Impact of antibiotics on the gut microbiota of critically ill patients.

We evaluated the relationship between the intestinal microbiota composition and clinical outcome in a group of 15 high-risk patients admitted for acute infection and/or surgical/accidental trauma who were treated with systemic antibiotics according to standard intensive care unit (ICU) protocols. There was a high mortality rate amongst these patients, each of whom had a considerable organ failure score at admission, respiratory assistance during the most of their ICU stay and a long length of stay. All of these individuals received sedation and enteral nutrition, and the majority also received insulin, vasoactive drugs and some stress-ulcer prophylaxis agents. The intestinal microbiota composition was assessed using denaturing gradient gel electrophoresis (DGGE), a molecular biology tool used to characterize bacterial ecosystems. As all of the patient subjects were in good health prior to their acute illness and admission to the ICU, the first faecal samples obtained from this group showed a DGGE banding pattern that was similar to that of healthy subjects. After 1 week of critical illness, coupled with intensive care treatment, including antibiotics, a very definite alteration in the overall microbiota composition was evident, as revealed by a reduction in the number of DGGE bands. Further pronounced changes to the DGGE banding profiles could be observed in patients remaining in the ICU for 2 weeks. Moreover, a dominant band, identified by sequencing as highly related to Enterococcus, was detected in the DGGE profile of some of our patient subjects. We also performed real-time PCR and obtained results that were in agreement with our qualitative evaluations using DGGE. The degree of organ failure and ICU mortality was significantly higher in patients for whom a high reduction in microbiota biodiversity was coupled with a massive presence of enterococci. A statistically significant link between these two ecological traits and the use of clindamycin was also found.

Sedation in the critically ill ventilated patient: possible role of enteral drugs.

OBJECTIVE: Sedation by the enteral route is unusual in intensive medicine. We analysed the feasibility/efficacy of long-term enteral sedation in ventilated critically ill patients. DESIGN: Prospective interventional cohort study. SETTING: General ICU. PATIENTS AND PARTICIPANTS: Forty-two patients needing ventilation and sedation for at least 4 days. INTERVENTIONS: At admission, sedation was induced with propofol or midazolam. Enteral hydroxyzine (+/- enteral lorazepam) was added in all patients within the second day. Intravenous drugs were gradually withdrawn, trying to maintain only enteral sedation after the initial 48 h. Analgesia was provided with continuous IV fentanyl. MEASUREMENTS AND RESULTS: Sedation level was assessed evaluating, on a daily basis, patients' compliance to the invasive care and comparing observed vs planned Ramsay scores three times a day. Excluding the first 2 days of patient-stabilisation and fast titration of sedation level, 577 days with ventilatory support were analysed. In 460 days (79.7%) total enteral sedation was given. This percentage rose to 94.2% when the requested Ramsay was 2 (347 days). Daily sedation was judged as adequate in 82.8% of days of total enteral sedation. Thirty-one patients had total enteral as the exclusive route of sedation. CONCLUSIONS: After 24-48 h, enteral sedation may replace, totally/in part, IV sedation in ventilated patients. Total enteral sedation easily fits the target when a Ramsay score 2 is planned. When a deeper sedation is needed, a mixed regimen is effective and lowers IV drug dosages. No side effects were reported.