Measurement of the Optic Nerve Diameter in Different Healthcare Operators

NCT06830460 | Not Yet Recruiting

• 1 other identifier: ONSD
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

The study evaluates the effectiveness of a theoretical-practical training course for the ultrasound measurement of the optic nerve sheath diameter (ONSD), a non-invasive method used to estimate intracranial pressure (ICP). The optic nerve sheath is continuous with the subarachnoid space, which contains cerebrospinal fluid (CSF). An increase in ICP leads to an increase in CSF within the sheath, enlarging its diameter. ONSD measurement is typically performed by placing an ultrasound probe on the closed eyelid, allowing visualization of the optic nerve behind the eyeball. While the correlation between ONSD enlargement and elevated ICP is well-documented, there is variability in diagnostic cut-off values due to differences in measurement techniques, equipment, and operator experience. Previous studies have shown that even novice operators can achieve clinically acceptable accuracy after brief training. This study aims to assess whether medical students, nursing students, anesthesiology and intensive care residents, and intensive care nurses can learn to perform reliable ONSD measurements after a short training session. Methodology: The study will involve 40 participants unfamiliar with ONSD measurement: 10 medical students, 10 nursing students, 10 anesthesiology and intensive care residents, and 10 experienced intensive care nurses. The training will consist of a four-hour session, including a 30-minute lecture on ocular anatomy and ultrasound techniques, a real-time demonstration, and supervised hands-on practice with at least 20 measurements. Participants must pass a multiple-choice test with at least 70% correct answers to proceed to practical verification, where they will measure ONSD in five healthy volunteers. These measurements will be compared with those taken by an expert tutor. Measurement Technique: The ultrasound technique follows expert consensus guidelines, using a linear probe with a minimum frequency of 7.5 MHz. Volunteers will be positioned semi-seated at a 45° head elevation with closed eyelids. The ONSD measurement will be taken 3 mm behind the retina on the right eye. Care will be taken to avoid pressure on the eyeball, and safety parameters will be monitored to ensure compliance with FDA guidelines. The study aims to demonstrate that various healthcare professionals can achieve accurate and reliable ONSD measurements with proper training, enhancing the utility of this technique in diverse clinical settings.

Conditions

Healthy Volunteer; Healthy Volunteer Study

Keywords

optic nerve sheath diameter; theoretical-practical course

Outcome Measures

Primary Outcomes (1)

• OSND measure affidability

  ONSD measure will be recorded and compared to that one from a expert tutor

  Through study completion, an average of 3 hours

Study Arms (1)

ONSD training

EXPERIMENTAL

Other: Training

Interventions

Training OTHER

The training will consist of a four-hour session, including a 30-minute lecture on ocular anatomy and ultrasound techniques, a real-time demonstration, and supervised hands-on practice with at least 20 measurements. Participants must achieve a score of at least 70% on a multiple-choice test to proceed to practical verification, where they will measure the ONSD in five healthy volunteers. These measurements will be compared to those taken by an expert tutor.

ONSD training

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• medical student, or nurse student, or residents in anesthesia or nurse with at least 3 years of Intensive care unit experience

You may not qualify if:

• previous skills on ONSD measurements

Sponsors & Collaborators

• University Magna Graecia: lead

Study Sites (1)

Magna Graecia University

Catanzaro, CZ, 88100, Italy

Location

Related Publications (5)

• Potgieter DW, Kippin A, Ngu F, McKean C. Can accurate ultrasonographic measurement of the optic nerve sheath diameter (a non-invasive measure of intracranial pressure) be taught to novice operators in a single training session? Anaesth Intensive Care. 2011 Jan;39(1):95-100. doi: 10.1177/0310057X1103900116.

  PMID: 21375098 BACKGROUND

• Soliman I, Johnson GGRJ, Gillman LM, Zeiler FA, Faqihi F, Aletreby WT, Balhamar A, Mahmood NN, Ahmad Mumtaz S, Alharthy A, Lazaridis C, Karakitsos D. New Optic Nerve Sonography Quality Criteria in the Diagnostic Evaluation of Traumatic Brain Injury. Crit Care Res Pract. 2018 Apr 30;2018:3589762. doi: 10.1155/2018/3589762. eCollection 2018.

  PMID: 29854448 BACKGROUND

• Hirzallah MI, Lochner P, Hafeez MU, Lee AG, Krogias C, Dongarwar D, Hartman ND, Ertl M, Robba C, Malojcic B, Valaikiene J, Sarwal A, Hakimi R, Schlachetzki F; Optic Nerve Sheath Diameter Point-of-Care Ultrasonography Quality Criteria Checklist (ONSD POCUS QCC) Expert Panelists. Optic Nerve Sheath Diameter Point-of-Care Ultrasonography Quality Criteria Checklist: An International Consensus Statement on Optic Nerve Sheath Diameter Imaging and Measurement. Crit Care Med. 2024 Oct 1;52(10):1543-1556. doi: 10.1097/CCM.0000000000006345. Epub 2024 Jun 5.

  PMID: 38836697 BACKGROUND

• Geeraerts T, Launey Y, Martin L, Pottecher J, Vigue B, Duranteau J, Benhamou D. Ultrasonography of the optic nerve sheath may be useful for detecting raised intracranial pressure after severe brain injury. Intensive Care Med. 2007 Oct;33(10):1704-11. doi: 10.1007/s00134-007-0797-6. Epub 2007 Aug 1.

  PMID: 17668184 BACKGROUND

• Liu D, Kahn M. Measurement and relationship of subarachnoid pressure of the optic nerve to intracranial pressures in fresh cadavers. Am J Ophthalmol. 1993 Nov 15;116(5):548-56. doi: 10.1016/s0002-9394(14)73195-2.

  PMID: 8238213 BACKGROUND

Study Officials

• Federico Longhini, MD

  Magna Graecia University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Federico Longhini, MD

CONTACT

+393475395967; flonghini@unicz.it

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: OTHER
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor in Anesthesia and Intensive Care Medicine

Study Record Dates

• First Submitted: February 6, 2025
• First Posted: February 17, 2025
• Study Start: March 1, 2025
• Primary Completion: March 31, 2025
• Study Completion: March 31, 2025
• Last Updated: February 17, 2025

Record last verified: 2025-02

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR, ANALYTIC CODE
• Time Frame: after study pubblication
• Access Criteria: On reasonable request for scientific purposes

Locations

IT (1)