Background: Although uncommon, anaphylaxis due to a colloid plasma expander can occur peri-operatively
Case Presentation: We present a case of an intra-operative cardiac arrest in a 72 year old Caucasian male patient who underwent prophylactic intramedullary nailing for a proximal femoral metastasis from prostate cancer. The patient was resuscitated successfully and the procedure was completed uneventfully. Elevated serum tryptase levels confirmed the diagnosis of an anaphylactic reaction and positive allergy skin prick testing identified gelofusine as the causative agent.