Optic nerve sheath diameter sonography for the diagnosis of increased intracranial pressure: a systematic review and meta-analysis protocol

Abstract

IntroductionIncreased intracranial pressure (ICP) is a significant neurological issue that may lead to permanent neurological sequelae. When evaluating patients with traumatic brain injury, it is crucial to identify those with high ICP in order to expedite ICP lowering measures and maintain adequate cerebral perfusion. Several measures are used to recognise patients with increased ICP including CT scan, MRI, ICP monitor, and lumbar puncture (LP). However, these tests can be invasive, associated with radiation exposure, contraindicated, or not readily available. Ultrasonography measurement of the optic nerve sheath diameter (ONSD) is proposed as a non-invasive and quick measure to identify high ICP. The aim of this systematic review and meta-analysis will be to examine the accuracy of ONSD sonography for increased ICP diagnosis.Methods and analysesWe will include published and unpublished randomised controlled trials, observational studies, and abstracts, with no publication type or language restrictions. Search strategies will be designed to peruse the MEDLINE, Embase, Web of Science, WHO Clinical Trials, ClinicalTrials.gov, CINAHL, and the Cochrane Library databases. We will also implement strategies to search grey literature. Two reviewers will independently complete data abstraction and conduct quality assessment. Included studies will be assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. We will construct the hierarchical summary receiver operating characteristic curve for included studies and pool sensitivity and specificity using the bivariate model. We also plan to conduct prespecified subgroup analyses to explore heterogeneity. The overall quality of evidence will be rated using Grading of Recommendations, Assessment, Development and Evaluations (GRADE).Ethics and disseminationResearch ethics board approval is not required for this study as it draws from published data and raises no concerns related to patient privacy. This review will provide a comprehensive assessment of the evidence on ONSD sonography diagnostic accuracy and is directed to a wide audience. Results from the review will be disseminated extensively through conferences and submitted to a peer-reviewed journal for publication.PROSPERO registration numberCRD42017055485.Clinical trial numberTrial registration number is NCT00783809.

Ultrasonographic optic nerve sheath diameter to detect increased intracranial pressure in adults: a meta-analysis

“…We searched the electronic databases PubMed, EMBASE, and the Cochrane central database from January 1990 to September 2017 using MeSH terms or keywords as follows (5,8,12) . Our inclusion criteria were as follows: (i) studies on adult patients (aged > 18 years) who underwent ONSD measurement on both US and CT; (ii) studies on patients who were suspected of having IICP; (iii) studies with ONSD procedures performed in > 10 cases; (iv) studies in which ONSD > 5.0 mm was used for detecting IICP on CT; (v) studies in which ONSD was measured 3 mm behind the optic globe; and (vi) randomized controlled, prospective, or retrospective case-controlled studies.…”

“…The feasibility of using optic nerve sheath diameter (ONSD) by ultrasonography (US) for identifying IICP has been increasingly reported (2,3). The optic nerve is sheathed in meningeal layers, allowing cerebrospinal fluid (CSF) to communicate between the intracranial and subarachnoid spaces within the optic nerve sheath (4,5). US ONSD can be performed at the bedside in 5 min without causing procedural complications or radiation exposure (1).…”

Reply to “Ultrasound evaluation of optic nerve sheath diameter to assess treatment efficacy in pediatric idiopathic intracranial hypertension”

“…ONSD in orbital ultrasonography regressed gradually consistent with clinical and radiologic improvement during follow-up. [2] We agree with you that B-scan orbital USG has some handicaps related to technique, patient, and clinicians, which were mentioned in the discussion section of our text and Vitiello et al's letter [3][4][5]. To avoid these disadvantages, ONSD assessments were performed on axial images, which were recorded 3 mm posterior to the anterior of the optic nerve head, three measurements were obtained in each eye, and their averages were recorded and the cut-off the ONSD enlargement was considered as ONSD of ≥ 5 mm in the present study.…”

Bedside Ultrasonographic Assessment of Optic Nerve Sheath Diameter As a Means of Detecting Raised Intracranial Pressure in Neuro-Trauma Patients

“…It is important to determine raised intracranial pressure (ICP) in traumatic and nontraumatic neurological and neurosurgical patients as it may cause significant neurological deterioration due to secondary brain damage. [ 1 2 ] Hence, a quick evaluation of increased ICP is important for the management of patients with traumatic brain injury (TBI) to allow timely ICP lowering measures and maintain adequate cerebral perfusion. [ 3 ] Direct methods of ICP measurement, such as epidural bolt, microdialysis catheter, lumbar puncture (LP), and intraventricular catheterization are accurate but are invasive in nature and can result in complications such as hemorrhage and infection.…”