Effect of Cervical Collar on the Optic Nerve Sheath in Minor Head Trauma Patients
Phase: NA
Conditions: Head Trauma
Sponsor: Marmara University

Effect of Cervical Collar on the Optic Nerve Sheath Diameter in Minor Head Trauma 
  
NCT03742427  
 
13.09.2018 
 
Study Protocol  
 
Patients appealed to emergency department with blunt head trauma patients, aged >18, Glasgow 
Coma Score >13 and who signed written informed consent to participate in this study were 
included. Subjects with known eye or intracranial disease were excluded. All the patients 
trauma etiology were recorded and were assessed for NEXUS Head Computerized Tomography 
(CT) Rules for CT scan and the sonographers were blinded for CT examination decision and 
results.  
Patients were lied on a stretcher in a supine position and were told to close their eyes. Sterile 
ultrasound gel applied to each eyelid of the patients. After gel appliance, 7.5 MHz linear probe 
with the ophthalmic setting (Mindray M5, Mindray, P.R.C.) was performed to measure the 
ONSD. The two experienced sonographers each performed at least 350 US per annum. They 
were certified for basic and advanced emergency sonography by the national emergency 
medicine society. The intraclass correlation coefficient of the two sonographers for sonographic 
measurement of ONSD was >0.9 according to local annual quality checks. Both sonographers 
measured 25 sonographic ONSD each, before this study. Both physicians were blinded to each 
other measurements. Ultrasound was performed individually in both sagittal and transverse 
planes. ONSD measruements were taken from the acknowledged standard location 3 mm 
posterior of the retina. Each eyes measurements were recorded for two times and then a mean 
binocular ONSD was calculated. In this way, baseline measurements were recorded.  
After this baseline measurement, a rigid c-collar (ENPLUS, EN2050, Turkey) was placed for 
indvidual patient according to the appropriate size.  
The same technique used to measure the ONSD after c-collar placement and the mean ONSD 
was again calculated. This process was done at time points after placement of c-collar; 5 
minutes and 20 minutes. There was only one patient in the ultrasonography room and one 
researcher in the room at the same time. In this way, both researchers were blinded to each 
other's measurements.  
We reported continuous variables as means and standard deviations (SD) with 95% confidence 
intervals (CI) since normality in distribution was observed by The Kolmogorov-Smirnov test. 
The significance of the difference between groups was assessed by ANOVA test. Categorical 
variables were reported as proportions and counts, and chi-squared test was used to compare 
proportions among groups. Student’s t-test was used as the post-hoc test for ANOVA test, and 
significance threshold was accepted as p < 0.0016 after Bonferroni correction. The inter-rater 
reliability of the sonographers for all time points were reported as interclass correlation values 
and 95% CI.