Bacteriologic findings from the nose, ethmoid, and bloodstream during endoscopic surgery for chronic rhinosinusitis: implications for antibiotic therapy.

This study addresses the bacterial flora of chronic rhinosinusitis at the time of endoscopic sinus surgery. We used the consensus definition of chronic rhinosinusitis as the presence of paranasal sinus inflammation present for greater than 12 weeks. In our patient study group, all cases of chronic rhinosinusitis had failed to respond to antibiotic therapy and had not been treated previously with surgery. By microscopic examination, chronic inflammatory changes were confirmed in the resected sinus lining of all study patients. Intraoperative cultures were obtained from the nasal vestibule, the middle meatus, ethmoid lining, and peripheral blood during and after the endoscopic procedure. We found approximately 30% of the patients with sterile sinuses, 50% with coagulase-negative staphylococci, and the remainder with a mixed group of "nonpathogenic" organisms. Anaerobes were conspicuously rare. The blood cultures were positive in 7% of cases and were consistent with an organism of the operative site. This is the first time bacteremia has been reported in association with endoscopic sinus surgery. The results suggest that chronic rhinosinusitis is not a bacterial disease, but rather the result of chronic inflammation produced by a previous acute inflammation. The incidence of positive blood cultures, while relatively low and cleared quickly, should alert the physician for the possible need for prophylactic antibiotics in patients with cardiac, prosthetic, or systemic conditions that could lead to metastatic infection.