Enhanced antimicrobial de-escalation for pneumonia in mechanically ventilated patients: a cross-over study

BACKGROUND: Antibiotics are commonly administered to hospitalized patients with infiltrates for possible bacterial pneumonia, often leading to unnecessary treatment and increasing the risk for resistance emergence. Therefore, we performed a study to determine if an enhanced antibiotic de-escalation practice could improve antibiotic utilization in mechanically ventilated patients with suspected pneumonia cared for in an academic closed intensive care unit (ICU). METHODS: This was a prospective cross-over trial comparing routine antibiotic management (RAM) and enhanced antimicrobial de-escalation (EAD) performed within two medical ICUs (total 34 beds) at Barnes-Jewish Hospital, an academic referral center. Patients in the EAD group had their antibiotic orders and microbiology results reviewed daily by a dedicated team comprised of a second-year critical care fellow, an ICU attending physician and an ICU pharmacist. Antibiotic de-escalation recommendations were made when appropriate based on microbiologic test results and clinical response to therapy. RESULTS: There were 283 patients evaluable, with suspected pneumonia requiring mechanical ventilation: 139 (49.1%) patients in the RAM group and 144 (50.9%) in the EAD group. Early treatment failure based on clinical deterioration occurred in 33 (23.7%) and 40 (27.8%) patients, respectively (P = 0.438). In the remaining patients, antimicrobial de-escalation occurred in 70 (66.0%) and 70 (67.3%), respectively (P = 0.845). There was no difference between groups in total antibiotic days ((median (interquartile range)) 7.0 days (4.0, 9.0) versus 7.0 days (4.0, 8.8) (P = 0.616)); hospital mortality (25.2% versus 35.4% (P = 0.061)); or hospital duration (12.0 days (6.0, 20.0) versus 11.0 days (6.0, 22.0) (P = 0.918). CONCLUSIONS: The addition of an EAD program to a high-intensity daytime staffing model already practicing a high-level of antibiotic stewardship in an academic ICU was not associated with greater antibiotic de-escalation or a reduction in the overall duration of antibiotic therapy. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02685930. Registered on 26 January 2016. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13054-017-1772-4) contains supplementary material, which is available to authorized users.