Antibiotic De-Escalation in Critically Ill Patients with Negative Clinical Cultures.

(1) Background: Antibiotics are received by a majority of adult intensive care unit (ICU) patients. Guidelines recommend antibiotic de-escalation (ADE) when culture results are available; however, there is less guidance for patients with negative cultures. The purpose of this study was in investigate ADE rates in an ICU population with negative clinical cultures. (2) Methods: This single-center, retrospective, cohort study evaluated ICU patients who received broad-spectrum antibiotics. The definition of de-escalation was antibiotic discontinuation or narrowing of the spectrum within 72 h of initiation. The outcomes evaluated included the rate of antibiotic de-escalation, mortality, rates of antimicrobial escalation, AKI incidence, new hospital acquired infections, and lengths of stay. (3) Results: Of the 173 patients included, 38 (22%) underwent pivotal ADE within 72 h, and 82 (47%) had companion antibiotics de-escalated. Notable differences in patient outcomes included shorter durations of therapy ( p = 0.003), length of stay ( p < 0.001), and incidence of AKI ( p = 0.031) in those that underwent pivotal ADE; no difference in mortality was found. (4) Conclusions: The results from this study show the feasibility of ADE in patients with negative clinical cultures without a negative impact on the outcomes. However, further investigation is needed to determine its effect on the development of resistance and adverse effects.