Antibiotic Stewardship: Comparing Meropenem De-Escalation and Continued Therapy When Cultures Show No Multi-Drug Resistance

BACKGROUND: Current practice recommends de-escalation of antibiotics once cultures are available and show susceptibility to less broad-spectrum antibiotics. Some providers still choose not to follow cultures and continue broad-spectrum antibiotics. This can lead to harm to the patient and resistance to antibiotics in the patient and in the community. METHODS: This is a retrospective cohort study conducted via chart review utilizing electronic healthcare record reports. Patients were screened for inclusion if they were admitted into the Intensive Care Unit and received meropenem for longer than 48 hours from January 1st, 2021, to December 31st, 2023. A total of 118 patients were included. The primary outcome was an increase in mortality in patients receiving meropenem when cultures showed no multidrug resistance (Extended Spectrum Beta-Lactamase, i.e., ESBL) and was not de-escalated, versus when cultures showed no multidrug resistance (ESBL) and was de-escalated. The secondary outcome was comparing the length of stay and duration of antibiotics in the meropenem group versus patients who were de-escalated from meropenem, as well as the cost of meropenem and the cost to the hospital. RESULTS: No statistically significant difference in mortality was observed (p = 0.182), although a numerical trend toward lower mortality in the de-escalation group was noted. The median length of stay was 14 days in the non-de-escalated group and 11 days in the de-escalated group (p = 0.439), indicating no statistical significance. The median days of therapy in the non-de-escalated group were seven days, and in the de-escalated group were four days (p < 0.001), showing statistical significance. The median meropenem cost for the non-de-escalated group was $2,286, while for the de-escalated group it was $1,344 (p = 0.003), showing a significant difference. The median hospital cost for the non-de-escalated group was $402,002.50, while in the de-escalated group, it was $200,334.50 (p = 0.5), showing no statistical significance. CONCLUSION: In hospitalized critical care patients, the de-escalation of meropenem when cultures indicate to do so can not only potentially decrease mortality but also decrease length of stay. Further studies could provide more robust data to support our findings and challenge providers who choose to use broad-spectrum antibiotics even when cultures indicate de-escalation.