Clinical impact of matrix-assisted laser desorption ionization-time of flight mass spectrometry combined with antimicrobial stewardship interventions in patients with bloodstream infections in a Japanese tertiary hospital.

Abstract

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has the potential to permit early organism identification and optimization of antibiotic therapy. However, MALDI-TOF MS combined with antimicrobial stewardship is available at only a limited number of institutions. Here, we evaluated the clinical impact of implementing MALDI-TOF MS combined with antimicrobial stewardship intervention in patients with bloodstream infections. We conducted a single-centre, prospective cohort study to evaluate the clinical impact of implementing MALDI-TOF MS combined with antimicrobial stewardship intervention in patients with bloodstream infections. Processes and clinical outcomes in patients with bloodstream infections were compared before and after implementation of MALDI-TOF MS. Compared with the conventional identification method, MALDI-TOF MS combined with antimicrobial stewardship intervention significantly decreased the time to organism identification (48.6±46.0hours vs 78.1±38.9hours, P<0.001), effective antimicrobial therapy (12.9±19.0hours vs 26.2±44.8hours, P<0.001) and optimal antimicrobial therapy (53.3±55.0hours vs 91.7±88.7hours, P<0.001. Moreover, the rate of clinical failure (14.0% vs 33.3%, P<0.001) and incidence of adverse events (7.5% vs 23.9%, P<0.001) was lower in the MALDI-TOF MS group than in the conventional identification group. A multivariate Cox proportional hazard analysis indicated that implementation of MALDI-TOF MS was a protective factor against clinical failure in patients with bloodstream infections (hazard ratio, 0.61; 95% confidence interval, 0.38-0.99; P=0.047). Implementation of the MALDI-TOF MS combined with antimicrobial stewardship intervention facilitated early optimization of antimicrobial therapy with a remarkable concomitant reduction in clinical failure and adverse events in patients with bloodstream infections.