Objective We describe a unique case of a patient who experienced atelectasis of the lower lobe of the left lung and pleural effusion manifested by chest pain after continuous interscalene brachial plexus block for postoperative analgesia.

Case Report A 45-year-old man with no respiratory disease was scheduled for left shoulder arthroscopy for rotator cuff repair under interscalene brachial plexus block and sedation. A continuous interscalene brachial plexus block provided postoperative analgesia. On the first postoperative day, the patient reported left-sided chest pain. The chest x-ray showed elevation of the left hemidiaphragm associated with a left lower lobe atelectasis and a minor pleural effusion. After catheter removal, clinical and radiologic signs resolved within few days without sequela.

Conclusion If chest pain presents after interscalene brachial plexus block, early postoperative chest x-ray is recommended to rule out pneumothorax, atelectasis, and/or pleural effusion secondary to ipsilateral phrenic block.