Review of topical gelatin-based haemostatic agents; an insidious culprit of intraoperative anaphylaxis?
An under-recognized complication of gelatin-based haemostatic agents is their potential to cause anaphylactic reactions. This review aims to collate and analyse case in the literature of intraoperative anaphylaxis secondary to locally applied haemostatic agents. An electronic search was performed on databases Medline, Embase, Pubmed and ProQuest. A total of 7671 articles were reviewed from title and abstract. After exclusion criteria and duplicates removed, 19 articles with 21 cases were included for analysis. Data extracted from each of the articles included patient demographics, haemostatic agent used, surgery type, known allergies and any objective evidence of hypersensitivity post anaphylactic episode, that is tryptase levels, IgE levels, skin prick testing. Fifty-seven percent of cases involved patients <18 years of age; 57% of cases involved spinal surgery; 100% of cases displayed objective evidence of hypersensitivity (tryptase levels, bovine or porcine IgE levels, or skin prick testing). Thirty-three percent of patients had exposure preoperatively to a known agent causing anaphylaxis or allergy which would preclude the use of a gelatin-based haemostat. These products included vaccines, spam meats, red meat, Jell-O and CollaPlug. Gelatin-based haemostat agents included Floseal, Gelfoam, Surgiflo, fibrin glue, Avitene, haemofibrine sponge, topical bovine thrombin and thrombin-soaked gelatin. Increased awareness of allergy to gelatin-based haemostats for surgical and anaesthetic is imperative, with 33% of cases having a known contraindication to gelatin-based haemostat. This review highlights important aspects in the pre-operative patient history and post-event patient investigation that could assist anaesthetists and surgeons in the prevention of future events.