The Turkish Journal of Pediatrics 2006 , Vol 48 , Num 3
Nonbronchoscopic bronchoalveolar lavage for diagnosing ventilator-associated pneumonia in newborns
1Departments of Pediatrics, Uludağ University Faculty of Medicine, Bursa, Turkey
2Departments of Infectious Diseases and Microbiology, Uludağ University Faculty of Medicine, Bursa, Turkey
Köksal N, Hacımustafaoğlu M, Çelebi S, Özakın C. Nonbronchoscopic bronchoalveolar lavage for diagnosing ventilator-associated pneumonia in newborns. Turk J Pediatr 2006; 48: 213-220.

The appropriate treatment of ventilator-associated pneumonia (VAP) must be based on accurate diagnosis, which can be done by microbiological examination of the samples obtained from the respiratory tract by nonbronchoscopic bronchoalveolar lavages (NB-BAL).

This study was designed to determine the effectiveness of NB-BAL in diagnosing VAP in newborns.

Two hundred and seven NB-BAL samples were obtained from 145 intubated neonates for microbiologic and cytologic evaluation of the distal airway. The NB-BAL samples were processed for microscopic quantification of the polymorphonuclear cells (PMN) containing intracellular bacteria (ICB) and quantitative culture (positive threshold, 105 cfu/ml). VAP was defined as a new, progressive, or persistent (>24 hrs) infiltrate on the chest radiograph, with two or more of the following criteria: a) macroscopically purulent tracheal secretions, b) fever or hypothermia, c) leukocytosis or leukopenia, and d) worsening of respiratory status with a Pa O2/F IO2 ratio of <240. Colonization was defined as mechanical ventilation for more than seven days, no signs of infection, and isolation of the same bacteria species in two previously obtained NB-BAL samples.

Of the 145 neonates, 40 (27.5%) were infected and 12 (8.3%) were colonized. Forty-four patients (30%) developed VAP according to diagnostic categories based on clinical and radiologic criteria. Forty newborns with VAP (90%) had positive NB-BAL culture. The sensitivity, specificity, and positive and negative predictive values of NB-BAL fluid culture for VAP diagnosis were 90%, 90%, 70%, and 97%, respectively. The percentage of ICB was significantly higher in newborns with VAP. The presence of ICB in 2% or more on Giemsastained smears corresponded to a sensitivity of 94%, specificity of 83%, positive predictive value of 94%, and negative predictive value of 83%. The sensitivity and specificity of combination of ICB and NB-BAL quantitative culture in diagnostic samples were 94% and 90%, respectively. The positive and negative predictive values were 71% and 98%.

In our study, the presence of leukocytes in the NB-BAL fluid smear of infants with VAP was higher than that of the colonized babies (84%, 26%). This difference was statistically significant (p<0.0001). The sensitivity and specificity of PMNs in NB-BAL fluid for the diagnosis were 86% and 75%, respectively, and the positive and negative predictive values were 89% and 69%.

We conclude that NB-BAL lavage is well tolerated and clinically useful in mechanically ventilated newborns. These results suggest that NB-BAL fluid microscopic examination and cultures can offer a sensitive and specific means to diagnose VAP in newborns and may provide relevant information about the causative pathogens. Keywords : nonbronchoscopic bronchoalveolar lavage, ventilator-associated pneumonia, newborn, sepsis, mechanical ventilation, premature

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