Ventilator-associated pneumonia pathogens

List the common pathogens that cause community-acquired pneumonia, aspiration pneumonia, ventilator-associated pneumonia (early versus late onset), and health care-associated pneumonia. 

Selective decontamination of the gastrointestinal tract was conceptualised with a view to preventing nosocomial infection (mainly due to enterobacteriaciae), specifically ventilator-associated pneumonia, in intensive care units. Protocols typically included the prescription of an intravenous cephalosporin with good activity against such Gram-negative pathogens (e.g. cefotaxime) with co-prescribed, poorly... 

Ventilation-associated pneumonia continues to be a common and costly complication of critical care [13 ]. It develops after aspiration of bacteria from the oropharynx into the lung and subsequent failure of host defences to clear the bacteria. Dental plaque biofilms are colonized by respiratory pathogens in ventilated patients. Thus, improvements in oral hygiene in these patients may prevent pneumonia. In a randomized study of the minimum frequency of apphcation of chlorhexidine gluconate necessary to reduce oral colonization by pathogens in 175 intubated patients, decontamination of the oral cavity did not reduce the total amount of potential respiratory pathogens. However the chlorhexidine oral rinse did reduce the number of Staphylococcus aureus organisms in the dental... 

Table 5 Pathogens in Ventilator-Associated Pneumonia from NNIS Hospitals, January 1996-April 1997...

Similar to cases with P. aeruginosa, nosocomial ventilator-associated pneumonia caused by Acinetobacter is associated with a high mortality rate. In a study of 48 patients (70), pneumonia caused by these two organisms have a mortality rate of 71.4% compared to other pathogens (40.7%), with the observation that this rate was in excess of that observed for the underlying disease however, the impact of antimicrobial therapy was not discussed. 

Empirical selection of antimicrobial therapy for ventilator-associated, health care-associated, and hospital-associated pneumonia is broad spectrum however, once culture and susceptibility information are available, the therapy should be narrowed (deescalation) to cover the identified pathogen(s). 

Health care-associated, ventilator-associated, or nosocomial pneumonia (Late onset and/or MDR pathogen risk factors) Antipseudomonal penicillin OR Antipseudomonal cephalosporin OR Antipseudomonal carbapenem plus Aminoglycoside OR Antipseudomonal fluoroquinolone plus Vancomycin or linezolid... 

Community-acquired pneumonia Health care-associated, ventilator-asociated, or nosocomial pneumonia (Early onset no risk factors for MDR pathogens) Third-generation cephalosporin plus a macrolide or doxycycline Third-generation cephalosporin OR Fluoroquinolone OR Ampicillin-sulbactam OR Ertapenem... 

The antipseudomonal penicillins have comparable spectra of activity against many gram-positive and gram-negative pathogens, including most anaerobes. Mezlocillin, piperacillin, and ticarcillin have similar clinical outcomes in patients with known or suspected P. aeruginosa infections. Antipseudomonal penicillins are used to treat pneumonias associated with cystic fibrosis or mechanical ventilation. 

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