Current guidelines for reducing venous thromboembolism in trauma patients recommend initiating prophylaxis within 48 hours. However, according to a large retrospective study, that’s not early enough.

Jason Hecht, PharmD, BCCCP, BCPS, reported that chemoprophylaxis within the first 24 hours significantly reduced the risk for VTE in stable trauma patients, even when compared with patients receiving prophylaxis between 24 and 48 hours after hospital presentation.

Dr. Hecht presented the data at the 2020 virtual annual meeting of the American Society for the Surgery of Trauma.

“These findings challenge the current gold standard in our literature of when to begin prophylaxis,” said Dr. Hecht, a clinical pharmacy specialist and pharmacy research director at St. Joseph Mercy Ann Arbor, in Michigan. “By starting chemoprophylaxis within 24 hours, we saw a significant decrease in the rate of VTE during patients’ hospital stay.

“Conversely, the risk of VTE events skyrocketed in patients who initiated chemoprophylaxis more than 48 hours after hospital presentation,” he added.

As Dr. Hecht explained, although current guidelines recognize the importance of chemoprophylaxis for VTE, the timing of initiation must balance the risks for thrombosis and bleeding. For this study, Dr. Hecht’s team analyzed patient data from the Michigan Trauma Quality Improvement Program taken from 34 Level 1 and 2 trauma centers. Patients who did not receive prophylaxis or who were hospitalized for less than 48 hours were excluded. Three comparison groups were based on timing of initiation of prophylaxis (<24, 24-48, and ≥48 hours).

Of the 89,165 patients analyzed, 1.9% (1,752) died and 1.8% experienced a VTE complication, Dr. Hecht said. After adjusting for type of prophylaxis and patient factors, the researchers found an increased risk for VTE events associated with delayed chemoprophylaxis. Although prophylaxis within 48 hours was efficacious, Dr. Hecht said, prophylaxis initiated within 24 hours of hospital presentation was associated with a significantly decreased risk for VTE events. Waiting longer than 48 hours to initiate prophylaxis resulted in increased mortality and thrombotic complications.

“The earlier you can get chemoprophylaxis started, the better off the patient is going to be during their hospital stay,” Dr. Hecht said. “Balancing the risk of bleeding versus the risk of a patient clotting is a clinical conundrum we face all the time. This study shows that getting that prophylaxis started as early as possible is going to improve patient outcomes.”

Although the researchers took care to overcome the study’s observational design with sensitivity analyses and by accounting for disease severity, Dr. Hecht acknowledged limitations. Most importantly, he said, the study was unable to look at the safety of the practice like previous research has shown.

“This is a really well-conducted pilot study with high-quality evidence showing that early chemoprophylaxis improves outcomes, but being able to validate the safety and efficacy of this practice prospectively in the future would certainly be ideal,” Dr. Hecht concluded.