Prospective Comparative Study of Different Etiologic Diagnostic Methods in Ventilator Associated Pneumonia (VAP)

Brief Summary

Detailed Description

Ventilator associated pneumonia is defined as one that occurs 48-72h after tracheal intubation, is classified into early and late and is responsible for a mortality of 24-50% to almost 70% in some studies. The clinical suspicion of ventilator associated pneumonia is based on the finding of new or progressive pulmonary opacity associated with two or more variables such as: fever, leukocytosis or leukopenia, and purulent pulmonary secretions. Some studies show that the etiologic diagnosis reduces spectrum of antimicrobials and bacterial resistance, reducing hospital stay and time of mechanical ventilation, as well as treatment costs. The collection of material for quantitative culture ensures greater specificity however there is no standard method. The investigator's hypothesis is that collection of material to confirm the etiologic diagnosis of ventilator associated pneumonia, held by bronchoscopic bronchoalveolar lavage, define the etiology in a larger number of patients when compared to the endotracheal aspirate and non-bronchoscopic bronchoalveolar lavage. The primary goal is evaluate and compare the sensitivity and specificity of noninvasive methods (endotracheal aspirate and non-bronchoscopic bronchoalveolar lavage) in comparison with invasive (bronchoscopic bronchoalveolar lavage) regarding the collection of material for etiologic diagnosis. The secondary objectives are determine the prevalence of ventilator associated pneumonia and antimicrobial susceptibility patterns of bacteria isolated, helping to update empirical antibiotic therapy protocols. This is a prospective comparative observational study on etiologic methods of diagnosis. All the patients, with clinical suspicion, will be submitted to collection of tracheal aspirate, bronchoscopic and non-bronchoscopic bronchoalveolar lavage. These procedures are already incorporated in the daily practice of our intensive cara unit and are routinely performed for investigation of patients with compatible framework of ventilator associated pneumonia, as availability of bronchoscopist. Whereas an analysis of variance will be performed to compare the three interventions, with a minimum difference between the treatment means, a power of 0.95 and a significance level of 0.05, with an estimation error of 0.1, will be required a total sample of 72 patients.There will be only one group of 72 patients, in which will be held in all the three samples of the study.

Primary Outcomes

Secondary Outcomes

• Prevalence of ventilator associated pneumonia (cases / time period)(10 months)
• Antimicrobial susceptibility patterns of bacteria isolated(72-96 hours)