PREVENT Trial

NEJM

May 4, 2019

Adjunctive Intermittent Pneumatic Compression for Venous Thromboprophylaxis.

Summarized by: 

Mazen Kherallah

What was the research question?

  • Does the addition of intermittent pneumatic compression to pharmacologic thromboprophylaxis in critically ill patients, reduce the incidence of deep-vein thrombosis?


How did they do it?

  • A multicenter, open label, randomized controlled trial 20 sites in Saudi Arabia, Canada, Australia, and India.

  • 2003 critically ill adults were randomized to receive intermittent pneumatic compression for at least 18 hours daily in addition to pharmacologic thromboprophylaxis (991 patients), or pharmacologic thromboprophylaxis alone (1012 patients) control group).

  • All patients had twice-weekly lower limb ultrasonography after the 3rd day of randomization.

  • The primary outcome was the incidence of proximal deep vein thrombosis.


What did they find?

  • Incidence of proximal deep vein thrombosis was not significantly different between the pneumatic compression group and the control group (3.9% vs. 4.2%, P=0.74).

  • A composite outcome of venous thromboembolism that included pulmonary embolism or all prevalent (present during the first 3 days) and incident lower-limb deep-vein thromboses occurred at no significant difference between the pneumatic compression group and the control group (10.4% vs. 9.4%, RR 1.11; 95% CI, 0.85 to 1.44).

  • 90-day all-cause mortality was not significantly different between the pneumatic compression group and the control group (26.1% vs 26.7%, RR 0.98; 95% CI, 0.84 to 1.13).


Are there any limitations?

  • Limited external validity of the study as more than 75% of recruited patients were from Saudi Arabia.

  • The rates of DVT were lower than anticipated, therefore, the study was underpowered.

  • There is heterogeneity in the type of compression device as more than 9 different devices were used among the different centers.

  • 10% of the control patients received compression devices.

  • Limited generalizability as high-risk groups, such as trauma ICU patients, were under-represented (less than 10% of study population).

  • The screening method does not detect pelvic vein DVT.


What does it mean?

  • The use of adjunctive intermittent pneumatic compression does not reduce the rate of proximal lower limb deep vein thrombosis in critically ill patients who are already on chemoprophylaxis.

  • The study impacted our practice as we no longer use sequential mechanical compression devices in ICU patients who are receiving prophylactic anticoagulation.

PREVENT Trial