Inadequate therapy and antibiotic resistance. Risk factors for mortality in the intensive care unit.

BACKGROUND: The impact of nosocomial infections and multidrug resistance on mortality is a topic of considerable controversy. METHODS: A prospective, nested case control study was conducted in four intensive care units (ICUs) in Mexico to measure the impact of antibiotic resistance on and identify the main risk factors for mortality in critically ill patients with nosocomial infections. RESULTS: One hundred thirteen patients developed 119 nosocomial infections. Multivariate analysis identified two variables that were significantly and independently associated with mortality: ventilator-associated pneumonia (p = 0.0041, odds ratio [OR] = 7.7) and inadequate antibiotic treatment (p <0.0001, OR = 70.5). Although antibiotic resistance in Gram-negative rods was not an independent risk factor for mortality, there was a strong association between antibiotic resistance and inadequate treatment (chi2 for linear trend = 29.3, p <0.00001). For patients with ventilator-associated pneumonia, predicted mortality calculated by APACHE II score was 23% compared to an observed mortality of 71%. CONCLUSIONS: In this study the major risk factors for mortality were inadequate antibiotic treatment and development of ventilator-associated pneumonia. Multidrug resistance significantly increased the probability of receiving inadequate antibiotic treatment. The striking differences between observed and predicted mortality in these four ICUs indicate the need for further research and a reassessment of the current programs for prevention and control of nosocomial infections in Mexico.

Epidemia de neumonía asociada a ventilación mecánica en Mérida, Yucatán / An aoutbreak of ventilator-associated pneumonia in Merida, Yucatan

Objetivo. Determinar las principales características epidemiológicas, clínica y microbiológicas de una epidemia de neumonía asociada a ventilación mecánica en una unidad de cuidados intensivos en Mérida, Yucatán. Material y métodos. Se diseño un estudio prospectivo y observacional de 11 meses para determinar incidencia, mortalidad, reservorios potenciales, agentes etiológicos y sus patrones de sensibilidad antimicrobiana. Resultados. La incidencia de neumonía asociada a ventilador fue de 74 por ciento. La mortalidad cruda fue de 88 por ciento, comparada con una mortalidad esperada de 19.5 por ciento. Se aislaron bacteria gramnegativas en 98 por ciento de los cutlivos, de las cuales 46 por ciento fueron sensibles a cefalosporinas de tercera generación, 59 por ciento a cefalosporinas de cuarta generación, 70 por ciento a ciprofloxacina y 100 por ciento a imipenem. Se aislaron klebsiella pneumoniae y pseudomonas aeroginosa de algunos circuitos del ventilador y el lavado. Conclusiones. La elevada incidencia de neumonía y la mortalidad asociada en esta unidad de cuidados intensivos se pueden atribuir a la falta de medidas de control de infecciones y a una elevada prevalencia de gérmenes multirresistentes que se relacionan con el uso desmesurado e irracional de antibióticos