High Risk for VTE in ICU Patients : Role for VTE Prophylaxis

Critically ill patients are at high risk for the development of VTE. Without VTE prophylaxis the incidence of DVT ranges from 13 to 30%.1,2 There is geographic variation in the frequency with which VTE occurs; studies from Asia report a prevalence of VTE in medical-surgical critically ill patients ranging from6.6 to 10.5%,3,4 slightly less than that reported in Western European and North America. UFH effectively prevents DVT.5 However, a failure rate as high as 5.1 to 15.5% has been reported.6,7 This rate underlines the high risk of VTE in critically ill patients despite anticoagulation. In a prospective cohort study of 261 medicalsurgical ICU patients given UFH 5,000 units subcutaneously bid, DVT developed in 9.6% of patients during hospitalization. Patients with DVT had a significantly longer duration of mechanical ventilation, ICU stay, and hospitalization than those without DVT.8 In a study conducted in Australia and New Zealand including 175,665 critically ill adult patients, omission of thromboprophylaxis within 24 hours of ICU admission was reported to be associated with an increased risk of mortality in critically ill adult patients.9 A recent observational study, conducted in adult ICU patients in the United States, included 294,896 episodes of critical illness and reported that the group of patientswho received prophylactic anticoagulation had a significantly lower risk of death than those not provided VTE prophylaxis.10 In summary, critically ill patients have high risk of developing VTE, which may occur despite prophylaxis that is effective in other, lower-risk, settings. VTE in critically ill patients is associated with poorer outcome. These results suggest that VTE pharmacological prophylaxis should be applied to all patients who do not have a contraindication to anticoagulants, and that intensification of anticoagulation may be warranted to further reduce the risk of VTE.