We report two cases of anesthesia of sciaticpopliteal interne nerve, sciaticpopliteal external nerve and femoral nerve in critical ill patients under vascular surgery of lower limbs. One case is a patient diagnosed of recent pulmonary embolism and the other one diagnosed of recent myocardial infarction. The procedures were successful in both cases without complications. We recommend this procedure in critical patients undergoing surgery of lower extremities.