Non-invasive ONSD-based Neuromonitoring in a Neurointensive Care Setting

Non-invasive Neuromonitoring Through Point-of-care Determination of ONSD and Assessment of Dynamic Properties of the Optic Nerve Sheath in a Neurointensive Care Setting

Intensive care patients with established invasive intracranial neuromonitoring due to neurotrauma are subjected to a repeated non-invasive sonographic recording of the optic-nerve-sheath-diameter (ONSD). The recorded images are analyzed through a machine-learning-algorithm and an experienced ultrasound operator. Results are correlated to the parallel recorded intracranial pressure (ICP). The study aims to establish ONSD as a supplementary for raised ICP.

During the intensive care stay, patients with implemented invasive intracranial pressure monitoring will have sonographic recording of the optic nerve sheath (video clip) with a parallel recording of the underlying ICP. The obtained image material is then i) analyzed by a machine-learning algorithm and ii) manually by 2 blinded differently experienced examiners (expert, novice) with respect to the ONSD. For the manual procedure, three individual measurements are made for each eye and the mean value is determined.

Subsequently, the measured values of the two examiners and the automated procedure are correlated with the ICP recorded during the sonographic examination.

Inclusion Criteria:

• Traumatic or non-traumatic (e.g. SAH) brain injury
• Established invasive intracranial pressure monitoring (either intraparenchymal or Intraventricular)

Exclusion Criteria:

• Soft tissue damage to orbital or periorbital region
• Fracture of the Orbita
• Status post decompressive craniectomy