Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 Dec 20;5(1):42.
doi: 10.1186/s40779-018-0189-y.

Military trainees can accurately measure optic nerve sheath diameter after a brief training session

Joseph Betcher  1 , Torben K Becker  2 , Peter Stoyanoff  3 , Jim Cranford  4 , Nik Theyyunni  5
Affiliations

Military trainees can accurately measure optic nerve sheath diameter after a brief training session

Joseph Betcher et al. Mil Med Res. .

Abstract

Background: Identification of elevated intracranial pressure is important following traumatic brain injury. We assessed the feasibility of educating military trainees on accurately obtaining optic nerve sheath diameter measurements using a brief didactic and hands-on training session. Optic nerve sheath diameter is a noninvasive surrogate marker for elevated intracranial pressure, and may be of value in remote military operations, where rapid triage decisions must be made without access to advanced medical equipment.

Methods: Military trainees with minimal ultrasound experience were given a 5-min didactic presentation on optic nerve sheath diameter ultrasound. Trainees practiced optic nerve sheath diameter measurements guided by emergency physician ultrasound experts. Trainees then measured the optic nerve sheath diameter on normal volunteers. Following this, a trained physician measured the optic nerve sheath diameter on the same volunteer as a criterion standard. An average of three measurements was taken.

Results: Twenty-three military trainees were enrolled. A mixed design ANOVA was used to compare measurements by trainees to those of physicians, with a mean difference of - 0.6 mm (P = 0.76). A Bland-Altman analysis showed that the degree of bias in optic nerve sheath diameter measures provided by trainees was very small: d = - 0.004 for the right eye and d = - 0.007 for the left eye.

Conclusion: This study demonstrates that optic nerve sheath diameter measurement can be accurately performed by novice ultrasonographers after a brief training session. If validated, point-of-care optic nerve sheath diameter measurement could impact the triage of injured patients in remote areas.

Keywords: Education; Intracranial pressure; Military; Optic nerve sheath diameter; Ultrasound.

PubMed Disclaimer

Conflict of interest statement

Ethics approval and consent to participate

Not applicable, as all data came from healthy volunteers, and no ED patients were used in this study.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
Optic nerve sheath diameter measurement. The optic nerve sheath is measured 0.3 cm posterior to the globe
Fig. 2
Fig. 2
Comfort level of trainees with point-of-care ultrasound. The majority of trainees stated that their overall comfort level with point of care ultrasound was minimal, while a smaller percentage of trainees felt a moderate / high level of comfort
Fig. 3
Fig. 3
Bland-Altman plot for 95% limits of agreement for measures of right eye optic sheath: experienced and inexperienced users, indicating that measurements made by trainee users had minimal bias and were, on average, slightly lower than those from physician users
Fig. 4
Fig. 4
Bland-Altman plot for 95% limits of agreement for measures of left eye optic sheath: experienced and inexperienced users, indicating again that measures made by trainee users had minimal bias and were, on average, slightly lower than those from physician users
See this image and copyright information in PMC

Comment in

References

    1. Hill M, Baker G, Carter D, Henman LJ, Marshall K, Mohn K, et al. A multidisciplinary approach to end external ventricular drain infections in the neurocritical care unit. J Neurosci Nurs. 2012;44(4):188–193. doi: 10.1097/JNN.0b013e3182527672. - DOI - PubMed
    1. Dimitriou J, Levivier M, Gugliotta M. Comparison of complications in patients receiving different types of intracranial pressure monitoring: a retrospective study in a single center in Switzerland. World Neurosurg. 2016;89:641–646. doi: 10.1016/j.wneu.2015.11.037. - DOI - PubMed
    1. Miller C, Tummala RP. Risk factors for hemorrhage associated with extenal ventricular drain placement and removal. J Neurosurg. 2017;126(1):289–297. doi: 10.3171/2015.12.JNS152341. - DOI - PubMed
    1. Dubourg J. Ultrasonography of optic nerve sheath diameter for detection of raised intracranial pressure : a systematic review and meta-analysis. Intensive Care Med. 2011;6(37):1059–1068. doi: 10.1007/s00134-011-2224-2. - DOI - PubMed
    1. Liu D, Li Z, Zhang X, Zhao L, Jia J, Sun F, et al. Assessment of intracranial pressure with ultrasonographic retrobulbar optic nerve sheath diameter measurement. BMC Neurol. 2017;17(1):1–7. doi: 10.1186/s12883-016-0787-9. - DOI - PMC - PubMed

MeSH terms