Successful and safe use of 2 min cold atmospheric argon plasma in chronic wounds: results of a randomized controlled trial

Background The development of antibiotic resistance by microorganisms is an increasing problem in medicine. In chronic wounds, bacterial colonization is associated with impaired healing. Cold atmospheric plasma is an innovative promising tool to deal with these problems. Objectives The 5-min argon plasma treatment has already demonstrated efficacy in reducing bacterial numbers in chronic infected wounds in vivo. In this study we investigated a 2-min plasma treatment with the same device and the next-generation device, to assess safety and reduction in bacterial load, regardless of the kind of bacteria and their resistance level in chronic wounds. Methods Twenty-four patients with chronic infected wounds were treated in a prospective randomized controlled phase II study with 2 min of cold atmospheric argon plasma every day: 14 with MicroPlaSter alpha device, 10 with MicroPlaSter beta device (next-generation device) in addition to standard wound care. The patient acted as his/her own control. Bacterial species were detected by standard bacterial swabs and bacterial load by semiquantitative count on nitrocellulose filters. The plasma settings were the same as in the previous phase II study in which wounds were exposed for 5 min to argon plasma. Results Analysis of 70 treatments in 14 patients with the MicroPlaSter alpha device revealed a significant (40%, P < 0.016) reduction in bacterial load in plasma-treated wounds, regardless of the species of bacteria. Analysis of 137 treatments in 10 patients with the MicroPlaSter beta device showed a highly significant reduction (23.5%, P < 0.008) in bacterial load. No side-effects occurred and the treatment was well tolerated. Conclusions A 2-min treatment with either of two cold atmospheric argon plasma devices is a safe, painless and effective technique to decrease the bacterial load in chronic wounds.