Biphasic Brachial Plexus Blockade Following Interscalene Administration of Liposomal Bupivacaine (Exparel): A Case Report

This case report describes a 70-year-old male who experienced a biphasic blockade following an interscalene block with 10 mL of liposomal bupivacaine (Exparel) mixed with 5 mL of 0.25% bupivacaine for shoulder arthroscopy. The patient exhibited complete motor and almost complete sensory recovery by postoperative day (POD) 1, followed by a recurrence of motor and sensory deficits on POD2, which resolved spontaneously by POD3. To our knowledge, this represents one of the earliest documented recurrences of dense motor blockade after brachial plexus block with Exparel. Potential mechanisms, including delayed drug release, inflammatory-mediated nerve compression, and anatomical variations, are discussed.