Effect of Antimicrobial Stewardship with Rapid MALDI-TOF Identification and Vitek 2 Antimicrobial Susceptibility Testing on Hospitalization Outcome

Introduction: Rapid organism identification (ID) and antimicrobial susceptibility testing (AST) along with antibiotic stewardship (ASP) are critical to appropriate treatment. We sought to capture time for bacterial culture and initiation of appropriate therapy for patients, from 2017 (without MALDI-TOF/Vitek 2 and ASP) and 2018 (with MALDI-TOF/Vitek 2 and ASP). Methods: Eligible patients admitted to our hospital with a positive sputum, blood, or urine culture. Sequential patients were retrospectively obtained from March 1 to May 31, 2017. Seventy-seven patients from 2017 were compared to 77 patients from 2018. A time-in-motion study was performed to compare time to identification (ID), AST results, and ASP team intervention for the two periods. Data were entered into SPSS (ver 25) for analysis. Results are reported as mean (± SD) or percentage. Results: Time to organism ID was significantly faster in 2018 (2018 24.9 ± 14.4, 2017 33.8 ± 17 h, p=0.001). Time to AST results was also significantly faster for patients in 2018 compared to 2017 (18.2 ± 14 compared to 28.5 ± 14.9 h, p<0.001). ASP team recommended significantly more adjustments to empiric antimicrobial therapy in 2018 (28% of 2018 vs. 2% in 2017, p< 0.001). Length of hospital stay was significantly shorter in 2018 compared to 2017 (2018 10.7 ± 11.1 days and 2017 15.5 ± 18.1 days, p=0.05). Conclusions: Use of MALDI-TOF/Vitek 2 leads to an average 21.5 h faster ID and AST results that can be acted upon by ASP for appropriate antimicrobial recommendations.