title: Effect of general anesthesia and orthopedic surgery on serum tryptase.
abstract: BACKGROUND
  Mast cell tryptase is used clinically in the evaluation of anaphylaxis during anesthesia, because symptoms and signs of anaphylaxis are often masked by the effect of anesthesia. No larger studies have examined whether surgery and anesthesia affect serum tryptase. The aim of this study was to investigate the effect of anesthesia and surgery on serum tryptase in the absence of anaphylaxis.
  
  
  METHODS
  The study included 120 patients (median age, 54 yr; range, 19-94 yr) undergoing elective orthopedic surgery in general anesthesia. Exclusion criteria were allergic reactions during this or previous anesthesia, hematologic disease, or high-dose corticosteroid treatment. Blood samples for tryptase analysis (ImmunoCAP; Phadia, Uppsala, Sweden) were drawn shortly before anesthesia and after anesthesia and surgery.
  
  
  RESULTS
  Median duration of anesthesia was 105 min (range, 44-263 min). Median interval between blood samples was 139 min (range, 39-370 min). Mean tryptase before surgery was 5.01 microg/l, with a mean decrease of 0.55 microg/l (P < 0.0001; 95% CI, 0.3-0.8) postoperatively. All patients received intravenous fluid (median value 750 ml; range, 200-2000 ml) perioperatively. There was no significant effect of gender, age, American Society of Anesthesiologist's physical status classification, or self-reported allergy on serum tryptase.
  
  
  CONCLUSIONS
  Serum tryptase shows small intraindividual variation in the absence of anaphylaxis. A small decrease was observed postoperatively, likely due to dilution by intravenous fluid. On suspected anaphylaxis during anesthesia, tryptase values, even within the normal reference interval, should, when possible, be compared with the patient's own basal level taken more than 24 h after the reaction.
authors.affiliation: Danish Anaesthesia Allergy Centre, Allergy Clinic KAA-816, Copenhagen University Hospital, Gentofte Hospital, Hellerup, Denmark. daac@geh.regionh.dk
authors.forename: Lene H
authors.initials: LH
authors.lastname: Garvey
authors.forename: Birgitte
authors.initials: B
authors.lastname: Bech
authors.forename: Holger
authors.initials: H
authors.lastname: Mosbech
authors.forename: Mogens
authors.initials: M
authors.lastname: Krøigaard
authors.forename: Bo
authors.initials: B
authors.lastname: Belhage
authors.forename: Bent
authors.initials: B
authors.lastname: Husum
authors.forename: Lars K
authors.initials: LK
authors.lastname: Poulsen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000768:Anesthesia, General; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures; D053802:Tryptases / Q000097:blood*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D053802:Tryptases