title: Antifactor Xa levels in critically ill Korean patients receiving enoxaparin for thromboprophylaxis: a prospective observational study.
abstract: The aim of this study was to investigate antifactor Xa (aFXa) levels after once daily dose of 40 mg of enoxaparin and to evaluate factors influencing aFXa levels among Korean intensive care unit (ICU) patients. This prospective observational study was conducted between August and December 2011 in medical ICUs at Samsung Medical Center. AFXa levels between 0.1 and 0.3 U/mL were considered to be effective for antithrombotic activity. Fifty-five patients were included. The median aFXa levels were 0.22 (IQR 0.17-0.26) at 4 hr, 0.06 (IQR 0.02-0.1) at 12 hr, and 0 U/mL (IQR 0-0.03) at 24 hr. The numbers of patients showing effective antithrombotic aFXa levels were 48 (87.3%), 18 (32.7%), and 0 (0%) at 4, 12 and 24 hr, respectively. At 12 hr, higher sequential organ failure assessment (SOFA) scores and hyperbilirubinemia were significantly associated with low aFXa levels (OR, 0.58; 95% CI, 0.36-0.93; P = 0.02 and 0.06; 0.003-0.87; 0.04, respectively). Once daily dose of 40 mg of enoxaparin is inadequate for maintaining effective antithrombotic aFXa levels, and the inadequacy is more salient for patients with high SOFA scores and hyperbilirubinemia.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: So Yeon
authors.initials: SY
authors.lastname: Lim
authors.forename: Kyeongman
authors.initials: K
authors.lastname: Jeon
authors.forename: Hee-Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Seon Mi
authors.initials: SM
authors.lastname: Kim
authors.forename: Junwhi
authors.initials: J
authors.lastname: Song
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Ha
authors.forename: Sang-Won
authors.initials: SW
authors.lastname: Um
authors.forename: Won-Jung
authors.initials: WJ
authors.lastname: Koh
authors.forename: Man Pyo
authors.initials: MP
authors.lastname: Chung
authors.forename: Hojoong
authors.initials: H
authors.lastname: Kim
authors.forename: O Jung
authors.initials: OJ
authors.lastname: Kwon
authors.forename: Gee Young
authors.initials: GY
authors.lastname: Suh
mesh_terms: D000368:Aged; D044466:Asian People; D016638:Critical Illness; D017984:Enoxaparin / Q000627:therapeutic use*; D015951:Factor Xa / Q000032:analysis; D065427:Factor Xa Inhibitors; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans; D006932:Hyperbilirubinemia / Q000378:metabolism; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D012044:Regression Analysis; D056910:Republic of Korea; D012307:Risk Factors; D054556:Venous Thromboembolism / Q000188:drug therapy*
chemical_list: D017984:Enoxaparin; D065427:Factor Xa Inhibitors; D005343:Fibrinolytic Agents; D015951:Factor Xa
keywords: Asia; Enoxaparin; Factor Xa; Intensive Care Units; Venous Thrombosis