Assessment of Time to Clinical Response in Patients with Sepsis Treated Before and After Implementation of a Matrix-Assisted Laser Desorption Ionization Time-of-Flight Blood Culture Identification Algorithm.

OBJECTIVE To evaluate time to clinical response before and after implementation of rapid blood culture identification technologies. DESIGN Before-and-after trial. SETTING Large, tertiary, urban, academic health-sciences center. PATIENTS Patients >18 years old with sepsis and concurrent bacteremia or fungemia were included in the study; patients who were pregnant, had polymicrobial septicemia, or were transferred from an outside hospital were excluded. INTERVENTION Prior to the intervention, polymerase chain reaction was used to identify Staphylococcus species from positive blood cultures, and traditional laboratory techniques were used to identify non-staphylococcal species. After the intervention, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) assay and FilmArray were also used to identify additional species. During both periods, the antimicrobial stewardship team provided prospective audit and feedback for all patients on antibiotics. RESULTS A total of 219 patients were enrolled in the study: 115 patients prior to the intervention and 104 after the intervention. The median time to clinical response was statistically significantly shorter in the postintervention group than in the preintervention group (2 days vs 4 days, respectively; P=.002). By Cox regression, the implementation of MALDI-TOF and FilmArray was associated with shorter time to clinical response (hazard ratio [HR], 1.360; 95% confidence interval [CI], 1.018-1.816). After controlling for potential confounders, the study group was not independently associated with clinical response (adjusted HR, 1.279; 95% CI, 0.955-1.713). Mortality was numerically, but not statistically significantly, lower in the postintervention group than in the preintervention group (7.6% vs 11.4%; P=.342). CONCLUSIONS In the setting of an existing antimicrobial stewardship program, implementation of MALDI-TOF and FilmArray was associated with improved time to clinical response. Further research is needed to fully describe the effect of antimicrobial stewardship programs on time to clinical response. Infect Control Hosp Epidemiol 2016;37:916-923.