Bacterial resistance and antimicrobial therapy in respiratory medicine andcritical care.

Bacterial resistance and antimicrobial therapy in respiratory medicine and critical care. Nosocomial pneumonia is the leading cause of mortality among the infections produced by multi-resistant microorganisms in intensive car e units (ICU). The solution of this problem created by the colonization and infection of the respiratory tract is beyond respiratory medicine and requ ires a multi-disciplinary approach, involving other nosocomial infections i n the ICU. Up to 80% ICU patents receive antimicrobiotics for severe infect ions or prophylactically, frequently with no clear justification for these treatments. The extended use of antibiotics increases the problem by exerti ng a selective pressure favoring the development of resistant organisms. So me evidences suggest that the infections produced by multi-resistant pathog ens increase the mortality of nosocomial pneumonia. The following mechanism s are responsible for the acquisition of resistance: alteration of bacteria l wall permeability; production of inactivating enzymes, modification of th e target site, or eflux. Resistance is genetically transmitted chromosomica lly or by plasmids. At the present time staphylococci (Staphylococcus aureu s and coagulase-negative staphylococci) and enterococci predominate among t he gram-positives, and non-fermenters (Pseudomonas aeruginosa, Acinetobacte r spp) and some Enterobacteriaceae among the gram-negatives. Antibiotics ar e the main determinants of the problem of resistance but also partially the ir vehicle. The solution of this problem includes infection control, diagno sis and adequate therapy (sufficient doses chosen according to the case and based on predesigned antibiotic politics). These antibiotic politics imply a rational use, reconsideration of the initial scheme according to microbi ologic results, limited use of combination antimicrobial strategies, restri cted list of drugs, rotation and correct use of prophylaxis.