Objective
To evaluate the effect of a postpartum risk-based low-molecular-weight heparin protocol for venous thromboembolism prevention.
Methods
We conducted a retrospective cohort of postpartum women at a safety-net hospital before (2013), during (2014), and after (2015) implementation of a risk-based enoxaparin thromboembolism prevention protocol. The calculated sample size was based on a primary outcome of enoxaparin administration rate. Secondary outcomes included incidence of postpartum thromboembolism, wound complications, and 30-day readmission rates. The prevalence of thromboembolism risk factors and protocol adherence was evaluated in two groups of women before (May 2013) and after (May 2015) protocol implementation. Exact chi-square or Cochran-Armitage trend tested differences in rates.
Results
Over 3 years, 9,766 deliveries were included. Enoxaparin was administered to 0.28% (95% CI 0.14–0.55) of postpartum women in 2013 (before) compared with 33.46% (95% 31.89–35.07%) after protocol implementation (p<0.001). Although underpowered to detect a difference in these outcomes, no differences were seen in rates of thromboembolism (0.16%, 0.12%, 0.15%, p=.9), wound complication (0.82%, 1.21%, 0.91%, p=0.7), or emergency department visits (8.30%, 7.96%, 8.34%, p=0.9), while readmissions increased (0.79%, 1.27%, 1.42%, p=0.02). Prevalence of thromboembolism risk factors did not differ between women delivered in May 2013 and May 2015. Physician adherence to the protocol was 89.5% in May 2015. Nine women had thromboembolic events after protocol implementation: 5 received appropriate treatment per protocol, but 4 did not. In 2014,3/4 of women with a thromboembolism were inadequately treated compared to 1/5 in 2015 with the addition of a computerized order set.
Conclusion
Implementation of a low-molecular-weight heparin risk-based protocol for postpartum thromboembolism prevention resulted in high physician adherence and over 30% of postpartum women receiving enoxaparin. Prior to implementing such a protocol on a wider scale, a much larger study is needed to evaluate the effect on thromboembolic disease and wound problems.