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.     

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.     

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.     

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.     

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®.     

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.     

Measuring pressure under burns pressure garments using the Oxford Pressure Monitor

Pressure garments are used extensively in the treatment of hypertrophic scarring following burn injuries. The Oxford Pressure Monitor was used to measure garment-scar interface pressure (mmHg) using a number of fabric types over various body parts. The results indicate a wide range of pressure values between different garments and body parts with the greatest pressures found over the dorsum of hands and feet. The problems of achieving 'optimal pressure' over hypertrophic scarring are discussed with emphasis on the need for more accurate measuring equipment.     

Short and long term reproducibility of urethral closure pressure profile parameters

Summary In ten incontinent female patients the reproducibility of urethral closure pressure profile parameters obtained with the Brown and Wickham technique in two consecutive measurements and in measurements after a one month interval was assessed. Variances after one month were statistically signifiantly larger than the variances between consecutive measurements. The mean values obtained with one month interval did not differ significantly.     

Measurement of elasticity and transepidermal water loss rate of burn scars with the Dermalab

This cross-sectional study investigated the reproducibility of repeated elasticity and transepidermal water loss (TEWL) measurements with the DermaLab^® on 32 active burn scars and healthy skin. Intra- and inter-observer reproducibility was examined by means of intra-class correlation coefficients (ICC) and standard error of measurements (SEM). Results showed good ICC values and rather high SEM values for inter- and intra-observer reproducibility of elasticity measurements. For TEWL measurements, ICC values were good and SEM values were high for inter- and intra-observer reproducibility. There was a significant difference between the estimated mean elasticity values of normal skin and grafted scars and between normal skin and spontaneously healed scars (p ≤ 0.003). For the estimated mean TEWL values, there was a significant difference between normal skin and spontaneously healed scars (p = 0.036). A significant negative relation was reported between mean TEWL and time after burn (p = 0.008). In clinical trials it is necessary to interpret patient-specific changes in elasticity and TEWL with caution, since the SEMs of both modes are rather high. We therefore recommend the use of a mean of repeated measurements of elasticity and TEWL to decrease the SEM.     

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.     

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.     

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.     

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.     

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.     

Applying negative pressure therapy to deep pressure ulcers covered by soft necrotic tissue

Negative pressure therapy was applied to 39 deep pressure ulcers covered by soft necrotic tissue. All of the wounds were so deep that there were bones or ligaments just beneath the soft necrotic tissue. They had already received several types of conservative therapy including a necrotomy for periods ranging from 1 to 72 months. The wounds were minimally debrided and put in an adequately wet environment with negative pressure. This environment was established by the application of a suction‐dressing. All of these wounds showed clear wound beds within only 1 month. All of the wounds were successfully cured, either with or without a musculocutaneous flap. Negative pressure wound therapy is thus considered to be one of the choices for the management of non healing deep pressure ulcers covered by soft necrotic tissue.     

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.     

A multicentered comparison of measurements obtained with microtip and external water pressure transducers

This study compared simultaneous intravesical pressure readings obtained with catheter-mounted microtip transducers and external water pressure transducer catheters during filling cystometry. Women undergoing multichannel urodynamic testing were randomly assigned to one of three groups: two microtip catheters, two external water pressure transducer catheters, or one of each type. Intravesical pressure was measured simultaneously for each transducer combination in each subject for minimal and maximal Valsalva effort and minimal, moderate, and maximal cough effort at two sequential bladder volumes (150 and 300 ml). Paired t tests were used to compare the means of the intravesical pressure obtained by the two types of catheters. The largest mean differences were observed when comparing microtip and water pressure transducers. Correlations of maximum pressure were consistently high between two microtip transducers and two water pressure transducers but lower for the microtip–water combination. Excellent reproducibility was demonstrated with transducers of similar types for intravesical pressures recorded during Valsalva and cough in women without prolapse. However, considerable variability was seen in pressures recorded by different transducers, particularly dependent on the water catheter manufacturer, indicating that intravesical pressure recordings from microtip and water-based systems are not interchangeable.Abstract presented at the International Continence Society Annual Meeting, Paris, France, August, 2004     

压力治疗联合点阵CO2激光治疗增生性瘢痕的疗效观察

目的观察压力治疗联合点阵CO₂激光治疗增生性瘢痕的临床疗效。方法回顾分析2018年1月至2020年6月收治的烧伤后增生性瘢痕患者74例。其中,对照组采用压力治疗(42例);观察组采用压力联合点阵CO₂激光治疗(32例)。治疗结束6个月后采用温哥华瘢痕量表(VSS)进行瘢痕评分,以视觉模拟评分法(VAS)进行瘢痕瘙痒及疼痛评分,并记录不良反应发生情况。结果观察组VSS评分显著高于对照组(P<0.05),且瘢痕的瘙痒及疼痛较对照组明显减轻,差异有统计学意义(P<0.05)。两组不良反应发生率差异无统计学意义(P>0.05)。结论压力治疗联合点阵CO₂激光是一种安全有效的治疗增生性瘢痕的方法。