Cefotaxime combined with selective decontamination in long term intensive care unit patients. Virtual absence of emergence of resistance.

Emergence of bacterial resistance to antimicrobial agents was studied during a period of 30 months of continuous use of parenteral cefotaxime combined with oral non-absorbable polymyxin E and tobramycin (selective decontamination) in a surgical intensive care unit (ICU). No increase in drug-resistance micro-organisms was found. Colonisation of the oropharyngeal cavity or intestine or both by strains resistant to polymyxin E occurred in 8% of patients (invariably Proteus and Morganella species). Tobramycin-resistant strains (Escherichia coli, Acinetobacter and Pseudomonas species) were found in 4% of patients. Intestinal colonisation with cefotaxime-resistant bacilli (e.g. Enterobacter, Pseudomonas and Acinetobacter species) occurred in 10% of patients, but in most patients these strains were eliminated by therapy with the topical antibiotics within one week. The control of emergence of resistance has major implications for the antibiotic policy in the ICU: firstly, the number of different antimicrobials used is sharply reduced since the switching of antibiotics to treat suprainfections is seldom necessary; secondly, it is possible to use a third generation cephalosporin such as cefotaxime for systemic prophylaxis, without risk of induction of resistance.