Ventilator-associated sinusitis - Microbiological results of sinus aspirates in patients on antibiotics

Background: The efficacy of systemic antibiotics on the treatment of ventil ator-associated infectious maxillary sinusitis (VAIMS) Is debated. The obje ctive of this study was to determine die etiologic diagnosis of VAIMS in pa tients receiving antibiotics. Methods: Patients mechanically ventilated for more than or equal to 72 h, w ho had persistent fever while on antibiotics for more than or equal to 48 h , underwent computed tomography scan followed by transnasal puncture of inv olved maxillary sinuses. VAIMS was defined as follows: fever greater than o r equal to 38 degreesC, radiographic signs (air fluid level or opacificatio n of maxillary sinuses on computed tomography scan), and a quantitative cul ture of sinus aspirate yielding more than or equal to 10(3) colony-forming units/ml. Results: Twenty-four patients had radiographic signs of sinusitis. The mean +/- SD prior durations of mechanical ventilation and antibiotic exposure w ere 9.5 +/- 4.7 days and 6 +/- 4 days, respectively. six unilateral and nin e bilateral VAIMS were diagnosed in 15 patients. The median number of etiol ogic organisms per patient was two (range, one to four). The bacteriologic cultures yielded gram-positive bacteria(n = 21), gram-negative bacteria (n = 22), and yeasts (n = 5). Forty percent of causative agents were susceptib le to the antibiotics prescribed. Seven patients with VAIMS developed 10 co ncomitant infections: ventilator-associated pneumonia (n = 5), urinary trac t infection (n = 3), catheter Infections (n = 2), In all cases of ventilato r associated pneumonia, the implicated agents were the causative agents of VAIMS. Conclusion: In VAIMS patients on antibiotics, quantitative cultures of sinu s aspirates may contribute to establish the diagnosis. The frequent recover y of microorganisms susceptible to the antimicrobial treatment administered suggests that therapy of VAIMS with systemic antibiotics map not be suffic ient.