Systemic tobramycin concentrations during selective decontamination of the digestive tract in intensive care unit patients on continuous venovenous hemofiltration

OBJECTIVE: To study whether selective decontamination of the digestive tract (SDD) results in detectable serum tobramycin concentrations in intensive care unit (ICU) patients with acute renal failure treated with continuous venovenous hemofiltration (CVVH). DESIGN AND SETTING: Prospective, observational, single-center study in a mixed medical-surgical ICU. PATIENTS: Adult ICU patients receiving SDD for at least 3 days and being treated with CVVH because of acute renal failure. MEASUREMENTS AND RESULTS: Tobramycin serum concentrations were measured at the 3rd day after start of CVVH and every 3 days thereafter. Detectable serum concentrations of tobramycin were found in 12 (63%) of 19 patients and in 15 (58%) of the 26 samples. With a toxic tobramycin concentration defined as more than 2.0 mg/l, we found one patient with a toxic concentration of 3.0 mg/l. In three other patients tobramycin concentrations of >or=1.0 mg/l were found. CONCLUSIONS: In patients with acute renal failure treated with CVVH, administration of SDD with tobramycin can lead to detectable and potentially toxic serum tobramycin concentration

Impact of digestive and oropharyngeal decontamination on the intestinal microbiota in ICU patients

Selective digestive microbial decontamination (SDD) is hypothesized to benefit patients in intensive care (ICU) by suppressing Gram-negative potential pathogens from the colon without affecting the anaerobic intestinal microbiota. The purpose of this study was to provide more insight to the effects of digestive tract and oropharyngeal decontamination on the intestinal microbiota by means of a prospective clinical trial in which faecal samples were collected from ICU patients for intestinal microbiota analysis. The faecal samples were collected from ICU patients enrolled in a multicentre trial to study the outcome of SDD and selective oral decontamination (SOD) in comparison with standard care (SC). Fluorescent in situ hybridization (FISH) was used to analyze the faecal microbiota. The numbers of bacteria from different bacterial groups were compared between the three regimens. The total counts of bacteria per gram faeces did not differ between regimens. The F. prausnitzii group of bacteria, representing an important group among intestinal microbiota, was significantly reduced in the SDD regimen compared to the SC and SOD. The Enterobacteriaceae were significantly suppressed during SDD compared to both SOD and SC; enterococci increased in SDD compared to both other regimens. The composition of the intestinal microbiota is importantly affected by SDD. The F. prausnitzii group was significantly suppressed during SDD. This group of microbiota is a predominant producer of butyrate, the main energy source for colonocytes. Reduction of this microbiota is an important trade-off while reducing gram-negative bacteria by SDD

All great truths are iconoclastic: selective decontamination of the digestive tract moves from heresy to level 1 truth. Intensive Care Med 29

Abstract Objective: The objective was to compare evidence of the effectiveness, costs and safety of the traditional parenteral antibiotic-only approach against that gathered from 53 randomised trials involving more than 8,500 patients and six meta-analyses on selective decontamination of the digestive tract (SDD) to control infection on the intensive care unit (ICU). Philosophy: Traditionalists believe that all infections are due to breaches of hygiene except those established in the first 2 days, and that all micro-organisms can cause death. In contrast, newer insights show that transmission via the hands of carers are responsible only for infections occurring after one week, and that only a limited range of 15 potential pathogens contribute to mortality. Interventions to prevent ICU infection: The traditional approach is based on hand disinfection aiming at the prevention of transmission of all micro-organisms, to control all infections that occur after 2 days on the ICU. The second feature is the restrictive use of systemic antibiotics, only in cases of microbiologically proven infection. In contrast, SDD aims to control the three types of infection: primary, secondary endogenous and exogenous due to 15 potential pathogens. The classical SDD tetralogy comprises four components: (i) a parenteral antibiotic, cefotaxime, administered for three days to prevent primary endogenous infections typically occurring 'early'; (ii) the oropharyngeal and enteral antimicrobials, polymyxin E, tobramycin and amphotericin B administered in throat and gut throughout the treatment on the ICU to prevent secondary endogenous infections tending to develop 'late'; (iii) a high standard of hygiene to control transmission of potential pathogens; and (iv) surveillance samples of throat and rectum to monitor the efficacy of the treatment. Endpoints: (i) Infectious morbidity; (ii) mortality; (iii) antimicrobial resistance; and (iv) costs. Results: Properly designed trials on hand disinfection have never demonstrated a reduction in either pneumonia and septicaemia, or mortality. Two randomised trials using restrictive antibiotic policies failed to show a survival benefit at 28 days. In both trials the proportion of resistant isolates obtained from the lower ways was >60% despite significantly less use of antibiotics in the test group. A formal cost effectiveness analysis of the traditional antibiotic policies has not been performed. On the other hand, two meta-analyses have shown that SDD reduces the odds ratio for lower airway infections to 0.35 (0.29-0.41) and mortality to 0.80 (0.69-0.93), with a 6% overall mortality reduction from 30% to 24%. No increase in the rate of super infections due to resistant bacteria could be demonstrated over a period of Intensive Care Med (2003) 29:677-690 DOI 10.1007/s00134-003-1722-2 R E V I