Measurement of the diameter of the sheath of the optic nerve in patients hospitalized in intensive care, with increased intracranial pressure (> 20mmHg) as a substitute measure for diagnosis and follow-up before and after different non-invasive strategies.

Three groups were created in which, through strategies already proven and non-invasive (mannitol, hypertonic solution 7.5% NaCl, reverse trendelenburg) to decrease the intracranial pressure, the optic nerve diameter measurement was performed and simultaneously the investigators monitored intracranial pressure through an intraventricular catheter continuously to determine if both correspond

Inclusion Criteria:

• Adult patients (≥ 18 years old) with traumatic or non-traumatic elevated ICP (defined as greater than 20 mm Hg for at least 10min)
• Hospitalized in ICU
• Patients with ICP continuous measurement through an intraventricular catheter
• Respiratory rate maintained at 10-18 breaths/min to maintain the end tidal carbon dioxide partial pressure between 35 and 40 mmHg
• Peak airway pressure <35 cmH2O
• Positive end-expiratory pressure <5 cmH2O

Exclusion Criteria:

• Patients who had undergone cranial decompression surgery
• Patients with ocular pathology
• Patients who had previously undergone eye surgery

Patients hospitalized in the intensive care unit of the Dr. Migel Pérez Carreño hospital with increased intracranial pressure of traumatic or non-traumatic etiology.