Endoscopically guided cultures in chronic sinusitis.

In chronic sinusitis, culture-directed antibiotics are often recommended as a cornerstone of treatment. The significance of Gram-negative rods (GNRs), coagulase-negative Staphylococci (SCN), and Staphylococcus aureus has been controversial. In an effort to determine host factors which correlate with culture results, 507 endoscopically-guided cultures are reviewed from 265 patients. A history of asthma, allergic rhinitis, prior sinus surgery, and the concurrent use of antibiotics, steroids, and irrigations were some of the host factors compared by X2. The results were compared to a control group of 50 cultures from healthy volunteers. SCN, S. aureus, P. aeruginosa, and Streptococcus were the most common isolates. GNRs were present in 27% of cultures and were more common in patients who had prior sinus surgery or were using irrigations. P. aeruginosa was more common in patients taking systemic steroids. SCN occurred with the same incidence in patients and control subjects but was more prevalent in cultures obtained intraoperatively and in patients taking systemic steroids. No identifiable host factor was associated with S. aureus. S. aureus occurred at similar rates in patients and control subjects but grew heavily in patients and exhibited only light growth in controls. Topical nasal steroids appear to have no statistically significant effect on bacterial cultures. Findings from this study further our understanding of chronic sinusitis and may help guide practitioners in the treatment of this disease.