The Effect of a Laryngeal Mask Airway on Optic Nerve Sheath Diameter

The Effect of a Laryngeal Mask Airway on Optic Nerve Sheath Diameter

The goal of this observational trial is to study the effect of a laryngeal airway mask on the optic nerve sheath diameter, as a surrogate for intracranial pressure.

The optic nerve sheath diameter of participants will be measured under general anesthesia, before, during and after insertion of a laryngeal airway mask.

Inclusion Criteria:

• In order to be eligible to participate in this study, a subject must meet all of the following criteria: aged 18 years or older, ASA I or ASA II, scheduled for elective surgery under general anesthesia, with a planned duration of > 30 minutes, that can be routinely performed with a LMA.

Exclusion Criteria:

• Scheduled for head or neck surgery
• Scheduled for neurosurgery
• Scheduled for laparoscopic or thorascoscopic procedures
• Scheduled for procedures that require Trendelenburg or anti-Trendelenburg positioning
• Neurological disorders
• Glaucoma
• History of bilateral eye related trauma
• Intellectual disability