Anti-Xa Levels in Bariatric Surgery Patients Receiving Prophylactic Enoxaparin

Abstract

Background

Limited data exist regarding efficacy and dosing of low-molecular-weight heparins, including enoxaparin, for morbidly obese patients. Prophylactic doses of 30 to 60 mg every 12 h have been described in bariatric surgery patients with appropriate anti-Xa levels reported between 0.18 and 0.6 units/mL.

Methods

Fifty-two laparoscopic gastric bypass or banding patients were enrolled. Patients were divided into two groups by the dose of enoxaparin that was given: Group 1—enoxaparin 30 mg every 12 hours—and Group 2—enoxaparin 40 mg every 12 h. Anti-Xa levels were obtained 4 h after the first and third doses. Levels between 0.18–0.44 units/mL were considered appropriate.

Results

There were 19 patients (74% female, mean body mass index [BMI] 48.4 kg/m2) in Group 1 and 33 patients (82% female, mean BMI 48.5 kg/m2) in Group 2. In Group 1, anti-Xa levels were 0.06 and 0.08 units/mL after the first and third doses, respectively. In Group 2, anti-Xa levels were 0.14 and 0.15 units/mL after first and third doses, respectively (p = NS). There was a statistically significant difference in anti-Xa levels between Group 1 first dose and Group 2 first dose (p < 0.05) and between Group 1 third dose and Group 2 third dose (p < 0.05). Percentage of appropriate anti-Xa levels at first dose differed 0% vs. 30.8% (Group 1 vs. Group 2; p = 0.01) and at third dose 9.1% vs. 41.7% (Group 1 vs. Group 2; p = 0.155).

Conclusion

When prophylactic dose enoxaparin of 30 mg every 12 h was changed to 40 mg every 12 h in bariatric surgery patients, anti-Xa levels significantly increased with prophylactic dose enoxaparin in bariatric surgery patients. The percentage of appropriate levels also increased; however, more than half of the patients receiving 40 mg every 12 hours failed to reach therapeutic levels. No levels were supratherapeutic. Dosage of 40 mg every 12 h may not be sufficient for bariatric surgery patients.

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References

  1. 1.

    Wu EC, Barba CA. Current practices in the prophylaxis of venous thromboembolism in bariatric surgery. Obes Surg 2000;10(1):7–13; discussion 14.

    PubMed  Article  CAS  Google Scholar 

  2. 2.

    Hirsh J, Guyatt G, Albers GW, et al. The seventh ACCP conference on antithrombotic and thrombolytic therapy. Chest 2004 Sep;126:172S–3S.

    Article  Google Scholar 

  3. 3.

    Enoxaparin. DRUGDEXTM System. Greenwood Village, CO: Thomson Micromedex, 2006 Feb. http://www.thomsonhc.com.

  4. 4.

    Lexi-Comp, Inc. Lexi-Complete. 2006 Feb.

  5. 5.

    Madan AK, Frantzides CT. Triple-stapling technique for jejunojejunostomy in laparoscopic gastric bypass. Arch Surg 2003;138(9):1029–32.

    PubMed  Article  Google Scholar 

  6. 6.

    DeMaria EJ, Sugerman HJ, Kellum JM, et al. Results of 281 consecutive total laparoscopic Roux-en-Y gastric bypasses to treat morbid obesity. Ann Surg 2002;235(5):640–7.

    PubMed  Article  Google Scholar 

  7. 7.

    Borkgren-Okonek MJ, Hart RW, Pantano JA, et al. Stratified enoxaparin dosing achieves prophylactic anti-factor Xa concentrations in gastric bypass surgery. Surg Obes Relat Dis 2005;1(3):226.

    Article  Google Scholar 

  8. 8.

    Scholten DJ, Hoedema RM, Scholten SW. A comparison of two different prophylactic dose regimens of low molecular weight enoxaparin in bariatric surgery. Obes Surg 2002;12:19–24.

    PubMed  Article  Google Scholar 

  9. 9.

    Paige JT, Gouda BP, Gaitor-Stampley V, et al. No correlation between anti-factor Xa levels, low-molecular-weight heparin, and bleeding after gastric bypass. Surg Obes Relat Dis 2007;3(4):469–75.

    PubMed  Article  Google Scholar 

  10. 10.

    Miller MT, Rovito PF. An approach to venous thromboembolism prophylaxis in laparoscopic Roux-en-Y gastric bypass surgery. Obes Surg 2004 Jun–Jul;14(6):731–7.

    Article  Google Scholar 

  11. 11.

    Prystowsky JB, Morasch MD, Eskandari MK, et al. Prospective analysis of the incidence of deep venous thrombosis in bariatric surgery patients. Surgery 2005 Oct;138(4):759–63; discussion 763–765.

    Article  Google Scholar 

  12. 12.

    Gonzalez R, Haines K, Nelson LG, et al. Predictive factors of thromboembolic events in patients undergoing Roux-en-Y gastric bypass. Surg Obes Relat Dis 2006 Jan–Feb;2(1):30–5; discussion 35–36.

    Article  Google Scholar 

  13. 13.

    Gonzalez QH, Tishler DS, Plata-Munoz JJ, et al. Incidence of clinically evident deep venous thrombosis after laparoscopic Roux-en-Y gastric bypass. Surg Endosc 2004 Jul;18(7):1082–4.

    Article  CAS  Google Scholar 

  14. 14.

    Hamad GG, Choban PS. Enoxaparin for thromboprophylaxis in morbidly obese patients undergoing bariatric surgery: findings of the prophylaxis against VTE outcomes in bariatric surgery patients receiving enoxaparin (PROBE) study. Obes Surg 2005 Nov–Dec;15(10):1368–74.

    Article  Google Scholar 

  15. 15.

    Kalfarentzos F, Stavropoulou F, Yarmenitis S, et al. Prophylaxis of venous thromboembolism using two different doses of low-molecular-weight heparin (nadroparin) in bariatric surgery: a prospective randomized trial. Obes Surg 2001 Dec;11(6):670–6.

    Article  CAS  Google Scholar 

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Correspondence to Brea O. Rowan.

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Rowan, B.O., Kuhl, D.A., Lee, M.D. et al. Anti-Xa Levels in Bariatric Surgery Patients Receiving Prophylactic Enoxaparin. OBES SURG 18, 162–166 (2008). https://doi.org/10.1007/s11695-007-9381-y

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Keywords

  • Morbid obesity
  • Anti-Xa
  • Enoxaparin
  • Bariatric surgery
  • DVT prophylaxis