Prophylactic Use of Enoxaparin in Adolescents During Bariatric Surgery—a Prospective Clinical Study

  • Janelle D. VaughnsEmail author
  • Victoria C. Ziesenitz
  • Elaine F. Williams
  • Evan P. Nadler
  • Gerd Mikus
  • Johannes van den Anker
Original Contributions



Severe obesity predisposes youth to a higher risk of venous thromboembolism (VTE). This study evaluates a BMI-stratified prophylactic dosing regimen of enoxaparin in adolescents with severe obesity undergoing surgery.


Adolescents aged 12–20 years received prophylactic enoxaparin at 40 mg SC (for a BMI < 50 kg/m2) and 60 mg SC (for a BMI ≥ 50 kg/m2) every 12 h until discharge. Blood samples were drawn at pre-dose, 1, 2, 4, 6, and 12 h. Plasma Anti-Factor Xa (Anti-FXa) activity was used as a surrogate marker for enoxaparin pharmacokinetics.


Ten female and two male obese adolescents (age range 14–19 years) had a mean BMI of 49.9 kg/m2 (38.4–58 kg/m2). Four patients had a BMI of less than 50 kg/m2 and received 40 mg enoxaparin, resulting in a mean dosage of 0.352 ± 0.070 mg/kg body weight. Eight patients were dosed with 60 mg enoxaparin every 12 h, resulting in a mean dosage of 0.395 ± 0.028 mg/kg. Peak plasma anti-FXa activity (Cmax) ranged from 0.14 to 0.30 IU/mL, median Cmax was 0.205 IU/mL. Median Tmax was 5.67 h (range 3.78–7.52 h). Median AUCi was 1.00 h IU/mL (range 0.42–1.67 h IU/mL). Ten out of 12 patients (83%) reached the primary endpoint with anti-FXa activity in the range for VTE prevention (0.1–0.3 IU/mL).


Our dosing scheme of 40 mg vs. 60 mg enoxaparin stratified according to BMI proved to be effective in reaching prophylactic anti-FXa activity in 83% of adolescent patients.


Enoxaparin LMWH Obesity Adolescents Bariatric surgery VTE prophylaxis 


Funding Information

This work was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (5T32HD087969) and with internal departmental funding.

Compliance with Ethical Standards

Conflict of Interest

The authors declare that they have no competing interests.

Statement of Human and Animal Rights

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This article does not contain any studies with animals performed by any of the authors.

Informed Assent and Consent

Informed assent and consent was obtained from all individual participants and their parents in this study.


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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Division of Anesthesiology, Pain and Perioperative MedicineChildren’s National Health System/The George Washington University School of Medicine and Health SciencesWashingtonUSA
  2. 2.Division of Pediatric Clinical PharmacologyChildren’s National Health System/The George Washington University School of Medicine and Health SciencesWashingtonUSA
  3. 3.Division of Pediatric Pharmacology & PharmacometricsUniversity of Basel Children’s HospitalBaselSwitzerland
  4. 4.Department of Pediatric and Congenital CardiologyUniversity Hospital HeidelbergHeidelbergGermany
  5. 5.Division of SurgeryChildren’s National Health System/The George Washington University School of Medicine and Health SciencesWashington DCUSA
  6. 6.Department of Clinical Pharmacology and PharmacoepidemiologyUniversity Hospital HeidelbergHeidelbergGermany

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