(486) Intravenous Push Versus IV Piggyback Ceftriaxone in Critically Ill Obese Patients With Sepsis

Introduction: Many healthcare systems have used IV push (IVP) administration of medications, such as ceftriaxone , due to shortages of IV fluids. Compared to IV piggyback (IVPB) administration, IVP ceftriaxone has previously been associated with increased rates of treatment failure. Critically ill (ICU), obese patients exhibit alterations in pharmacokinetic parameters that may further impact the efficacy of IVP ceftriaxone. The purpose of this study is to compare the rate of treatment failure in obese and non-obese ICU patients receiving IVP and IVPB ceftriaxone.

Methods: A retrospective, single-center, observational, pre/post-protocol change study included adult ICU patients admitted between 3/2016-1/2021 who received ceftriaxone ≥72 hours. 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 IVP and IVPB administration. Secondary outcomes included individual components of 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 the primary outcome. All statistical analyses were completed using IBM SPSS Statistics Version 29 with p< 0.05 indicating significance.

Results: 206 non-obese and 187 obese patients were included, with 47% and 55% of patients receiving IVP ceftriaxone, respectively. Age, gender, and SOFA score were similar across groups. There was no difference in the primary outcome between non-obese and obese patients (28% vs 30%, p=0.696). There was also no difference when patients were further subdivided by IVP (non-obese 38% vs obese 38%, p=0.967) and IVPB (19% vs 20%, p=0.866). There was no difference in secondary outcomes between any groups. In regression analyses, obesity was not associated with treatment failure with either IVP or IVPB ceftriaxone.

Conclusions: In ICU patients receiving IVP or IVPB ceftriaxone, there was no difference in treatment failure in obese versus non-obese patients. While increased treatment failure has previously been shown with IVP ceftriaxone in the ICU, obesity does not seem to further contribute to worse outcomes with IVP administration.