Traqueobronquitis Asociada al Ventilador (TAV), Implicancias del Diagnóstico Clínico y Microbiológico en una Cohorte de Pacientes en Ventilación Mecánica

the ventilator associated tracheobronchitis (vat) is a process between airway colonization and ventilator-associated pneumonia (vap). the antimicrobial therapy of vat would reduce the incidence of vap and its consequences. methods: daily follow up and twice a week routine quantitative culture of endotracheal aspirates (ceta) up to weaning were performed in 323 mechanically ventilated patients. when a lower respiratory tract infection was suspected (2/3 clinical criteria), if a new radiographic infíltrate was present, vap was diagnosed and a bronchoalveolar lavage (bal) culture was performed; if a radiographic infiltrate was absent, vat was diagnosed. the bacteriological criteria for diagnosis were a bal culture positive (≥ 104 colony forming units - cfu/ml) for vap and a ceta positive culture (low count from ≥ 103 to < 106 cfu/ ml and high count ≥ 106 ufc/ml) for vat. results: in 443 of 2,309 radiographs an infiltrate was absent or was diffuse and stable; 92 of them met diagnostic clinical criteria for vat. in 13 (12 with ceta culture ≥ 106 cfu/ml), a vap episode happened during the following 3 days (12 with bal culture ≥ 104 cfu/ml). in 11/15 (73.3%) vap cases, the isolated pathogens were the same that had been present in the preceding vat episode. on the other side, ten episodes of vat were diagnosed during the 7 days after the vap. only 4/12 (33.3%) isolated pathogens were the same than those isolated in the vat preceding the vap, p=0.045. seventy vats had not any temporal relationship with episodes of vap. discusion: this study suggests that antimicrobial therapy could prevent a vap in 14% of the tav cases. therefore, exposure to antibiotics was unnecessary in 86% of cases. this finding could represent a severe limitation to the recommendation of treating tavs with antibiotics to prevent vaps.