Delayed Nonimmune Anaphylaxis Caused by Ropivacaine for Preoperative Nerve Blocks: A Case Report.

Ropivacaine is an amide local anesthetic with rare reports of anaphylaxis. To our knowledge, this is the first report of delayed nonimmune anaphylaxis induced by ropivacaine. A 70-year-old man underwent general anesthesia with a nerve block for a total knee arthroplasty. The patient developed symptoms of anaphylaxis 3.5 hours after receiving ropivacaine for femoral and tibial nerve blocks. A basophil activation test (BAT) revealed ropivacaine as the causative agent. Notably, anaphylaxis can be caused by medications even hours after their administration, and all administered drugs should be suspected of potentially causing anaphylaxis.