- OBJECTIVE: To evaluate the prevalence of antibiotic de-escalation in patients diagnosed with severe sepsis or septic shock at a public academic tertiary hospital and to evaluate antibiotic adequacy and culture positivity. METHODS: The prevalence of antibiotic de-escalation, the adequacy of antibiotic treatment and the rates of culture positivity were analyzed in patients with severe sepsis and septic shock between April and December 2013 at an intensive care unit in a tertiary university hospital. RESULTS: Among the 224 patients included in the study, de-escalation was appropriate in 66 patients (29.4%) but was implemented in 44 patients (19.6%). Among the patients who underwent de-escalation, half experienced narrowing of the antimicrobial spectrum. The mortality rate was 56.3%, with no differences between the patients with or without de-escalation (56.8% versus 56.1%; p = 0.999) nor in the length of hospital stay. Empirical antibiotic therapy was appropriate in 89% of cases. Microorganisms were isolated from total cultures in 30% of cases and from blood cultures in 26.3% of cases. CONCLUSION: The adequacy rate of empirical antibiotic therapy was high, reflecting an active institutional policy of monitoring epidemiological profiles and institutional protocols on antimicrobial use. However, antibiotic de-escalation could have been implemented in a greater number of patients. De-escalation did not affect mortality rates.