Effectiveness of a multi‐layer foam dressing in preventing sacral pressure ulcers for the early acute care of patients with a traumatic spinal cord injury: comparison with the use of a gel mattress

Individuals with spinal cord injury are at risk of sacral pressure ulcers due to, among other reasons, prolonged immobilisation. The effectiveness of a multi‐layer foam dressing installed pre‐operatively in reducing sacral pressure ulcer occurrence in spinal cord injured patients was compared to that of using a gel mattress, and stratified analyses were performed on patients with complete tetraplegia and paraplegia. Socio‐demographic and clinical data were collected from 315 patients admitted in a level‐I trauma centre following a spinal cord injury between April 2010 and March 2016. Upon arrival to the emergency room and until surgery, patients were transferred on a foam stretcher pad with a viscoelastic polymer gel mattress (before 1 October 2014) or received a multi‐layer foam dressing applied to their sacral‐coccygeal area (after 1 October 2014). The occurrence of sacral pressure ulcer during acute hospitalisation was similar irrespective of whether patients received the dressing or the gel mattress. It was found that 82% of patients with complete tetraplegia receiving the preventive dressing developed sacral ulcers as compared to only 36% of patients using the gel mattress. Although multi‐layer dressings were suggested to improve skin protection and decrease pressure ulcer occurrence in critically ill patients, such preventive dressings are not superior to gel mattresses in spinal cord injured patients and should be used with precaution, especially in complete tetraplegia.     

Cost‐effectiveness of multi‐layered silicone foam dressings for prevention of sacral and heel pressure ulcers in high‐risk intensive care unit patients: An economic analysis of a randomised controlled trial

Pressure ulcer incidence is high in intensive care units. This causes a serious financial burden to healthcare systems. We evaluated the cost‐effectiveness of multi‐layered silicone foam dressings for prevention of sacral and heel pressure ulcers in addition to standard prevention in high‐risk intensive care units patients. A randomised controlled trial to assess the efficacy of multi‐layered silicone foam dressings to prevent the development of pressure ulcers on heels and sacrum among 422 intensive care unit patients was conducted. Direct costs for preventive dressings in the intervention group and costs for treatment of incident pressure ulcers in both groups were measured using a bottom‐up approach. A cost‐effectiveness analysis by calculating the incremental cost‐effectiveness ratio using different assumptions was performed. Additional dressing and labour costs of €150.81 (€116.45 heels; €34.36 sacrum) per patient occurred in the intervention group. Treatment costs were €569.49 in the control group and €134.88 in the intervention group. The incremental cost‐effectiveness ratio was €1945.30 per PU avoided (€8144.72 on heels; €701.54 sacrum) in the intervention group. We conclude that application of preventive dressings is cost‐effective for the sacral area, but only marginal on heels for critically ill patients.     

The effectiveness of the Australian Medical Sheepskin for the prevention of pressure ulcers in somatic nursing home patients: A prospective multicenter randomized‐controlled trial (ISRCTN17553857)

A multicenter prospective randomized clinical trial was undertaken to investigate the effectiveness of the Australian Medical Sheepskin (AMS) in the prevention of sacral pressure ulcers in somatic nursing home patients. Patients were randomized at admission and were then followed daily for 30 days. The experimental group received usual care plus an AMS as a layer on the mattress within ultimately 48 hours after admission; the control group received usual care only. Usual care was all the care that nursing wards normally applied for pressure ulcer prevention without any further standardization for this study. A total of 588 patients were randomized (293 control and 295 experimental group) and the data of 543 patients could be analyzed (272 from the control and 271 from the experimental group). The incidence of sacral pressure ulcers grade 1 or higher was significantly lower in the experimental group than in the control group (8.9% vs. 14.7%). In a multilevel analysis on the incidence of pressure ulcers adjusted for Braden risk score, age, and gender, it shows an odds ratio of 0.53 (95% confidence interval: 0.29–0.95), meaning a significant protective effect of the AMS. These results are in line with the results of two earlier trials on the AMS in hospital patients. The majority of patients in our trial that used an AMS rated it positively, but one‐third found the sheepskin too warm. We conclude that the AMS is an effective aid in the prevention of sacral pressure ulcers in nursing home patients.     

A randomised controlled trial of the effectiveness of soft silicone multi‐layered foam dressings in the prevention of sacral and heel pressure ulcers in trauma and critically ill patients: the border trial

The prevention of hospital acquired pressure ulcers in critically ill patients remains a significant clinical challenge. The aim of this trial was to investigate the effectiveness of multi‐layered soft silicone foam dressings in preventing intensive care unit (ICU) pressure ulcers when applied in the emergency department to 440 trauma and critically ill patients. Intervention group patients (n = 219) had Mepilex^® Border Sacrum and Mepilex^® Heel dressings applied in the emergency department and maintained throughout their ICU stay. Results revealed that there were significantly fewer patients with pressure ulcers in the intervention group compared to the control group (5 versus 20, P = 0·001). This represented a 10% difference in incidence between the groups (3·1% versus 13·1%) and a number needed to treat of ten patients to prevent one pressure ulcer. Overall there were fewer sacral (2 versus 8, P = 0·05) and heel pressure ulcers (5 versus 19, P = 0·002) and pressure injuries overall (7 versus 27, P = 0·002) in interventions than in controls. The time to injury survival analysis indicated that intervention group patients had a hazard ratio of 0·19 (P = 0·002) compared to control group patients. We conclude that multi‐layered soft silicone foam dressings are effective in preventing pressure ulcers in critically ill patients when applied in the emergency department prior to ICU transfer.     

Clinical and epidemiologic evaluation of pressure ulcers in patients at a university hospital in Turkey.

OBJECTIVE: We sought to measure the incidence of pressure ulcer development at a university health center in Turkey, and to determine whether the Waterlow Pressure Sore Risk (PSR) Scale score predicted pressure ulcer development, stage, or number of ulcers. DESIGN: We prospectively evaluated patients who were hospitalized at our university-based medical center. SETTING AND SUBJECTS: We analyzed data from 22,834 patients hospitalized at the Baskent University Adana Teaching and Medical Research Center in Ankara, Turkey from January 1, 2004 to December 31, 2004, including 360 patients who developed pressure ulcers. INSTRUMENTS: The Waterlow PSR Scale was used to assess pressure ulcer risk. In addition, age, sex, the ward or unit in which the patient was hospitalized, reason for hospitalization, and location and stage of ulcers were collected on a data form designed specifically for this study. METHODS: A single nurse physiotherapist assessed all patients daily during their hospitalization. When a pressure ulcer was diagnosed by the nurse physiotherapist, a physician staged the pressure ulcers based on the US National Pressure Ulcer Advisory Panel (NPUAP) staging system. RESULTS: Three hundred sixty out of 22,834 patients developed 1 or more pressure ulcers, resulting in an incidence rate of 1.6%. Most ulcers (59.2%) occurred in patients hospitalized in the intensive care unit (n = 213). A positive correlation between the Waterlow PSR Scale score and number of ulcers per patient (r: 0.178, P < .01) was identified. No significant correlation was found linking Waterlow PSR Scale score and ulcer stage or the development of a single ulcer. CONCLUSION: We found significantly lower pressure ulcer incidence rates than those commonly reported in the literature, which we believe is principally attributable to short hospital stays and a strong emphasis on preventive nursing care. While high Waterlow PSR scale Scores correlated positively with development of multiple ulcers, this did not predict ulcer stage or the presence of a single pressure ulcer.     

Outcomes for surgical coverage of pressure sores in nonambulatory,nonparaplegic, elderly patients

Pressure sores are a common complication of long-term institutional care. Surgical coverage of late-stage ulcers in the elderly refractory to conservative therapy remains controversial. The authors reviewed the outcome of 22 predominately nonambulatory, nonparaplegic, elderly patients with coverage of 27 pressure sores. The mean patient age was 59 years (range, 50-82 years). The average follow-up was 6 months (range, 3 months-2 years). There were 11 complications for the 22 patients (50%) and the 27 ulcers (41%). Postoperatively, a well-healed ulcer was present in 19 of 27 patients (70%) at 6 months. Of the 19 reconstructed sacral ulcers, there were 10 complications (53%) and one recurrence at 6 months. Seven trochanteric ulcers were covered with tensor fascia lata flaps without complications or recurrences at the 6-month follow-up. One ischial ulcer was managed using a V-Y hamstring advancement flap, resulting in dehiscence and a subsequent revision. The authors advocate surgical coverage to treat late-stage pressure sores in nonparalyzed elderly persons to reduce the morbidity, mortality, and economic burden of patients with late-stage pressure ulcers. With an increasing geriatric population, prevention and postoperative care are necessary to diminish the incidence, recurrence, and burden of pressure sores.     

Management of sacral pressure sores with a myocutaneous flap

Sacral ulcers usually are caused by pressure leading to pathologic changes in the layers of tissue extending from the skin to the bone. This type of ulcer occurs most commonly in paraplegic or unconscious patients. In a series of 25 patients with sacral pressure sores studied during a one year period of time, the initial management consisted of conservative treatment with excision of the ulcer and daily dressing changes. The results with this method of treatment were satisfactory in ten cases and unsatisfactory in 15 cases. The 15 cases in which the results were unsatisfactory then underwent treatment with operative methods including excision of the ulcer and primary closure, myocutaneous flaps, skin grafting, and transcutaneous skin flaps. In six of ten cases in which a myocutaneous flap was used, the wounds healed satisfactorily. In four cases an infection occurred; in three of these cases the wound healed after infection control, while skin grafting was required for the fourth patient. Overall, the postoperative results with the use of a myocutaneous flap were satisfactory, and the results also were good at follow-up.     

Prospective clinical study of a new adhesive gelling foam dressing in pressure ulcers

This prospective, non comparative study evaluated the safety and effectiveness of an adhesive gelling foam dressing in pressure ulcer management. Twenty-three subjects with exuding pressure ulcers were recruited from seven centres in the USA and Canada. Study treatment included an adhesive gelling foam dressing, optional tape/roll bandaging and mandatory pressure-reducing/relieving devices. Subjects were followed until ulcer healing, for up to 28 days, or on patient withdrawal from the study, whichever came first. Dressings were changed at least once every 7 days. Mean percentage change in ulcer area from baseline to final measurement was -13%. Investigators reported healing or subjective improvement of ulcer condition in 61% of patients. Mean dressing wear time was 4.2 days. Subjects found the dressing was comfortable, soothing and cushioning in situ at 80%, 64% and 70% of dressing changes, respectively. Subjects reported pain severity of none or mild for every dressing change. Fourteen subjects experienced adverse events, including seven subjects with study-related maceration, erythema, wound enlargement, blister or infection. A regimen including an adhesive gelling foam dressing proved to be safe and effective for managing exudate, protecting the surrounding skin, minimising pain and supporting healing of pressure ulcers with exudate.     

Description of pressure ulcer pain at rest and at dressing change.

PURPOSE: To describe and compare the pain experienced by patients with stage II, III, and IV pressure ulcers both at rest and during dressing change. PATIENTS AND SETTING: Thirty-two subjects were recruited from acute, extended, and home care settings in the Midwest. The sample population ranged in age from 47 to 95 years (mean age 74.7 years, SD = 12.8), were white, and evenly divided between male and female patients. METHODS: Patients used the McGill Pain Questionnaire to rate their pressure ulcer pain at rest and again at dressing change. RESULTS: Twenty-eight subjects (87.5%) reported pain at dressing change and 27 (84.4%) experienced pain at rest, compared with 4 (12.5%) subjects who reported no pressure ulcer-related pain. Of the 28 reporting pain, 21 (75%) rated their pain as mild, discomforting, or distressing, and 5 (18%) described their pain as horrible or excruciating. Twelve (42%) reported their pain as continuous, occurring both at rest and during dressing changes. Despite these reports, only 2 (6%) subjects had received medication for their pressure ulcer pain. Although none of the hypotheses were statistically significant, we observed that patients with stage II, III, and IV pressure ulcers experienced pain. CONCLUSIONS: Within this study sample, the majority of patients had pressure ulcer-related pain, which for some was severe and constant. Therefore we conclude that the potential for pressure ulcer-related pain should be anticipated and assessed on a regular basis. In addition, further research is needed to increase our understanding of pressure ulcer pain and to find effective interventions for its relief.     

Release of sodium pyruvate from sacral prophylactic dressings: A computational model

The use of sacral dressings for pressure ulcer prevention is growing rapidly. In addition to their passive biomechanical role in pressure and shear reduction, in the near future, prophylactic dressings may also provide active tissue protection by releasing preventive agents or drugs into skin and deeper tissues. We investigated delivery of sodium pyruvate (NaPy) from an active dressing to potentially protect the sacral skin and underlying tissues in addition. We used four finite element model variants describing different skin roughness levels to determine time profiles of NaPy diffusion from the dressing into the skin layers. The NaPy concentrations for the different modelled cases stabilised after 1 to 6.5 hours from the time of application of the dressings, at 1% to 3% of the NaPy concentration in the dressing reservoir, which is considered potent. We conclude that prophylactic sacral dressings have the potential to deliver NaPy into skin and subdermally, to potentially increase soft tissue tolerance to sustained bodyweight‐caused cell and tissue deformations. The time durations to achieve the steady‐state potent NaPy dermal concentrations are clinically feasible, for example, for preparation of patients for surgery or for use in intensive care units.     

Effectiveness of using a new polyurethane foam multi‐layer dressing in the sacral area to prevent the onset of pressure ulcer in the elderly with hip fractures: A pragmatic randomised controlled trial

Hip fractures in the elderly are a serious problem for the health service due to the high rate of complications. One of these complications is pressure ulcers that, according to the literature, occur in 8.8% to 55% of patients and mainly arise in the sacral area. The present randomised controlled trial tests whether applying a new innovative multi‐layer polyurethane foam dressing (ALLEVYN LIFE™), reduces the onset of pressure ulcers in the sacral area. From March to December 2016, 359 fragility hip fracture patients were randomly divided into 2 groups: 182 in the control group and 177 in the experimental group. Pressure ulcers occurred overall in 36 patients (10%): 8 patients (4.5%) in the experimental group compared to 28 (15.4%) in the control group: P = 0.001, relative risk 0.29 (95% CI 0.14‐0.61) with NNT of 9 (95% CI 6‐21). In the experimental group the onset of pressure ulcers occurred on average on the 6th day compared to the 4th day in the control group (HR 4.4). Using polyurethane foam is effective at reducing the rate of pressure ulcers in the sacrum in elderly patients with hip fracture. The adhesiveness of this device also enables costs to be kept down.     

Risk factors for pressure ulcers among elderly hip fracture patients

The purpose of this study was to estimate the incidence of hospital-acquired pressure ulcers among elderly patients hospitalized for hip fracture surgery and to identify extrinsic factors that are associated with increased risk. We conducted a secondary analysis of data abstracted from medical records at 20 hospitals in Pennsylvania, Texas, New Jersey, and Virginia. Participants were patients aged 60 years and older admitted with hip fracture to the study hospitals between 1983 and 1993. The incidence of hospital-acquired pressure ulcers was 8.8% (95% confidence interval 8.2%-9.4%). After adjusting for confounding variables, longer wait before surgery, intensive care unit stay, longer surgical procedure, and general anesthesia were significantly associated with higher pressure ulcer risk. Extrinsic factors may be important markers for high pressure ulcer risk in hospitalized hip fracture patients. Although it is not possible to eliminate factors such as requiring an intensive care unit stay or having a long surgical procedure, it may be possible to develop interventions that minimize pressure ulcer risk in patients who experience these factors.     

The cost‐benefit of using soft silicone multilayered foam dressings to prevent sacral and heel pressure ulcers in trauma and critically ill patients: a within‐trial analysis of the Border Trial

Little is known about the cost‐benefit of soft silicone foam dressings in pressure ulcer (PU) prevention among critically ill patients in the emergency department (ED) and intensive care unit (ICU). A randomised controlled trial to assess the efficacy of soft silicone foam dressings in preventing sacral and heel PUs was undertaken among 440 critically ill patients in an acute care hospital. Participants were randomly allocated either to an intervention group with prophylactic dressings applied to the sacrum and heels in the ED and changed every 3 days in the ICU or to a control group with standard PU prevention care provided during their ED and ICU stay. The results showed a significant reduction of PU incidence rates in the intervention group (P = 0·001). The intervention cost was estimated to be AU$36·61 per person based on an intention‐to‐treat analysis, but this was offset by lower downstream costs associated with PU treatment (AU$1103·52). Therefore, the average net cost of the intervention was lower than that of the control (AU$70·82 versus AU$144·56). We conclude that the use of soft silicone multilayered foam dressings to prevent sacral and heel PUs among critically ill patients results in cost savings in the acute care hospital.     

Leg ulcer: proposal of a new method for comparing different wound dressings

The study proposes a new method for measuring peripheral trophic lesions (leg ulcers) of the same patient medicated with different type of dressing, avoiding errors of evaluation due to comparing different patients who generally present different concomitant pathologies and aetiologies wigh are hard to compare. We studied the wound care of 11 patients with leg ulcers. Half of the ulceration was treated with a traditional dressing (group A) and the other half with a more advanced type of dressing (group B). We first photographed the ulceration at a predefined distance an then the ulcer was separated in two identical parts and measured with millimetre paper. The limits and sides of each part were marked with a indelible marker pencil. The dressings were changed at regular interval and the ulcers were re-measured and photographed every week from the same distance. We examined 19 ulcers of the 11 patients (7 men, 4 women; mean age: 71 years). Although wound healing appeared to be faster in group B, the difference was not statistically significant (p = 0,246), but the aim of the study was not to explore the difference or otherwise in healing rate between two dressings. The study confirms that this method enables the physician to compare two different wound care dressings on the same ulcer. Interpatient variability is thus avoided by applying the dressings to the same ulcer. Changes in ulcer size are easily monitored and the statistical analysis of the areas compared allows objective assessment of the wound treatments, avoiding the common bias due to comparing different ulcers on different patients with different underlying pathologies.     

The prevalence of pressure ulcers in a tertiary care pediatric and adult hospital.

OBJECTIVE: To describe the pressure ulcer prevalence, stage and body location, and demographic characteristics of patients with pressure ulcers at a tertiary care adult hospital and a tertiary care pediatric hospital. DESIGN: Prevalence survey. SETTING AND SUBJECTS: A total of 513 inpatients, including 416 adults admitted to a tertiary care hospital and 97 children admitted to a tertiary care pediatric hospital. Only inpatients with mental health-related diagnoses were excluded. INSTRUMENTS: The Kinetics Concepts International's Prevalence and Incidence Study Collection Form was used to assess variables, including demographic information; presence, location, and stage of pressure ulcers; and presence of special support surfaces. METHODS: All patients had head-to-toe skin assessments performed during an 8-hour period by teams of 3 multidisciplinary staff members. Kinetics Concepts International's Prevalence and Incidence Program software and Microsoft Excel were used for data entry and analysis. RESULTS: Combined pressure ulcer prevalence was 26.3%, with 29.2% in adult patients and 13.1% in pediatric patients. The most common body locations for pressure ulcers were the sacrum (22.1%), heels (14.8%), ears (12.9%), elbows (10.6%), and the buttocks (6.8%). Forty-eight percent of the ulcers were stage I, 36% Stage II, 6% Stage III-IV, and 10% unable to stage. CONCLUSIONS: Overall combined pressure ulcer prevalence and common body locations were consistent with findings from comparable hospitals. Patients at the extreme ends of the age spectrum had an increased risk of pressure ulcers. Stage I and II ulcers occurred most frequently. Potential prevention and early management strategies may be effective in decreasing the prevalence of these ulcers.     

Effectiveness of a honey dressing for healing pressure ulcers.

OBJECTIVE: To compare the effect of a honey dressing vs an ethoxy-diaminoacridine plus nitrofurazone dressing in patients with pressure ulcers. DESIGN: This 5-week randomized clinical trial evaluated the effect of a honey dressing on pressure ulcer healing. SETTING AND SUBJECTS: Thirty-six patients with a total of 68 stage II or III pressure ulcers referred from a university hospital in Izmir were enrolled in the study. Twenty-six subjects completed the trial. INSTRUMENTS: Ulcers were measured with acetate tracings and Pressure Ulcer Scale for Healing (PUSH) evaluations. METHODS: Fifteen patients with 25 pressure ulcers were treated with honey dressings, and 11 patients with 25 pressure ulcers were treated with ethoxy-diaminoacridine plus nitrofurazone dressings. Wound healing was assessed weekly using the PUSH tool, version 3.0. The primary outcome measure was the change in PUSH tool scores in each group at 5 weeks. RESULTS: The two groups were statistically similar with regard to baseline and wound characteristics. After 5 weeks of treatment, patients who were treated by honey dressing had significantly better PUSH tool scores than subjects treated with the ethoxy-diaminoacridine plus nitrofurazone dressing (6.55 +/- 2.14 vs 12.62 +/- 2.15, P < .001). CONCLUSION: By week 5, PUSH tool scores showed that healing among subjects using a honey dressing was approximately 4 times the rate of healing in the comparison group. The use of a honey dressing is effective and practical.     

Cost consequences due to reduced ulcer healing times – analyses based on the Swedish Registry of Ulcer Treatment

Resource use and costs for topical treatment of hard‐to‐heal ulcers based on data from the Swedish Registry of Ulcer Treatment (RUT) were analysed in patients recorded in RUT as having healed between 2009 and 2012, in order to estimate potential cost savings from reductions in frequency of dressing changes and healing times. RUT is used to capture areas of improvement in ulcer care and to enable structured wound management by registering patients with hard‐to‐heal leg, foot and pressure ulcers. Patients included in the registry are treated in primary care, community care, private care, and inpatient hospital care. Cost calculations were based on resource use data on healing time and frequency of dressing changes in Swedish patients with hard‐to‐heal ulcers who healed between 2009 and 2012. Per‐patient treatment costs decreased from SEK38 223 in 2009 to SEK20 496 in 2012, mainly because of shorter healing times. Frequency of dressing changes was essentially the same during these years, varying from 1·4 to 1·6 per week. The total healing time was reduced by 38%. Treatment costs for the management of hard‐to‐heal ulcers can be reduced with well‐developed treatment strategies resulting in shortened healing times as shown in RUT.     

A national study of pressure ulcer prevalence and incidence in acute care hospitals.

OBJECTIVE: This study sought to establish national benchmarks for pressure ulcer prevalence and incidence among acute care health organizations served by Novation LLC. SETTING AND SUBJECTS: One hundred sixteen acute care facilities from 34 states participated; the sample consisted of 17,560 patients in hospital-based medical-surgical or intensive care units. INSTRUMENTS: Standardized education kits were provided to each participating site. The kits included an educational video about pressure ulcer staging, a post-test and answer key, and assessment form for patient data collection. METHODS: Pressure ulcer prevalence was measured during a predetermined 24-hour period at each facility. Incidence was measured over the average length of stay determined for each participating facility. Subjects were assessed by teams consisting of a registered nurse and one other health care professional (e.g. licensed practical nurse, physical therapist). Demographic, wound, and other data were collected for these patients. Data collection forms were audited and submitted to a central site for database entry, analysis, and generation of reports. RESULTS: The average length of stay for the participating facilities was 5 days. Pressure ulcers developed in 7% of the subjects (n = 383); 90% were stage I or II pressure ulcers, and 73% occurred in patients older than 65 years. The most sites based on both prevalence and incidence measurements were the sacrum and coccyx at 26% and 31%, respectively. CONCLUSIONS: Prevalence and incidence studies must be routinely conducted to clearly identify the extent of the pressure ulcer problem to provide guidance for efficient and effective corrective action.     

Chronic wounds and nursing care

This study has collated data on the prevalence of chronic wounds and the demography of patients with these wounds. Diagnostic methods, nursing care, the presence of diabetes and pain are analysed, as well as data on healing, amputation and mortality three months post-study. A total of 694 patients were identified: 406 with leg or foot ulcers, 117 with pressure ulcers and 171 with other wounds. Most patients were treated in the community. Leg ulcer aetiology was verified with ultrasound Doppler examination. There was a correlation between low Norton score (< 20) and severity of pressure ulcer (Stage III or IV). The use of 113 different wound dressings or combinations of products was reported. Time spent on dressing changes was the equivalent of full-time employment for 57 nurses. Wound cleansing was not predominantly performed with tap water, as recommended, but with saline. Almost all patients with venous leg ulcers (88%) were treated with compression but in 35% of these support stockings were used. Pain was present in almost half of all patients, more commonly in Stage III or IV pressure ulcers than in Stages I and II, and was most often reported in older patients. Diabetes was present in 25% of all patients with leg and pressure ulcers, and in 57% of patients with foot ulcers. At three-month follow-up, 28% of pressure ulcers, 40% of leg ulcers and 61% of other wounds had healed. Mortality was 35% in patients with pressure ulcers, 4% in those with leg ulcers and 7% in those with foot ulcers. These data have been presented to politicians in the county, resulting in allocation of resources for a wound healing centre.