Optic Nerve Sheath Diameter Affected by Cervical Collar Placement in Minor Head Trauma Patients

Head trauma may cause an increase in intracranial pressure (ICP). The use of ocular ultrasound to measure optic nerve sheath diameter (ONSD) is a method to determine the ICP. The use of the rigid cervical collar in head trauma patients contribute to elevating ICP, and therefore, potentially causing further deterioration in their condition.

This study aimedto describe changes in ONSD after the placement of a c-collar and analyze these changes depending on the time in the c-collar.

This prospective study measured the ONSD of minor head trauma patients before and after the placement of a c-collar. Patients aged 18 with blunt head trauma and Glasgow Coma Score 13 were included in the study. Each eye was scanned twice. This was done before c-collar placement, at 5 and 20 min after placement. The mean values of both eyes were calculated and analyzed.

This study investigated 50 patients. The mean baseline ONSD was obtained at 4.71mm±0.22 (4.54-4.77). Furthermore, T5 and T20 measurements were 5.19±0.41 (5.07-5.31) and 5.26±0.45 (5.14-5.39), respectively. The ONSD increased at T5 and T20. The changes from the baseline measurements were statistically significant (P=0.000, P=0.000). The difference between T5 and T20 groups was an increase in ONSD, and these differences were also statistically significant (0.07±0.19; P=0.008).

Our results revealed that minor head trauma patients using a c-collar may increase ONSD by timeline the clinical effects of which have to be determined with further studies. Enlargement in ONSD should be considered when interpreting ICP.