Integrating Rapid Diagnostics and Antimicrobial Stewardship Improves Outcomes in Patients With Antibiotic-Resistant Gram-negative Bacteremia

J Infect. 2014 Sep;69(3):216-25. doi: 10.1016/j.jinf.2014.05.005. Epub 2014 May 17.

Abstract

Background: An intervention for Gram-negative bloodstream infections that integrated mass spectrometry technology for rapid diagnosis with antimicrobial stewardship oversight significantly improved patient outcomes and reduced hospital costs. As antibiotic resistance rates continue to grow at an alarming speed, the current study was undertaken to assess the impact of this intervention in a challenging patient population with bloodstream infections caused by antibiotic-resistant Gram-negative bacteria.

Methods: A total of 153 patients with antibiotic-resistant Gram-negative bacteremia hospitalized prior to the study intervention were compared to 112 patients treated post-implementation. Outcomes assessed included time to optimal antibiotic therapy, time to active treatment when inactive, hospital and intensive care unit length of stay, all-cause 30-day mortality, and total hospital expenditures.

Results: Integrating rapid diagnostics with antimicrobial stewardship improved time to optimal antibiotic therapy (80.9 h in the pre-intervention period versus 23.2 h in the intervention period, P < 0.001) and effective antibiotic therapy (89.7 h versus 32 h, P < 0.001). Patients in the pre-intervention period had increased duration of hospitalization compared to those in the intervention period (23.3 days versus 15.3 days, P = 0.0001) and longer intensive care unit length of stay (16 days versus 10.7 days, P = 0.008). Mortality among patients during the intervention period was lower (21% versus 8.9%, P = 0.01) and our study intervention remained a significant predictor of survival (OR, 0.3; 95% confidence interval [CI], 0.12-0.79) after multivariate logistic regression. Mean hospital costs for each inpatient survivor were reduced $26,298 in the intervention cohort resulting in an estimated annual cost savings of $2.4 million (P = 0.002).

Conclusions: Integration of rapid identification and susceptibility techniques with antimicrobial stewardship resulted in significant improvements in clinical and financial outcomes for patients with bloodstream infections caused by antibiotic-resistant Gram-negatives. The intervention decreased hospital and intensive care unit length of stay, total hospital costs, and reduced all-cause 30-day mortality.

Keywords: Antimicrobial stewardship; Bloodstream infections; MALDI-TOF; Multidrug resistant; Rapid diagnostics.

MeSH terms

  • Acinetobacter Infections / diagnosis
  • Acinetobacter Infections / drug therapy
  • Acinetobacter Infections / microbiology
  • Acinetobacter Infections / mortality
  • Acinetobacter baumannii / isolation & purification*
  • Adult
  • Aged
  • Anti-Bacterial Agents / therapeutic use*
  • Bacteremia / diagnosis
  • Bacteremia / drug therapy*
  • Bacteremia / microbiology
  • Bacteremia / mortality
  • Drug Resistance, Multiple, Bacterial
  • Escherichia coli / enzymology
  • Escherichia coli / isolation & purification*
  • Escherichia coli Infections / diagnosis
  • Escherichia coli Infections / drug therapy
  • Escherichia coli Infections / microbiology
  • Escherichia coli Infections / mortality
  • Female
  • Gram-Negative Bacterial Infections / diagnosis
  • Gram-Negative Bacterial Infections / drug therapy*
  • Gram-Negative Bacterial Infections / microbiology
  • Gram-Negative Bacterial Infections / mortality
  • Hospital Costs
  • Hospital Mortality
  • Humans
  • Intensive Care Units
  • Klebsiella / enzymology
  • Klebsiella / isolation & purification*
  • Klebsiella Infections / diagnosis
  • Klebsiella Infections / drug therapy
  • Klebsiella Infections / microbiology
  • Klebsiella Infections / mortality
  • Length of Stay
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Pseudomonas Infections / diagnosis
  • Pseudomonas Infections / drug therapy
  • Pseudomonas Infections / microbiology
  • Pseudomonas Infections / mortality
  • Pseudomonas aeruginosa / isolation & purification*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Survival Rate
  • Time Factors
  • Time-to-Treatment
  • Treatment Outcome
  • beta-Lactam Resistance
  • beta-Lactamases / metabolism

Substances

  • Anti-Bacterial Agents
  • beta-Lactamases