Pressure garment design tool to monitor exerted pressures

Pressure garments are used in the treatment of hypertrophic scarring following serious burns. The use of pressure garments is believed to hasten the maturation process, reduce pruritus associated with immature hypertrophic scars and prevent the formation of contractures over flexor joints. Pressure garments are normally made to measure for individual patients from elastic fabrics and are worn continuously for up to 2 years or until scar maturation. There are 2 methods of constructing pressure garments. The most common method, called the Reduction Factor method, involves reducing the patient's circumferential measurements by a certain percentage. The second method uses the Laplace Law to calculate the dimensions of pressure garments based on the circumferential measurements of the patient and the tension profile of the fabric. The Laplace Law method is complicated to utilise manually and no design tool is currently available to aid this process. This paper presents the development and suggested use of 2 new pressure garment design tools that will aid pressure garment design using the Reduction Factor and Laplace Law methods. Both tools calculate the pressure garment dimensions and the mean pressure that will be exerted around the body at each measurement point. Monitoring the pressures exerted by pressure garments and noting the clinical outcome would enable clinicians to build an understanding of the implications of particular pressures on scar outcome, maturation times and patient compliance rates. Once the optimum pressure for particular treatments is known, the Laplace Law method described in this paper can be used to deliver those average pressures to all patients. This paper also presents the results of a small scale audit of measurements taken for the fabrication of pressure garments in two UK hospitals. This audit highlights the wide range of pressures that are exerted using the Reduction Factor method and that manual pattern ‘smoothing’ can dramatically change the actual Reduction Factors used.     

What is the prevalence of hypertrophic scarring following burns?

Hypertrophic scarring after burns remains a major problem and is considered to be "common". Pressure garments are commonly used as treatment even though there is little sound data that they reduce the prevalence or magnitude of the scarring. In 1999 we began a study of the efficacy of pressure garments on forearm burns. After studying 30 patients, mainly white adults, we found no hypertrophic scar in either those treated with pressure or without. This prompted us to review the literature on the prevalence of hypertrophic scarring after burns and found only four articles with a relatively small number of patients and only three geographical locations. It became clear that the prevalence of hypertrophic scarring is really unknown. We then did a retrospective study of 110 burn survivors and counted all hypertrophic scars of all sizes and locations in all races and found the prevalence hypertrophic scarring to be 67% which conflicts with the published reports and our prospective study and suggests that further research is necessary. We concluded that a worldwide, prospective survey is necessary to establish the prevalence of hypertrophic scarring after burns. In this article we are calling for and offering to organize this survey.     

Designing pressure garments capable of exerting specific pressures on limbs

Pressure garments have been used prophylactically and to treat hypertrophic scars, resulting from serious burns, since the early 1970s. They are custom-made from elastic fabrics by commercial producers and hospital staff. However, no clear scientifically established method has ever been published for their design and manufacture. Previous work [2] identified the most commonly used fabrics and construction methods for the production of pressure garments by hospital staff in UK burn units. These methods were evaluated by measuring pressures delivered to both cylinder models and to human limbs using I-scan pressure sensors. A new calibration method was developed for the I-scan system to enable measurement of low interface pressures to an accuracy of +/-2.5 mmHg. The effects of cylinder/limb circumference and pressure garment design on the pressures exerted were established. These measurements confirm the limitations of current pressure garment construction methods used in UK hospitals. A new method for designing pressure garments that will exert specific known pressures is proposed and evaluated for human thighs. Evaluation of the proposed design method is ongoing for other body parts.     

12-Year within-wound study of the effectiveness of custom pressure garment therapy

Pressure garment therapy is standard of care for prevention and treatment of hypertrophic scarring after burn injury. Nevertheless there is little objective data that confirms effectiveness. The purpose of this study was to determine the effectiveness of pressure garment therapy with objective data obtained with a randomized within-wound comparison. We enrolled consecutive patients with forearm injuries over a 12-year period. The subjects wore custom garments with normal and low compression randomized to either the proximal or distal zones. Hardness, color and thickness of wounds were objectively measured using appropriate devices; clinical appearance was measured by a panel masked to the identity of the pressure treated area. Wounds treated with normal compression were significantly softer, thinner, and had improved clinical appearance. There was no interaction of any effect with patient ethnicity. However, these findings were clinically evident only with moderate to severe scarring. We conclude that pressure garment therapy is effective, but that the clinical benefit is restricted to those patients with moderate or severe scarring.     

Pressure therapy in the treatment of post-burn hypertrophic scar—A critical look into its usefulness and fallacies by pressure monitoring

Pressure therapy is generally accepted as the best non-invasive means of preventing and controlling hypertrophic scarring after burn injury. Most studies in the past have failed to correlate clinical response with magnitude of the garment-scar interface pressure.This study looked critically at our usual techniques of pressure therapy using pressure ‘sensors’ manufactured locally and based on electro-pneumatic principles. Many pitfalls, such as large variations of pressure at different geometric sites on the body, elastic deterioration in garments, problems of garment manufacture, and the unfavourable properties of the Lycra garments, were observed. Recommendations on pressure treatment were made based on our experiences, to improve the present technique of pressure therapy. These included the standardization of measurement techniques and garment tailoring, the regular checking of pressure at the garment-scar interface using pressure transducers, the appropriate garment adjustments, a strict regimen for garment wearing, and the intelligent use of pressure-padding and reinforcement. Areas of further research are also discussed.     

Effect of facial pressure garments for burn injury in adult patients after orthodontic treatment

Pressure garments are commonly used to prevent and control hypertrophic scar tissue. Complications are unusual, though in children with facial burns, pressure garments may lead to skeletal and dental deformities. Studies in adolescents and adults are sparse. We describe a 24-year-old woman who sustained facial burns. Prior to injury, the patient had undergone premolar extraction in preparation for orthodontic treatment. Her post-burn care consisted of application of a Jobst pressure garment. After 2 months treatment, severe deformation of the dental-alveolar structure was observed. This reports suggests that adults after dental extraction are at a high risk of dental-alveolar deformities from pressure garments and might benefit from the use of occlusal wafers.     

Pressure garments for use in the treatment of hypertrophic scars--a review of the problems associated with their use

Pressure garments have been the mainstay of hypertrophic scar treatment since the 1970s. However, there are many problems associated with their use. This is the first in a series of papers on pressure garments that will review the literature published to date on the origins of pressure garments for hypertrophic scar treatment and the problems associated with current pressure garment use.     

Adherence to pressure garment therapy in adult burn patients

Pressure garment therapy (PGT) is a generally accepted procedure to prevent hypertrophic scarring after severe burns. Wearing pressure garments is uncomfortable and challenging for the patient and, consequently adherence is low. In order to improve adherence, precise knowledge about the advantages and disadvantages of PGT is necessary. In this study we investigated specific aspects which inhibit or reinforce the application of PGT on the patients’ part. Twenty-one patients participated in a semi-structured interview concerning their experiences with PGT. The complaints most frequently mentioned were ‘physical and functional limitations’ caused by the garments, ‘additional effort’ created by the need to care for garments and ‘perceived deficiencies’ of the treatment. At the same time, most of the patients reported coping strategies used to persevere with the therapy. Coping can be categorised into ‘behavioural’ and ‘cognitive coping strategies’. Besides the ‘expectation of success’, ‘emotional’ as well as ‘practical support’ and experiencing ‘good outcome’ were motivating factors for the patients. Based on the analyses of limitations and resources, recommendations for future interventions enhancing adherence are outlined.     

Pressure-related analysis of compression therapy after burn injuries in childhood

BACKGROUND: Burns and scalds are among the most common traumas in childhood and more than often lead to hypertrophic scarring. Compression therapy is one of the main concepts in the prophylaxis and therapy for hypertrophic scars. However, the mode of action and the optimum value for pressure are still unknown. In this study, we evaluated the possibility of measuring the pressure under compression garments with a simple pressure measuring device. MATERIAL AND METHODS: Pressure generation occurred by an air-filled balloon connected to a piezoresistive pressure sensor, which showed the pressure as a value of voltage. Calibration was possible with p相似文献   

The assessment of erythema and thickness on burn related scars during pressure garment therapy as a preventive measure for hypertrophic scarring

The aim of this study was threefold: (1) Assess the pressure loss of two types of pressure garments that are used in the treatment of hypertrophic scars after burn injury, (2) investigate the influence of two different levels of compression on erythema and thickness of burn scars and (3) examine the association between erythema and thickness. The study was a prospective trial in which 76 burn scars in 60 patients were objectively assessed with the Minolta Chromameter CR-300 for erythema and with the Dermascan C for thickness of the scar over a period of 3 months. Each patient was randomly assigned to a "normal" or "lower" compression class treatment, with respectively mean values of 15 and 10 mmHg pressure after wearing the garment for 1 month. Measurements for both parameters were taken at 0, 1, 2 and 3 months of treatment. Pressure garments with "normal" compression did lose significantly more compression over 1 month (4.82 mmHg) than did the garments from the low compression class (2.57 mmHg). Scars that were treated with garments from a "normal" compression class did score significantly better for thickness compared to the "low" compression class. The difference in thickness was most evident at 1 month. Thereafter no further significant improvement between the two different treatments over time could be obtained. This difference was not found for erythema. Positive correlations could be found between erythema and thickness values at all of the three test points while changes in erythema and thickness only correlated significantly after the first month. The pattern of change of both parameters correlated at a high level of significance after 3 months of treatment. These data suggest that pressure garments that deliver a pressure of at least 15 mmHg pressure tend to accelerate scar maturation and that measurements of the pattern of change of the erythema can be used to predict changes in scar thickness and vice versa.     

Pressure by design: How to improve the consistency of pressure garments in the clinical environment and implement a simple method for gathering evidence to establish efficacy

Pressure garments are used to treat scars after major trauma including burns. However, the ideal pressure for treatment is not known. Pressures exerted are not routinely measured and garments exert a wide range of pressures. Therefore, current treatment and its efficacy are variable.Pressure Garment Design Tools were introduced in 2012 but their application in hospitals has not been reported. A Garment Dimension and Pressure Calculator was used to audit pressures delivered by 8 pressure garments made for children using the hospital department’s standard reduction factor. The tool was easy to use and showed that pressures exerted by standard garments ranged from 15 to 54 mmHg with highest pressures exerted on wrists.Results of our pilot study indicated that the Garment Dimension and Pressure Calculator was slightly quicker to use than our normal manual process for calculating garment dimensions and enabled easy auditing of past treatment. The Pressure Garment Design Tool was easy to use and calculated garments that exerted the mean target pressures of 15 mmHg and 25 mmHg, improving consistency.Pressures exerted by garments were difficult and time consuming to measure with the Picopress sensor. Pressure was not distributed evenly around the limbs and measurements were inaccurate on the smallest limbs.     

A novel technique to determine pressure in pressure garments for hypertrophic burn scars and comfort properties

Current recommendations state that pressure garments should be worn for up to 2 years for hypertrophic burn scars. Thermo-physiological properties of pressure garments were assessed by the thermo-physiological tests and a comparison of the fabric with a sportwool which is a single-jersey knitted fabric was performed. In this novel technique, it was aimed to determine the exact pressure of pressure garments on the applied body part. For the theoretical part of this study, the Laplace equation was used with an optimum pressure of 20 mmHg and a relationship between change in length versus circumference was calculated. To determine the change in length a ruler was prepared for each predetermined circumference value using this relationship. Grid printed fabric samples were prepared with an interval of 2 cm in width direction to be used for the calculation of mean pressure on a Mannequin Leg. The resultant mean pressure calculated experimentally on Mannequin Leg as 24 mmHg was compared to the optimum pressure of 20 mmHg. It was observed that the two values were not statistically significantly different.     

Evidence of invasive and noninvasive treatment modalities for hypertrophic scars: A systematic review

Currently, there are various therapeutic approaches to reduce hypertrophic scarring; however, there is no standard evidence‐based treatment protocol. Hence, a systematic review was performed to obtain a summary of the latest clinical trials to evaluate evidence for the treatment of hypertrophic scars. The review protocol was registered and approved by PROSPERO (CRD42015027040). PubMed and Web of Science were searched using predefined MeSH‐Terms to identify studies published within the last 10 years regarding treatment for hypertrophic scars. Exclusion criteria included a level of evidence (LoE) lower than I, nonhuman in vivo studies, in vitro studies, studies on keloids, literature reviews, and non‐English articles. The literature search identified 1,029 unique articles, whereas 6 articles were prospective, randomized, blinded, controlled clinical trials with a LoE I, and were thus included in the systematic analysis. Three clinical trials evaluated silicone products and pressure garments, and the other three studies investigated the efficacy of intralesional injections of triamcinolone (TAC), 5‐Fluorouracil (5‐FU) combined with TAC as well as the additional irradiation with a 585 nm pulsed‐dye laser (PDL). Intralesional injections revealed significant improvements of the scar quality in terms of height, thickness, erythema, and pigmentation. Pressure garments showed favorable results but there was no evidence that silicone products were able to improve the scar quality. The systematic review demonstrated that there are just a few clinical trials with a LoE of I. Consequently, evidence is still lacking especially for noninvasive treatment regimens for hypertrophic scars. Intralesional injections of 5‐FU mixed with a low dose of TAC can be seen as most appropriate treatment modality. Prospective clinical trials to determine the efficiency of silicone products are warranted.     

Reproducibility of repeated measurements with the Kikuhime pressure sensor under pressure garments in burn scar treatment

This study investigated the reproducibility of repeated measurements with the Kikuhime pressure sensor under two different types of pressure garments used in the treatment and prevention of scars after burns. Also efficiency of garments was assessed in clinical circumstances by assessing pressure loss and residual pressure after 1 month. Intra- and inter-observer reproducibility and repeated measurements with 1-month time lapse were examined on 55 sites in 26 subjects by means of intra-class correlation coefficients and standard error of measurements. Results showed good to excellent ICC and low SEMs in the two conditions. There was a significant difference in pressure after 1 month between elastic tricot and weft knit garments, although evolution of pressure loss after 1 month was similar. Concerning different locations, there was a significant difference in pressure loss after 1 month between gloves and sleeves with the largest pressure loss for sleeves. Considering these results we concluded that the Kikuhime pressure sensor provides valid and reliable information and can be used in comparative clinical trials to evaluate pressure garments used in burn scar treatment. Secondly, elastic tricot garments in our study tended to have higher clinical pressures but both types of garments had similar pressure loss over time.     

Comparison between the portable pressure measuring device and PicoPress® for garment pressure measurement on hypertrophic burn scar during compression therapy

PurposeThe current standard treatment for hypertrophic scars following burn injury is pressure garment therapy. The experimenters developed the novel portable pressure measuring device using silicon piezoresistive sensors. As PicoPress® is the most accurate (i.e., lowest variation and error) manometric sensor for pressure measurement, we sought to compare and examine the accuracy of the novel device regarding in vitro pressure measurements at the hypertrophic scar–pressure garment interface.MethodsThe novel device was designed to operate in non-corrosive media, such as air. The device can use up to six pressure sensing points and was developed to adjust the number of pressure sensors according to the size of the scar. Pressure measurements were acquired through a readout circuit consisting of an analog-to-digital converter, a microprocessor, and a Bluetooth transmission module for wireless data transmission to an external device. All signals were converted into mean pressure expressed in millimeters of mercury (mmHg). The mean pressure values measured by the sensors were compared to those obtained from PicoPress®. 55 garment pressures recordings were obtained from the sensors over this study conducted in 2018–February 2020. We then analyzed the test–retest reliability using the intraclass correlation coefficients (ICC). PicoPress® was also employed in the same pressure garments for obtaining similar measurements. A two way random effects model ICC with 95% confidence intervals was used to compare the mean pressure values obtained from the silicon piezoresistive sensors to the PicoPress® measurements.ResultsThe test–retest reliability of the pressure sensors was close to the acceptable level for clinical use regarding stationary interface pressure measurement (ICC = 0.99, 95% CI 0.990−0.997). The mean pressure obtained from the silicon piezoresistive pressure sensors showed an accordance with the measurements from PicoPress® (ICC = 0.97, 95% CI 0.947−0.985).ConclusionThe novel device may present a viable alternative to PicoPress® for garment pressure measurements. In addition, the novel device improves adaptability to the hypertrophic scar shape and size. Complementary characteristics such as wireless transmission to an external device may allow burn patients to continuously wear the device for real-time measurements during pressure garment therapy, thus improving existing devices including PicoPress®.     

Cones of skin occur where hypertrophic scar occurs

Hypertrophic scarring is devastating for the patient, however the pathophysiology and treatment remain unknown after decades of research. The process follows deep dermal injury, occurs only on certain body parts, does not occur in the early fetus or in animals, and is a localized event. This suggests that an anatomic structure in human, deep dermis may be involved. The dermis is a matrix perforated by cones containing many structures including skin appendages and fat domes. We hypothesized that studying the cones might reveal a structure related to scarring. We examined tangential wounds from various body parts on human cadavers along with skin histology from various human body parts, the early fetus, partial thickness burns, hypertrophic scars, and two other species-rats and rabbits. We found that the cones may in fact be the structure. They exist where hypertrophic scar occurs-cheek, neck, chest, abdomen, back, buttock, arm, forearm, dorsal hand, thigh, leg, dorsal foot, helix and ear lobe. They do not exist where hypertrophic scar does not occur-scalp, forehead, concha, eyelid, palm, early fetus, and in rat, or rabbit. It also became apparent that the cones have been omitted from most considerations of skin histology. We suggest that the cones need to be studied in relation to hypertrophic scarring and restored to skin diagrams.     

Effect of different pressure magnitudes on hypertrophic scar in a Chinese population

Introduction

This study aimed to investigate the effect of different pressure magnitudes on treatment outcomes of hypertrophic scars, and determine pressure loss over time.

Methods

A randomized clinical trial was adopted. 53 hypertrophic scar samples from 17 Chinese participants were recruited and randomly assigned into a high pressure group (20–25 mmHg) and low pressure group (10–15 mmHg) for a five-month intervention program. The scars were assessed objectively before intervention and monthly after intervention for thickness, color (redness, yellowness and lightness) and scar pliability. Pressure magnitude at each assessment was also measured. Two-way repeated ANOVA was used to compare for differences between groups.

Results

The results showed that both levels of pressure produced reduction in scar thickness and redness, but the improvement in the high pressure group was statistically better than that of the counterpart (both p < 0.05). Monthly pressure measurement revealed that pressure loss in the high pressure group was more severe. However, no major changes in other color parameters and pliability were observed for both the groups.

Conclusion

High pressure was demonstrated to be more effective for scar management, but it was also more prone to higher pressure loss. Pressure therapy integrated with regular monitoring of the interface pressure is suggested to improve its therapeutic efficacy.     

A simple device to encourage the unwilling child to wear a pressure garment

This brief report describes how, with commendable psychological insight, the father of a child recently treated in our burns unit adopted a very simple device to encourage his youngster to wear a pressure garment to deal with hypertrophic scarring.     

New calibration method for I-scan sensors to enable the precise measurement of pressures delivered by 'pressure garments'

Accurate measurement of the pressure delivered by medical compression products is highly desirable both in monitoring treatment and in developing new pressure inducing garments or products. There are several complications in measuring pressure at the garment/body interface and at present no ideal pressure measurement tool exists for this purpose. This paper summarises a thorough evaluation of the accuracy and reproducibility of measurements taken following both of Tekscan Inc.’s recommended calibration procedures for I-scan sensors; and presents an improved method for calibrating and using I-scan pressure sensors. The proposed calibration method enables accurate (±2.1 mmHg) measurement of pressures delivered by pressure garments to body parts with a circumference ≥30 cm. This method is too cumbersome for routine clinical use but is very useful, accurate and reproducible for product development or clinical evaluation purposes.     

A semi-rigid transparent face mask in the treatment of postburn hypertrophic scars

Scars, following burns to the face or subsequent skin grafts, can become hypertrophic. The concept of pressure in their treatment is not new. Elastic garments have been popularised and used successfully. However, they have certain limitations. To date, very little reference has been made in the literature to the use of masks. The use of a semi-rigid face mask in the treatment of hypertrophic scars is described. These masks are comfortable to wear, well tolerated and very effective. Case reports are presented and the technique of manufacture detailed.