Changes in Antibiotic Resistance in Tracheal Aspirates Following Selective Decontamination of the Digestive Tract
| Autor: | C. Busse, R. Rüchel, H. Burchardi, M. Sydow, W. Seyde, T. A. Crozier |
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| Rok vydání: | 1989 |
| Předmět: |
Minimum bactericidal concentration
Cefotaxime biology business.industry medicine.drug_class Antibiotics medicine.disease biology.organism_classification Intensive care unit Microbiology law.invention Pneumonia Antibiotic resistance medicine.anatomical_structure law Staphylococcus epidermidis medicine business medicine.drug Respiratory tract |
| Zdroj: | Update in Intensive Care and Emergency Medicine ISBN: 9783540510413 |
| Popis: | Colonization of the oropharynx and gastrointestinal tract with gram-negative bacilli and Candida increases the risk of pulmonary infections, especially during intubation. To avoid this we began in 1987 to selectively decontaminate the digestive tract of all long term (>3 days) ventilated patients with non-absorbable antibiotics, as described by Stoutenbeek et alp]. All intubated patients without an infection upon admission also received prophylactic systemic antibiotic therapy with cefotaxime to prevent early pneumonia until SDD was established. Patients with an established infection upon admission were given a broad-spectrum systemic antibiotic cornbination until the causative microorganism was identified. We preferred systemic antibiotics with minimal effects on the endogenous flora (predominantly anaerobes). We compared the positive bacteriological findings (microorganisms and antibiotic resistance) of all tracheal aspirates of patients receiving SDD from February 1987 to January 1988 with those found in patients 12 months before initiation of the SDD regimen (2/86–1/87), when antibiotics were given only in cases of established infections. There were 973 isolates in 149 patients before SDD, and 541 isolates in 158 patients under SDD. Both relative and absolute numbers of gram-negative isolates were significantly reduced by the SDD regimen. The total number of gram-positive isolates increased slightly due to selection of Staphylococcus epidermidis. The antibiotics tested were those which are standardly used in our intensive care unit. Antibiotic resistance was tested by a disc-diffusion procedure and defined by the diameter of growth inhibition. The pattern of antibiotic resistance did not change during the observation period: multi-drug-resistant strains did not emerge. On the contrary, we observed a slight tendency towards greater sensitivity in some isolated gram-negative strains to the antibiotics given systemically. This may be because the intestinal lumen is probably the main site for selection of resistant strains during systemic antibiotic therapy, since effective antibiotic concentrations are usually not reached there. SDD effectively eradicates all gram-negative intestinal microorganisms since antibiotic concentrations an order of magnitude higher than minimal bactericidal concentrations are achieved. We observed a higher incidence of S. epidermidis isolates in tracheal aspirates without evidence of a respiratory tract infection. However, patients highly colonized with S. epidermidis might be at higher risk of wound infections and so-called plastic infections. Also plasmid-mediated resistance could possibly be transferred from S. epidermidis to S. aureus. These facts show that SDD should not be employed indiscriminately or without bacteriological surveillance. |
| Databáze: | OpenAIRE |
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