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.

Blood Flow in the Scaphoid Is Improved by Focused Extracorporeal Shock Wave Therapy.

BACKGROUND: Extracorporeal shock wave therapy (ESWT) has shown benefits in patients with nonunion or delayed bone healing, pseudarthrosis, and avascular necrosis of bone. Until now, these effects were explained by the release of growth factors, activation of cells, and microfractures occurring after ESWT. Microcirculation is an important factor in bone healing and may be compromised in fractured scaphoids because its blood supply comes from the distal end. Due to this perfusion pattern, the scaphoid bone is prone to nonunion after fracture. The ability of ESWT to enhance microcirculation parameters in soft tissue was of interest to determine if it improves microcirculation in the scaphoid. QUESTIONS/PURPOSES: (1) Does capillary blood flow increase after a single session of ESWT in the scaphoid? (2) Do oxygen saturation in the bone and postcapillary venous filling pressure increase after a single session of ESWT in the scaphoid? METHODS: ESWT (0.3 mJ/mm, 8Hz, 1000 impulses) was applied to the intact scaphoid of 20 volunteers who were without wrist pain and without any important metabolic disorders. Mean age was 43 ± 14 years, 12 men and eight women (40% of total). Volunteers were recruited from January 2017 to May 2017. No anesthetic was given before application of ESWT. An innovative probe designed for measurements in bone by compressing soft tissue and combining laser-Doppler flowmetry and spectrophotometry was used to noninvasively measure parameters of microcirculation in the scaphoid. Blood flow, oxygenation, and venous filling pressure were assessed before and at 1, 2, 3, 5, 10, 15, 20, 25, and 30 minutes after ESWT application. Room temperature, humidity, ambient light and measuring sequences were kept consistent. A paired t-test was performed to compare experimental data with baseline (p < 0.05 taken as significant). RESULTS: At baseline, capillary blood flow of the bone was 108 ± 46 arbitrary units (AUs) (86 to 130). After treatment with ESWT, it was 129 ± 44 AUs (106 to 150; p = 0.011, percentage change of 19 %) at 1 minute, 138 ± 46 AUs (116 to 160; p = 0.002, percentage change of 28%) at 2 minutes, 146 ± 54 AUs (121 to 171; p = 0.002, percentage change of 35%) at 3 minutes and 150 ± 52 AUs (126 to 174; p < 0.001, percentage change of 39%) at 5 minutes. It remained elevated until the end of the measuring period at 30 minutes after treatment at 141 ± 42 AUs (121 to 161; p = 0.002) versus baseline). Oxygen saturation and postcapillary venous filling pressure in bone showed no change, with the numbers available. CONCLUSIONS: A single session of ESWT increased capillary blood flow in the scaphoid during measuring time of 30 minutes. Bone oxygenation and postcapillary venous filling pressure, however, did not change. Because increased oxygenation is needed for improved bone healing, it remains unclear if a sole increase in capillary blood flow can have clinical benefits. As the measuring period was limited to only 30 minutes, bone oxygenation and postcapillary filling pressure may subsequently show change only after the measuring-period ended. CLINICAL RELEVANCE: Further studies need to evaluate if increased capillary blood flow can be sustained for longer periods and if bone oxygenation and postcapillary venous filling pressure remain unchanged even after prolonged or repetitive ESWT applications. Moreover, clinical studies must validate if increased microcirculation has a positive impact on bone healing and to determine if ESWT can be therapeutically useful on scaphoid fractures and nonunions.

Improvement of cutaneous microcirculation by cold atmospheric plasma (CAP): Results of a controlled, prospective cohort study.

BACKGROUND: Cold atmospheric plasma (CAP) has proven its benefits in the reduction of various bacteria and fungi in both in vitro and in vivo studies. Moreover, CAP generated by dielectric barrier discharge (DBD) promoted wound healing in vivo. Charged particles, chemically reactive species (such as O3, OH, H2O2, O, NxOy), ultraviolet radiation (UV-A and UV-B), strong oscillating electric fields as well as weak electric currents are produced by DBD operated in air. However, wound healing is a complex process, depending on nutrient and oxygen supply via cutaneous blood circulation. Therefore, this study examined the effects of CAP on cutaneous microcirculation in a prospective cohort setting. HYPOTHESIS: Cold atmospheric plasma application enhances cutaneous microcirculation. METHODS: Microcirculatory data of 20 healthy subjects (11 males, 9 females; mean age 35.2 ± 13.8 years; BMI 24.3 ± 3.1 kg/m(2)) were recorded continuously at a defined skin area at the radial forearm. Under standardized conditions, microcirculatory measurements were performed using a combined laser Doppler and photospectrometry system. After baseline measurement, CAP was applied by a DBD plasma device for 90 s to the same defined skin area of 22.5 cm(2). Immediately after the application cutaneous microcirculation was assessed for 30 min at the same site. RESULTS: After CAP application, tissue oxygen saturation immediately increased by 24% (63.8 ± 13.8% from 51.4 ± 13.2% at baseline, p<0.001) and stayed significantly elevated for 8 min. Cutaneous blood flow increased by 73% (41.0 ± 31.2 AU from 23.7 ± 20.8 AU at baseline, p<0.001) and remained upregulated for 11 min. Furthermore, cutaneous blood flow showed two peaks at 14 (29.8 ± 25.0 AU, p=0.049) and 19 min (29.8 ± 22.6 AU, p=0.048) after treatment. Postcapillary venous filling pressure continuously increased, but showed no significant change vs. baseline in the non-specific BMI group. Subgroup analysis revealed that tissue oxygen saturation, postcapillary venous filling pressure and blood flow increased more in case of a lower BMI. CONCLUSION: CAP increases cutaneous tissue oxygen saturation and capillary blood flow at the radial forearm of healthy volunteers. 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 diabetic foot ulcers. Moreover, repetitive application protocols have to be compared with a single session treatment approach.

Immediate Dose-Response Effect of High-Energy Versus Low-Energy Extracorporeal Shock Wave Therapy on Cutaneous Microcirculation.

Elucidation of the precise mechanisms and therapeutic options of extracorporeal shock wave therapy (ESWT) is only at the beginning. Although immediate real-time effects of ESWT on cutaneous hemodynamics have recently been described, the dose response to different ESWT energies in cutaneous microcirculation has never been examined. Thirty-nine Sprague-Dawley rats were randomly assigned to three groups that received either focused high-energy shock waves (group A: total of 1000 impulses, 10 J) to the lower leg of the hind limb, focused low-energy shock waves (group B: total of 300 impulses, 1 J) or placebo shock wave treatment (group C: 0 impulses, 0 J) using a multimodality shock wave delivery system (Duolith SD-1 T-Top, Storz Medical, Tägerwilen, Switzerland). Immediate microcirculatory effects were assessed with the O2C (oxygen to see) system (LEA Medizintechnik, Giessen, Germany) before and for 20 min after application of ESWT. Cutaneous tissue oxygen saturation increased significantly higher after high-energy ESWT than after low-energy and placebo ESWT (A: 29.4% vs. B: 17.3% vs. C: 3.3%; p = 0.003). Capillary blood velocity was significantly higher after high-energy ESWT and lower after low-energy ESWT versus placebo ESWT (group A: 17.8% vs. group B: -22.1% vs. group C: -5.0%, p = 0.045). Post-capillary venous filling pressure was significantly enhanced in the high-energy ESWT group in contrast to the low-energy ESWT and placebo groups (group A: 25% vs. group B: 2% vs. group C: -4%, p = 0.001). Both high-energy and low-energy ESWT affect cutaneous hemodynamics in a standard rat model. High-energy ESWT significantly increases parameters of cutaneous microcirculation immediately after application, resulting in higher tissue oxygen saturation, venous filling pressure and blood velocity, which suggests higher tissue perfusion with enhanced oxygen saturation, in contrast to low-energy as well as placebo ESWT. Low-energy ESWT also increased tissue oxygen saturation, albeit to a lower extent, and decreases both blood velocity and venous filling pressure. Low-energy ESWT reduced tissue perfusion, but improved oxygen saturation immediately after the application.

Progressive fluid removal can avoid electrolyte disorders in severely burned patients.

INTRODUCTION: Extensive burn injury has systemic consequences due to capillary leak. After restoration of cellular integrity, infused fluid volume has to be removed partially. This can provoke electrolyte disorders. PURPOSE: We investigated the effect of progressive fluid removal on serum sodium level. METHOD: Retrospective study. Patients admitted to a burn unit were analyzed and separated in two groups without (Group A) or with (Group B) prolonged hypernatremia. Daily infusion-diuresis-ratio (IDR) was analyzed. RESULTS: Fourty (12 female; 28 male) patients with a mean age of 47±19 years, a total burn surface area (TBSA) of 26±12%, and a mean abbreviated burned severity index (ABSI) score of 7.3±2 were included. In Group A 25 patients with a mean age of 47±18 years, a mean TBSA of 23±11%, and a mean ABSI score of 6.9±2.1 were summarized. In Group B 15 patients with a mean age of 47±22 years, a mean TBSA of 30±13%, and a mean ABSI score of 8.1±1.7 were included. Hypernatremia occurred on day 5±1.4. There was no significant difference between both groups for fluid resuscitation amount within the first 24 hours. Statistical analysis of the first 7 days after burn injury showed a significantly higher percentage of removed fluid in Group B for day 3, day 4, day 5, day 6 and day 7. CONCLUSIONS: Amount and velocity of fluid removal regimen after burn injury can provoke electrolyte disorders. Serum sodium concentration can be used to calculate need of fluid resuscitation for fluid maintenance. There is a need of an established fluid removal strategy.

Early postoperative alterations of ventilation parameters after tracheostomy in major burn injuries.

PURPOSE: In patients with major burn injuries mechanical ventilation is often required for longer periods. Tracheostomy (TS) plays an integral role in airway management. We investigated the effect of TS on ventilation parameters within 8 hours after TS. MATERIALS: A retrospective analysis of severely burned patients admitted to the burn unit of a German University Hospital was performed. Ventilation parameters 8 hours before and after TS were registered. RESULTS: A retrospective analysis of 20 patients which received surgical TS was performed. Mean age was 52+/-19 years. Mean abbreviated burned severity index (ABSI) was 8.3+/-2.2. A mechanical ventilation was required for 14.3+/-4.8 days. TS was performed on day 7+/-4. Inspiratory oxygen concentration (FiO(2)) (p<0.001), peak inspiratory pressure (p<0.001), positive end-expiratory pressure (p=0.003) and pulmonary resistance (p<0.001) were reduced significantly after TS. The arterial partial pressure of oxygen/FiO(2)-ratio increased significantly after TS (p<0.001). CONCLUSIONS: We demonstrate that TS reduces invasiveness of ventilation in severely burned patients and by this can optimize lung protective ventilation strategy.