Interscalene Nerve Block: Potential Severe Complications

Case Synopsis

A 25-year-old man presents for rotator cuff repair and has an interscalene block and catheter placed. The block is performed using Winnie’s landmarks and with the aid of a nerve stimulator. A triceps response is obtained at a depth of 2.5 cm. The catheter is threaded 6 cm past the tip of the stimulating needle. The procedure is uneventful, except for transient resistance encountered during catheter placement. After negative aspiration for blood and cerebrospinal fluid, 0.5% bupivacaine is slowly injected through the catheter. After 10 mL is injected, the patient becomes drowsy, then unresponsive and apneic, with loss of muscle tone in all extremities; his pupils are widely dilated. The patient is given oxygen with manual assisted ventilation, followed by tracheal intubation.