[Concordance between two methods of bronchoalveolar lavage for the microbiological diagnosis of pneumonia in mechanically ventilated patients].
BACKGROUND
Microbiological diagnosis of pneumonia allows the optimal use of antibiotics in mechanically ventilated patients. That is why samples of bronchoscopic bronchoalveolar lavage had been quantitatively cultivated, but this procedure is not always possible.


OBJECTIVE
To evaluate the microbiological concordance between respiratory samples obtained by non-bronchoscopic protected bronchoalveolar lavage compared to the bronchoscopic ones, and to find out whether concordance was affected by previous use of antibiotics or the time of pneumonia onset.


METHODS
Prospective study conducted at Hospital Universitario San Vicente de Paúl, in 38 patients with suspected pneumonia in mechanical ventilation. Bronchoalveolar lavage specimens were taken by two methods, the traditional one and non-bronchoscopic bronchoalveolar lavage, using a telescoping preformed tip catheter (Balcath). All samples were processed using conventional microbiologic protocols.


RESULTS
Considering flexible bronchoscopy with bronchoalveolar lavage as the gold standard, cultures allowed the identification of at least one respiratory pathogen in 60.5% of cases. Diagnostic agreement was achieved in 82% of patients and 79% of microbiologic isolates. Using the Cohen's kappa coefficient, general concordance between both methods was 0.76 [0.60-0.93]; but in those who received previously antibiotics was 0.26 [0.05-0.48], versus 1.0 in those who did not (p<0.0001). Concordance did not differ significantly when cases of early or late pneumonia were compared.


CONCLUSIONS
Concordance between non-bronchoscopic and bronchoscopic bronchoalveolar lavage is good in mechanically ventilated patients with pneumonia. However, the use of antibiotics previously, but not the time of pneumonia presentation, significantly decreases that concordance.
Vélez
Lázaro Agustín
LA
Grupo Investigador de Problemas en Enfermedades Infecciosas, Universidad de Antioquia, Medellín, Colombia. clamona@une.net.co
Loaiza
Natalia
N
Gaviria
Lina María
LM
Maya
María Angélica
MA
Rueda
Zulma Vanessa
ZV
Correa
Luz Teresita
LT
Ortega
Jorge
J
Ortega
Héctor
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D018893:Bronchoalveolar Lavage / Q000379:methods*; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology*; D001999:Bronchoscopy / Q000379:methods; D003428:Cross Infection / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology / Q000382:microbiology*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012121:Respiration, Artificial / Q000009:adverse effects; D055815:Young Adult
D000900:Anti-Bacterial Agents