Patients admitted in the Intensive Care Unit (ICU) frequently display and excessive fluid balance over a very short period of time. This positive fluid balance is the consequence of different organ failures (pulmonary, cardio-vascular, kidney…) or aggressive fluid resuscitation, which is mandatory in the early phase of ICU course. However recent data strongly suggest that an excessive fluid balance could be detrimental per se (increase of ICU morbidity or even mortality). There are controversies regarding the potential benefit of controlling this fluid balance with diuretics which are commonly used worldwide in various indications (acute and chronic heart failure, chronic kidney failure). In the ICU literature data are lacking, regarding the possible advantages and drawbacks of diuretics in this indication. The aim of our study is to test an algorithm with furosemide to reduce fluid overload in severe ICU-patients.