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Higher doses of low-molecular-weight heparin (enoxaparin) are needed to achieve target anti-Xa concentrations in critically ill children*. Pediatr Crit Care Med 2014 Sep;15(7):e294-9



Pubmed ID




Scopus ID

2-s2.0-84926087005   14 Citations


OBJECTIVES: To demonstrate that low-molecular-weight heparin (enoxaparin) can be used in critically ill pediatric patients to achieve target anti-factor Xa concentrations and determine appropriate dosing corrected for age and illness severity.

DESIGN: Retrospective cohort study.

SETTING: Single tertiary level PICU.

PATIENTS: One hundred ninety-two children age 1 day through 18 years admitted to PICU undergoing every 12-hour enoxaparin therapy with at least one anti-factor Xa concentration obtained. Patients receiving renal replacement therapy or infants with corrected gestational age less than 37 weeks were excluded.


MEASUREMENTS AND MAIN RESULTS: We collected patient characteristics including age, weight, height/length, gender, corrected gestational age, illness severity markers, diagnosis, creatinine, enoxaparin dose and times of administration, anti-factor Xa concentrations, and collection times. Only 42% of critically ill children (80 of 192) and only 29% of children (9 of 31) on inotropes achieved recommended target range of anti-factor Xa concentrations on initial recommended enoxaparin dosing (1.5 mg/kg/dose < 2 mo; 1 mg/kg/dose > 2 mo), but 81% were ultimately within target range with dose titration. Increased enoxaparin dose was required to reach target concentrations in younger patients and those with worse illness severity as evidenced by concurrent use of inotropes, previous ICU admission, mechanical ventilation, cardiac surgery, and increased risk of mortality defined by severity-of-illness scores.

CONCLUSIONS: Enoxaparin can be used to reach recommended target range of anti-factor Xa concentrations in the PICU patient. However, younger patients and patients with higher illness severity are less likely to achieve target concentrations using currently recommended dosing and may require higher doses of enoxaparin to reach target anti-factor Xa concentrations. Starting enoxaparin dose at least 1.3 mg/kg dosed every 12 hours for treatment of thromboembolic disease in critically ill patients aged 61 days to 1 year or those requiring inotropic support should be confirmed in prospective study.

Author List

Schloemer NJ, Abu-Sultaneh S, Hanson SJ, Yan K, Hoffmann RG, Punzalan RC, Havens PL


Sheila Hanson MD Professor in the Pediatrics department at Medical College of Wisconsin
Peter L. Havens MD Professor in the Pediatrics department at Medical College of Wisconsin
Rowena C. Punzalan MD Associate Professor in the Pediatrics department at Medical College of Wisconsin
Nathan Schloemer MD Assistant Professor in the Pediatrics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Age Factors
Child, Preschool
Critical Care
Dose-Response Relationship, Drug
Factor Xa Inhibitors
Fibrinolytic Agents
Infant, Newborn
Retrospective Studies
Venous Thromboembolism
jenkins-FCD Prod-482 91ad8a360b6da540234915ea01ff80e38bfdb40a