Comparison of enoxaparin 40 mg versus 60 mg dosage for venous thromboprophylaxis in patients undergoing bariatric surgery: A randomized controlled trial.

BACKGROUND: Venous thromboembolism (VTE) is a common cause of morbidity and mortality after bariatric surgery. Morbid obesity is an independent risk factor for VTE, with goals of prophylactic anti-factor Xa levels within 0.2-0.5 IU/mL. The recommended dosing regimen of enoxaparin for VTE prophylaxis in patients with morbid obesity is lacking in available guidelines.

OBJECTIVES: To evaluate the achieving prophylactic anti-factor Xa levels with different dosages of enoxaparin for morbid obesity patients.

SETTING: We conducted a study at Chulalongkorn Bariatric and Metabolic Institute, King Chulalongkorn Memorial Hospital.

METHODS: We conducted a randomized controlled trial comparing anti-factor Xa levels 4 h after the administration of enoxaparin. All recruited patients randomly received 40 mg or 60 mg of enoxaparin 12 h before the operation. Blood specimens were collected 4 h after the administration of enoxaparin.

RESULTS: In total, 56 patients who presented between April 2019 and March 2020 at King Chulalongkorn Memorial Hospital were recruited. Of these patients, 28 received 40 mg and 28 received 60 mg of enoxaparin. In both groups, the rates of achieving target levels were 53.57% and 78.57%, respectively (p-value = 0.048). The mean anti-factor Xa levels were 0.19 IU/mL ± 0.06 IU/mL and 0.28 and 0.28 ± 0.10 IU/mL, respectively (p < 0.001). No significant difference was found in the estimated blood loss between the groups. No patient obtained anti-factor Xa levels exceeding 0.5 IU/mL. In both groups, no symptomatic VTE occurred.

CONCLUSIONS: A 60 mg of enoxaparin regimen achieved more prophylactic anti-factor Xa levels than 40 mg in obese patients undergoing bariatric surgery without any adverse events.