Comparison of endoscopically-guided swab vs aspirate culture techniques in post-endoscopic sinus surgery patients: blinded, prospective analysis.

BACKGROUND

Culture-directed antibiotic therapy remains imperative in the management paradigm of chronic rhinosinusitis (CRS). The objective of this study was to conduct a prospective, blinded comparison of endoscopically-guided swab and aspirate cultures from the same sinonasal site in patients presenting with acute infectious exacerbations post-sinus surgery.

METHODS

Forty-nine CRS patients were prospectively enrolled in a tertiary care rhinology clinic. At the conclusion of the study, all cultures were unblinded to determine mean culture yield, most common pathogens, potential contaminants, and therapeutic correlation.

RESULTS

The mean patient age was 49 years and 40.8% were males. All patients had evidence of symptomatic exacerbation with purulence on endoscopy at the time of presentation. There was a mean of 1.367 pathogens assayed per aspirate culture vs a mean of 1.102 per swab culture (p = 0.0032). The prevalence of Pseudomonas aeruginosa was 42% for aspirate vs 30% for swab cultures, respectively. The prevalence of Staphylococcus aureus was 49% for suction cultures vs 45% for swab cultures. There were 9 and 11 likely contaminants using aspirate and swab cultures, respectively. Therapeutic correlation was strong in 67%, moderate in 18%, and weak in 14% of patients.

CONCLUSION

This prospective analysis demonstrated higher culture yield, particularly with Pseudomonas, with aspirate vs swab cultures in postoperative patients. There is a strong clinical correlation between the 2 methods, and both aspirate and swab techniques serve as acceptable alternatives for endoscopic-guided cultures in patients with post-functional endoscopic sinus surgery infectious exacerbations.