Rentabilidad microbiológica del lavado broncoalveolar en la Unidad de Endoscopia Respiratoria del Hospital Universitario 12 de Octubre

Introduction

The objectives of this study were to determine the microbiological diagnostic yield of the bronchoalveolar lavage (BAL) and to identify the most frequently isolated microorganisms according to the risk populations.

Material and methods

All the BALs done between January 2008 and December 2009 were studied. The microbiological protocol was carried out for all the BAL samples (bacteria, fungus, mycobacteria, virus and Pneumocystis jiroveci). Social demographic data, priority of the procedure, unit that required the procedure, microbiological results and complications variables were noted. The Chi square statistical test was used, the results being considered as statistically significant when p<0.05.

Results

A total of 244 BALs were done, 46.7% of which were positive (bacteria 15.1%, fungus 16%, mycobacteria 2.5%, virus 5.3% and Pneumocystis jiroveci 7.8%). The population was divided into the following risk subgroups: solid organ transplant, HIV infection or AIDS, diffuse interstitial lung disease with or without immunosuppressant treatment, hematologic diseases, rheumatologic diseases with immunosuppressant treatment, cancer with chemotherapy or radiotherapy. An analysis of BAL microbiological diagnostic yield was done in each group. Those BAL patients with HIV infection or AIDS disease showed a higher frequency of virus, fungus and Pneumocystis jiroveci while the BAL in patients with hematological diseases showed a higher frequency of Pneumocystis jiroveci. No differences were found in the other groups.

Conclusion

Almost half of the BALs carried out showed a final positive microbiological result. The medical background of the patient makes it possible to predict the responsible germ with greater likelihood, especially in HIV positive patients and those with hematological diseases.