Measures to Minimize Antimicrobial Resistance in Intensive Care Unit

Abstract

SUMMARY R esistance is a measure of decreased ability of an antimicrobial agent to kill or inhibit the growth of a microbial organism. In practice, this is determined by testing a patient isolate against an antimicrobial in an invitro assay system. In a patient exposed to an antimicrobial agent, resistant organisms can emerge by selection for and expansion of subpopulations of spontaneously generated, less susceptible mutants of antimicrobial target. The epidemiology of resistance is extremely local. Most outbreaks and clusters involve a few patients in a unit, and the prevalence of resistance is often highest in those units where the most vulnerable patients are congregated and where antibacterial use consequently is heaviest. Successful epidemic strains are critical to the accumulation of many resistances. Common vectors in hospitals are contact with staff members and contact with non-sterile devices, or procedures. Spread in the community is favored by those factors that have aided epidemics throughout history; that is, crowding and travel. Many strains, resistant or otherwise, spread locally, but a few achieve a much wider distribution. The previous use of antimicrobial agents has been identified as an important factor in the emergence of antibiotic resistant bacterial infections in the ICU. Non clinical use of antibiotic. and inhibition of the normal intestinal flora are other contributing factors to the development of resistance. In addition, inappropriate dosing and/or duration of antibiotics as well as increased antibiotic usage contribute directly to the increased prevalence of resistance.