The effect of colloidal silver in chronic rhinosinusitis

INTERVENTION: Patients in the treatment group will receive 20 pre‐prepared sinonasal flush bottles containing 240 mL of colloidal silver solution at a concentration of 30 ppm (equivalent to approximately 0.03 g/L or 0.278 nM) to use twice daily for 10 days. They will also receive 20 encapsulated dextrose tablets and will be asked to take these orally twice daily for 10 days. Patients will be required to bring back the empty sinonasal rinse bottles to demonstrate they are compliant with the medication regimen. If patients culture a positive swab at 10 days, they will be immediately crossed over to the control group, and receive 20 pre‐prepared sinonasal flush bottles containing an isotonic saline solution, to be used for a further 10 days. They will also receive 20 encapsulated antibiotic tablets (either 1g amoxicillin/clavulanic acid or 500mg clarithromycin) to take orally twice daily for 10 days. Antibiotic use will be pre‐prescribed by the treating surgeon before being sent to the pharmacy (who will be responsible for the blinding), and will be based on sinonasal swab results and will be an antibiotic that is sensitive to the organism cultured. CONDITION: Chronic rhinosinusitis PRIMARY OUTCOME: Presence/absence of growth on culture from sinonasal swab. SECONDARY OUTCOME: Change in endoscopic sinus score (Modified Lund‐Kennedy score). Change in subjective symptom questionnaires (Visual Analogue Scale & SNOT‐22). INCLUSION CRITERIA: Diagnosis of chronic rhinosinusitis. Undergone previous endoscopic sinus surgery for chronic rhinosinusitis at least 3 months ago or later. Active bacterial infection proved by positive sinonasal swab.