Bedside Ultrasonographic Assessment of the Optic Nerve Sheath Diameter to Assess Intracranial Pressure in Patients Given Ketamine in Emergency Department

Abstract

Background: There is an ongoing debate if ketamine exerts any effect on intracranial pressure (ICP). ICP can be evaluated noninvasively by means of optic nerve sheath diameter (ONSD) measurement. In the present study, we aimed to determine if ketamine has any perceivable effect on ICP using ONSD. Material and Methods: In this single-center observational study, we prospectively enrolled patients who were admitted to the ED and received intravenous ketamine for induction, analgesia, procedural sedation for any procedure (ie, fracture reduction, laceration repair, pacemaker implantation). ONSD was used to rate ICP changes noninvasively both before and after ketamine application. Results: There were a total of 75 patients with a mean age of 59.8 ± 20.5 years. The majority of patients were applied Procedural Sedation (53.3%). In patients who were administered ketamine for induction, the median ONSD before and after ketamine were 5.10 (IQR: 1) mm and 5.00 (IQR: 1.30) mm, respectively. There occurred no significant diameter change (p=0.832). In patients who were administered ketamine for analgesia, the median ONSD 3.70 (IQR: 0.40) mm and 3.65 (IQR: 0.23) mm prior to and after the procedure, respectively. There occurred no significant diameter change (p=0.549). In patients who were administered ketamine for procedural sedation, the median ONSD before and after the procedure were 4.05 (IQR:0.67) mm and 3.97 (IQR: 0.69) mm, respectively. This time, however, ONSD was significantly reduced after ketamine administration (p=0.001). Conclusions: In this patient population, ketamine did not cause any incremental effect on ONSD, a surrogate marker of ICP.