title: Does prior administration of enoxaparin influence the effects of levobupivacaine on blood clotting? Assessment using the Thrombelastograph.
abstract: The low molecular weight heparin, enoxaparin (by inhibition of factors Xa and IIa) and amide local anaesthetics (by altering platelet function) exert anti-clotting effects. Although these agents are often used in combination during the perioperative period, their potential interactive effect on clotting has not been defined. Blood from 10 ASA I-II patients who received enoxaparin 0.5 mg kg(-1) s.c. was studied using a Thrombelastograph (TEG) either alone or in combination with levobupivacaine (2.5 mg ml(-1) or 2.5 microg ml(-1)) or saline (50% dilution). In blood from patients who had received enoxaparin 0.5 mg kg(-1) s.c. 12 h previously, levobupivacaine 2.5 mg ml(-1) (but not 2.5 microg ml(-1)) produced significant changes in TEG clotting parameters (mean (SD) 15.7 (4.8) mm, 29.6 (25.6) mm, 34.4 (14.6) mm, 34.3 (12.2) degrees compared with control values of 6.1 (1.3) mm, 2.5 (0.5) mm, 63.5 (6.4) mm and 74.1 (2.9) degrees for r, K, MA, and alpha angle respectively).
authors.affiliation: Department of Anaesthesia and Intensive Care Medicine, Cork University Hospital and University College, Ireland.
authors.forename: S A
authors.initials: SA
authors.lastname: Leonard
authors.forename: A
authors.initials: A
authors.lastname: Lydon
authors.forename: M
authors.initials: M
authors.lastname: Walsh
authors.forename: C
authors.initials: C
authors.lastname: Fleming
authors.forename: J
authors.initials: J
authors.lastname: Boylan
authors.forename: G D
authors.initials: GD
authors.lastname: Shorten
mesh_terms: D000328:Adult; D000779:Anesthetics, Local / Q000494:pharmacology*; D000925:Anticoagulants / Q000627:therapeutic use*; D001777:Blood Coagulation / Q000187:drug effects*; D002045:Bupivacaine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D017984:Enoxaparin / Q000627:therapeutic use*; D015951:Factor Xa / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures; D013916:Thrombelastography / Q000295:instrumentation
chemical_list: D000779:Anesthetics, Local; D000925:Anticoagulants; D017984:Enoxaparin; D015951:Factor Xa; D002045:Bupivacaine