Study protocol. During the first 2 days of treatment, clinical conditions may require ‘deep sedation’ (RASS target from −4 to 0), achievable only by intravenous drugs. As soon as possible, even if critical conditions persist, the ‘conscious sedation’ period begins (RASS target −1/0). Within 24 h after meeting enrollment criteria, patients undergo a single-blind RCT lasting until ICU discharge: in the intravenous (control) arm, patients receive only i.v. drugs, according to ABC protocol ; in the enteral (intervention) arm, patients must interrupt i.v. sedatives within 48h, maintaining enteral ones until ICU discharge . All sedatives have to be carefully tapered off to use the lowest effective dose. NGT, Naso-gastric tube; NJT, Naso-jejunal tube; RASS, Richmond Agitation Sedation Scale; RCT, Randomized controlled trial.