2.4. Data Management
The ONSD values were measured by an experienced anesthesiologist who was not informed about the study using an Esaote MyLab 30 GOLDThe mean arterial pressure (MAP), HR, and ONSD values of the patients were recorded before induction (T0), 1 min after SAD placement (T1), 5 min after SAD placement (T5), and 10 min after SAD placement (T10). The same observer, who did not have any information about the study, recorded all the parameters that were examined in the study.