The Prognostic Value of Optic Nerve Sheath Diameter/Eyeball Transverse Diameter Ratio in the Neurological Outcomes of Out-of-Hospital Cardiac Arrest Patients

Abstract

Background and objectives: The optic nerve sheath diameter (ONSD) is indicative of elevated intracranial pressure. However, the usefulness of the ONSD for predicting neurologic outcomes in cardiac arrest survivals has been debatable. Reportedly, the ONSD/eyeball transverse diameter (ETD) ratio is a more reliable marker for identifying intracranial pressure than sole use of ONSD. Materials and Methods: This retrospective study aimed to investigate the prognostic value of the ONSD/ETD ratio in out-of-hospital cardiac arrest (OHCA) patients. We studied the brain computed tomography scans of adult OHCA patients with return of spontaneous circulation, who visited a single hospital connected with a Korean university between January 2015 and September 2020. We collected baseline characteristics and patient information from electronic medical records and ONSD and ETD were measured by two physicians with a pre-defined protocol. According to their neurologic outcome upon hospital discharge, patients were divided into good neurologic outcome (GNO; cerebral performance category [CPC] 1–2) and poor neurologic outcome (PNO; CPC 3–5) groups. We evaluated the ONSD/ETD ratio between the GNO and PNO groups to establish its prognostic value for neurologic outcomes. Results: Of the 100 included patients, 28 had GNO. Both the ONSD and ETD were not significantly different between the two groups (ONSD, 5.48 mm vs. 5.66 mm, p = 0.054; ETD, 22.98 mm vs. 22.61 mm, p = 0.204). However, the ONSD/ETD ratio was significantly higher in the PNO group in the univariate analysis (0.239 vs. 0.255, p = 0.014). The area under the receiver operating characteristic curve of ONSD/ETD ratio for predicting PNO was 0.66 (95% confidence interval, 0.56–0.75; p = 0.006). There was no independent relationship between the ONSD/ETD ratio and PNO in multivariate analysis (aOR = 0.000; p = 0.173). Conclusions: The ONSD/ETD ratio was more reliable than sole use of ONSD and might be used to predict neurologic outcomes in OHCA survivors.

Association between optic nerve sheath diameter/eyeball transverse diameter ratio and neurological outcomes in patients with aneurysmal subarachnoid hemorrhage

“…A retrospective study showed that the OER was a more reliable predictor of comatose status in patients with supratentorial lesions than the ONSD [ 23 ]. Cho et al [ 4 ] found that the OER was more reliable than the ONSD in predicting neurological outcomes in out-of-hospital cardiac arrest survivors.…”

“…A recent meta-analysis showed a limitation in using the ONSD alone in post-cardiac arrest patients [ 4 ]. The authors found that ONSD alone may be affected by patient characteristics and that using the ONSD/eyeball transverse diameter (ETD) ratio (OER) was more reliable.…”

Diagnostic accuracy of optic nerve sheath diameter on ultrasound for the detection of increased intracranial pressure in patients with traumatic brain injury: A systematic review and meta‑analysis

“…In recent years, the use of ultrasound has markedly increased due to various factors, including technological advances, a minimally invasive nature, affordability and the ease of use (25,26). The use of optic nerve ultrasound as an accurate, non-invasive, safe, reproducible and cost-effective ICP tool has recently been validated by the measurement of ONSD, thereby reducing the potentially deleterious consequences of invasive transcranial measurements (14,27,28). Ultrasound of the optic nerve can be used to differentiate between both normal and elevated ICP and can be a useful screening tool in resource-limited practices (29).…”