(937) Evaluation of IV Push Versus Piggyback Cefepime in Critically Ill Patients With Sepsis and Obesity

Introduction: Cefepime is often administered via the intravenous push (IVP) route; however, compared to IV piggyback (IVPB), IVP could result in worse safety and efficacy due to pharmacokinetic (PK) properties, which may be amplified in critically ill and obese populations that exhibit increased volumes of distribution and other alterations in PK. The purpose of this study is to compare the rate of treatment failure in obese and non-obese ICU patients with sepsis receiving IVP and IVPB cefepime.

Methods: This single-center, observational, pre/post-protocol change study included adult ICU patients who received IVPB or IVP cefepime for 72+ hours between 8/2015-8/2021. The primary outcome was treatment failure, defined as a composite of antibiotic escalation and all-cause mortality, and was compared between obese (BMI ≥30) and non-obese patients and between IVPB and IVP administration. Secondary outcomes included the individual components of the composite, days of therapy, and length of stay. Categorical and continuous variables were compared using the Chi-squared and Mann-Whitney U tests, respectively. Binary logistic regression was applied to treatment failure. All analyses were completed using SPSS with p< 0.05 indicating significance.

Results: The study included 116 obese and 164 non-obese patients. Median age was 70 years with the majority male Caucasians, and 70% received IVP cefepime. SOFA was higher in the obese group (6 vs 5, p=0.02). Treatment failure was more common in obese patients (31% vs 21%, p=0.05), driven by the subgroup receiving IVP (IVPB 19% vs 19%, p=0.98; IVP 37% vs 21%, p=0.02). This trend was similar for individual components of the composite (Mortality: IVPB 16% vs 19%, p=0.73; IVP 29% vs 18%, p=0.07; Escalation: IVPB 3% vs 2%, p=0.86; IVP 15% vs 6%, p=0.03). In multivariate binary logistic regression, obesity was not associated with treatment failure following IVPB (OR 1.30, 95% CI 0.35-4.85, p=0.69) or IVP (OR 1.99, 95% CI 0.97-4.10, p=0.06) cefepime. Other secondary outcomes were similar between groups.

Conclusions: Treatment failure may be higher in obese patients receiving IVP cefepime; this trend was not observed with IVPB and was not sustained when accounting for confounders. Limitations include single-center, retrospective design and baseline imbalances between groups