title: Single dose of acetylsalicylic acid prevents thromboxane release after tourniquet ischemia.
abstract: BACKGROUND
  Ischemia, such as that caused by a tourniquet, stimulates thromboxane (Tx) A(2) synthesis. TxA(2) might sensitize the operated limb to various complications, such as compartment syndrome and thromboembolic events.
  
  
  METHODS
  We studied the effect of pretreatment with a single dose of acetylsalicylic acid (ASA) (25, 100, and 500 mg) given 3 hours before surgery on the formation of TxB(2), a stable metabolite of TxA(2), after tourniquet deflation in 32 knee or ankle surgery patients.
  
  
  RESULTS
  Tourniquet time varied between 60 +/- 8 to 71 +/- 7 (SE) minutes. In control patients without ASA pretreatment, the platelet-produced femoral vein serum TxB(2) concentration over 30 minutes in vitro coagulation increased remarkably (from 40.0 +/- 20 ng/mL to 73.5 +/- 39 ng/mL) immediately after tourniquet deflation. Plasma concentrations increased similarly, approximately threefold. Pretreatment with 100 or 500 mg ASA prevented the increase in TxB(2) concentrations. Radial artery concentrations of TxB(2) were similar to venous concentrations in the different treatment groups.
  
  
  CONCLUSIONS
  Pretreatment with a single 100-mg dose of ASA prevents the release of TxB(2) after tourniquet deflation.
authors.affiliation: Department of Anaesthesia and Intensive Care, Tampere University Hospital, Finland.
authors.forename: Raimo
authors.initials: R
authors.lastname: Ojanen
authors.forename: Liisa
authors.initials: L
authors.lastname: Kaukinen
authors.forename: Erkki
authors.initials: E
authors.lastname: Seppälä
authors.forename: Seppo
authors.initials: S
authors.lastname: Kaukinen
authors.forename: Heikki
authors.initials: H
authors.lastname: Vapaatalo
mesh_terms: D000328:Adult; D001241:Aspirin / Q000494:pharmacology*; D006801:Humans; D007511:Ischemia / Q000097:blood*; D013929:Thromboxane B2 / Q000097:blood*; D014111:Tourniquets
chemical_list: D013929:Thromboxane B2; D001241:Aspirin