Effect of Cervical Collar on the Optic Nerve Sheath Diameter in Minor Head Trauma
Condition: Head Trauma
MeSH terms: Craniocerebral Trauma; Wounds and Injuries
Study type: Interventional

Summary: 
      This is randomized, controlled and blinded study was performed in minor head trauma patients.
      Two sonographers measured optic nerve sheath diameters (ONSD) of each subjects' eyes
      separately for different time points. Then a mean ONSD was calculated for before c-collar
      placement (T0), 5 and 20 minutes in supine position.
    

Detailed description: 
      Head trauma is an important cause of morbidity and mortality. Increased intracranial pressure
      (ICP) can lead to decreased cerebral perfusion and tissue damage. It is important to be able
      to detect increased ICP on time, so that treatment can be initiated to prevent further brain
      damage. The measurement of optic nerve sheath diameter (ONSD) has been proposed as a
      non-invasive and rapid way to assess elevated ICP (1-2). Traditional ICP monitoring methods
      such as external ventricular devices are invasive and time-consuming and can only be
      performed by trained personnel at trauma centers.

      The optic nerve is surrounded by a protective sheath and is found on the back of the globe.
      Easily evaluated with ultrasonics. This is typically done with a linear probe measuring the
      diameter of the optic nerve sheath 3 mm back from where the contrast is highest. The normal
      upper limit for adults is 5 mm, the values above are considered abnormal. Many studies have
      shown that an increased ONSD measured by bedside ultrasound correlates with increased IDC and
      in one study there is a correlation between ONSD> 5 mm and ICP> 20 cm H2O.

      Cervical spine (c-arms) and cervical vertebrae are often temporarily immobilized in patients
      with head trauma. It has been shown that placement of c-arms increases IBP. The decrease in
      venous outflow caused by c-arms in the forehead is an important mechanism for this increase
      in ICP. The increase in ICP occurs simultaneously with the application of c-arms in cadaver.
      It is thought that increased ONSD in trauma patients may be related to c-arms.

      If a c-collar application is found to increase ONSD, this trauma may make it difficult to use
      ONSD as an non-invasive estimate of ICP in patients.

      To the best of our knowledge, there is a study in healthy individuals investigating the
      possible effect of c-collar administration on ONSD. However, there is no comparative study of
      patients with head trauma. The investigators tried to measure ONSD before and after placement
      of cervical limbs in cases with minor head trauma. The aim of our study is to identify
      changes in the optic nerve sheath measurement after placement of the c-arms, and to determine
      whether these changes are due to the time immobilized by the c-arms.

      This is randomized, controlled and blinded study was performed in minor head trauma patients.
      Two sonographers measured optic nerve sheath diameters (ONSD) of each subjects' eyes
      separately for different time points. Then a mean ONSD was calculated for before c-collar
      placement (T0), 5 and 20 minutes in supine position.
    

Intervention name(s): ultrasonography
Intervention type(s): Diagnostic Test
Intervention description(s): optic nerve sheath diameter measurement will be done by ultrasonography on both eyes
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: ultrasonography; optic nerve sheath; head trauma