Anterior scalene plane block at the superior trunk level relieves referred shoulder pain after liver radiofrequency ablation: a technical report.

We report the first case of using an anterior scalene plane block at the superior trunk level achieving phrenic nerve blockade to treat intolerable referred shoulder pain after liver Radiofrequency Ablation (RFA) of a diaphragm-abutting liver tumor despite prevention with a full-dose non-steroidal anti-inflammatory drug. The anterior scalene plane block rapidly alleviated pain without significant complications.