Comparison of the effects of desflurane and total intravenous anesthesia on the optic nerve sheath diameter in robot assisted laparoscopic radical prostatectomy 
Background: Optic nerve sheath diameter (ONSD) is well known as surrogate marker for intracranial pressure (ICP) in robot-assisted laparoscopic radical prostatectomy (RALP). We compared the effect of total intravenous anesthesia (TIVA) with desflurane anesthesia on the changes in ICP during RALP, which is known to increase ICP due to steep Trendelenburg position and carbon dioxide pneumoperitoneum.
Methods: Sixty patients were randomly assigned to the TIVA or desflurane (DES) group. Anesthesia was maintained with propofol and remifentanil in the TIVA group, and desflurane and remifentanil in the DES group. Ultrasonographic measurements of optic nerve sheath diameter (ONSD) were performed at before induction of anesthesia (T0), 10 min after Trendelenburg position (T1), 1 hour after Trendelenburg position (T2), 2 hour after Trendelenburg position (T3), 10 min after resuming supine position (T4), arrival in the postanesthetic care unit (T5). 
Results: The mean ONSD at time points (T1, T2, T3, T4, and T5) after anesthesia significantly increased compared with that before induction of anesthesia (T0). The changes of ONSD at T1, T2, T3, and T4 were significantly less in the TIVA group compared to the DES group (p=0.024, 0.000, 0.000, and 0.035, respectively) 
Conclusion: Trendelenburg position and carbon dioxide pneumoperitoneum in RALP increased the diameter of optic nerve sheath. The change of ONSD in TIVA group was significantly less than that in desflurane group during operation time in RALP. Through this results, TIVA could be a better choice for patients with the risk of cerebral hypoperfusion or with increased intracranial pressure.

A comparison of the effects of desflurane and propofol on the Optic Nerve Sheath Diameter during robot-assisted laparoscopic radical prostatectomy