Utilidad del estudio de la actividad antibiótica por bioensayo en el manejo de los derrames pleurales

Abstract

ObjectiveThe aim of this study was to determine the presence of antibiotic activity in the pleural fluid samples submitted to the laboratory for study, and to assess its possible influence on the clinical management of patients. Material and methodsAn observational and prognostic study that included 81 samples of pleural fluid sent to the Biochemistry Department of Valme University Hospital, Seville, Spain.The study of antibiotic activity was performed by bioassay based on the recommendations of the Pneumonia Aetiology Research for Child Health project.All samples were subjected to a biochemical, cytological, and bacteriological study based on conventional techniques.In addition, previous use of antibiotics was evaluated based on what was recorded in the medical records. ResultsBased on the medical records, it was observed that 26 (32.1%) of the 81 fluids studied had previous use of antibiotics, with 23 (28.4%) showing antibiotic activity by bioassay.Antibiotic activity was detected in 15 (62.5%) of the exudates and in 8 (19%) of the transudates, with a median inhibition zone of 17mm (range: 11-22mm).In the 23 fluids in which antibiotic activity was detected, all had negative cultures. ConclusionsThe results of this study demonstrate a high percentage of previous use of antibiotics prior to culture (32.1%). The evaluation of the antibacterial activity by bioassay in the pleural fluid parallel to bacteriological culture could help in the treatment approach, using the biochemical and cytological parameters to assess its suitability.