Optic nerve sheath diameter measurements to predict delayed neurological sequelae after carbon monoxide poisoning

Abstract

Objectives

Delayed neurological sequelae are a major complication of carbon monoxide poisoning. However, today there is still no objective screening tool for predicting delayed neurological sequelae in patients with carbon monoxide poisoning. The present study aimed to assess the usefulness of optic nerve sheath diameter measurements in predicting delayed neurological sequelae after carbon monoxide poisoning.

Methods

In this retrospective study, patients with a diagnosis of carbon monoxide poisoning in the emergency department from 2010 to 2021 were included in the study. Right and left optic nerve sheath diameters were calculated based on cranial computed tomography scans, and the presence of delayed neurological sequelae was evaluated.

Results

The mean (± standard deviation) optic nerve sheath diameter in patients who developed delayed neurological sequelae was statistically significantly greater on both the right and left compared to patients who did not develop delayed neurological sequelae (right; 5.02 ± 0.06 mm versus 4.89 ± 0.07 mm, P < 0.001; left; 5.03 ± 0.09 mm versus 4.85 ± 0.10 mm, P < 0.001). A multivariate linear regression analysis revealed that carboxyhemoglobin and both right and left optic nerve sheath diameter were the factors associated with the delayed neurological sequelae.

Discussion

The present study revealed that optic nerve sheath diameter measurements may be a useful screening tool to predict delayed neurological sequelae after carbon monoxide poisoning. The ability to predict a poor neurological prognosis in carbon monoxide poisoning is important for initiating early rehabilitation interventions and make help future trials. Limitations of this study include that normal optic nerve sheath diameters are not well established, and that not every patient underwent computed tomography.

Conclusions

Optic nerve sheath diameters measurements may be a helpful screening tool for predicting delayed neurological sequelae after carbon monoxide poisoning.

Keywords:

• Carbon monoxide poisoning; delayed neuropsychiatric syndrome; optic nerve sheath diameter; cranial computed tomography; toxicology

Acknowledgment

The author wishes to thank İsmail Şalk, Nisa Başpınar, İlhan Korkmaz, and Onur Türkdoğan for their assistance the interpretation and evaluation of optic nerve sheath measurements.

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Funding

The author reported there is no funding associated with the work featured in this article.