Detect the clinical causitive pathogen of Ventilator Associated Pneumonia (VAP) patients by the bronchoalveolar lavage (BAL) method.

Any patient admitted into the chosen ICU will be a potential patient for this study. One of the main purposes of this study is to discover the various types of bacteria that cause VAP, and their frequency of occurrence. In order to obtain accurate and applicable results, as many subjects should be tested as possible. Approximately 500 patients will be included in this study.

VAP is defined as any lower respiratory tract infection that developed after 2 day of MV.

The criteria for clinical suspicion of pneumonia are as follows:

Presence of a new or persistent lung opacity on chest radiographs, plus two of the following items:

1. Fever > 38.3ºC or hypothermia < 36ºC;
2. WBC count > 10,000/mm3 or < 5,000/mm3, and/or purulent endoctracheal aspirate;
3. Purulent endotracheal aspirate.

Every patient suspected of having pneumonia will undergo fiberoptic bronchoscopy to obtain samples by means of a bronchoalveolar lavage (BAL). VAP will be diagnosed based on results of BAL where BAL cultures yielding > 104 cfu/ml.

Inclusion:

• Patients hospitalized and mechanically ventilated for more than 48 hours are eligible for the study.
• Fever > 38.3ºC or hypothermia < 36ºC or WBC count > 10,000/mm3.
• Presence of a new or persistent lung opacity on chest radiographs.
• Willing to provide informed legal consent. If the patient is a minor or incapacitated, legal consent may be given by a legal guardian or representative.

Exclustion:

• Patients whose antibiotic strategy had been changed during the 3 days preceding the diagnostic procedure will not be included.