Evaluation of the Effect of Interscalene Brachial Plexus Block on Intracranial Pressure Using Optic Nerve Sheath Diameter and Internal Jugular vein Collapsibility Index

Abstract

Objective: To determine the effect of single-shot interscalene brachial plexus (ISBP) block on intracranial pressure (ICP) by eval uating the extravascular volume effect of the medicine on the internal jugular vein (IJV). Study Design: Interventional study. Place and Duration of Study: Department of Anaesthesiology and Reanimation, Sivas Cumhuriyet University, Sivas, Turkey, from January to June 2022. Methodology: Thirty-four patients were included in this prospective clinical study. All patients had single-shot ISBP block with 25 ml of local anaesthetic. Optic nerve sheath diameter (ONSD), maximum (Dmax) and minimum (Dmin) diameters of IJV and IJV collapsibility index (IJV-CI) were recorded before the block (basal), 20 minutes, and 60 minutes after the block. Results: Twenty-nine patients had higher ONSD values at 60th minute compared to their basal values. There were negative correlations between the changes of ONSD and IJVCI (r=0.616, p<0.001) and ONSD and Dmax (r=0.581, p<0.001) in time period between basal and 20th minute. There were negative correlations between the changes of ONSD and IJVCI (r=0.518,p=0.002), ONSD and Dmax (r=0.664, p<0.001) in time period between basal and 60th minute. Conclusion: Single-shot ISBP block with 25 ml of local anaesthetic may be a factor that increases ICP. Repeated intraoperative ONSD measurements are recommended in patients operated with ISBP block.