Pharmacodynamics of low molecular weight heparin in patients undergoing bariatric surgery: A prospective, randomised study comparing two doses of parnaparin (BAFLUX STUDY)

Imberti, Davide; Legnani, Cristina; Baldini, Edoardo; Cini, Michela; Nicolini, Alberto; Guerra, Manuela; De Paoli, Marco; Zanardi, Alberto; Palareti, Gualtiero

doi:10.1016/j.thromres.2009.04.021

« Previous Next »Thrombosis Research
Volume 124, Issue 6 , Pages 667-671, December 2009

Pharmacodynamics of low molecular weight heparin in patients undergoing bariatric surgery: A prospective, randomised study comparing two doses of parnaparin (BAFLUX STUDY)☆

Davide Imberti
- Ospedale Civile, Piacenza, Italy
- Corresponding author. Thrombosis Centre, Emergency Department, Piacenza Hospital, Via Taverna 49, 29100 Piacenza, Italy. Tel.: +39 523 303313; fax: +39 523 303315.
Cristina Legnani
- Azienda Ospedaliera Universitaria S.Orsola Malpighi, Bologna, Italy
Edoardo Baldini
- Ospedale Civile, Piacenza, Italy
Michela Cini
- Azienda Ospedaliera Universitaria S.Orsola Malpighi, Bologna, Italy
Alberto Nicolini
- Ospedale S. Maria Nuova, Reggio Emilia, Italy
Manuela Guerra
- Azienda Ospedaliera Universitaria S.Orsola Malpighi, Bologna, Italy
Marco De Paoli
- Ospedale Galliera, Genova, Italy
Alberto Zanardi
- Ospedale Civile Mortara (PV), Italy
Gualtiero Palareti
- Azienda Ospedaliera Universitaria S.Orsola Malpighi, Bologna, Italy

Received 21 November 2008; received in revised form 30 April 2009; accepted 30 April 2009.

Abstract

Background

The optimal dose of low-molecular-weight-heparin (LMWH) to prevent venous thromboembolism (VTE) after bariatric surgery remains controversial.

Aim

The aim of this study was to evaluate the pharmacodynamic parameters of two doses of the LMWH parnaparin administered to patients undergoing bariatric surgery.

Methods

Patients were enrolled in a multicentre, open label, pilot study and were randomised to receive 4250 IU/day [n=36; 30 females; median age: 38 years (23-56); median BMI: 46.7 Kg/m² (36.5-58.8)] or 6400 IU/day [n=30; 24 females; median age: 42 years (22-63); median BMI: 43.7 Kg/m² (36.1-64.1)] of parnaparin s.c. for 7-11 days. The pharmacodynamic effects of parnaparin were analysed by measuring the anti Factor Xa activity on day 0 (12 hours after the first parnaparin injection), day 4 and day 6 after surgery (before and 4 hours after parnaparin administration).

Results

In 98.3% of patients receiving 4250 IU/day the peak anti-Xa levels were in the range of 0.1-0.4 IU/ml. Higher anti-Xa levels were observed in patients receiving 6400 IU/day: in 62.3% of these patients the peak anti-Xa levels were greater than 0.4 IU/ml. The anti-Xa levels measured 4 hours after injection on days 4 and 6 were not statistically correlated with BMI for either dose of-parnaparin (p=0.077 and p=0.401 for 4250 or 6400 IU/day, respectively).

Conclusion

The dose of 4250 IU/day seems adequate to achieve prophylactic anti-Xa levels in morbid obese patients undergoing bariatric surgery. Conversely, most of the patients receiving 6.400 IU/day show anti-Xa levels higher than the recommended prophylactic values.

Keywords: Venous thromboembolism, Prophylaxis, Parnaparin, Bariatric surgery, Obesity