الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Pneumonia is the most common nosocomial infection reported among mechanically ventilated patients (Kollef, et al., 1995). The estimated prevalence of ventilator-associated pneumonia within the ICU setting ranges from 10% to 65% with high morbidity in most of the reported studies (Bowton, 1999). Despite remarkable progress in our understanding of V AP over the past decade, controversy persists over the optimal method of diagnosis. Accurate diagnosis is critical for identifying specific etiologic agents, for implementing appropriate therapy, and for prevention strategies (Ibrahim, et al., 2001b). Currently, there is no well¬accepted ”gold standard” for diagnosis, but, rather, there is a variety of diagnostic procedures with variable sensitivities and specificities (Carven, 2000). The treatment of ventilator-associated pneumonia consists of establishing the etiological agent of infection and providing an adequate antimicrobial regimen to allow resolution of the infection by the host (Wunderink, 1997). Unfortunately, increasing antibiotic resistance among the bacterial pathogens associated with ventilator-associated pneumonia makes the treatment of this infection with an adequate antimicrobial regimen problematic (Ibrahim, et al., 2001 b). Effective host defense against bacterial infection is dependent on the activation and recruitment of phagocytic cells. The initiation, maintenance, and resolution of this inflammatory response in the setting of bacterial pneumonia are dependent on the expression of cytokines (Nelson, 2001).