RISK-FACTORS FOR PNEUMONIA, AND COLONIZATION OF RESPIRATORY-TRACT ANDSTOMACH IN MECHANICALLY VENTILATED ICU PATIENTS

Risk factors for the development of ventilator-associated pneumonia (V AP) and colonization of the respiratory tract and stomach with enteric gram-negative bacteria (EGB) and Pseudomonadaceae were determined in 141 ventilated patients using univariate analysis and the Cox proporti onal hazards model. VAP was caused by EGB in 14 patients (10%), and by Pseudomonadaceae in 19 patients (13%). The duration of ventilation wa s a significant risk factor for VAP caused by EGB and Pseudomonadaceae , and for acquired colonization in oropharynx, stomach, and trachea wi th these species. Of 20 other variables, oropharyngeal colonization wi th EGB on admission (hazard ratio [HR] = 4.5) and an infection on admi ssion (HR = 2.7) were selected as risk factors for VAP caused by EGB. Acquired colonization with Pseudomonadaceae in oropharynx (HR = 5.0) w as the most important risk factor for VAP caused by these species. Gas tric colonization with EGB or Pseudomonadaceae were no risk factors fo r VAP. For acquired oropharyngeal colonization with EGB only the durat ion of ventilation was a risk factor, whereas preceding colonization o f the trachea with Pseudomonodaceae and duration of ventilation were r isk factors for acquired oropharyngeal colonization with these species . In the Cox model, only the duration of ventilation was significantly related to acquired gastric colonization with EGB. Preceding coloniza tion of the orophayrnx and of the trachea with Pseudomonadaceae were r isk factors for acquired colonization with these species in the stomac h. Twelve patients with VAP (46%) and 38 without VAP (33%) died (p = 0 .21). In conclusion, duration of ventilation and colonization of the u pper respiratory tract are the most important risk factors for VAP cau sed by EGB or Pseudomonadaceae.