Prolongation of Pain Free Time by the Use of Dexamethasone in Peripheral Nerve Blockade

The Effect of Dexamethasone Used Together With Low Volume Ropivacaine in a Single Shot Interscalene Block on the Pain Free Time Experienced by the Patient

The main aim of the study is to investigate the proven effect of dexamethsone on the duration of the interscalene block. The investigators try to define optimal dose and volume for ropivacaine, when used together with dexamethsone. The current literature uses often very high volumes of ropivacain when used together with dexamethasone. The investigators try to research the effect of using dexamethsone together with low volume, high concentration ropivacaine for interscalene blockade. The investigators' hypothesis is that dexamethasone has an positive effect on the pain free after used together with ropivacaine at the scalene block.

Inclusion Criteria:

• atroscopy of the shoulder
• repair of the RM

Exclusion Criteria:

• patient under 18 years
• patient is fertile
• chronic opiat use more than 30mg oxycodone per day
• operations at the shoulder that involves the bone
• usage of cortisone for more than 2 weeks
• risk greater as asa III
• damage to nerves
• neuropathy at the target arm