40 is the targeted number of patients who are going to have humerus fracture or opened rotator-cuff surgery. Single shot-ISBP block with 25 ml local anesthetic will be performed as anesthetic approach for surgery to all participants. Intraoperative ONSD and IJV-CI measurements will be performed before the ISBP block, 20 minutes and 60 minutes after the block. Hypothesis; external drug-volume effect on internal jugular vein causes decreasing maximum diameter of internal jugular vein (Dmax), venous return from cranium to heart decreases, intracranial pressure can increase.
The study aims to show the effects of interscalene brachial plexus (ISBP) block on intracranial pressure by measuring optic nerve sheath diameter (ONSD) and internal vein collapsibility index (IJV-CI).