Efficacy of a theoretical‑practical course for the ultrasound measurement of the optic nerve diameter in different healthcare operators
Keywords:
Optic nerve sheath diameter, Training, Nurse, Student, Intracranial pressure, Ultrasound, Intensive care unit, AccuracyAbstract
Background: The measurement of the optic nerve sheath diameter (ONSD) via ultrasound is a non-invasive technique to estimate intracranial pressure. Brief training has been shown to be effective in accurately teaching the ONSD technique in specialized healthcare providers. This study evaluates the ability of medical and nursing students, Intensive Care Unit (ICU) nurses, and ICU residents to perform ONSD measurements after a brief training.
Methods: Forty participants underwent a 4-h training session consisting of 30 min of lecture focusing on the key principles of the technique for ONSD measurement, followed by at least 20 measurements with an expert tutor. Thereafter, all participants assessed 5 ONSD measurements on healthy volunteers and their assessments were compared to those by the expert tutor.
Results: All participants successfully visualized the optic nerve and recorded similar values among groups (p > 0.05 for all comparisons). ICU nurse residents and medical students demonstrated a good accuracyof measurements, as defined by an upper and lower limits of agreement with the expert tutor not exceeding 0.5 mm in the Bland–Altman analysis. On the opposite, nurse students had the highest error rates and poor accuracy in ONSD assessment.
Conclusions: These findings highlight the feasibility of training medical students, ICU nurses and residents in ONSD measurement, opening the possibility of a wider application of this technique. After dedicated training, ONSD assessment and monitoring could be performed not only by specialists but also by other healthcare providers, including specialized nurses. This may serve as an additional tool for the rapid triage of patients, even in out-of-hospital settings.
References
1. Liu D, Kahn M (1993) Measurement and relationship of subarachnoid pressure of the optic nerve to intracranial pressures in fresh cadavers. Am J Ophthalmol 116:548–556
2. Geeraerts T, Launey Y, Martin L, Pottecher J, Vigue B, Duranteau J et al (2007) Ultrasonography of the optic nerve sheath may be useful for detecting raised intracranial pressure after severe brain injury. Intensive Care Med 33:1704–1711
3. Hirzallah MI, Lochner P, Hafeez MU, Lee AG, Krogias C, Dongarwar D et al (2024) 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 52:1543–1556
4. Soliman I, Johnson G, Gillman LM, Zeiler FA, Faqihi F, Aletreby WT et al (2018) New optic nerve sonography quality criteria in the diagnostic evaluation of traumatic brain injury. Crit Care Res Pract 2018:3589762
5. Potgieter DW, Kippin A, Ngu F, McKean C (2011) 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 39:95–100
6. Aletreby W, Alharthy A, Brindley PG, Kutsogiannis DJ, Faqihi F, Alzayer W et al (2022) Optic nerve sheath diameter ultrasound for raised intracranial pressure: a literature review and meta-analysis of its diagnostic accuracy. J Ultrasound Med 41:585–595
7. Fernando SM, Tran A, Cheng W, Rochwerg B, Taljaard M, Kyeremanteng K et al (2019) Diagnosis of elevated intracranial pressure in critically ill adults: systematic review and meta-analysis. BMJ 366:l4225
8. Hirzallah MI, Lochner P, Hafeez MU, Lee AG, Krogias C, Dongarwar D et al (2022) Quality assessment of optic nerve sheath diameter ultrasonography: scoping literature review and Delphi protocol. J Neuroimaging 32:808–824
9. Montorfano L, Yu Q, Bordes SJ, Sivanushanthan S, Rosenthal RJ, Montorfano M (2021) Mean value of B-mode optic nerve sheath diameter as an indicator of increased intracranial pressure: a systematic review and meta-analysis. Ultrasound J 13:35
10. Oberfoell S, Murphy D, French A, Trent S, Richards D (2017) Inter-rater reliability of sonographic optic nerve sheath diameter measurements by emergency medicine physicians. J Ultrasound Med 36:1579–1584
11. Ballantyne SA, O’Neill G, Hamilton R, Hollman AS (2002) Observer variation in the sonographic measurement of optic nerve sheath diameter in normal adults. Eur J Ultrasound 15:145–149
12. Robba C, Poole D, Citerio G, Taccone FS, Rasulo FA (2020) Brain ultrasonography consensus on skill recommendations and competence levels within the critical care setting. Neurocrit Care 32:502–511
13. Zeiler FA, Ziesmann MT, Goeres P, Unger B, Park J, Karakitsos D et al (2016) A unique method for estimating the reliability learning curve of optic nerve sheath diameter ultrasound measurement. Crit Ultrasound J 8:9
14. von Elm E, Altman DG, Egger M, Pocock SJ, Gotzsche PC, Vandenbroucke JP (2014) The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement: guidelines for reporting observational studies. Int J Surg 12:1495–1499
15. Garofalo E, Bruni A, Pelaia C, Landoni G, Zangrillo A, Antonelli M et al (2019) Comparisons of two diaphragm ultrasound-teaching programs: a multicenter randomized controlled educational study. Ultrasound J 11:21
16. Bora V, Sood G, Dunville LM, Kramer J. Oculocardiac reflex; 2025.
17. Dugar S, Mehkri O, Li M, Hastings A, Siuba MT, Vashisht R et al (2022) Validation of a web-based platform for online training in point-of-care diaphragm ultrasound. ATS Sch 3:13–19
18. Vicente V, Bergqvist L, Kvist M, Rubenson Wahlin R, Sjolin H (2021) Nurse’s experiences of the caring encounter as single responder in prehospital emergency care. Int Emerg Nurs 58:101051
19. Lichtenhahn A, Kruse M, Busing J, Vogel M, Konrad C (2019) Analysis of a first responder system for emergency medical care in rural areas: first results and experiences. Anaesthesist 68:618–625
20. Carlstrom E, Freden L (2017) The first single responders in Sweden—evaluation of a pre-hospital single staffed unit. Int Emerg Nurs 32:15–19
21. Magnusson C, Kallenius C, Knutsson S, Herlitz J, Axelsson C (2016) Pre-hospital assessment by a single responder: the Swedish ambulance nurse in a new role: a pilot study. Int Emerg Nurs 26:32–37
22. Naeem S, Edmunds C, Hirst T, Williams J, Alzarrad A, Ronaldson J et al (2022) A national survey of prehospital care services of United Kingdom for use, governance and perception of prehospital point of care ultrasound. POCUS J 7:232–238
23. Griffiths E (2021) Helicopter emergency medical services use of thoracic point of care ultrasound for pneumothorax: a systematic review and meta-analysis. Scand J Trauma Resusc Emerg Med 29:163
24. Nelson BP, Chason K (2008) Use of ultrasound by emergency medical services: a review. Int J Emerg Med 1:253–259
25. Whiting MD, Dengler BA, Rodriguez CL, Blodgett D, Cohen AB, Januszkiewicz AJ et al (2020) Prehospital detection of life-threatening intracranial pathology: an unmet need for severe TBI in austere, rural, and remote areas. Front Neurol 11:599268
26. Robba C, Picetti E, Vasquez-Garcia S, Abulhasan YB, Ain A, Adeleye AO et al (2025) The Brussels consensus for non-invasive ICP monitoring when invasive systems are not available in the care of TBI patients (the B-ICONIC consensus, recommendations, and management algorithm). Intensive Care Med 51:4–20
27. Shackford SR, Rogers FB, Osler TM, Trabulsy ME, Clauss DW, Vane DW (1999) Focused abdominal sonogram for trauma: the learning curve of nonradiologist clinicians in detecting hemoperitoneum. J Trauma 46:553–562 (discussion 62-4)
28. Smith RS, Kern SJ, Fry WR, Helmer SD (1998) Institutional learning curve of surgeon-performed trauma ultrasound. Arch Surg 133:530–535 (discussion 5-6)
29. Scalea TM, Rodriguez A, Chiu WC, Brenneman FD, Fallon WF Jr, Kato K et al (1999) Focused Assessment with Sonography for Trauma (FAST): results from an international consensus conference. J Trauma 46:466–472
30. Tayal VS, Neulander M, Norton HJ, Foster T, Saunders T, Blaivas M (2007) Emergency department sonographic measurement of optic nerve sheath diameter to detect findings of increased intracranial pressure in adult head injury patients. Ann Emerg Med 49:508–514
31. Bauerle J, Lochner P, Kaps M, Nedelmann M (2012) Intra- and interobsever reliability of sonographic assessment of the optic nerve sheath diameter in healthy adults. J Neuroimaging 22:42–45
32. Betcher J, Becker TK, Stoyanoff P, Cranford J, Theyyunni N (2018) Military trainees can accurately measure optic nerve sheath diameter after a brief training session. Mil Med Res 5:42
33. Sedgwick P, Greenwood N (2015) Understanding the hawthorne effect. BMJ 351:h4672
34. Jujo S, Sakka BI, Lee-Jayaram JJ, Kataoka A, Izumo M, Kusunose K et al (2022) Medical student medium-term skill retention following cardiac point-of-care ultrasound training based on the American Society of Echocardiography curriculum framework. Cardiovasc Ultrasound 20:26
35. Kimura BJ, Sliman SM, Waalen J, Amundson SA, Shaw DJ (2016) Retention of ultrasound skills and training in “point-of-care” cardiac ultrasound. J Am Soc Echocardiogr 29:992–997
36. Kelm DJ, Ratelle JT, Azeem N, Bonnes SL, Halvorsen AJ, Oxentenko AS et al (2015) Longitudinal ultrasound curriculum improves long-term retention among internal medicine residents. J Grad Med Educ 7:454–457
Downloads
Published
Issue
Section
License
Copyright (c) 2025 Eugenio Garofalo, Giuseppe Neri, Vincenzo Bosco, Zaninni Caroleo, Fabiola Virdò, Helenia Mastrangelo, Giusy Guzzi, Gianmaria Cammarota, Chiara Robba, Federico Longhini, Andrea Bruni, ONSD study group (Author)
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Transfer of Copyright and Permission to Reproduce Parts of Published Papers.
Authors retain the copyright for their published work. No formal permission will be required to reproduce parts (tables or illustrations) of published papers, provided the source is quoted appropriately and reproduction has no commercial intent. Reproductions with commercial intent will require written permission and payment of royalties.
