Ocular ultrasound to estimate intracranial pressure: Feasibility of the technique

Intracranial pressure (ICP) is a parameter of high clinical relevance.today invasive methods are reference for its measurement.The diameter of the optic nerve sheath (NOSD) is influenced by changes in ICP.A NOSD higher than 5 mm is well correlated with a ICP over 20 mmHg.Objective: To evaluate the feasibility in measuring NOSD by ultrasound (ECO) made by an anesthesiologist.the secondary objective is to assess the impact of the trendelenburg position in the NOSD.material and methods: A descriptive study was carried out between April-September 2014, with the participation of 89 volunteers, ages 20 to 39 years old, 49 men, without fasting, with defined inclusion criteria to ensure absence of underlying disease, chronic drugs intake and normovolemic state.After application of gel, a linear transducer (10-15 MHz) was positioned on the eyeball to measure the NOSD; measurements were performed with 0º tilt and then after five minutes in 45º.Statistical analysis was performed with StAtA 10.0, with p-value < 0,05 for statistical significance.Results: The procedure was well tolerated.Echocardiograph windows obtained allowed measurements in all cases with an average NOSD of 2.3 ± 6 mm at 0º and 2,4 ± 0,8 mm at 45º (p = 67).Conclusion: In this group of patients, young, healthy, without underlying disease, not undergoing anesthesia and outside the operating room, the use of ocular ECO allowed measurements of DVNO in a simple and reproducible way, without adverse effects.the existence of this tool, that estimates the PIC indirectly, is of great anesthesiology utility.