title: Transfusion-associated anaphylaxis during anaesthesia and surgery--a retrospective study.
abstract: OBJECTIVE
  Transfusion-associated anaphylaxis (TAA) is a severe adverse reaction reported to occur in 1:9000-90,000 transfusions. According to the Danish Registration of Transfusion Risks (DART), the frequency is 1:300,000 transfusions, which suggests insufficient reporting of TAA in Denmark. Our aims were to identify possible cases of TAA, to characterize their symptoms and tryptase levels and to investigate the reporting of TAA to the haemovigilance systems.
  
  
  METHODS
  We reviewed 245 patients with suspected allergic reactions during anaesthesia and surgery, investigated at the Danish Anaesthesia Allergy Centre (DAAC). Based on the outcome of this investigation, the patients were classified as DAAC positive (confirmed hypersensitivity to identified agent, n = 112), or DAAC negative (no confirmed hypersensitivity, n = 133). Data on case history, details of blood transfusion and results of laboratory and clinical investigations were collected. TAA cases were identified according to the recommendations of the International Society of Blood Transfusion (ISBT).
  
  
  RESULTS
  Ten possible TAA cases (30% of all transfused patients) were identified, all DAAC negative. The frequency of elevated serum tryptase, hypotension and male sex was significantly higher among these cases compared with the remaining DAAC negative (P < 0·05), but not different from the DAAC-positive patients. One case had been reported to the Blood Bank haemovigilance system and none to DART.
  
  
  CONCLUSIONS
  We identified unreported cases of possible TAA, which resembled the DAAC-positive patients with respect to elevated tryptase and symptoms. By applying the ISBT criteria of adverse transfusion reactions, we conclude that TAA during anaesthesia and surgery is likely to be underreported in Denmark.
authors.affiliation: Section for Transfusion Medicine, Capital Region Blood Bank, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark; Danish Anaesthesia Allergy Centre, Allergy Clinic, Copenhagen University Hospital, Gentofte, Denmark.
authors.forename: G
authors.initials: G
authors.lastname: Lindsted
authors.forename: R
authors.initials: R
authors.lastname: Larsen
authors.forename: M
authors.initials: M
authors.lastname: Krøigaard
authors.forename: L H
authors.initials: LH
authors.lastname: Garvey
authors.forename: L K
authors.initials: LK
authors.lastname: Poulsen
authors.forename: H
authors.initials: H
authors.lastname: Mosbech
authors.forename: B
authors.initials: B
authors.lastname: Sørensen
authors.forename: A
authors.initials: A
authors.lastname: Norgaard
mesh_terms: D000328:Adult; D000368:Aged; D000707:Anaphylaxis / Q000209:etiology*; D058731:Blood Safety; D003718:Denmark; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D065227:Transfusion Reaction
keywords: adverse transfusion reactions; anaesthesia; anaphylaxis; blood transfusion; haemovigilance; surgery