A single application of cold atmospheric plasma (CAP) improves blood flow parameters in chronic wounds.

OBJECTIVE: To find out whether application of cold atmospheric plasma (CAP) affects microcirculation in chronic wounds. METHODS: We treated 20 patients with chronic wounds on the lower extremity with CAP. Blood flow parameters of wounds were assessed with combined Laser-Doppler-Flowmetry and spectrophotometry in tissue depth of 2 and 6-8 mm. Parameters were assessed under standardized conditions before and over the course of 30 min after application of CAP. RESULTS: Deep capillary blood flow increased significantly by up to 24.33% (percentage change) after treatment with CAP and remained significantly elevated until the end of measuring period at 30 min. Superficial oxygen tissue saturation was significantly elevated by 14.05% for the first 5 min after treatment. Postcapillary venous filling pressure was significantly elevated by 10.23% 19 min after CAP and stayed significantly elevated starting from minute 24 until the end of measuring. CONCLUSION: Cold atmospheric plasma increases microcirculation parameters in chronic wounds significantly. As CAP is known for its benefits in wound healing, the effects observed may explain the improved healing of chronic wounds after its use. Whether CAP-application can increase blood flow in chronic wounds for longer periods of time or boosts blood flow when applied more than once should be subject to further research.

The repetitive application of cold atmospheric plasma (CAP) improves microcirculation parameters in chronic wounds.

BACKGROUND: Chronic wounds, such as venous leg ulcers, diabetic foot ulcers, and pressure ulcers, impose a significant burden on patients and health care systems worldwide. Cold atmospheric plasma (CAP) accelerates wound healing and decreases bacterial load in chronic wounds in both in vitro and in vivo experiments. For the first time, we examined the effects of a repetitive application of CAP on the microcirculation in chronic wounds. HYPOTHESIS: The repetitive application of cold atmospheric plasma application further improves microcirculation in chronic wounds. METHODS: Twenty patients with chronic wounds were treated repetitively with CAP. The repetitive application consisted of three CAP sessions, each lasting 90 s and separated by a 10-minute microcirculation measuring period. Microcirculation parameters were assessed with combined Laser-Doppler-Flowmetry and spectrophotometry in a tissue depth of 2 mm. RESULTS: Tissue oxygen saturation was significantly increased after the first CAP application. The effect amplitude and duration were further increased after the second and third CAP application with a maximum increase by 16,7% (percent change; p = 0,004 vs. baseline) after the third application. There was no significant increase in capillary blood flow until the third CAP application. After the third CAP application, an increase by 22,6% (p = 0,014) was observed. Postcapillary filling pressure was not significantly increased over the measuring period. The repetitive application of CAP further enhances the microcirculation in chronic wounds compared to a single application. CONCLUSION: The repetitive application of CAP boosts and prolongs tissue oxygen saturation and capillary blood flow in chronic wounds compared to a single application. This insight could provide an impetus for new treatment protocols.

Cold atmospheric plasma improves cutaneous microcirculation in standardized acute wounds: Results of a controlled, prospective cohort study.

BACKGROUND: Given the high prevalence of wounds and their challenging treatment, the research of therapies to improve wound healing is of great clinical interest. In addition, the general consequences of developing chronic wounds constitute a large health economic aspect, which underscores the interest in the development of efficient treatment strategies. Direct cold atmospheric plasma (di_CAP) has been shown to have beneficial effects on microcirculation of human tissue (Kisch et al., 2016a). It also affects microbial settlements, which may have supportive effects on wound healing processes (Balzer et al., 2015). To treat these adequately, in our view, the positive effects on wound healing should be objectified by application on standardized wounds. However, wound healing is a complex process, depending on nutrient and oxygen supply by cutaneous blood circulation. In spite of microcirculation has been shown to improve in healthy skin by CAP, a quantification of the effect in a standardized wound model has never been evaluated (Kisch et al., 2016a). Based on this, we hypothesize that CAP also influences the microcirculation in standardized acute wounds in a prospective cohort study. METHODS: Microcirculatory data of 20 healthy subjects (14 males, 6 females; mean age 40.85 ± 15.84 years; BMI 26.83 ± 7.27 kg/m2) were recorded continuously at a standardized acute wound after skin transplantation (donor site) at the thigh. Under standardized conditions, microcirculatory measurements were performed using a combined laser Doppler and photospectrometry system. After baseline measurement, CAP was applied by a dielectric barrier discharge (DBD) plasma device for 90 s to the acute wound area. Immediately after the application, cutaneous microcirculation was assessed for 30 min (min) at the same site. RESULTS: After CAP application, tissue oxygen saturation immediately increased by 5% (92,66 ± 4,76% vs. Baseline 88,21 ± 6,52%, p < 0,01) in the first 60 s and remained significantly elevated for 4 min. Capillary blood flow increased by 19.3% within the first minute of CAP therapy (220.14 ± 65.91 AU vs. Baseline 184.52 ± 56.77 AU, p < 0.001). The statistically highly significant increase in blood flow continued over the entire measurement time. A maximum value was shown in the blood flow in the 15th minute (232.15 ± 58.90 AU, p < 0.001) according to CAP application. With regard to the output measurement, it represents a percentage increase of 25.8%. The measurement of post-capillary venous filling pressure at a tissue depth of 6-8 mm was 59.39 ± AU 12.94 at baseline measurement. After application, there were no significant changes. CONCLUSION: CAP increases cutaneous tissue oxygen saturation and capillary blood flow at the standardized acute wound healing model. These results support recently published data on wound healing after CAP treatment. However, further studies are needed to determine if this treatment can improve the reduced microcirculation in chronic wounds. Moreover, repetitive application protocols have to be compared with a single session treatment approach.