Last update:
21-Apr-2024

The emerging need for the implementation of reliable and safe neuromonitoring, both perioperatively and in the Intensive Care Unit (ICU) setting, has contributed to the development of contemporary minimally invasive methods of monitoring acute brain injury. Among these, the most important seem to be the ultrasound measurement of the diameter of the optic nerve sheath (optic nerve sheath diameter, ONSD), the pupillometry, and the pressure reactivity index (PRx). ONSD estimation by ultrasound implementation is an easy-to-use, practical, and reliable method of intracranial pressure (ICP) assessment. The digital pupillometry device quantifies with enhanced sensitivity the adequacy of the photokinetic reflex through the Neurological Pupil index (NPi). Current evidence links NPi changes with those provided by invasive ICP monitoring. Finally, PRx is the linear coefficient of variables related both to cerebral perfusion (mean arterial pressure, MAP) and intracranial pressure (ICP) – factors directly linked to cerebral autoregulation monitoring. The above methods of minimally invasive neuromonitoring tools have practical applications in primary brain lesions, in the monitoring of secondary lesions, as well as in the prognosis of patients reliably and with the fewest possible complications compared to invasive methods of intracranial pressure monitoring.

Key words: Automated infrared pupillometry, Cerebral autoregulation, Intracranial pressure, Optic nerve sheath diameter, Pressure reactivity index.