Iptive study was conducted from 2000 to 2014. All patients admitted consecutively were included. Patients with ICU LOS less than 24 hours were excluded. They were divided into 3 periods of five years each one. Demographic data (age and gender) were collected. In each patient, scales of severity estimated by MPM0, MPM24, SAPS2 and APACHEIII were applied and registered, as well as lenght of stay and