The effect of negative pressure wound therapy with periodic instillation using antimicrobial solutions on Pseudomonas aeruginosa biofilm on porcine skin explants

Negative pressure wound therapy with instillation (NPWTi) is increasingly used as an adjunct therapy for a wide variety of infected wounds. However, the effect of NPWTi on mature biofilm in wounds has not been determined. This study assessed the effects of NPWTi using saline or various antimicrobial solutions on mature Pseudomonas aeruginosa biofilm using an ex vivo porcine skin explant biofilm model. Treatment consisted of six cycles with 10‐minute exposure to instillation solution followed by 4 hours of negative pressure at −125 mm Hg over a 24‐hour period. NPWTi using saline reduced bacterial levels by 1‐log (logarithmic) of 7‐log total colony‐forming units (CFUs). In contrast, instillation of 1% povidone iodine (2‐log), L‐solution (3‐log), 0·05% chlorhexidine gluconate (3‐log), 0·1% polyhexamethylene biguanide (4‐log), 0·2% polydiallyldimethylammonium chloride (4‐log) and 10% povidone iodine (5‐log), all significantly reduced (P