Nonleg DVTs were not associated with ICU mortality ( HR , 1.09 ; 95 % CI , 0.62-1 .92 ) in a model adjusting for age , APACHE II , vasopressor use , mechanical ventilation , renal replacement therapy , and platelet count below 50 10 ( 9 ) / L. CONCLUSIONS AND RELEVANCE Despite universal heparin thromboprophylaxis , nonleg thromboses are found in 2.2 % of medical-surgical critically ill patients , primarily in deep veins and proximal veins .