Harlequin-like syndrome after migrated interscalene catheter bolus injection

Interscalene catheters have known to migrate leading to failure or even more dangerous complications like intravascular injection related toxicity. We present a case of ipsilateral facial blanching and contralateral facial flushing (Harlequin-like syndrome) immediately after bolus injection of local anesthetics into interscalene catheter. Reviewing the ultrasound image, the incident was most likely triggered by migrated interscalene catheter with intravascular local anesthesia injection. This case emphasizes the importance of vigilance in monitoring regional catheters and illustrates value for ultrasonography in investigating unexpected clinical presentations. *Correspondence to: Ching-Rong Cheng, Department of Anesthesiology, University of California San Diego, USA, E-mail: crcheng@ucsd.edu