Randomized Trial of Postoperative Venous Thromboembolism Prophylactic Compliance: Aspirin and Mobile Compression Pumps

Background: Aspirin, as a routine venous thromboembolism (VTE) prophylaxis, is approved along with pneumatic compression pumps by the American College of Chest Physicians. We assessed compliance of aspirin and pump use after total joint arthroplasty. Methods: A randomized trial of aspirin alone or aspirin/mobile compression pumps after total joint arthroplasty was performed. Aspirin and pump compliance, VTE events, and satisfaction with pump use were collected. Compliance was assessed through an internal device monitor and drug log book. Patients were also contacted 90 days postoperatively for reported symptomatic VTEs. Results: Each group had 40 patients and greater than 94% compliance with aspirin use, with no difference between groups (P = 0.55). Overall pump compliance during the first 14 days after hospital discharge was 51% (SD +/- 33), which was significantly worse than aspirin compliance at 99% (SD +/- 4.1) (P < 0.0001). Only 10 patients were compliant (>20 hr/d) with recommended pump use throughout the entire recommended period. There was no notable association between aspirin compliance and VTE within 90 days. There was no notable association between pump compliance and VTE at 90 days. However, average pump use compliance was 20% in patients with VTE and 54% in patients without VTE within 90 days. With the numbers available in this compliance study, there was no significant difference (P = 0.11). Discussion: Aspirin compliance was notably greater than pump compliance. In this study, we found that pump compliance was not associated with lower VTE risk. In fact, no increased risk was recognized in patients with an average pump usage of >50%. Further study is warranted to define the duration of pump use required for clinical significance. The recommended use of compression pumps should continue to be examined.