Deep vein thrombosis is a common problem in the intensive care unit and diagnosis is often delayed due to limited availability of a formal duplex ultrasound. Physician performed 2 point compression ultrasonography has been shown to have reasonable accuracy when performed in the emergency department and outpatient setting, but has not been studied on patients in the intensive care unit. We propose an observational study to assess the ability of intensivists to evaluate for deep vein thrombosis using 2 point compression ultrasonography.