超声测量视神经鞘直径与眼球横径比值在重症颅脑损伤患者颅内压监测中的应用

目的研究重症颅脑损伤(TBI)患者颅内压监测中超声测量视神经鞘直径(ONSD)与眼球横径(ETD)比值的应用价值。方法回顾性选取2020年1月至2021年1月保定市第二中心医院收治入院的98例重症TBI患者为研究对象。所有患者均于入院24 h内接受开颅手术治疗,采用腰椎穿刺术测定颅内压,手术完成后24 h内选取索诺声超声M-Turbo与6-13 MHz线阵超声探头测定ETD、ONSD,选取颅内压监护仪记录颅内压值。参考颅内压值分为研究组(n=58,颅内压≤20 mmHg)与对照组(n=40,颅内压>20 mmHg)。分析并比较两组入院后同期监测指标水平及与ONSD/ETD比值相关性;分析两组超声测量ONSD/ETD比值、ONSD与颅内压相关性;超声测量ONSD/ETD比值、ONSD预测颅内压水平上升的准确性经受试者工作特征(ROC)曲线评价,并比较金标准脑室内测压与超声测量ONSD/ETD比值、ONSD诊断一致性。结果研究组较对照组GSC评分、颅内温度、ETD更高,颅内压、ONSD、ONSD/ETD比值更低,差异均有统计学意义(P <0.05)。两组患者GCS与ONSD/E...     

Non-invasive assessment of intracranial pressure using ocular sonography in neurocritical care patients

Objective  To assess the relationship between optic nerve sheath diameter (ONSD) and intracranial pressure (ICP) in neurocritical care patients. Design  Prospective, observational study. Setting  Surgical critical care unit, level 1 trauma center. Patients  A total number of 37 adult patients requiring sedation and ICP monitoring after severe traumatic brain injury, subarachnoid hemorrhage, intracranial hematoma, or stroke. Measurements and main results  Optic nerve sheath diameter was measured with a 7.5 MHz linear ultrasound probe. ICP was measured invasively via a parenchymal device. Simultaneous measurements were performed atleast once a day during the first 2 days after ICP insertion and in cases of acute changes. There was a significant relationship between ONSD and ICP (78 simultaneous measures, r = 0.71, P < 0.0001). Changes in ICP were strongly correlated with changes in ONSD (39 measures, r = 0.73, P < 0.0001). Enlarged ONSD was a suitable predictor of elevated ICP (>20 mmHg) (area under ROC curve = 0.91). When ONSD was less than 5.86 mm, the negative likehood ratio for raised ICP was 0.06. Conclusion  In sedated neurocritical care patients, non-invasive sonographic measurements of ONSD are correlated with invasive ICP, and the probability to have raised ICP if ONSD is less than 5.86 mm is very low. This method could be used as a screening test when raised ICP is suspected. The authors received no financial support for this work.     

Correlation of Optic Nerve Sheath Diameter with Direct Measurement of Intracranial Pressure

Background: Measurements of the optic nerve sheath diameter (ONSD) using bedside ultrasound (US) have been shown to correlate with clinical and radiologic signs and symptoms of increased intracranial pressure (ICP). Objectives: Previous literature has identified 5 mm as the ONSD measurement above which patients exhibit either clinical or radiologic signs of elevated ICP. The goals of this study were to evaluate the association between ONSD and ICP and to validate the commonly used ONSD threshold of 5 mm using direct measurements of ICP as measured by ventriculostomy. Methods: A prospective blinded observational study was performed using a convenience sample of adult patients in both the emergency department (ED) and the neurologic intensive care unit (ICU) who had invasive intracranial monitors placed as part of their clinical care. Ocular USs were performed with a 10–5 MHz linear probe. Emergency physicians (EPs) with previous ocular US experience performed ONSD measurements while blinded to the contemporaneous ICP reading obtained directly from invasive monitoring. The association between ONSD and ICP was assessed with the Spearman rank correlation coefficient, and a receiver operator characteristic (ROC) curve was created to determine the optimal ONSD cutoff to detect ICP > 20 cm H₂O. Results: Thirty‐eight ocular USs were performed on 15 individual patients. Spearman rank correlation coefficient of ONSD and ICP was 0.59 (p < 0.0005) demonstrating a significant positive correlation. An ROC curve was created to assess the ability of ONSD to distinguish an abnormal ICP greater than 20 cm H₂O. The area under the ROC curve was 0.93 (95% confidence interval [CI] = 0.84 to 0.99). Based on inspection of the ROC curve, ONSD > 5 mm performed well to detect ICP > 20 cm H₂O with a sensitivity of 88% (95% CI = 47% to 99%) and specificity of 93% (95% CI = 78% to 99%). Conclusions: Using an ROC curve the authors systematically confirmed the commonly used threshold of ONSD > 5 mm to detect ICP > 20 cm H₂O. This study directly correlates ventriculostomy measurements of ICP with US ONSD measurements and provides further support for the use of ONSD measurements as a noninvasive test for elevated ICP.     

Using MRI of the optic nerve sheath to detect elevated intracranial pressure

The current gold standard for the diagnosis of elevated intracranial pressure (ICP) remains invasive monitoring. Given that invasive monitoring is not always available or clinically feasible, there is growing interest in non-invasive methods of assessing ICP using diagnostic modalities such as ultrasound or magnetic resonance imaging (MRI). Increased ICP is transmitted through the cerebrospinal fluid surrounding the optic nerve, causing distention of the optic nerve sheath diameter (ONSD). In this issue of Critical Care, Geeraerts and colleagues describe a non-invasive method of diagnosing elevated ICP using MRI to measure the ONSD. They report a positive correlation between measurements of the ONSD on MRI and invasive ICP measurements. If the findings of this study can be replicated in larger populations, this technique may be a useful non-invasive screening test for elevated ICP in select populations.     

超声测量视神经鞘直径预测颅内压增高的围手术期应用进展

视神经鞘(ONS)是颅内硬脑膜的直接延续,内有横梁式的蛛网膜下腔。当患者颅内压(ICP)升高时,脑脊液会经蛛网膜滤出使视神经鞘增宽,因此可以用视神经鞘直径(ONSD)预测ICP增高。目前,围手术期ICP监测手段较少,超声测量ONSD预测ICP的技术因具有无创、床旁、快速等优势在临床上被广泛应用,将该技术应用于围术期患者中可以提供术中ICP监测。本文就ICP监测现状、ONSD与ICP的关系、ONSD预测ICP增高的临界值及ONSD预测围术期ICP增高的应用前景作一综述,以期为围手术期应用超声测量ONSD预测ICP增高提供支持。     

Optic nerve sheath diameter and lumbar puncture opening pressure in nontrauma patients suspected of elevated intracranial pressure

ObjectiveThe purpose of this study was to determine if patients with nontraumatic causes of elevated intracranial pressure (ICP) could be identified by ultrasound measurement of optic nerve sheath diameter (ONSD). It was hypothesized that an ONSD greater than or equal to 5 mm would identify patients with elevated ICP.MethodThis was a prospective observational trial comparing ONSD with ICP measured by opening pressure manometry on lumbar puncture (LP). The cohort consisted of a convenience sample of adult patients presenting to the emergency department, requiring LP. The ONSD measurement was performed before computed tomography and LP. The physician performing the LP was blinded to the result of the ONSD measurement. An opening pressure on manometry of greater than or equal to 20 cm H₂O and an ONSD greater than or equal to 5 mm were considered elevated.ResultsFifty-one patients were included in our study, 24 (47%) with ICP greater than or equal to 20 cm H₂O and 27 (53%) with ICP less than 20 cm H₂O. The sensitivity of ONSD greater than or equal to 5 for identifying elevated ICP was 75% (95% confidence interval, 53%-90%) with specificity of 44% (25%-65%). The area under the receiver operator characteristic curve was 0.69 (0.54-0.84), suggesting a relationship between ONSD and ICP.ConclusionAn ONSD greater than or equal to 5 mm was associated with elevated ICP in nontraumatic causes of elevated ICP. Although a relationship exists, a sensitivity of 75% does not make ONSD measurement an adequate screening examination for elevated ICP in this patient population.     

Optic nerve sonography in the diagnostic evaluation of adult brain injury

Introduction  

The optic nerve sheath diameter (ONSD) may be increased in brain-injured patients, especially children, with intracranial hypertension. We investigated whether measurements of ONSD correlated with simultaneous noninvasive and invasive measurements of the intracranial pressure (ICP) in brain-injured adults.     

Optic nerve sheath diameter on computed tomography is correlated with simultaneously measured intracranial pressure in patients with severe traumatic brain injury

Purpose

Assess the relationship between optic nerve sheath diameter (ONSD) measured on bedside portable computed tomography (CT) scans and simultaneously measured intracranial pressure (ICP) in patients with severe traumatic brain injury.

Methods

Retrospective cohort study of 57 patients admitted between 2009 and 2013. Linear and logistic regression were used to model the correlation and discrimination between ONSD and ICP or intracranial hypertension, respectively.

Results

The cohort had a mean age of 40 years (SD 16) and a median admission Glasgow coma score of 7 (IQR 4–10). The between-rater agreement by intraclass coefficient was 0.89 (95 % CI 0.83–0.93, P < 0.001). The mean ONSD was 6.7 mm (SD 0.75) and the mean ICP during CT was 21.3 mmHg (SD 8.4). Using linear regression, there was a strong correlation between ICP and ONSD (r = 0.74, P < 0.001). ONSD had an area under the curve to discriminate elevated ICP (≥20 mmHg vs. <20 mmHg) of 0.83 (95 % CI 0.73–0.94). Using a cutoff of 6.0 mm, ONSD had a sensitivity of 97 %, specificity of 42 %, positive predictive value of 67 %, and a negative predictive value of 92 %. Comparing linear regression models, ONSD was a much stronger predictor of ICP (R ² of 0.56) compared to other CT features (R ² of 0.21).

Conclusions

Simultaneous measurement of ONSD on CT and ICP were strongly correlated and ONSD was discriminative for intracranial hypertension. ONSD was much more predictive of ICP than other CT features. There was excellent agreement between raters in measuring ONSD.     

超声检测视神经鞘直径在急性颅内压增高患者诊断与治疗的临床价值研究

目的 探讨超声检测视神经鞘直径(ONSD)在急性颅内压(ICP)增高患者诊断与治疗的临床价值。方法 选择2020年3月至2023年3月在本院治疗的急性ICP增高患者180例,收集患者术前(T0)、麻醉后(T1)、手术开始(T2)、术后即刻(T3)、术后清醒时刻(T4)的ONSD以及ICP,分析各时刻ONSD与ICP的关系。并参考格拉斯哥预后评分(GOS)进行预后评估,分为预后良好组(157例)和预后不良组(23例),比较两组术前、术后即刻ONSD,并分析ONSD与GOS的相关性,采用受试者工作特征(ROC)曲线分析ONSD对围术期急性ICH患者预后的预测价值。结果 T0～T2时刻患者ONSD、ICP无明显变化,T3～T4时刻患者ONSD、ICP明显降低,差异均有统计学意义(P<0.05)。Pearson相关性结果发现,T0～T4时刻ONSD均与ICP呈正相关(P<0.05)。预后良好组与预后不良组术后ONSD、ICP水平均降低,且预后良好组术后ONSD、ICP水平更低,差异均有统计学意义(P<0.05)。Spearman相关性结果发现,术后即刻ONSD、ICP均与GOS呈负相关(P<0.05)。ROC曲线分析结果显示,术后即刻ONSD、ICP预测患者预后不良的的AUC分别为0.886、0.782,均有较好的预测价值(P<0.05)。结论 超声检测ONSD可有效评估急性ICP增高患者的ICP情况,且对患者预后有一定的预测价值。     

Ultrasonography of the optic nerve sheath may be useful for detecting raised intracranial pressure after severe brain injury

Objective To assess at admission to the ICU the relationship between optic nerve sheath diameter (ONSD) and intracranial pressure (ICP) and to investigate whether increased ONSD at patient admission is associated with raised ICP in the first 48 h after trauma. Design and setting Prospective, blind, observational study in a surgical critical care unit, level 1 trauma center. Patients and participants 31 adult patients with severe traumatic brain injury (TBI; Glasgow coma scale ≤ 8) requiring sedation and ICP monitoring, and 31 control patients without brain injury requiring sedation. Measurements and results ONSD was measured with a 7.5-MHz linear ultrasound probe. Two TBI groups were defined on the basis of ICP profile. If ICP exceeded 20 mmHg for more than 30 min in the first 48 h (before any specific treatment), patients were considered to have high ICP; if not, they had normal ICP. The largest ONSD value (the highest value for the right and left eye) was significantly higher in high ICP patients (6.3 ± 0.6 vs. 5.1 ± 0.7 mm in normal ICP patients and 4.9 ± 0.3 mm in control patients). There was a significant relationship between the largest ONSD and ICP at admission (r = 0.68). The largest ONSD was a suitable predictor of high ICP (area under ROC curve 0.96). When ONSD was under 5.7 mm, the sensitivity and negative predictive values for high ICP were 100%. Conclusions In the early posttraumatic period, ocular ultrasound scans may be useful for detecting high ICP after severe TBI. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. This article is discussed in the editorial available at: .     

Optic nerve sheath diameter measurement: a means of detecting raised ICP in adult traumatic and non-traumatic neurosurgical patients

Introduction

Bedside ultrasound measurement of optic nerve sheath diameter (ONSD) is emerging as a non-invasive technique to evaluate and predict raised intracranial pressure (ICP). It has been shown in previous literature that ONSD measurement has good correlation with surrogate findings of raised ICP such as clinical and radiological findings suggestive of raised ICP.

Optic nerve sheath diameter on initial brain CT,raised intracranial pressure and mortality after severe TBI: an interesting link needing confirmation

Optic nerve sheath diameter (ONSD) enlargement on initial computed tomography (CT) scan has been found to be associated with increased mortality after severe traumatic brain injury. This could offer the possibility to detect patients with raised intracranial pressure requiring urgent therapeutic interventions and/or invasive intracranial monitoring to guide the treatment. The method to measure ONSD using CT scan, however, needs further confirmation. Moreover, the link between ONSD enlargement on initial CT scan and raised intracranial pressure also needs to be confirmed by further studies.In a very interesting study performed on 77 severe traumatic brain injury patients, Legrand and colleagues found that the optic nerve sheath diameter (ONSD) measured on the initial brain computed tomography(CT) scan (performed within the first 3 hours of injury) was a very good predictor of ICU mortality [1]. In the multivariate analysis, ONSD >7.3 mm was independently associated with ICU mortality, and performed better than age >32 years, anisocoria at admission, and basal cistern compression on initial CT scan.The optic nerve is surrounded by a dural sheath that can inflate in cases of raised pressure in the cerebrospinal fluid. An enlarged ONSD, measured using ocular sonography, has been found in patients with raised intracranial pressure (ICP) [2]. Even if in Legrand and colleagues'' study the ICP was measured in only 9% of the patients, we can assume that the strong association between ONSD enlargement of initial CT and mortality was related to raised ICP occurring very early after trauma, as suggested by the fact that ONSD enlargement was also associated with other signs of raised ICP in the first CT scan as basal cistern effacement and midline shift. This is probably the major interest of this study: ONSD measurement on initial CT scan could offer the possibility to detect patients with raised ICP needing urgent therapeutic interventions and/or invasive intracranial monitoring to guide the treatment.Our enthusiasm must be tempered, however, as the method to measure ONSD using CT scan needs clarification and confirmation. ONSD has been measured 3 mm behind the globe - where the dural sheath is distensible, as has previously been determined using sonography [2-4] and magnetic resonance imaging [5]. In Legrand and colleagues'' study, ONSD has been measured on a millimetric slice brain CT scan but only in one plane. As suggested by Unsold and colleagues [6], since the optic nerve has a sinuous course in the horizontal and the vertical plane, a section of the nerve in a single plane can conduce one to overestimate ONSD. Actually, the values of ONSD in Legrand and colleagues'' study are larger than values obtained with ultrasound or magnetic resonance imaging or even with CT [7]. Moreover, the precise limits of the sheath and the orbital fat surrounding the sheath can be very difficult to determine. This study probably needs further confirmation of the reliability of the ONSD measurement, after realignment in the optic nerve plane and measurement in several axes.     

Pediatric point-of-care ultrasound of optic disc elevation for increased intracranial pressure: A pilot study

ObjectivePapilledema is often difficult to detect in children. Ocular point-of-care ultrasound (POCUS) measurement of the optic nerve sheath diameter (ONSD) is a non-invasive test for increased intracranial pressure (ICP), but no consensus exists on normal pediatric ONSD values. Detection of optic disc elevation (ODE, a component of papilledema) using POCUS has recently been qualitatively described. We sought to establish the diagnostic accuracy of different ODE cutoffs to detect increased ICP in children who underwent ocular POCUS in our pediatric emergency department (PED).MethodsWe retrospectively reviewed charts of patients ages 0–18 years who received ocular POCUS in our tertiary PED between 2011 and 2016. Patients were included if their archived POCUS examinations were deemed high-quality by a POCUS expert and they underwent ICP determination within 48 h after ocular POCUS. A blinded POCUS expert measured ODE, optic disc width at mid-height (ODWAMH), and ONSD. Receiver-operator curve analysis was performed for various cutoffs for these measurements in detecting increased ICP.Results76 eyes from 40 patients met study criteria. 26 patients had increased ICP. The mean ODE of both eyes (ODE-B) generated the largest area under the curve (0.962, 95% CI 0.890–1). The optimal ODE-B cutoff was 0.66 mm, with a sensitivity of 96% (95% CI 79–100%) and a specificity of 93% (95% CI 79–100%). 1/40 (2.5%) of patients with ODE-B < 0.66 had increased ICP.ConclusionsODE-B may represent the optimal ocular POCUS measurement for detecting increased ICP in children, and future prospective studies could more accurately describe the diagnostic performance of different pediatric ODE-B cutoffs.     

The effects of spinal immobilization at 20° on intracranial pressure

ObjectiveIn this study, it was aimed to evaluate whether spinal immobilization at 20°, instead of the traditional 0°, affects intracranial pressure (ICP) via the ultrasonographic (USG) measurement of optic nerve sheath diameter (ONSD).Methods140 healthy, adult, non-smoking volunteers who had no acute or chronic diseases were included this study. Volunteers were randomly divided into two groups; performed spinal immobilization at 0° (Group 1) and at 20° (Group 2). After spinal immobilization (at 0 or 20°), measurements of ONSD were performed at 0, 30, and 60 min in an immobilized position.ResultsWhen evaluating the change in ONSD over time (at 30 and 60 min) as compared to basal measurements at 0 min, it was found that the ONSD values of both sides (the right and left eyes) were significantly increased in Group 1 and Group 2. For Groups 1 and 2, these differences existed both between 0 and 30 min and between 30 and 60 min.In addition, in this study, the amounts of increase in the ONSD measurements from 0 to 30 min and from 30 to 60 min (ΔONSD0–30 min and ΔONSD30–60 min) in both groups were compared. The results showed that there was no significant difference between Group 1 and Group 2 in terms of ΔONSD measurements.ConclusionsSpinal immobilization at 0° as a part of routine trauma management increased ONSD and thus ICP. Secondly, we found that similar to immobilization at 0°, spinal immobilization at 20° increased ONSD.     

Quality And Feasibility of Sonographic Measurement of the Optic Nerve Sheath Diameter to Estimate the Risk of Raised Intracranial Pressure After Traumatic Brain Injury in Prehospital Setting

Objective: In patients with traumatic brain injury (TBI), early detection and subsequent prompt treatment of elevated intracranial pressure (ICP) is a challenge in the prehospital setting, because physical examination is limited in comatose patients and invasive device placement is not possible. The aim of this study was to evaluate the quality and feasibility of optic nerve sheath diameter (ONSD) measurements obtained during the prehospital management of patients with TBI. Methods: This study was a prospective, observational study of 23 patients with moderate and severe TBI during prehospital medical care. The primary endpoint was the quality of ONSD measurements expressed as the percentage of ONSD validated by the experts. Secondary endpoints included the feasibility of ONSD measurements as the percentage of ONSD performed and assessment by operators of ease and duration to perform. Results: Ultrasound ONSD was performed in 19 (82%) patients and 80% of ONSD measurements were validated by the experts. The ONSD measurements were possible in 15 (79%) cases. The physicians have assessed the ease of use at 8 (interquartile range [IQR]?=?2.5–8) on 10 for and the median time to obtain ONSD measurement was 4?min (IQR?=?3–5). ONSD measurement was performed in 12 (63%) cases during the transport and in 7 (37%) cases on scene, with 58% (n?=?7) and 71% (n?=?5) validated ONSD, respectively. The success rate in the helicopter was 43% compared to 80% in the ambulance. Conclusion: This study shows that it is feasible to obtain high-quality ONSD measurements in the management of patients with TBI in a prehospital setting. A randomized study evaluating the usefulness of ONSD to guide management of TBI in the prehospital phase may be of great interest.     

Intraoperative non invasive intracranial pressure monitoring during pneumoperitoneum: a case report and a review of the published cases and case report series

Non-invasive measurement of ICP (nICP) can be warranted in patients at risk for developing increased ICP during pneumoperitoneum (PP). Our aim was to assess available data on the application of nICP monitoring during these procedures and to present a patient assessed with an innovative combination of noninvasive tools. Literature review of nICP assessment during PP did not find any studies comparing different methods intraprocedurally and only few studies of any nICP monitoring were available: transcranial Doppler (TCD) studies used the pulsatility index (PI) as an estimator of ICP and failed to detect a significant ICP increase during PP, whereas two out of three optic nerve sheath diameter (ONSD) studies detected a statistically significant ICP increase. In the case study, we describe a 52 year old man with a high grade thalamic glioma who underwent urgent laparoscopic cholecystectomy. Considering the high intraoperative risk of developing intracranial hypertension, he was monitored through parallel ONSD ultrasound measurement and TCD derived formulae (flow velocity diastolic formula, FVdnICP, and PI). ONSD and FVdnICP methods indicated a significant ICP increase during PP, whereas PI was not significantly increased. Our experience, combined with the literature review, seems to suggest that PI might not detect ICP changes in this context, however we indicate a possible interest of nICP monitoring during PP by means of ONSD and of TCD derived FVdNICP, especially for patients at risk for increased ICP.     

Real time optic nerve sheath diameter measurement during lumbar puncture

Measurement of optic nerve sheath diameter (ONSD) using point of care ultrasound has been used to indirectly assess the intracranial pressure (ICP) particularly in conditions where it is raised. Direct pressure measurements using probes reaching the ventricle system correlated with ONSD using ultrasound. Attempts were made to measure the ONSD pre and post lumbar puncture (LP) after draining cerebrospinal fluid (CSF) as well as post ventricular shunt placement. We report ONSD measurement and demonstrate dynamic changes during LP in a patient with known idiopathic intracranial hypertension (IIH).     

Use of T2-weighted magnetic resonance imaging of the optic nerve sheath to detect raised intracranial pressure

Introduction  

The dural sheath surrounding the optic nerve communicates with the subarachnoid space, and distends when intracranial pressure is elevated. Magnetic resonance imaging (MRI) is often performed in patients at risk for raised intracranial pressure (ICP) and can be used to measure precisely the diameter of optic nerve and its sheath. The objective of this study was to assess the relationship between optic nerve sheath diameter (ONSD), as measured using MRI, and ICP.     

Optic nerve sheath diameter measurement for predicting raised intracranial pressure in adult patients with severe traumatic brain injury: A meta-analysis

ObjectiveTo evaluate and compare the diagnostic feasibility of measuring the optic nerve sheath diameter (ONSD), via brain computed tomography (CT) and ocular ultrasonography (US) for prediction of raised intracranial pressure (ICP) in severe traumatic brain injury (TBI) patients.MethodsThe PubMed and EMBASE databases were searched for studies assessing the diagnostic accuracy of brain CT or ocular US for predicting raised ICP. Bivariate and hierarchical summary receiver operating characteristic modeling were performed to evaluate and compare the diagnostic feasibility of measuring the ONSD in adult patients with severe TBI according to modality (ocular US vs. brain CT).ResultsFive studies (four with ocular US and one with brain CT) were included. The ONSD had a pooled sensitivity of 0.91, pooled specificity of 0.77, and area under the HSROC curve of 0.92 for predicting raised ICP. More importantly, studies using ocular US found an almost equal sensitivity (0.91 vs. 0.90; p = .35) and higher specificity (0.82 vs. 0.58; p = .01) than those using brain CT.ConclusionsMeasurement of the ONSD may be a useful method for predicting raised ICP in adult patients with severe TBI.