Assessing Venous Thromboembolism Prophylaxis Strategies in Patients Who Develop a Hospital‐Acquired Deep Venous Thrombosis or Pulmonary Embolism

Background:

Acquired inpatient venous thromboembolism (VTE) accounts for significant morbidity and mortality and is considered largely preventable with pharmacologic prophylaxis. Appropriate VTE prevention has emerged as an important hospital quality measure and has become a factor influencing third‐party payer reimbursement. In addition to failure to initiate prophylaxis, inadequate prophylaxis based on patient‐specific risk factors for developing VTE while hospitalized or during the posthospitalization period may result in preventable VTE events, although ideal prophylactic strategies remain unclear. We performed a review of our hospital‐acquired VTE events to determine the pharmacologic prophylaxis utilized in patients developing VTE.

Methods:

All hospital‐acquired VTE events in patients admitted to a general medicine service at a large university hospital from October 1, 2006, to April 27, 2008, were reviewed. Administrative data were used to identify patients who were discharged with a diagnosis of VTE or who were readmitted to our institution within 1 month of discharge with a diagnosis of VTE. Charts were reviewed to confirm newly acquired VTE events. Each patient identified with a new VTE was risk‐stratified using the Caprini VTE risk assessment tool. The VTE prophylaxis strategy used for each patient was recorded.

Results:

In the general medicine population, we identified 15 DVT events and 20 PE events that were deemed hospital acquired. Four of 15 deep vein thromboses (DVTs) and 7 of 20 pulmonary embolisms (PEs) were associated with a surgical procedure. Among PE events, 6 of 20 occurred in high‐risk patients, and 13 of 20 occurred in very high‐risk patients. Among high‐ and very high‐risk patients, 1 of 19 received only sequential compression devices (SCDs) because of bleeding risk. Nine of 19 patients received twice daily heparin prophylaxis, 2 of 19 received 3 times daily heparin prophylaxis, and 2 of 19 received prophylactic‐dose enoxaparin. VTE developed in 5 of 19 patients despite treatment dose anticoagulation with either warfarin or weight‐based enoxaparin. Among DVT events, 1 of 15 occurred in high‐risk patients and 10 of 15 in very high‐risk patients. For these patients, 1 of 10 received no prophylaxis, 1 of 10 had prophylaxis held due to bleeding, 5 of 10 received twice daily heparin, and 3 of 10 received 3 times daily heparin. A delay in VTE prophylaxis greater than 24 hours because of anticipation of a surgical procedure occurred in 3 very high‐risk patients. Overall, 15 of 22 patients who were candidates for prophylaxis received twice daily heparin or SCDs.

Conclusions:

Failure of VTE prophylaxis was a rare occurrence among general medicine patients who developed a hospital‐acquired VTE. Alternatively, the majority of VTE events in high‐ or very high‐risk patients transpired in patients receiving twice‐daily heparin, indicating that this strategy may be inappropriate for this patient population. Further studies should focus on patient‐specific risk factors to better determine those at greatest risk of developing a hospital‐acquired VTE.

Author Disclosure:

N. Schneider, none; P. Grant, none.