Randomization
organ dysfunction
Patients were randomized to receive usual care plus epidural analgesia for at least 72 h (intervention group) or usual care alone (control group). Randomization was stratified by site, duration of symptoms (< 48 vs. ≥ 48 h), and severity as assessed by the modified Marshall scoring system for organ dysfunction (three strata of increasing severity were defined according to the maximum score obtained for at least one of the respiratory, renal, or hemodynamic functions) [