Decline of multidrug-resistant Gram negative infections with the routine use of a multiple decontamination regimen in ICU

Abstract

Objectives: We have shown that the routine use of a multiple decontamination regimen with oropharyngeal and digestive polymyxin/tobramycin/amphotericin B plus mupirocin/chlorhexidine in intubated patients reduced all-cause acquired infections (AIs) in the intensive care unit (ICU). We now assessed the long-term impact of this strategy on AIs involving multidrug-resistant aerobic Gram negative bacilli (AGNB) and acquired episodes of extended-spectrum betalactamase (ESBL)-producing Enterobacteriaceae rectal carriage.

Methods: This was an observational single center study of all patients admitted to an ICU over 5 years (study population). Decontamination was given for the period of intubation and standard care otherwise. AIs and colonization rates were prospectively recorded. AIs rates were compared between the study period and a 1-year pre-intervention period. During study, trends were analyzed by semester using a Poisson regression model.

Results: The incidence rate of multidrug-resistant AGNB AIs was lower during the study (1.59 per 1000 patient-days, versus pre-intervention: 5.43‰, p < 0.001) and declined with time (adjusted OR = 0.85, 95 percent confidence interval 0.77-0.93, p < 0.001). ESBL-producing Enterobacteriaceae acquired colonization episodes (OR = 0.94 [0.88-1.00] P = 0.04) and the use of five major antibiotics (p < 0.001) also declined.

Conclusion: A multiple decontamination regimen did not favor the emergence of multidrug-resistant AGNB. In contrast, infection and colonization rates declined with time.

Keywords: Chlorhexidine; Intensive care unit; Multidrug-resistant Gram negative bacilli; Mupirocin; Selective digestive decontamination; Topical antibiotics.