Simplified Selective Digestive Tract Decontamination for the Prevention of Intensive Care Unit Acquired Infections

Overview

A simplified graded gut decontamination protocol combined with rigorous bi-weekly screening and appropriate bacterial prophylaxis, will lead to a 25% reduction in the acquisition of blood stream infections and to a 25% reduction in lower airway colonization with multi drug resistant organisms. There will be no concomitant rise in gram-positive or fungal infection or a surgency of new resistance patterns.

Simplified Selective Digestive Tract Decontamination for the prevention of ICU infections in a setting of high-level antibiotic resistance Scientific Background: Aerobic gram-negative bacilli (AGNB), Gram-positive bacteria and fungi are responsible for hospital acquired infections. This problem is especially typical in intensive care units (ICUs) due to the complexity of disease and wide use of invasive procedures. The common use of empiric wide-range antibiotic therapy had lead to the development significant resistance of these pathogens and this group of bacteria was defined as Multi-Drug Resistant Organisms (MDRO). Among these bacteria the most important and virulent are: Carbapenem Resistant Enterobacteriaceae (CRE), Extended Spectrum Beta Lactamases (ESBL), Methicillin Resistant Staphylococcus Aureus (MRSA), Vancomycin Resistant Enterococci (VRE) as well as Fluconazol resistant Candida. The main reservoir of these organisms is the intestinal tract, which raises the possibility that their primary eradication may lead to control of the MDRO epidemic. Selective Digestive tract Decontamination (SDD) has been studied extensively over the last 10-15 years and there is a body of evidence that shows that this method can reduce acquired infections, bacterial drug resistance and mortality in various ICU settings. It should be pointed out however that many of these studies were performed in units with a low prevalence of infection from MDROs and that they were never performed in units were CREs are endemic. According to the described protocols, SDD was performed as a combination of an a oral antibiotic paste - Selective Oropharyngeal Decontamination (SOD) together with enteral medication given through a gastric feeding tube, as well as a few days of prophylactic intra-venous treatment with an early generation cephalosporin. This treatment method did not become a standard of care - mostly due to the concern that new resistance will develop to the prescribed enteral antibiotics, or that there will be a rise in the prevalence of other enteral infections as VRE, Clostridium difficile or MRSA acquired infections. Despite evidence that during the SDD treatment period there was actually a reduction of drug resistance, the Center for Disease Control and prevention (CDC) and the protocols of the surviving sepsis campaign do not recommend SDD as a means of coping with the MDRO epidemic. In published SDD protocols there was a use of wide-spectrum antibiotics that covered the range of gram-positive, gram-negative bacteria and fungi, without correlation to the results of primary screening in these patients. Even though this approach did not lead to a rise in bacterial resistance, it raised enough anxiety and resistance within the caregivers to prevent its penetration to daily use. The endemic spread of CRE infection at Rambam Medical Center has lead us to focus on these pathogens in our SDD program, while performing rigorous bi-weekly screening for all bacteria. We gave enteral antibiotic treatment (Neomycin + Polymixin E) targeting AGNB, and only if the primary screening found MRSA or Fungi, did we prescribe enteral preventive treatment against them (Vancomycin or Nystatin). Therefore, a prospective study was performed during 2011 at Rambam department of critical care medicine, on the influence of a simplified SDD protocol on the acquisition of AGNB infection in the ICU. The results show a significant reduction in blood stream infections and a change in the epidemiology of colonization of the respiratory tract - from resistant to sensitive bacteria. There was a concomitant reduction in the use of MDRO- targeted antibiotics. The proposed multi-center study is based on this successful experience and will focus on the influence of a simplified SDD protocol on colonization and infection with MDROs in israeli ICUs where CREs are endemic.