A 53-year-old woman with extreme obesity (body mass index = 82 kg/m) presented for an open reduction and internal fixation of the proximal humerus. This report describes the novel management of her continuous brachial plexus catheter in the setting of her comorbidities. Phrenic nerve paralysis from brachial plexus blocks can cause clinically significant dyspnea in obese patients. Brachial plexus catheters can be used effectively for these patients with some modification to routine management. We detail our use of a short-acting chloroprocaine test dose for phrenic paralysis and demand-only dosing to provide effective analgesia while avoiding respiratory complications associated with these blocks.