Assay Aids Anticoagulant Dosing of Obese Patients for Bariatric Sx
Thrombin generation assay may allow more accurate determination of anticoagulation adequacy
FRIDAY, Jan. 25, 2019 (Pharmacist's Briefing) -- Endogenous thrombin potential (ETP) may provide better information than anti-factor Xa (anti-XA) in determining the best dosage for blood thinners among obese patients undergoing bariatric surgery, according to a study recently published in Surgery for Obesity and Related Disorders.
Luigi Brunetti, Pharm.D., M.P.H., from the State University of New Jersey in Piscataway, and colleagues sought to assess the optimal dose, timing, and duration of prophylactic anticoagulation for 60 obese patients undergoing sleeve gastrectomy. Patients were given standard prophylactic therapy (subcutaneous enoxaparin [40 mg twice daily] or unfractionated heparin [UFH; weight-based: 5,000 units for <120 kg or 7,500 units for ≥120 kg every eight hours]).
The researchers found that patients receiving enoxaparin achieved goal anti-Xa more frequently than the UFH group (93.8 versus 4.5 percent; P < 0.0001). Similarly, target ETP reduction was more frequently obtained among patients receiving enoxaparin than those receiving UFH (50 versus 27.7 percent; P = 0.12). For the majority of patients receiving UFH, anti-Xa was below the limit of detection, although the thrombin generation assay suggested patients did experience anticoagulation at some level of effectiveness. The majority of patients receiving enoxaparin (80 percent) had minor bleeding during surgery, which correlated with the ETP measurement.
"Currently, most physicians prescribe 40 milligrams of enoxaparin twice daily, and some are advocating for even higher doses for patients with extreme obesity," Brunetti said in a statement. "That dosage is ill-advised based on our study. ETP can potentially help physicians better understand the right dosage, so obese patients will see benefits without being harmed."
One study author is an employee of Stago Diagnostica, the manufacturer of the coagulation assays used in the study.