Phrenic nerve palsy following interscalene brachial plexus block; a long lasting serious complication.

Interscalene brachial plexus block (ISBPB) offers good analgesia for painful surgical procedures on the shoulder. We here describe two cases of long-term phrenic palsy following ISBPB that occurred in our practice in a relative short time period and both clearly illustrate the devastating impact of this complication for the patient. We will discuss the benefit of ISBPB in the context of the incidence and significant disability of hemi diaphragm paresis. Anesthesiologists must be aware of this complication and carefully weigh the advantages of ISPBP against the risks of this complication. When ISPBP is considered, the fact that the incidence of prolonged phrenic nerve palsy may be higher than previously expected should be taken into account carefully. A reevaluation on the indication and patient selection of ISBPB may even be warranted.