Impact of rapid identification of Acinetobacter Baumannii via matrix-assisted laser desorption ionization time-of-flight mass spectrometry combined with antimicrobial stewardship in patients with pneumonia and/or bacteremia

Abstract

We evaluated the clinical and economic outcomes of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) with stewardship intervention in patients with Acinetobacter baumannii (AB) pneumonia and/or bacteremia. 66 patients were included in the pre-intervention group and 53 in the intervention group. The combination of AB identification via MALDI-TOF MS and ID PharmD intervention significantly reduced the median time to effective therapy compared to conventional identification without intervention [77.7 (95% CI: 73.1-84.8) to 36.6 (95% CI: 25.9-50.9) hours (P < 0.0001)]. Rapid organism identification along with ID PharmD intervention was also associated with a 19% increase in clinical cure (15% versus 34%, P = 0.016) and a decreased length of stay during antibiotic therapy (13 [8-18] versus 11 [7-15] days, P = 0.021). No difference in 14-day mortality was observed (20% versus 25%, P = 0.526). Median costs during infection were approximately $6500 less in the intervention group ($49,402 [35,307-86,566] versus $42,872 [26,966-74,506]; P = 0.243). AB identification via MALDI-TOF MS combined with stewardship intervention allows for timely, effective antimicrobial therapy and is associated with increased clinical cure.

Keywords: Acinetobacter baumannii; Antimicrobial stewardship; Bacteremia; MALDI-TOF MS; Pneumonia.