[Routes of endotracheal colonization in patients with mechanical ventilation]

We prospectively evaluated the frequency and route of endotracheal colonization in intubated children in order to know what microorganisms, either by primary infection or through previous colonization of oropharynx and/or stomach and progression towards the lower respiratory tract, are responsible for these infections.

Oropharyngeal, tracheal and gastric samples of 43 patients were collected for culture at the moment of intubation and at 24-h intervals for 4 days. The colonization route for each endotracheal microorganism was classified depending on the initial isolation site. Isolated microorganisms were considered as belonging to the same strain if the biochemical pattern and antibiogram were identical.

Of the patients studied, 84% presented positive cultures the first day. Tracheal colonization was detected at day 1 in 22 patients (51%) and in 35 (82%) at the end of the study. A colonization sequence was seen in 18 patients (41%). The microorganisms most frequently isolated were S. aureus, P. aeuruginosa and C. albicans.

The mechanisms of tracheal colonization in intubated children is similar to adults. Oropharynx colonization is the key antecedent. Prophylaxis measures should avoid the proliferation at the oropharyngeal and/or gastric level.