Ventilator-associated pneumonia and atelectasis: evaluation through bronchoalveolar lavage fluid analysis.
OBJECTIVE
Surfactant offers protection against alveolar collapse and contributes to the local defense mechanism, but it is unclear if surfactant alterations have a role in the development of atelectasis or ventilator-associated pneumonia (VAP). The present study was undertaken to monitor surfactant, as well as biochemical BAL fluid alterations, during the course of VAP and atelectasis in mechanically ventilated patients without primary cardiopulmonary disease, to elucidate the pathogenesis and to differentiate these two entities. DESIGN. Prospective controlled study.


METHODS
14-bed general ICU of a 750-bed University Hospital.


METHODS
Sixty-one ventilated patients, without primary cardiopulmonary disease-normal initial chest X-ray, satisfactory oxygenation (PaO(2)/FiO(2)>300 mmHg), and expected time of ventilation exceeding 2 weeks-were initially enrolled. Twelve of them developed VAP and eight lobar or segmental atelectasis during the 2-week study period.


METHODS
An initial BAL was performed in all patients within 48 h from admission. Patients who developed VAP or atelectasis were subjected to a second and third BAL during and after the resolution of VAP or atelectasis, respectively.


RESULTS
VAP and atelectasis resulted in a significant increase of total protein and markers of inflammation, such as PAF and neutrophils, which partially remitted after their resolution. Large surfactant aggregates, which contribute to surface tension decrease, were significantly reduced during both entities and remained low even after their resolution.


CONCLUSIONS
BAL alterations during VAP and atelectasis suggest increased alveolar-capillary permeability, severe surfactant abnormalities, and signs of local inflammatory reaction. These alterations are associated with the observed deteriorated gas exchange and lung mechanics and could predispose to further lung injury in ventilated patients.
Nakos
G
G
Intensive Care Unit Department, University Hospital of Ioannina, University Street, 45500, Ioannina, Greece. gnakos@cc.uoi.gr
Tsangaris
H
H
Liokatis
S
S
Kitsiouli
E
E
Lekka
M E
ME
D000704:Analysis of Variance; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology*; D001999:Bronchoscopy; D005260:Female; D006801:Humans; D008297:Male; D011014:Pneumonia / Q000150:complications / Q000209:etiology* / Q000382:microbiology; D011446:Prospective Studies; D001261:Pulmonary Atelectasis / Q000150:complications / Q000209:etiology*; D011663:Pulmonary Surfactants; D012121:Respiration, Artificial / Q000009:adverse effects*; D018709:Statistics, Nonparametric
D011663:Pulmonary Surfactants