Emergence of panresistant gram negative bacilli has lead to the progressive reintroduction of intravenous colistin. Aim: To describe the clinical experience observed with this compound. Methodology: A retrospective analysis was performed for all treatments lasting > 48 hours. Medical records were analyzed to obtain clinical parameters and microbiological data, evaluate clinical response and evolution until discharge. Main results: 24 treatments lasting > 48 hours were applied between June 2005 and September 2006. Intravenous colistin was indicated to treat cases of ventilator-associated (VA) pneumonia (n = 10; 41.7%), abscess or collections (12.5%), bloodstream infections, non-VA pneumonia or urinary tract infections (4.2% each one, respectively). Treatment was initiated on average at 3.2 days (± 2.85) from diagnosis of infection. All courses were microbiologically-guided, and involved P. aeruginosa or A. baumannii isolates. Susceptibility was evaluated by E-test in 11 isolates (MIC 90 3.6 ”g/mL, range 0.38 to 4 ”g/mL). One isolate was resistant to colistin (9%). A favorable response was observed in 12 treatments (50%) with a relapse in 5 cases (41.7%). Being treated for pneumonia was the only factor associated to failure. (p = 0.04) Eradication was documented in 8 cases (33.3%) and persistence in 11 (45.8%). In 5 cases a microbiological follow-up was not available. Survival at time of discharge was 45.5%. (n = 10) None of the treatment courses was associated with nefrotoxicity. Conclusions: Intravenous colistin is a safe compound useful to treat various nosocomial infections due to pan-resistant gram negative bacilli. Nonetheless, its clinical efficacy is limited, especially among patients treated for nosocomial pneumonia.Key words: colistin, sepsis, Gram negative bacilli, panresistance. Palabras claves: colistĂn, bacilos gramnegativos, infecciones, pan-resistencia.Los datos epidemiolĂłgicos sobre la frecuencia de bacilos gramnegativos multi o pan-resistentes son escasos en el paĂs, debido a que sĂłlo recientemente se ha creado un sistema de vigilancia activo. Se trata, sin embargo, de un hecho progresivo radicado, especialmente, en las unidades de cuidados intensivos de hospitales de la RegiĂłn Metropolitana. En el Hospital ClĂnico de la Universidad de Chile, la frecuencia de aislados de A. baumannii o P. aeruginosa pan-resistentes ha aumentado en forma constante desde el año 2004, motivando la importaciĂłn de colistĂn para el manejo de estas infecciones.ColistĂn endovenoso es un fĂĄrmaco de alto costo, no exento de toxicidad renal y carece de una evaluaciĂłn rigurosa de su eficacia clĂnica. Por ejemplo, el costo diario de tratamiento con este antimicrobiano supera los 60 mil pesos chilenos (aproximadamente 120 U$). Habitualmente, los pacientes son tratados por 10 o mĂĄs dĂas.
IntroducciĂłnas infecciones nosocomiales son un problema frecuente y se asocian a morbilidad, aumento de los costos y letalidad atribuible. EstĂĄn asociadas a microorganismos multi o pan-resistentes que limitan, seriamente, las posibilidades de m...