Inclusion Criteria:  Admission to one of the participating ICUs; Invasively ventilated for less than 24 hours at randomization; Expected to be under invasive ventilation for longer than 24 hours after randomization.  Exclusion Criteria:  Age below 18 years old; Suspected or confirmed pregnancy; Participation in other interventional trials with similar endpoints; Use of long term home mechanical ventilation; Neurological condition that can prolong duration of mechanical ventilation (i.e.Guillain-Barré syndrome, high spinal cord lesion, amyotrophic lateral sclerosis, multiple sclerosis, or myasthenia gravis); Conditions in which LUS cannot be performed or correctly interpreted (i.e. chest wall abnormalities, morbid obesity, and pre-existing interstitial lung disease); Conditions in which targeting a negative fluid balance is discouraged (i.e. subarachnoid bleeding, severe rhabdomyolysis (CK > 20.000); Previous participation in this RCT; Patients transferred from another center and invasively ventilated for longer than 24 hours.