Rapid detection of biofilm by wound blotting following sharp debridement of chronic pressure ulcers predicts wound healing: A preliminary study

For optimal wound bed preparation, wound debridement is essential to eliminate bacterial biofilms. However, it is challenging for clinicians to determine whether the biofilm is completely removed. A newly developed biofilm detection method based on wound blotting technology may be useful. Thus, we aimed to investigate the effect of biofilm elimination on wound area decrease in pressure ulcers, as confirmed using the wound blotting method. In this retrospective observational study, we enrolled patients with pressure ulcers who underwent sharp debridement with pre‐ and post‐debridement wound blotting. Biofilm was detected on the nitrocellulose membrane using ruthenium red or alcian blue staining. Patients were included if the test was positive for biofilm before wound debridement. Percent decrease in wound area after 1 week was calculated as an outcome measure. We classified the wounds into a biofilm‐eliminated group and a biofilm‐remaining group based on the post‐debridement wound blotting result. Sixteen wound blotting samples from nine pressure ulcers were collected. The percent decrease in wound area was significantly higher in the biofilm‐eliminated group (median: 14.4%, interquartile range: 4.6%‐20.1%) than in the biofilm‐remaining group (median: −14.5%, interquartile range: −25.3%‐9.6%; P = .040). The presence of remaining biofilms was an independent predictor for reduced percent decrease in wound area (coefficient = −22.84, P = .040). Biofilm‐based wound care guided by wound blotting is a promising measure to help clinicians eliminate bacterial bioburden more effectively for wound area reduction.