[Etiologic diagnosis of severe acute pneumopathies in infants and children]

In infants and children suffering from severe acute lung disease the problem of aetiological diagnosis arises in two sets of circumstances. In cases of diffuse primary pneumonitis, which occurs mainly in immunocompromised subjects, broncho-alveolar lavage is the ideal technique to discover opportunistic infections; besides, the technique is little invasive and well tolerated. It is only when its results are negative that lung biopsy still has a few indications. In hospital-acquired lung diseases occurring in children under mechanical ventilation the results of broncho-alveolar lavage are more difficult to evaluate owing to possible contamination by tracheal organisms. The various ways of solving this problem (bacterial counts, sampling by means of a protected brush operated by remote control) are discussed.