How to evaluate scar colour after burn injuries - A clinical comparison of the Mexameter® and the subjective scar assessment (POSAS/VSS)

INTRODUCTION

Scarring after burn injuries remains one of the major challenges in burn medicine and is the subject of current research. Accurate and high-quality assessment of scars is needed to enable exact outcome evaluation of different treatments. Our aim was to evaluate the most common subjective scar evaluation scores-the POSAS (Patient and Observer Scar Assessment Scale) and VSS (Vancouver Scar Scale)-in comparison with the objective device Mexameter® for colour evaluation.

METHODS

A prospective monocentre study was performed, which included 120 examined scar areas of 60 patients with third degree burns who had received skin grafts between 1975 and 2018 with a total burned surface area (TBSA) > 2%. Two different scar areas in comparison with one healthy skin area concerning 'colour', 'pigmentation', and 'vascularization' were evaluated by the Mexameter® MX 18, the OSAS, and the VSS by the same examiner, as well as the PSAS by the patient.

RESULTS

The mean TBSA of the 60 patients was 24.3%. In the OSAS, 61% of the scars were evaluated as 'hyper-', 19% as 'hypo-', and 19% as 'mix-pigmented'. Furthermore, 65% of the scars were estimated as highly vascularized. In the Mexameter®, the melanin index values of the scar areas compared to the healthy skin areas showed a small difference of 12 (p < 0.05). The mean difference of erythema between the scar and the healthy skin areas was 84 (p < 0.001). For the Mexameter®, moderate correlations were found when comparing 'erythema' with the OSAS category 'vascularization' (r = 0.33, p < 0.05) and 'melanin' with the OSAS parameter 'pigmentation' (r = 0.28, p < 0.05). When comparing the Mexameter® measurements to the OSAS questionnaire, 27% of the scars were wrongly evaluated as 'hyperpigmented' by the observer and 21% as 'hypervascularized', while showing low measurements in the device. Additionally, a novel Mexameter® ordinal scare scale was calculated.

CONCLUSION

In this study, we were able to show on a relatively large patient population that with the Mexameter®, the subjectivity of the scar colour assessment by examiner/patient can be overcome, but precise differentiation can still be ensured with subjective evaluation tools. We further introduced a novel Mexameter® Scar Scale. It is necessary to further investigate the vast range of objective devices and develop scar panels for with an incorporation of objective and subjective devices to further improve reliability with reduced bias in terms of scar assessment.

The BUrn Mortality Prediction (BUMP) Score - An improved mortality prediction score based on data of the German burn registry

BACKGROUND

Burn injuries constitute the fourth most common injuries globally. Patient outcomes must be currently assessed to provide appropriate patient care with high quality standards. However, existing mortality prediction scoring methods have been shown to lack accuracy in current burn patient populations. Therefore, this study aimed to validate existing scores using current patient data and assess whether new prediction parameters can provide better accuracy.

METHODS

A retrospective analysis of the patient data from the German Burn Registry between 2016 and 2019 was performed to evaluate all Abbreviated Burn Severity Index (ABSI) score parameters. All patients over 16 years of age who received intensive care were included. Descriptive statistics and logistic regression analysis were used to identify novel prediction parameters based on the parameters documented at admission and establish a new prediction score, the BUrn Mortality Prediction (BUMP) score. The quality of the new score was subsequently compared to that of the original ABSI, modified ABSI, Galeiras, Revised Baux score and TIMM. The new prediction score was then validated using patient data collected in the German Burn Registry in 2020.

RESULTS

In total, 7276 patients were included. Age; the presence of at least two comorbidities; burn injuries caused by work-related accidents, traffic accidents and suicide attempts; total burn surface area; inhalation trauma and full-thickness burns were identified as independent significant predictors of mortality (p < 0.001). Additionally, we evaluated new age groups to improve prediction accuracy. The number of comorbidities (p < 0.001) and the aetiology (burns occurring at work [p = 0.028], burns caused by traffic accidents [p < 0.001] or burns due to attempted suicide [p < 0.001]) had a significant influence on mortality. The BUMP score, which was developed based on these parameters, showed the best fitness and showed more accurate mortality prediction than all the above-mentioned scores (area under the receiver operating characteristic curve: 0.947 [0.939-0.954] compared to 0.926 [0.915-0.936], 0.928 [0.918-0.939], 0.937 [0.928-0.947], 0.939 [0.930-0.948], 0.940 [0.932-0.949] respectively).

CONCLUSIONS

A novel score (BUMP score) was developed for the purpose of external quality assessment of burn centres participating in the German burn registry, where observed and expected outcomes are compared on a hospital level, and for scientifically applications. The clinical impact of this score and its generalisability to other patient populations needs to be evaluated.

Patients' satisfaction with anesthesia in enzymatic debridement from a surgical perspective

INTRODUCTION

Various clinical studies found that enzymatic debridement (EDNX) is superior to tangential excision after severe burns. The current study evaluates patients' satisfaction with pain management in EDNX with special respect to different anesthesia techniques.

METHODS

Between 2015 and 2016, all patients at a department of plastic surgery were asked to complete a German-wide validated pain questionnaire. In a retrospective study design, satisfaction with pain management was compared between the control group (diagnosis from the whole field of plastic surgery except burns) and the EDNX group (burns treated with EDNX only). Analgosedation, general, regional and local anesthesia were chosen for pain management.

RESULTS

In the control group 403 patients (153 females, 250 males, medium age 53 years) could be included The EDNX group included 88 patients (20 females, 68 males, medium age 38 years). The mean burn size was 5.3% TBSA. Between 0.5%-10.5% of the surface was treated with EDNX. EDNX patients could be treated under analgosedation and regional anesthesia, by topical anesthesia creme and without any anesthesia. They reported less pain during stress (p = 0.04) and were less frequently affected by motion (p = 0.024) and nausea (<0.001). However, they felt that they need more information about alternative anesthetic treatments (<0.001).

CONCLUSION

EDNX can be performed sufficiently either under analgosedation, regional or local anesthesia. Thus, side effects of general anesthesia can be reduced and treatment costs can be decreased. However, it was found that neither after topical anesthetic creme nor after hand block pain treatment was sufficient.