The following is a summary of “Overcultured? Blood cultures on discharged ED patients were ordered more frequently after the SEP-1 bundle initiation,” published in the May 2023 issue of Emergency Medicine by Sterk, et al.
In 2015, the Severe Sepsis and Early Septic Shock Management Bundle (SEP-1) introduced a hospital reimbursement metric that tied performance to various time-sensitive indicators, including ordering blood cultures for patients with severe sepsis or septic shock. However, the metric may have influenced blood culture ordering practices in the Emergency Department (ED), even for patients who did not meet severe sepsis or septic shock criteria. For a study, researchers sought to assess changes in the frequency of blood culture orders for adult patients discharged from the ED following the implementation the SEP-1 metric. Additionally, the study examined whether there were changes in pathogen or contaminant growth rates after the SEP-1 metric and if similar changes were observed in orders for other laboratory tests.
The retrospective evaluation analyzed blood culture orders for adult patients discharged from a suburban academic hospital between January 1, 2012, and June 30, 2019. The study compared the number of blood cultures per discharged adult patient before and after implementing the SEP-1 metric. Each culture that resulted in the growth of an organism was categorized as either a pathogen or a contaminant, and the rates of pathogen and contaminant growth were compared before and after SEP-1. The study also compared the rates of blood culture and lactate orders (labs related to SEP-1) with the rates of D-dimer, lipase, human chorionic gonadotropin (HCG), and brain natriuretic peptide (BNP) orders (labs unrelated to SEP-1) before and after the implementation of the SEP-1 metric.
During the study period, there were 144,343 adult patients discharged from the ED. Among these visits, 6,754 blood cultures were drawn from 3,827 patients. The rate of blood culture orders increased from 43.1 cultures per 1,000 discharged patients before the SEP-1 metric to 75.9 blood cultures per 1,000 discharged patients after the SEP-1 metric, representing a 76.2% increase (P < 0.001). In addition, the cultures showed a decreased rate of pathogen growth (from 3.93% before SEP-1 to 3.03% after SEP-1, P = 0.044) and a similar rate of contaminant growth (2.49% to 1.85%, P = 0.071). Overall, orders for labs unrelated to SEP-1 increased by an average of 16.8% after the SEP-1 metric, while orders for labs related to SEP-1 increased by 81.0%.
Following the implementation of the SEP-1 bundle, blood cultures were ordered more frequently for discharged ED patients. However, these cultures showed a lower rate of pathogen growth and a consistent rate of contaminant growth. A similar increase in other laboratory tests did not mirror the increase in blood culture orders. The findings suggested that the SEP-1 metric unintentionally led to increased blood culture orders for patients deemed healthy enough to be discharged from the ED.