Daniel S Urias, MD, Paul Williams, MD, Jennifer Silvis, DO, Thomas Simunich, MS, MBA, Russell Dumire, MD, FACS, D’arcy Duke, MD. Conemaugh Memorial Medical Center
Introduction: Venous thromboembolic (VTE) disease is a rare life-threatening condition, yet one of the most commonly reported causes of death after bariatric surgery. Prevention is critical; however, ideal agents, dosage, bleeding risk and methods of monitoring complicate treatment prophylaxis. In an attempt to determine optimal prophylactic anticoagulation dosing, we used Rotational Thromboelastometry (ROTEM®) to identify baseline coagulopathy and the change in same following subcutaneous enoxaparin in obese patients undergoing bariatric surgery.
Methods: We conducted a prospective study including patients eligible for bariatric surgery, > 18 years of age, and without any known underlying coagulopathy. Baseline coagulation state was determined during the routine pre-operative testing appointment. Following surgery, the patient received 40 mg subcutaneous enoxaparin within 2 hours and a second dose of 40 mg at 4 am on post-operative day one. The post-operative ROTEM® was performed approximately 2 hours after the second dose of enoxaparin. Patient demographics and characteristics were gathered, including: age, gender, body mass index (BMI), smoking history, presence of comorbidities (diabetes, hypertension and obstructive sleep apnea), Table 1. All ROTEM® analyses were interpreted by an experienced surgeon blinded to patient identity, characteristics and timing of ROTEM® testing, Table 2A and B.
Results: Forty patients meeting inclusion criteria were consented, enrolled, and completed the study. The majority of the patients were female (82.5%). The average patient was revealed to be morbidly obese (mean BMI of 43.6) and 44 years of age (Table 1). The ROTEM® analyses (Table 2) showed over half (57.5%) the patients were hypercoagulable at baseline. The second ROTEM® results showed 57.5% of patients as hypercoagulable and 42.5% normal, representing no statistically significant change from baseline (P = 1.000). Two patients had baseline hypocoagulability and became hypercoagulable post-operatively despite two doses of enoxaparin.
Conclusions: The results imply that obese patients may be inherently hypercoagulable. Despite two doses of 40 mg of subcutaneous enoxaparin approximately every 12 hours, no patient became hypocoagulable. Thirty-five (87.5%) patients clearly had insufficient dosing; while only five patients seemingly had adequate dosing evidenced by their shift from a hypercoagulable to a normal coagulable state. These findings suggest that two doses of enoxaparin are ineffective in achieving the desired prophylaxis in obese patients undergoing bariatric surgery.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 86429
Program Number: S023
Presentation Session: Bariatrics 1 Session
Presentation Type: Podium