Respiratory microbiology patterns within the first 24 h of ARDS diagnosis: influence on outcome

Airway colonization and infection are frequent complications during the course of ARDS. The impact on outcomes of microbiological patterns recovered within the first 24 h after diagnosis has not been evaluated.

To describe the incidence and patterns of bronchial colonization and lung infection within the first 24 h of ARDS diagnosis and to evaluate the influence on ICU outcomes.

Prospective study of ARDS patients evaluated within 24 h of diagnosis. Patients were studied with tracheobronchial aspirate and right and left bronchoscopic protected specimen brush. All samples were cultured quantitatively.

Fifty-five consecutive patients were included. Twelve patients (22%) were clinically suspected of having nosocomial pneumonia (NP), which was confirmed microbiologically in 7 patients, a frequency of 13%. In those patients without suspected pneumonia, we also found potentially pathogenic microorganisms (PPMs) and potentially drug-resistant microorganisms (PDRMs) in 36% and 31%, respectively. Mortality was not significantly higher in those patients with recovery of a PPM (87% vs 73%, p = 0.31), PDRM (89% vs 74%, p = 0.18), or with NP (79% vs 85%, p = 1.0).

There is a strikingly high rate of PPM recovery in early ARDS. However, neither isolation of pathogenic microorganisms nor the confirmation of NP could be associated with an increased mortality.