Common Wound Irrigation Solutions Produce Different Responses in Infected vs Sterile Host Tissue: Murine Air Pouch Infection Model

BACKGROUND: Despite desirable microbicidal actions of irrigation solutions in surgical site infection treatment, several studies demonstrate potential cytotoxic effects. This study investigated tissue damage caused by irrigation solutions in the presence or absence of infection. METHODS: Air pouches were created in 60 mice and evenly divided into 2 groups as infected with Staphylococcus aureus and control. Groups were then subdivided both by type of solution and by timing after irrigation. Solutions included control (0.9% saline), bacitracin (33 IU/ml), 0.2% sodium oxychlorosene, 0.05% chlorhexidine gluconate, and 0.013% benzalkonium chloride. RESULTS: Inflammation decreased in infected pouches compared to the sterile ones for all solutions except bacitracin on day 0 and for all on day 7. On day 0, infected pouches had increased necrosis with bacitracin (P = .006), chlorhexidine gluconate (P = .18), and benzalkonium chloride (P = .07); on day 7, there was decreased necrosis in infected pouches for all solutions (P < .05) except for sodium oxychlorosene (P = .18). Edema decreased in infected pouches on day 0 for all solutions. On day 7, infected pouches had decreased edema with 0.9% saline, bacitracin, and benzalkonium chloride (P < .05) and increased edema with chlorhexidine gluconate (P < .05) and sodium oxychlorosene (P = .069). Bacitracin allowed for more bacteria growth than sodium oxychlorosene (P = .024), chlorhexidine gluconate (P = .025), and benzalkonium chloride (P = .025). CONCLUSIONS: The presence of bacteria led to less immediate tissue inflammation and edema, while tissue necrosis varied over time. The current study may guide surgeons on which solution to use and whether to irrigate a possibly sterile wound or joint.