title: The influence of drugs used in cardiac anaesthesia and critical care on multiple electrode aggregometry: an in-vitro volunteer study.
abstract: BACKGROUND
  Multiple electrode aggregometry (MEA) is a point-of-care test evaluating platelet function and the efficacy of platelet inhibitors. In MEA, electrical impedance of whole blood is measured after addition of a platelet activator. Reduced impedance implies platelet dysfunction or the presence of platelet inhibitors. MEA plays an increasingly important role in the management of perioperative platelet dysfunction. In vitro, midazolam, propofol, lidocaine and magnesium have known antiplatelet effects and these may interfere with MEA interpretation.
  
  
  OBJECTIVE
  To evaluate the extent to which MEA is modified in the presence of these drugs.
  
  
  METHODS
  An in-vitro study using blood collected from healthy volunteers.
  
  
  METHODS
  Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland, 2010 to 2011.
  
  
  METHODS
  Twenty healthy volunteers.
  
  
  METHODS
  Measurement of baseline MEA was using four activators: arachidonic acid, ADP, TRAP-6 and collagen. The study drugs were then added in three increasing, clinically relevant concentrations.
  
  
  METHODS
  MEA was compared with baseline for each study drug.
  
  
  RESULTS
  Midazolam, propofol and lidocaine showed no effect on MEA at any concentration. Magnesium at 2.5 mmol l had a significant effect on the ADP and TRAP tests (31 ± 13 and 96 ± 39 AU, versus 73 ± 21 and 133 ± 28 AU at baseline, respectively), and a less pronounced effect at 1 mmol l on the ADP test (39 ± 0 AU).
  
  
  CONCLUSIONS
  Midazolam, propofol and lidocaine do not interfere with MEA measurement. In patients treated with high to normal doses of magnesium, MEA results for ADP and TRAP-tests should be interpreted with caution.
  
  
  BACKGROUND
  Clinicaltrials.gov (no. NCT01454427).
authors.affiliation: From the Department of Anaesthesiology (APM, FG, CB, PF, CM), the Department of Cardiac Surgery (EF), and the Service and Central Laboratory of Haematology (AAS), Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Annouk Perret
authors.initials: AP
authors.lastname: Morisoli
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Gronchi
authors.forename: Enrico
authors.initials: E
authors.lastname: Ferrari
authors.forename: Catherine
authors.initials: C
authors.lastname: Blanc
authors.forename: Philippe
authors.initials: P
authors.lastname: Frascarolo
authors.forename: Anne
authors.initials: A
authors.lastname: Angelillo-Scherrer
authors.forename: Carlo
authors.initials: C
authors.lastname: Marcucci
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism*; D000328:Adult; D000777:Anesthetics / Q000008:administration & dosage / Q000494:pharmacology*; D006348:Cardiac Surgical Procedures / Q000379:methods; D004305:Dose-Response Relationship, Drug; D017097:Electric Impedance; D004566:Electrodes; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects*
chemical_list: D000777:Anesthetics; D000244:Adenosine Diphosphate