Stimulation of fibroblast growth in vitro by intermittent radiant warming

Wound microenvironment regulatory poly(L-glutamic acid) composite hydrogels containing metal ion-coordinated nanoparticles for effective hemostasis and wound healing

Regulating the wound microenvironment to promote proliferation, vascularization, and wound healing is challenging for hemostats and wound dressings. Herein, polypeptide composite hydrogels have been simply fabricated by mixing a smaller amount of metal ion-coordinated nanoparticles into dopamine-modified poly(L-glutamic acid) (PGA), which had a microporous size of 10-16 μm, photothermal conversion ability, good biocompatibility, and multiple biological activities. In vitro scratch healing of fibroblast L929 cells and the tube formation of HUVECs provide evidence that the PGA composite hydrogels could promote cell proliferation, migration, and angiogenesis with the assistance of mild photothermia. Moreover, these composite hydrogels plus mild photothermia could effectively eliminate reactive oxygen species (ROS), alleviate inflammation, and polarize the pro-inflammatory M1 macrophage phenotype into the pro-healing M2 phenotype to accelerate wound healing, as assessed by means of fluorescent microscopy, flow cytometry, and quantitative real-time polymerase chain reaction (qRT-PCR). Meanwhile, a rat liver bleeding model illustrates that the composite hydrogels reduced the blood loss ratio to about 10% and shortened the hemostasis time to about 25 s better than commercial chitosan-based hemostats. Furthermore, the full-thickness rat skin defect models showcase that the composite hydrogels plus mild photothermia could proheal wounds completely with a fast healing rate, optimal neovascularization, and collagen deposition. Therefore, the biodegradable polypeptide PGA composite hydrogels are promising as potent wound hemostats and dressings.

A Wound Environment Control System to Avoid Major Amputation in Diabetic Foot Ulcers

We report the case of a 58-year-old patient with a diabetic foot lesion at high risk of major amputation successfully treated by a new innovative wound environment control system.

Wound pH and Surface Temperature as a Predictive Biomarker of Healing in Diabetic Foot Ulcers

Aim

To monitor wound pH and surface temperature as predictors of wound healing in diabetic foot ulcers (DFU).

Methods

Prospective, observational, time-bound study of 18 months, enrolling patients aged 18 to 60 years with uninfected DFU. The wound was assessed at baseline and after that, every week for 4 weeks according to the leg ulcer measurement tool (LUMT). Concurrently, wound surface pH and temperature were measured. The data were analyzed using descriptive statistics, and a P-value < .05 was considered statistically significant.

Results

Fifty-four patients with DFU were included in the study with a mean age of 55 years and a male to female ratio of 1.57. The wound showed progressive improvement, a maximum mean LUMT score of 48.89 (± 2.81) at the initial evaluation and decreased progressively to the mean of 19.80 at week 4 (± 3.43), both of which were statistically significant ( P-value < .001). Similarly, the median wound pH progressively reduced from 7.7 at baseline to 7.20 in the fourth week, and median wound temperature decreased from 90°F (32.22 °C) at baseline to 85°F (29.44 °C) in the fourth week, both of which were statistically significant ( P-value < .001).

Conclusion

Progressive and significant change in wound pH to acidic and drop in wound surface temperature, both corresponding to improvement in the status of DFU, maximum at 4 weeks, make them valuable predictors of wound healing. However, further, more extensive studies are required to establish a concrete relationship.

Smart bioadhesives for wound healing and closure

The high demand for rapid wound healing has spurred the development of multifunctional and smart bioadhesives with strong bioadhesion, antibacterial effect, real-time sensing, wireless communication, and on-demand treatment capabilities. Bioadhesives with bio-inspired structures and chemicals have shown unprecedented adhesion strengths, as well as tunable optical, electrical, and bio-dissolvable properties. Accelerated wound healing has been achieved via directly released antibacterial and growth factors, material or drug-induced host immune responses, and delivery of curative cells. Most recently, the integration of biosensing and treatment modules with wireless units in a closed-loop system yielded smart bioadhesives, allowing real-time sensing of the physiological conditions (e.g., pH, temperature, uric acid, glucose, and cytokine) with iterative feedback for drastically enhanced, stage-specific wound healing by triggering drug delivery and treatment to avoid infection or prolonged inflammation. Despite rapid advances in the burgeoning field, challenges still exist in the design and fabrication of integrated systems, particularly for chronic wounds, presenting significant opportunities for the future development of next-generation smart materials and systems.

Transparent photothermal hydrogels for wound visualization and accelerated healing

Utilizing photothermal hydrogels as a wound dressing is a promising strategy to accelerate wound healing. Usually, a photothermal hydrogel has a strong light-absorbing capability, and hence its transparency can be largely sacrificed, which is unbeneficial for the visual monitoring of wound states. It remains challenging to balance the trade-off between the photothermal conversion and wound visualization for the photothermal hydrogel dressing. Herein, a composite photothermal hydrogel film with high transparency is presented for the visual monitor of the wound, which is constructed by incorporating CsxWO3 nanorods into the networks of polyacrylamide hydrogels. The composite photothermal hydrogel film exhibits high light absorption in the near-infrared region and high transmittance in the visible light region. Under 980 nm laser irradiation, the composite hydrogel can be heated up to 45 °C. In vivo animal experiment on mouse skin wound model shows that the composite hydrogel film can locally heat the skin wound to accelerate healing while maintaining more than 70% transparency to realize real-time observation of the wound. This study provides the first attempt to solve the problem of opacity in photothermal hydrogel dressings, promoting the possibility of its clinical applications.

Effect of Platelet-Rich Fibrin Application on Non-Infectious Complications after Surgical Extraction of Impacted Mandibular Third Molars

Due to the frequent development of non-infectious complications after surgical removal of the third lower impacted tooth, many techniques are used to reduce their severity. Among them is the technique of applying platelet-rich fibrin to the post-extraction alveolus. The study included 90 consecutively enrolled patients. Eligible patients were randomly assigned to two groups: patients with and without platelet-rich fibrin introduced into the postoperative alveolus. Pain, swelling, trismus, and temperature were evaluated after the procedure. Pain intensity was significantly higher in the control group than in the study group at 6 h, 1, and 3 days after surgery. PRF application did not significantly affect the intensity of swelling. Body temperature was significantly higher in the control group than the study group on day two after surgery. The trismus was significantly higher in the control group than in the study group at one, two, and seven days after surgery. Application of the PRF allows for a faster and less traumatic treatment process. It will enable for speedier recovery and return to active life and professional duties.

A novel atmospheric-pressure air plasma jet for wound healing

Current low‐temperature plasma (LTP) devices essentially use a rare gas source with a short working distance (8 to 20 mm), low gas flow rate (0.12 to 0.3 m³/h), and small effective treatment area (1‐5 cm²), limiting the applications for which LTP can be utilised in clinical therapy. In the present study, a novel type of LTP equipment was developed, having the advantages of a free gas source (surrounding air), long working distance (8 cm), high gas flow rate (10 m³/h), large effective treatment area (20 cm²), and producing an abundance of active substances (NOγ, OH, N₂, and O), effectively addressing the shortcomings of current LTP devices. Furthermore, it has been verified that the novel LTP device displays therapeutic efficacy in terms of acceleration of wound healing in normal and Type I diabetic rats, with enhanced wound kinetics, rate of condensation of wound area, and recovery ratio. Cellular and molecular analysis indicated that LTP treatment significantly reduced inflammation and enhanced re‐epithelialization, fibroblast proliferation, deposition of collagen, neovascularization, and expression of TGF‐β, superoxide dismutase, glutathione peroxidase, and catalase in Type I diabetic rats. In conclusion, the novel LTP device provides a convenient and efficient tool for the treatment of clinical wounds.

What is the "normal" wound bed temperature? A scoping review and new hypothesis

Wound bed temperature measurement holds the potential to be a safe, easy to use, and low-cost tool to aid objective wound bed assessment, clinical decision making and improved patient outcomes. However, there is no consensus on the normal range of wound bed temperature in chronic wounds. We conducted a scoping review including any study type, from 2010 to 2020 in which chronic wound bed temperature was reported. Thirteen studies including 477 patients met our criteria. Venous ulcers (VLU) accounted for 46.5% (n = 222) of wounds; diabetic foot ulcers (DFU) for 25.4% (n = 121) with pressure ulcers (PU), mixed arterial venous ulcers (MAVLU) and unknown aetiology accounting for the remainder. The weighted mean of means for wound bed temperature was 31.7°C (n = 395) for all wound types; 31.7°C for VLU; 31.6°C for DFU; 33.3°C for PU; 30.9°C for MAVLU; and 32.0°C for those with unknown aetiology. Based on our review, we hypothesise that normal wound bed temperature is within a range of 30.2-33.0°C.

Mobile Health-Based Thermometer for Monitoring Wound Healing After Endovascular Therapy in Patients With Chronic Foot Ulcer: Prospective Cohort Study

BACKGROUND

Foot temperature may increase after endovascular therapy, but the relationship between foot temperature and wound healing is unclear.

OBJECTIVE

This study was performed to evaluate the feasibility of a mobile health (mHealth)-based thermometer for foot temperature monitoring in patients with chronic foot ulcer before and after endovascular therapy and to determine the association between temperature change and wound healing time.

METHODS

This was a prospective cohort study. Patients who had a chronic foot ulcer (>3 months) and underwent endovascular therapy between June 2019 and December 2019 were included. The participants received standard medical care and endovascular therapy for revascularization. The mHealth-based thermometer, composed of 4 temperature-sensing chips, was put on the foot before and after endovascular therapy. Data from the chips were transferred to an associated mobile phone app via Bluetooth. Wound healing time was estimated using the Kaplan-Meier method, and the associations between baseline characteristics and clinical outcomes were evaluated using a Cox proportional hazard model.

RESULTS

A total of 163 patients with chronic foot ulcer who underwent endovascular therapy were enrolled and followed up until wound healing was complete or for 180 days. The mean foot temperature before endovascular therapy was 30.6 (SD 2.8 °C). Foot temperature increased significantly (mean 32.1 °C, SD 2.8 °C; P=.01) after the procedure. Wound healing time was significantly different in the Kaplan-Meier curves of the patient group with temperature changes ≥2 °C and the group with temperature changes ≤2 °C (log-rank P<.001). A foot temperature increase ≥2 °C after endovascular therapy was associated with increased wound healing in univariate analysis (hazard ratio [HR] 1.78, 95% CI 1.24-2.76, P=.02), and the association remained significant in multivariate analysis (HR 1.69, 95% CI 1.21-2.67, P=.03).

CONCLUSIONS

The mHealth-based thermometer was feasible and useful for foot temperature monitoring, which may provide health care professionals with a new endpoint for endovascular therapy. Foot temperature increases ≥2 °C after endovascular therapy were associated with faster wound healing in patients with chronic foot ulcer. Further studies are needed, however, to confirm these findings.

What is the optimal treatment time for larval therapy? A study on incubation time and tissue debridement by bagged maggots of the greenbottle fly, Lucilia sericata

The effective use of larvae of the greenbottle fly, Lucilia sericata, in wound debridement requires a working knowledge of how feeding changes over time. Using a laboratory assay and bagged larval dressings, the effect of incubation time on larval feeding rates and body mass was investigated for up to 120 hours at 32°C. The mass of tissue digested increased significantly in incremental 24-hour periods up to 72 hours, with no significant consumption occurring afterwards. Larval mass increased only up to 48 hours. A further test comparing the efficacy of a single 96-hour application of larvae against two consecutive 48-hour applications found that the mass of tissue digested in the latter was 14.3% higher than the former, a difference that was statistically significant. Current clinical guidance suggests a 4-day application period for bagged larvae. Based on these results, an incubation time of 72 hours (3 days) for bagged larvae would be the most effective at the study temperature. However, it is acknowledged that wound temperature can vary, whereby feeding rates would likely differ. In view of this, we conclude that a period of 3 to 4 days is optimum for the application of larvae, and current guidelines should be adhered to.

Self-adhesive photothermal hydrogel films for solar-light assisted wound healing

Self-adhesive photothermal hydrogel films can adhere to skin wound and convert solar light into heat, warming up the wound locally and promoting wound repair.

Sensors and Biosensors for C-Reactive Protein, Temperature and pH, and Their Applications for Monitoring Wound Healing: A Review

Wound assessment is usually performed in hospitals or specialized labs. However, since patients spend most of their time at home, a remote real time wound monitoring would help providing a better care and improving the healing rate. This review describes the advances in sensors and biosensors for monitoring the concentration of C-reactive protein (CRP), temperature and pH in wounds. These three parameters can be used as qualitative biomarkers to assess the wound status and the effectiveness of therapy. CRP biosensors can be classified in: (a) field effect transistors, (b) optical immunosensors based on surface plasmon resonance, total internal reflection, fluorescence and chemiluminescence, (c) electrochemical sensors based on potentiometry, amperometry, and electrochemical impedance, and (d) piezoresistive sensors, such as quartz crystal microbalances and microcantilevers. The last section reports the most recent developments for wearable non-invasive temperature and pH sensors suitable for wound monitoring.

Measurement of pH, exudate composition and temperature in wound healing: a systematic review

OBJECTIVE

To assess the potential of measurements of pH, exudate composition and temperature in wounds to predict healing outcomes and to identify the methods that are employed to measure them.

METHOD

A systematic review based on the outcomes of a search strategy of quantitative primary research published in the English language was conducted. Inclusion criteria limited studies to those involving in vivo and human participants with an existing or intentionally provoked wound, defined as 'a break in the epithelial integrity of the skin', and excluded in vitro and animal studies. Data synthesis and analysis was performed using structured narrative summaries of each included study arranged by concept, pH, exudate composition and temperature. The Evidence Based Literature (EBL) Critical Appraisal Checklist was implemented to appraise the quality of the included studies.

RESULTS

A total of 23 studies, three for pH (mean quality score 54.48%), 12 for exudate composition (mean quality score 46.54%) and eight for temperature (mean quality score 36.66%), were assessed as eligible for inclusion in this review. Findings suggest that reduced pH levels in wounds, from alkaline towards acidic, are associated with improvements in wound condition. Metalloproteinase-9 (MMP-9), matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase (TIMP), neutrophil elastase (NE) and albumin, in descending order, were the most frequently measured analytes in wounds. MMP-9 emerged as the analyte which offers the most potential as a biomarker of wound healing, with elevated levels observed in acute or non-healing wounds and decreasing levels in wounds progressing in healing. Combined measures of different exudate components, such as MMP/TIMP ratios, also appeared to offer substantial potential to indicate wound healing. Finally, temperature measurements are highest in non-healing, worsening or acute wounds and decrease as wounds progress towards healing. Methods used to measure pH, exudate composition and temperature varied greatly and, despite noting some similarities, the studies often yielded significantly contrasting results. Furthermore, a limitation to the generalisability of the findings was the overall quality scores of the research studies, which appeared suboptimal.

CONCLUSION

Despite some promising findings, there was insufficient evidence to confidently recommend the use of any of these measures as predictors of wound healing. pH measurement appeared as the most practical method for use in clinical practice to indicate wound healing outcomes. Further research is required to increase the strength of evidence and develop a greater understanding of wound healing dynamics.

Wound healing during hibernation by black bears (Ursus americanus) in the wild: elicitation of reduced scar formation

Even mildly hypothermic body or limb temperatures can retard healing processes in mammals. Despite this, we observed that hibernating American black bears (Ursus americanus Pallas, 1780) elicit profound abilities in mounting inflammatory responses to infection and/or foreign bodies. In addition, they resolve injuries during hibernation while maintaining mildly hypothermic states (30-35 °C) and without eating, drinking, urinating or defecating. We describe experimental studies on free-ranging bears that document their abilities to completely resolve cutaneous cuts and punctures incurred during or prior to hibernation. We induced small, full-thickness cutaneous wounds (biopsies or incisions) during early denning, and re-biopsied sites 2-3 months later (near the end of denning). Routine histological methods were used to characterize these skin samples. All biopsied sites with respect to secondary intention (open circular biopsies) and primary intention (sutured sites) healed, with evidence of initial eschar (scab) formation, completeness of healed epidermis and dermal layers, dyskeratosis (inclusion cysts), and abilities to produce hair follicles. These healing abilities of hibernating black bears are a clear survival advantage to animals injured before or during denning. Bears are known to have elevated levels of hibernation induction trigger (delta-opioid receptor agonist) and ursodeoxycholic acid (major bile acid within plasma, mostly conjugated with taurine) during hibernation, which may relate to these wound-healing abilities. Further research as to the underlying mechanisms of wound healing during hibernation could have applications in human medicine. Unique approaches may be found to improve healing for malnourished, hypothermic, diabetic and elderly patients or to reduce scarring associated with burns and traumatic injuries.

Effect of polarized light emitting diode irradiation on wound healing

BACKGROUND

We propose a new phototherapy using polarized light from light emitting diode (LED). The purpose of this study is to clarify the effect of polarized LED irradiation on wound healing.

METHODS

Five groups were classified: control (C), unpolarized (U), linearly polarized (L), right circularly polarized (RC), and left circularly polarized (LC) LED irradiation. In vitro study, fibroblast cell cultures were irradiated, and cellular proliferation was evaluated with a WST-8 assay. In vivo study, full-thickness skin defect of 20 mm diameter was created on the dorsal side of rats. The ratio of the residual wound area was measured, and expression of type 1 and type 3 procollagen mRNA in granulation tissue was determined by real-time reverse transcription polymerase chain reaction method.

RESULTS

The cellular proliferation rates of group RC and L were significantly higher than other groups. The ratio of the residual wound area of group RC and L was significantly reduced than group C and U. Expression of type 1 procollagen mRNA in group RC was found to be significantly increased about 1.5-fold in comparison with the group C. There were no significant differences for type 3 procollagen.

CONCLUSIONS

The right circularly polarized light and linearly polarized light promoted the process of wound healing by increasing the proliferation of fibroblasts, and the right circularly polarized light increased the expression of type 1 procollagen mRNA. The effectiveness of right circularly polarized light suggests that some optical active material, which has a circular dichroic spectrum, takes part in a biochemical reaction.

Effects of perioperative hypothermia and warming in surgical practice

Perioperative hypothermia is common and adversely affects clinical outcomes due to its effect on a range of homeostatic functions. Many of these adverse consequences are preventable by the use of warming techniques. A literature search was conducted to identify relevant published articles on perioperative hypothermia and warming. The databases searched include MEDLINE (1966 to February 2005), EMBASE (1974 to February 2005), CINAHL, the Cochrane library and the health technology assessment database. Reference lists of key articles were also searched. The primary beneficial effects of warming are mediated through increased blood flow and oxygen tension at tissue level. Reduction in wound infection, blood loss and perioperative pain with warming is promising. However, more evidence from good-quality prospective randomised controlled trials is needed to evaluate the role of warming in improving overall morbidity, mortality and hospital stay as well as to clarify its role as an adjunct to resuscitation and during the pre-hospital transport phase of critically ill patients. Awareness of the risks of perioperative hypothermia is the key to prevention. Achieving normothermia throughout the patient's journey is a worthwhile goal in surgical patients.

A Prospective Study Comparing Diathermy and Scalpel Incisions in Tension-Free Inguinal Hernioplasty

Although still controversial, the use of diathermy instead of scalpel for skin incision and underlying tissue dissection is gradually gaining wide acceptance. This is due to the observation that no change in wound complication rates or postoperative pain are reported with the use of electrocautery. However, these studies include operations without the use of prosthetic materials during abdominal wall closure. The purpose of this study was to investigate the hypothesis that a) application of extreme heat may result in significant postoperative pain and poor wound healing because of excessive tissue damage and scarring respectively, and b) skin incision with the use of diathermy entails increased risk of wound infection in the presence of an underlying prosthetic material. One hundred twenty-five consecutive patients submitted to inguinal hernioplasty using the tension-free technique and fulfilling the inclusion criteria for the study were allocated alternately to either scalpel (n = 60), or diathermy (n = 57) groups. Eight patients had bilateral hernias. Five of them were allocated to the scalpel group and three to the diathermy group. According to the study protocol, they received both approaches for skin and underlying tissues incision, thus resulting in a total of 68 scalpel and 65 diathermy individual hernioplasties. Parameters measured included blood loss during the skin incision and underlying tissue dissection, postoperative pain and requirements for analgesics, the presence of wound dehiscence in the absence of infection, and postoperative wound infection on the day of discharge, on the day staples were removed, and 1 month after surgery. The two groups of patients were similar in relation to patient demographics, type of hernias, and operation details. Blood loss was minimal, and the amount of blood lost did not differ between the two groups. Diathermy group patients required less parenteral analgesics on the first postoperative day. A higher proportion of patients in the scalpel group continued to need oral analgesics on the second postoperative day compared to patients in the diathermy group. There was no difference between the two groups in terms of wound strength. Infectious complications were totally absent. The use of diathermy for skin incision during inguinal hernioplasty is as safe as the use of scalpel in terms of wound healing and reduces the analgesics requirements in the postoperative period.

Effects of warming on healing

Systemic and local warming may accelerate wound healing and minimise postoperative wound infection, although more research is needed to confirm this. The existing evidence of the benefits of warming therapies is outlined here.

A controlled, randomized, comparative study of a radiant heat bandage on the healing of stage 3–4 pressure ulcers: A pilot study

OBJECTIVES

Pressure ulcers, like other chronic wounds, fail to proceed through an orderly and timely process to produce anatomical or functional integrity. Treatment of pressure ulcers is directed to improving host factors and providing an optimum wound environment. In addition to providing a moist wound environment, it has been theorized that preventing hypothermia in a wound and maintaining a normothermic state might improve wound healing.

DESIGN/SETTING

Forty-one subjects with a stage 3 or stage 4 truncal pressure ulcer >1.0 cm(2) were recruited from outpatient clinics, long-term care nursing homes, and a rehabilitation center. The experimental group was randomized to a radiant-heat dressing device and the control group was randomized to a hydrocolloid dressing, with or without a calcium alginate filler. Subjects were followed until healed or for 12 weeks.

RESULTS

Eight subjects (57%) in the experimental group had complete healing of their pressure ulcer compared with 7 subjects (44%) with complete healing in the control group (P = .46).

CONCLUSION

Although a 13% difference in healing rate between the two arms of the study was found, this difference was not statistically significant. At almost all points along the healing curve, the proportion not healed was higher in the control arm.

Gingival Cell Proliferation Induced by Use of a Sonic Toothbrush With Warmed Silicone Rubber Bristles

BACKGROUND

Toothbrushing promotes gingival cell proliferation, which may occur as the result of the physical stimulation of the gingiva. The present study evaluated the effects of temperature and silicone rubber bristles of a sonic toothbrush on gingival cell proliferation in dogs.

METHODS

During the 5-week experimental period, one quadrant in each of eight dogs received a different toothbrushing regimen: a manual toothbrush or a sonic toothbrush with 1) nylon, 2) silicone rubber, or 3) warmed silicone rubber bristles. The proliferative activity of gingival cells was evaluated based on expression of proliferating cell nuclear antigen (PCNA).

RESULTS

Use of the sonic toothbrushes produced a higher density of PCNA-positive and total fibroblasts than did use of a manual toothbrush. The warm silicone rubber bristles resulted in a higher density of PCNA-positive fibroblasts compared with the cooler silicone rubber bristle. The number of PCNA-positive basal cells in the junctional epithelium also increased following electric toothbrushing with warmed silicone rubber bristles.

CONCLUSIONS

The sonic toothbrush with silicone rubber bristles induced gingival fibroblast proliferation to a greater degree than a manual toothbrush. Warming the silicone rubber bristles increased their stimulatory effects on the proliferative activity of gingival cells.

Topical radiant heating in wound healing: an experimental study in a donor site wound model*

The importance of temperature in the wound-healing process is rapidly being recognised as a novel way in which to manipulate the wound-healing environment. In this study, we aimed to investigate the direct effect of topical radiant heating (TRH), using a novel bandaging system (Warm-Up, Arizant Health care Inc., Eden Prairie MN, USA; Augustine Medical, USA), on wound healing at a physiological and cellular level. Experimental bandages were positioned over split-thickness skin graft donor site wounds of 12 patients undergoing graft harvesting from the anterior thigh. The experimental group (n=6) underwent intermittent heating for 5 hours (three 1-hour heating cycles at 38 degrees C, separated by two 1-hour rest periods), whilst the control group (n=6) received no radiant heating. Physiological blood-flow recordings both in the control group and the topical radiant heat cohort were undertaken using Laser Doppler Imaging (LDI). Skin biopsies were obtained at identical time points, and immunohistochemical analysis was undertaken using antibodies against neutrophils (NP57), lymphocytes (CD3) and macrophages (CD68). We found that TRH significantly increased local dermal blood flow (P<0.001) by up to 100% in both injured and intact skin. Furthermore, this increase in flow was associated with a significant (P<0.05) increase in CD3 immunoreactivity on day 1 postoperatively. This study demonstrates that TRH increases local blood flow and lymphocyte (CD3) extravasation, and we postulate that these changes may enhance local innate immunity within the healing wound environment.

Influence of dressing changes on wound temperature

OBJECTIVE

When wound-tissue temperature falls below 33 degrees C neutrophil, fibroblast and epithelial cell activity decreases. This study examined the influence of dressing changes on wound temperature.

METHOD

The wound-bed temperatures of patients with a wound resulting from trauma or surgical debridement were measured immediately before and after dressing changes using a DermaTemp infrared body surface scanning device. The temperature on the surface of the dressing product was measured immediately before the dressing change and then every five minutes it until the pre-procedural temperature was reached.

RESULTS

A total of 133 dressing episodes were measured, yielding 266 wound-bed temperature measurements and 619 external dressing temperature measurements. Pre-procedural temperatures showed that the wound beds were on average marginally below the 33 degrees C threshold immediately after dressing takedown (mean: 32.7 degrees C). This figure dropped two degrees on average as a result of the dressing-change procedure (mean: 29.9 degrees C). Reapplied wound-dressing products return to the pre-procedural temperature within 30 minutes (mean: 23 minutes).

CONCLUSION

This study provides baseline data for future research aimed at promoting maintenance of a normothermic wound bed.

DECLARATION OF INTEREST

None.

Heat Treatment Enhances Healing Process of Experimental Pseudomonas Corneal Ulcer

We investigated the effects of hyperthermia on the healing process of experimental Pseudomonas corneal ulceration (PCU). Hartley guinea pigs were used to develop animal models of PCU. As a heat source, disposable chemical pocket warmers were applied. The healing process of PCU was compared between the heat-treated corneas and the control corneas. The severity of infection and the degree of angiogenesis were classified by a clinical scoring system. The animals were euthanized 14 days after infection and the corneas were submitted for histopathological examination. The expression of vascular endothelial growth factor (VEGF) was examined immunohistochemically. Comparative reverse transcription polymerase chain reaction was performed to measure the expression level of VEGF in the cornea. Hyperthermia significantly promoted corneal epithelization and neovascularization in the PCU model. Heat treatment significantly decreased the number of viable Pseudomonas organisms present in PCU. On immunohistochemistry, the heated cornea demonstrated more intense staining for VEGF. Comparative reverse transcription polymerase chain reaction showed upregulation of the expression level of VEGF mRNA in the heat-treated cornea. Hyperthermia accelerated the healing process of PCU with increased corneal neovascularization. Angiogenesis may play an important role in the PCU healing process, which is enhanced by the heat treatment.

A randomized controlled clinical trial to evaluate the effects of noncontact normothermic wound therapy on chronic full-thickness pressure ulcers

OBJECTIVE

To determine the effect of noncontact normothermic wound therapy (NNWT) versus standard wound care on chronic full-thickness pressure ulcers.

DESIGN

Prospective, randomized, controlled trial.

SETTING

Veterans administration medical center and 7 long-term-care facilities.

PATIENTS

40 inpatients with 43 Stage III and IV pressure ulcers.

INTERVENTIONS

A sterile noncontact wound dressing was applied to 21 wounds for 24 hours per day, 7 days per week. Each day after the wound was irrigated and the noncontact dressing was changed, a heating element in the dressing was activated for 3 1-hour periods for 12 weeks or until wound closure. Twenty-two control wounds were treated with standard, moisture-retentive dressings 24 hours per day, 7 days per week for 12 weeks or until wound closure.

MAIN OUTCOME MEASURE

Measurement of wound surface area.

MAIN RESULTS

Healing rate for the NNWT group was significantly greater than for the control group (0.52 cm2 per week and 0.23 cm2 per week, respectively; P<.02). A clinically significant increase was seen among the NNWT group in the incidence of closure among wounds that completed the entire 12-week protocol compared with controls (11 of 14 or 79% and 8 of 16 or 50%, respectively; not significant). The mean slope of the individual regression analyses for the NNWT group was significantly different from the mean slope for the control group (-0.07 and -0.033, respectively; P<.05). Large wounds in the NNWT group demonstrated a significantly greater healing rate than large wounds in the control group (P <.05).

CONCLUSION

Wounds treated with NNWT healed significantly faster than wounds in the control group. The healing rate was greatest for larger wounds treated with NNWT.

Sodium carboxyl-methyl-cellulose dressings in the management of deep ulcerations of diabetic foot

AIMS

To test the safety and effectiveness of carboxyl-methyl-cellulose dressing (Aquacel; ConvaTec, UK) in the management of deep diabetic foot ulcers, a group of consecutive out-patients attending the foot clinic of the Department of Metabolic Diseases was studied.

METHODS

Patients were selected according to the following inclusion criteria: a foot ulcer deeper than 1 cm for > 3 weeks, good peripheral blood supply (palpable peripheral pulses or ABPI > 0.9). Exclusion criteria were as follows: active infection, as evident from clinical signs (purulent discharge, redness, swelling, tenderness) and confirmed by culture exams, plasma creatinine > 2 mg/dl, recent episodes of ketoacidosis, malignancies, and any therapy or pathology which might interfere with the healing process. Twenty patients were enrolled in the study and having obtained their informed consent, their lesions were surgically debrided with the complete elimination of all necrotic tissue and debris up to the bleeding healthy tissue; then ulcers were staged and measured, and patients were randomly assigned to two different treatment groups. Patients in group A were dressed with saline-moistened gauze, while patients in group B were dressed with Aquacel according to the manufacturer's instructions. All patients in both groups received special post-operative shoes (Podiabetes; Zeno Buratto, Treviso, Italy) and crutches until complete re-epithelialization. Ulcers were all left to heal by secondary intent. After 8 weeks patients were blindly evaluated for: the rate of reduction of lesional volume (RLV), rate of granulation tissue (GT), number of infective complications (IC). Intralesional (ILTC) and perilesional (PLTC) temperatures were also recorded with a thermocouple surface digital thermometer, and the difference between the two values (Delta TC) was calculated. Healing time (HT, days), was then compared between the two groups. Data were compared by analysis of variance (ANOVA), linear regression, Kaplan-Meier survival analysis and Fisher's exact test.

RESULTS

HT was significantly shorter in Group B than in Group A (P < 0.001). RLV was significantly (P < 0.01) higher in Group B patients compared with Group A, as well as GT (P < 0.05). IC were in 1/10 Group B and in 3/10 Group A (P = 0.582). In addition, both ILTC and Delta TC were higher in Group B compared with Group A ones (P < 0.01).

CONCLUSIONS

Carboxyl-methyl-cellulose dressings were shown to be safe, effective and well tolerated in the management of non-ischaemic, non-infected deep diabetic foot ulcers.