Antimicrobial resistance in the intensive care unit: understanding the problem.

Antimicrobial resistance is a problem that affects healthcare delivery around the globe. Factors associated with antimicrobial resistance include overuse or misuse of antimicrobial agents, immunosuppressed patients, and increased technology. Cellular mechanisms of antimicrobial resistance include the decreased uptake of a drug, efflux of the drug, enzymatic inactivation, and alterations in the antimicrobial target site. New treatment options are currently available for resistant organisms. Therapeutic strategies such as antibiotic control policies and antibiotic "cycling" have been proposed as methods for minimizing the emergence of more resistant organisms. Little evidence is available to indicate that these strategies are effective in limiting the emergence of resistance. Clinicians are urged to be judicious in their use and choice of antimicrobials.