Carbapenem Usage in the Initial Antibiotic Therapy of Sepsis in Japanese Intensive Care Units

Background Achieving a balance between the utilization and limitation of carbapenems for initial sepsis therapy is imperative, yet documentation on the use of carbapenems in sepsis treatment is limited. This study aimed to ascertain the prevalence of carbapenem use in Japanese intensive care units (ICUs) and evaluate the association between its use in the initial antibiotic therapy for sepsis and patient prognosis.  Methods This study is a post hoc descriptive analysis of the Focused Outcome Research on Emergency Care for Acute Respiratory Distress Syndrome, Sepsis, and Trauma (FORECAST), a multicenter, prospective cohort study conducted in 59 ICUs in Japan from January 2016 to March 2017. This study described the rate of carbapenem use overall and in each ICU and assessed the association between carbapenem use and in-hospital mortality by generalized linear mixed effect model adjusting for patient characteristics as fixed effect confounders and the hospitals as random effect confounders. Results Out of 1140 participants, 627(55.0%) received and 513 (45.0%) did not receive carbapenems following the diagnosis of severe sepsis or septic shock. Patient severity was similar in both groups in terms of Sepsis-related Organ Failure Assessment (SOFA; 9 and 8) and Acute Physiology and Chronic Health Evaluation II (APACHE II; 23 and 22) scores. Among 48 of the 59 ICUs that registered more than three patients in the FORECAST registry, the median carbapenem utilization rate stood at 55.2% (minimum: 20.0%, maximum: 100.0%, IQR: 43.6%-67.2%). Hospital mortality rates were 25.6% and 20.5% in carbapenem recipients and non-recipients, respectively. A correlation between initial carbapenem use and increased in-hospital mortality was discerned in the unadjusted model (difference of 5.2%), but this association was not evident in the adjusted model (difference of 1.2%; 95%CI: -4.3,6.6; p=0.66). Conclusions Initial antibiotic therapy with carbapenems was noted in over half of the sepsis patients in Japanese ICUs. In-hospital mortality was not associated with the use of carbapenems.