near Infrared Spectroscopy (NIRS) in children with increased ICP.MethodsPatients who were hospitalized in our pediatric ICU at Çukurova University Medical Faculty between June 2018 and June 2019 due to the suspicion of increased ICP were included in this study. The demographic characteristics of patients, diagnosis at admission, results of the cranial CT and MRI examinations, and results of the simultaneous ONSD and NIRS measurements were recorded.ResultsA total of 36 patients were included in our study. With respect to the diagnosis, non-traumatic causes were at the forefront in 30 patients (83.3%), and the most common causes were meningoencephalitis (n = 9; 25%) and non-traumatic bleeding (n = 7; 19.4%). Six of the patients were under the age of one year (16.7%), and the mean values of ONSD and NIRS were 4.8 ± 0.7 mm and 71.1 ± 12.4% respectively in this group. Fourteen patients were in the one to ten year age group and the mean values of ONSD and NIRS were 6.1 ± 0.6 mm and 72.7 ± 9.3% respectively. Sixteen patients were over ten years of age (44.4%), and the mean values of ONSD and NIRS were 5.6 ± 0.7 mm and 74.2 ± 16% respectively. There was no correlation between the ONSD and NIRS values (r:0.307; p = 0.068).ConclusionOur study showed that ONSD measurements were helpful in children with increased ICP and reflected the increase in ICP. However, our study also demonstrated that ONSD was not in correlation with the NIRS monitoring. We believe that there is a need for further studies focused on the use of ONSD and NIRS in the monitoring of increased ICP.

Optic nerve sheath diameter measured using magnetic resonance imaging and factors that influence results in healthy Chinese adults: a cross-sectional study.

Background and objectivesProgressive cerebral edema worsens prognosis in large hemispheric infarction (LHI). Ultrasonographic optic nerve sheath diameter (ONSD) measurement provides a non-invasive method for estimating intracranial pressure. This study aimed to evaluate the predictive value of affected- and unaffected-side ONSD for clinical deterioration at discharge in LHI patients and to provide reference data on factors linked to deterioration, follow-up outcomes, and longitudinal ONSD monitoring.MethodsThis retrospective study enrolled 35 LHI patients, classified into two groups: improved and deteriorated, based on clinical and imaging findings at discharge. Demographic and clinical characteristics were compared. Receiver operating characteristic (ROC) analysis evaluated the predictive performance of affected- and unaffected-side ONSD. Area under the curve (AUC) difference was compared using the DeLong test. Post-discharge follow-up at 30 and 90 days was conducted via telephone interviews. Longitudinal changes in affected- and unaffected-side ONSD were depicted using line graphs for patients with extended stays in the neuro-intensive care unit (NICU).ResultsStatistically significant variables included age (p = 0.002), female (p = 0.002), history of atrial fibrillation (p = 0.044), GCS score (p = 0.028), affected-side ONSD (p = 0.002), unaffected-side ONSD (p = 0.012), and duration of NICU stay (p = 0.002). A positive linear correlation was identified between ONSD values and discharge outcomes. The optimal cut-off for predicting deterioration was 5.54 mm for affected-side ONSD (sensitivity 81.3%, specificity 78.9%, AUC = 0.814) versus 5.57 mm for the unaffected-side (68.8, 78.9%, AUC = 0.757), with no significant AUC difference between sides. The overall 30-day post-discharge mortality was 39.29%. Longitudinal changes in bilateral ONSD showed remarkable overlap in both individual and group observations. Patients with improved outcomes exhibited decreasing ONSD trends, whereas those with deterioration displayed increasing trends.ConclusionPreoperative ONSD measurement is a feasible and practical predictor of discharge prognosis in LHI patients, with both affected and unaffected sides providing reliable monitoring. Factors including age, female, history of atrial fibrillation, GCS score, ONSD on either side, and NICU stay duration may influence outcomes. The high short-term mortality underscores the importance of the post-discharge transition management. The clinical value of longitudinal ONSD monitoring requires further investigation.

This study aims to investigate the relationship between optic nerve sheath diameter (ONSD) measurements and clinical outcomes in patients undergoing decompressive craniectomy (DC) due to cerebral infarction. The study evaluated the effect of ONSD on intracranial pressure (ICP) and neurological recovery after DC and determined the prognostic value of this measurement. This study was conducted on 54 patients who underwent DC for cerebral infarction between 2018 and 2024 at a tertiary university hospital, Atatürk university faculty of medicine. Demographic data (age, gender), clinical data (preoperative and postoperative Glasgow Coma Scale [GCS] scores, Glasgow Outcome Scale [GOS] scores), and ONSD measurements were obtained from patient records. ONSD measurements were taken at preoperative 1 h, postoperative 1 h, postoperative 24 h, and postoperative 72 h. Measurements were performed with an ultrasound probe on both eyes while patients were in a supine position with their eyes closed. Patients were divided into two groups based on their GCS scores: Group 1 (GCS > 8) and Group 2 (GCS ≤ 8). Statistical analyses of the data were performed using Student's t-test and Mann-Whitney U-test, with P < 0.05 considered statistically significant. Group 1 consisted of 26 patients (mean age 67.2 ± 6.4 years), and Group 2 consisted of 28 patients (mean age 72.4 ± 5.8 years) (P = 0.019). Preoperative ONSD was significantly wider in Group 2 (6.3 ± 0.5 mm) compared to Group 1 (5.2 ± 0.4 mm) (P ≈ 0). Postoperative 1-h ONSD values were also significantly wider in Group 2 (6.0 ± 0.6 mm) compared to Group 1 (4.8 ± 0.5 mm) (P ≈ 0). At 24 and 72 h, ONSD values in Group 2 remained significantly wider compared to Group 1. GOS scores were lower in Group 2 (2.1 ± 0.9) compared to Group 1 (3.2 ± 0.8) (P ≈ 0). There was a strong negative correlation between ONSD measurements and GOS scores. ONSD is an important non-invasive indicator in the assessment of ICP and clinical outcomes. High ONSD values are associated with poor clinical outcomes, and a reduction in postoperative ONSD reflects the success of surgical intervention. ONSD measurements can be used as a prognostic tool in clinical practice and play a crucial role in the management and monitoring of patients with high ICP. It is recommended that these findings be validated in larger patient groups and different clinical scenarios.

To determine the distensibility and elastic characteristics of the optic nerve sheath for development of a basic understanding of ultrasound studies aimed to measure optic nerve sheath diameter (ONSD) for detection of acutely elevated intracranial pressure (ICP). Isolated human optic nerves preparations obtained from autopsies were submitted to predefined pressure alterations, and consecutive changes in ONSD were measured by B-scan ultrasound under defined conditions. Following submission to pressure, the diameter of the nerve sheath increased up to 140% of its baseline value. The increase (mean 1.97 mm, SD 0.52 mm) corresponded to the magnitude of pressure steps measured in the perineural subarachnoidal space (SAS). Similarly, the ONSD declined in each of the preparations within a few minutes after the optic nerve was decompressed. However, it did not reach its baseline value again when pressure loads of 45-55 mmHg or more had been applied. The elasticity of the anterior sheath of the optic nerve is sufficient for the detection of pressure changes in the SAS especially for upward pressure steps. This is basically important for the application of clinical monitoring of the sheath diameter to facilitate the identification of patients with elevated ICP non-invasively (screening). However, further implementation of this procedure in neurointensive care and emergency medicine has to consider that the sheath diameter reversibility may be impaired after episodes of prolonged intracranial hypertension and a model for hysteresis is proposed.

Background: Idiopathic intracranial hypertension (IIH), characterized by increased intracranial pressure (ICP) without a clear cause, typically affects obese women of reproductive age. Although lumbar puncture (LP) is diagnostic, its invasiveness limits its repeated use. Consequently, a non-invasive alternative is essential. Therefore, we assessed whether optic nerve sheath diameter (ONSD) measurement via orbital ultrasonography could serve as an alternative method for monitoring changes in ICP in patients with IIH. Methods: In this prospective observational study, patients with IIH, diagnosed using the modified Dandy criteria, underwent ONSD assessment using B-scan ultrasonography. Bilateral measurements were performed 3 mm posterior to the optic disc with the probe and sterile gel placed on the closed upper eyelid. ONSD was recorded before LP and one month after initiation of medical treatment. Comprehensive ophthalmologic examinations were also conducted. Patients with ocular pathology, neuroimaging abnormalities, or contraindications to LP were excluded. Results: Twenty-four eyes from 12 female patients with IIH were evaluated. The mean (standard deviation [SD]) age was 27.3 (6.9) years, and the mean ICP was 34.8 (10.3) cm H2O. Although the ONSD decreased one month after LP, changes in mean ONSD of the right eye, left eye, and their average were not statistically significant (all P &gt; 0.05). No significant correlations were observed between baseline ICP and ONSD values (all P &gt; 0.05). Conclusion: Although ONSD measurement via ultrasonography provides a noninvasive method for assessing ICP in IIH, our findings revealed no significant change one month after treatment initiation. ONSD may gradually decrease following LP; however, a return to baseline values appears to require a prolonged period, even after ICP normalization. This should be considered during patient follow-up. Our findings underscore the limitations of using ONSD as a standalone marker for monitoring therapeutic response. Further research is warranted to explore the factors influencing ONSD dynamics and to establish standardized, patient-centered measurement protocols.

ObjectiveThis study aimed to determine the extent to which ultrasonographic and computed tomographic (CT) measurements of the optic nerve sheath diameter (ONSD) correlate with the prognosis and severity of traumatic brain injury (TBI).MethodologyA prospective cohort study was conducted among 200 adult patients admitted to a Level 1 trauma center over one year. All patients were between 18 and 70 years of age and had sustained mild to severe TBI. Based on the Glasgow Coma Scale (GCS), patients were stratified into three categories of injury severity: mild, moderate, and severe. The ONSD was measured using both bedside ultrasonography and CT imaging. CT scans served as the reference standard for identifying intracranial pathologies. The primary objective was to evaluate whether ONSD measurement could help identify patients with intracranial hypertension (elevated intracranial pressure, ICP). CT findings, mortality, and long-term neurological outcomes were analyzed to assess the association between ONSD values and clinical prognosis.ResultsA moderate to strong positive correlation was found between the ONSD measured by ultrasonography and the severity of TBI, as assessed by the GCS. Increasing injury severity was associated with larger ONSD values. A significant association was also observed between ONSD measurements and CT indicators of elevated ICP, including midline shift, basal cistern effacement, and brain herniation. Moreover, higher ONSD values were significantly associated with poorer clinical outcomes, including increased mortality and delayed neurological recovery. The relationship between ONSD and these outcome measures appeared strong and consistent.ConclusionUltrasound-based measurement of ONSD proved to be a reliable, non-invasive indicator of TBI severity and intracranial pressure. It demonstrated significant correlation not only with the degree of brain injury but also with patients’ clinical outcomes. Overall, these findings support the use of ONSD as a practical and effective surrogate tool for assessing raised ICP, particularly in situations where direct measurement is not feasible.

Inter-rater reliability of ultrasonographic measurements of optic nerve sheath diameter performed by emergency nurses

Optic nerve sheath diameter measurement using bedside ultrasound: Is it accurate?

Pseudotumor cerebri syndrome (PTCS) is characterized by raised intracranial pressure (ICP) with no neuroradiological abnormalities. Ocular ultrasound has been in use to measure optic nerve sheath diameter (ONSD), and retinal artery Doppler indices have been used for indirect assessment of ICP by pediatric intensivists. Here, we aimed to evaluate the correlation of the lumbar puncture (LP) opening pressure with the ultrasonographic ONSD and retinal resistive index (RRI) measures in patients with PTCS. And we wanted to find an answer to the following question: Can ultrasonographic ONSD measures serve as a follow-up tool in patients with PTCS? A prospective, single-center, case-control study was performed by pediatric intensive care and pediatric neurology departments. A total of 7 patients with PTCS were evaluated as patient group and 15 healthy children were evaluated as control group. The mean age of patient group was 138.8 ± 43.7 months. The mean right ONSD was 6.7 ± 0.5 mm and the mean left ONSD was 6.7 ± 0.6 mm. The mean right RRI value was 0.73 ± 0.03 and the mean left RRI was 0.73 ± 0.09. For the patient group, ONSD and RRI values of both eyes were statistically significant higher values than for the control group. The mean LP opening pressure was 56.57 ± 16.36 cmH 2 O. We detected strong, positive, and statistically significant correlations between the LP opening pressure and ONSD baseline measures for both the right eye ( r = 0.882, p = 0.009) and the left eye ( r = 0.649, p = 0.004). There was no correlation between opening pressure in LP and RRI measurements. We detected a statistically significant decrease in the right ONSD and left ONSD values and visual analog scale scores at the third-month follow-up. Our study results demonstrate that ultrasonographic ONSD measurements can be used as a noninvasive tool for assessment of the ICP at first admission and can be used as a follow-up tool in PTSC patients.

Background:Diabetes mellitus is a disease associated with several complications in its acute and chronic stages.Objective:The aim of the study was to determine the treatment‐associated changes in optic nerve sheath diameter in patients admitted to the emergency department due to one of the acute hyperglycemic complications of diabetes mellitus.Materials and method:Diabetic patients with serum glucose levels of 250 mg/dL or higher were included in the study. Healthy volunteers were included in the control group. Optic nerve sheath diameter was measured at 0th hour and at the end of the second hour. Blood samples were collected simultaneously with optic nerve sheath diameter measurements.Results:The study included 100 individuals. Group 1 included 50 patients and Group 2 included 50 healthy adults. Optic nerve sheath diameter was 4.5 ± 0.4 mm in Group 1 and 4.4 ± 0.5 mm in Group 2 in 0th hour, and no statistical difference was found between the groups (p = 0.162). In Group 1, optic nerve sheath diameter increased 0.6 ± 0.4 mm after the treatment. Of the patients in Group 1, 22 (44%) patients with diabetic ketoacidosis or hyperosmolar hyperglycemic state were assigned to Group 1A and 28 (56%) patients with isolated hyperglycemia were assigned to Group 1B. There was not a difference between the pre‐ and post‐treatment optic nerve sheath diameter values of the patients in Group 1A and Group 1B. Optic nerve sheath diameter was observed to enlarge after treatment. The difference in optic nerve sheath diameter was 0.6 ± 0.4 mm in Group 1A and 0.5 ± 0.4 mm in Group 1B (p = 0.294).Conclusion:Pre‐treatment optic nerve sheath diameter values of the patients who were diagnosed with one of the acute hyperglycemic complications of diabetes mellitus are not different from healthy adults. Furthermore, optic nerve sheath diameter values do not change with the severity of the disease. However, optic nerve sheath diameter values change with treatment. For this reason, optic nerve sheath diameter can be used to following the development of brain edema.

Elevated intracranial pressure (ICP), a common complication in traumatic brain injuries (TBI), can lead to optic nerve sheath diameter (ONSD) enlargement and flow spectrum changes from the internal carotid artery (ICA) to middle cerebral artery (MCA). This study will investigate the use of Cervical-Cerebral Arterial Ultrasound (CCAU) for non-invasive ICP assessment and evaluating the related indices' clinical utility in TBI patients with decompressive craniotomy (DC). ONSD and flow spectrum changes were measured within 24 h after DC in 106 patients via ultrasonic ONSD measurement and CCAU, simultaneously. Intracranial pressures were invasively monitored, using a microsensor or ventricular catheter as the gold standard. Patients were classified into two groups, namely the normal group and the elevated group, based on distinct intracranial pressure thresholds of 15 mmHg, 20 mmHg and 22 mmHg. Subsequently, Bland Altman plot used for evaluating agreement between estimate for ICP (ICPe) and invasive ICP (ICPi). Then, the correlation between ONSD, MCAPI (pulsatility index of MCA), PI-ratio (MCAPI/ICAPI), and ICPe was examined through linear regression analysis. Finally, receiver operator characteristic curves (ROC) were also analyzed for different indexes and their combinations (using logistic model). Significant differences were observed between the normal and elevated ICP groups with respect to ONSD, PI-ratio, MCAPI and MCAFVd (diastolic flow velocity of MCA) (p < 0.05). The correlation coefficients for the relationships between ONSD, PI ratio, FVdMCA, and PI with ICPi were 0.62, 0.33, 0.32 and 0.21, respectively, each demonstrating statistical significance (p < 0.05). Analysis of the ROC curves demonstrated that the area under the curve (AUC) for predicting elevated ICPi at thresholds of 15 mmHg, 20 mmHg, and 22 mmHg via combined ultrasonographic measurements of the PI ratio and ONSD was the largest, specifically 0.74 (95% CI: 0.65-0.82), 0.77 (95% CI: 0.69-0.85), and 0.79 (95% CI: 0.70-0.86), respectively. Ultrasonographic measurements of ONSD, PI-ratio, MCAPI and MCAFVd demonstrate a moderate to low weak correlation with ICPi measurements. ICPe is not considered sufficiently precise for noninvasive accurate ICP assessment. The concurrent utilization of CCAU and ONSD measurements may offer superior accuracy for elevated ICP in TBI patients with DC, especially in specificity. Further research is imperative to validate these findings within a more extensive patient population.

We aimed to describe the neurosonological findings related to cerebral hemodynamics acquired using transcranial Doppler and to determine the frequency of elevated ICP by optic nerve sheath diameter (ONSD) measurement in patients with severe coronavirus disease (COVID-19) hospitalized in the intensive care unit of a national referral hospital in Peru. We included a retrospective cohort of adult patients hospitalized with severe COVID-19 and acute respiratory failure within the first 7 days of mechanical ventilation under deep sedoanalgesia, with or without neuromuscular blockade who underwent ocular ultrasound and transcranial Doppler. We determine the frequency of elevated ICP by measuring the diameter of the optic nerve sheath, choosing as best cut-off value a diameter equal to or >5.8 mm. We also determine the frequency of sonographic patterns obtained by transcranial Doppler. Through insonation of the middle cerebral artery. Likewise, we evaluated the associations of clinical, mechanical ventilator, and arterial blood gas variables with ONSD ≥5.8 mm and pulsatility index (PI) ≥1.1. We also evaluated the associations of hemodynamic findings and ONSD with mortality the effect size was estimated using Poisson regression models with robust variance. This study included 142 patients. The mean age was 51.39 ± 13.3 years, and 78.9% of patients were male. Vasopressors were used in 45.1% of patients, and mean arterial pressure was 81.87 ± 10.64 mmHg. The mean partial pressure of carbon dioxide (PaCO2) was elevated (54.08 ± 16.01 mmHg). Elevated intracranial pressure was seen in 83.1% of patients, as estimated based on ONSD ≥5.8 mm. A mortality rate of 16.2% was reported. In the multivariate analysis, age was associated with elevated ONSD (risk ratio [RR] = 1.07). PaCO2 was a protective factor (RR = 0.64) in the cases of PI ≥ 1.1. In the mortality analysis, the mean velocity was a risk factor for mortality (RR = 1.15). A high rate of intracranial hypertension was reported, with ONSD measurement being the most reliable method for estimation. The increase in ICP measured by ONSD in patients with severe COVID-19 on mechanical ventilation is not associated to hypercapnia or elevated intrathoracic pressures derived from protective mechanical ventilation.

The crtierion standard method for monitoring intracranial pressure (ICP) can result in complications and pain. Hence, noninvasive, repeatable methods would be valuable. To examine how ultrasonographic optic nerve sheath diameter (ONSD) correlated with noninvasive and dynamically monitored ICP changes. The ONSD was measured before the lumbar puncture (LP) in 60 patients on admission. Patients with elevated ICP were divided into group 1 (200 < LP ≤ 300 mm H2O) and group 2 (LP > 300 mm H2O). Patients underwent follow-up ONSD and LP measurements within 1 month. We analyzed the correlations between the ONSD and ICP on admission and between the changes in ONSD and ICP, which were the respective changes in ONSD and ICP from admission to follow-up. The ultrasonographic ONSD and ICP were measured on admission and follow-up. The correlations between the ONSD and ICP on admission and between the changes in ONSD and ICP were analyzed using Pearson correlation analyses. For 60 patients (Han nationality; mean [SD] age, 36.2 [12.04] years; 29 [48%] female) on admission, the ONSD and ICP values were strongly correlated, with an r of 0.798 (95% CI, 0.709-0.867; P < .001). Twenty-five patients with elevated ICP who completed the follow-up were included. The mean (SD) ONSD and ICP on admission were 4.50 (0.54) mm and 302.40 (54.26) mm H2O, respectively. The ONSD and ICP values obtained on admission were strongly correlated , with an r of 0.724 (95% CI, 0.470-0.876; P < .001). The mean (SD, range) changes in ICP and ONSD were 126.64 (52.51 mm H2O, 20-210 mm H2O) (95% CI, 106.24-146.07) and 1.00 (0.512 mm, 0.418-2.37 mm) (95% CI, 0.83-1.20), respectively. The change in ONSD was strongly correlated with the change in ICP, with an r of 0.702 (95% CI, 0.425-0.870; P < .001). The follow-up evaluations revealed that the elevated ICP and dilated ONSD had returned to normal, and no evidence of difference was found in the mean ONSDs between group 1 (3.49 mm; 95% CI, 3.34-3.62 mm) and group 2 (3.51 mm; 95% CI, 3.44-3.59 mm) (P = .778) at follow-up. The dilated ONSDs decreased along with the elevated ICP reduction. Ultrasonographic ONSD measurements may be a useful, noninvasive tool for dynamically evaluating ICP.

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. 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. 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). 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.