# Empiric Antibiotic Therapy in Suspected Sepsis: Impact of Gentamicin-Based Regimens on Incident Renal Failure and Mortality

## TL;DR

Using narrow-spectrum antibiotics with gentamicin for sepsis does not increase kidney damage or death risk and may help reduce overuse of broad-spectrum antibiotics.

## Contribution

Demonstrates that gentamicin-based narrow-spectrum therapy is safe and may support antibiotic stewardship.

## Key findings

- Narrow-spectrum β-lactam/gentamicin was not linked to higher AKI or death compared to broad-spectrum β-lactams.
- Creatinine levels normalized in patients who experienced AKI during the 30-day follow-up.
- Broad-spectrum β-lactam use was associated with worse AKI or death outcomes.

## Abstract

The efficacy and safety of administering a narrow-spectrum β-lactam and gentamicin as empirical therapy for community-acquired sepsis has been questioned. We compared the efficacy and safety of this combination with that of broad-spectrum β-lactams (cefotaxime, piperacillin-tazobactam, or meropenem) in patients with suspected sepsis.

In this retrospective study, we included patients initiated on narrow-spectrum β-lactam/gentamicin or broad-spectrum β-lactams for suspected sepsis between January 2017 and December 2022. Patients without baseline creatinine and at least 1 subsequent creatinine measurement were excluded. We compared the impact of antibiotic regimens using a 5-level ordinal outcome scale ranging from no acute kidney injury (AKI) to all-cause death during 30-day follow-up.

Among 1917 patients, 33.1% received narrow-spectrum β-lactam/gentamicin, and 66.9% received broad-spectrum β-lactams. Patients initiated on broad-spectrum β-lactams had more comorbidities, had lower estimated glomerular filtration rate on admission, and more frequently required treatment with noradrenaline, respiratory support, and admission to the intensive care and medical intermediate care units. Therapy with broad-spectrum β-lactams was associated with a higher posttreatment stage of AKI or death (adjusted odds ratio, 1.61 [95% confidence interval, 1.27–2.04]). We found no significant association between cumulative dose of gentamicin and peak creatinine value. For patients treated with gentamicin experiencing AKI, creatinine normalized during 30-day follow-up.

In patients with suspected sepsis, empirical treatment with narrow-spectrum β-lactam/gentamicin was not associated with an increased risk of AKI or death. If local antimicrobial resistance patterns permit, narrow-spectrum β-lactam/gentamicin may reduce broad-spectrum β-lactam usage, addressing a key element of antibiotic stewardship.

Empirical narrow-spectrum β-lactam/gentamicin was not associated with an increased risk of acute kidney injury (AKI) or death. In patients experiencing AKI, creatinine normalized within 30 days. If local antimicrobial resistance patterns permit, narrow-spectrum β-lactam/gentamicin may reduce broad-spectrum β-lactam usage.