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