Ex vivo culture of keratinocytes on papillary and reticular dermal layers remodels skin explants differently: towards improved wound care

In this study, we characterised the efect that seeding keratinocytes on the papillary and reticular dermis had on the extracellular matrix and tissue integrity ex vivo. Human skin explants from consented patients (n=6) undergoing routine surgery were cultured at a liquid–air interface, dermal-side up, and autologous keratinocytes seeded on the exposed papillary or reticular layer. After 7–21 days, histological and immunohistochemical evaluation of the morphology and extracellular matrix was performed. While the dermis remained robust in all explants cultures, keratinocytes seeded on the papillary layer showed less tissue infltration and remodelling and formed clusters across the tissue. In contrast, keratinocytes seeded on the reticular layer infltrated the tissue homogenously with an intact single-cell-layer surface coverage and structural changes characterised by increased deposition of ground substance, glycosaminoglycans, and collagen VII in 14 days. In addition, while the papillary section showed more new laminin deposition by 14 days than the reticular section, the latter expressed more connexin 43. These diferences in re-epithelialisation and extracellular matrix characteristics suggest that wound depth and graft thickness may play a key role in wound healing and indicate that ECM characteristics should be factored in when designing biomaterials for wound applications and in the selection of recipient sites when using cells for grafting

Protocol for the development of a core indicator set for reporting burn wound infection in trials: ICon-B study

INTRODUCTION: Systematic reviews of high-quality randomised controlled trials are necessary to identify effective interventions to impact burn wound infection (BWI) outcomes. Evidence synthesis requires that BWI is reported in a consistent manner. Cochrane reviews investigating interventions for burns report that the indicators used to diagnose BWI are variable or not described, indicating a need to standardise reporting. BWI is complex and diagnosed by clinician judgement, informed by patient-reported symptoms, clinical signs, serum markers of inflammation and bacteria in the wound. Indicators for reporting BWI should be important for diagnosis, frequently observed in patients with BWI and assessed as part of routine healthcare. A minimum (core) set of indicators of BWI, reported consistently, will facilitate evidence synthesis and support clinical decision-making. AIMS: The Infection Consensus in Burns study aims to identify a core indicator set for reporting the diagnosis of BWI in research studies. METHODS: (1) Evidence review: a systematic review of indicators used in trials and observational studies reporting BWI outcomes to identify a long list of candidate indicators; (2) refinement of the long list into a smaller set of survey questions with an expert steering group; (3) a two-round Delphi survey with 100 multidisciplinary expert stakeholders, to achieve consensus on a short list of indicators; (4) a consensus meeting with expert stakeholders to agree on the BWI core indicator set. ETHICS AND DISSEMINATION: Participants will be recruited through professional bodies, such that ethical approval from the National Health Service (NHS) Health Research Authority (HRA) is not needed. The core indicator set will be disseminated through peer-reviewed publication, co-production with journal editors, research funders and professional bodies, and presentation at national conferences. PROSPERO REGISTRATION NUMBER: CRD42018096647

Eschar removal by bromelain based enzymatic debridement (Nexobrid®) in burns: European consensus guidelines update

INTRODUCTION Bromelain-based Enzymatic Debridement has been introduced as an additional concept to the burn surgeon's armamentarium and is best indicated for mid-to deep dermal burns with mixed patterns. Increasing evidence has been published focusing on special regions and settings as well as on limitations of Enzymatic Debridement to improve patient care. To better guide Enzymatic Debridement in view of the increasing experience, there is a need to update the formerly published consensus guidelines with user-orientated recommendations, which were last produced in 2017. METHODS A multi-professional expert panel of plastic surgeons and burn care specialists from twelve European centers was convened, to assist in developing current recommendations for best practices with use of Enzymatic Debridement. Consensus statements were based on peer-reviewed publications and clinical relevance, and topics for re-evaluation and refinement were derived from the formerly published European guidelines. For consensus agreement, the methodology employed was an agreement algorithm based on a modification of the Willy and Stellar method. For this study on Enzymatic Debridement, consensus was considered when there was at least 80 % agreement to each statement. RESULTS The updated consensus guidelines from 2019 refer to the clinical experience and practice patterns of 1232 summarized patient cases treated by the panelists with ED in Europe (2017: 500 cases), reflecting the impact of the published recommendations. Forty-three statements were formulated, addressing the following topics: indications, pain management and anesthesia, large surface treatment, timing of application for various indications, preparation and application, post-interventional wound management, skin grafting, outcome, scar and revision management, cost-effectiveness, patient´s perspective, logistic aspects and training strategies. The degree of consensus was remarkably high, with consensus in 42 out of 43 statements (97.7%). A classification with regard to timing of application for Enzymatic Debridement was introduced, discriminating immediate/very early (≤12 h), early (12-72 h) or delayed (>72 h) treatment. All further recommendations are addressed in the publication. CONCLUSIONS The updated guidelines in this publication represent further refinement of the recommended indication, application and post-interventional management for the use of ED. The published statements contain detailed, user-orientated recommendations aiming to align current and future users and prevent pitfalls, e.g. for the successful implementation of ED in further countries like the USA. The significance of this work is reflected by the magnitude of patient experience behind it, larger than the total number of patients treated in all published ED clinical trials

Dosing regimen of meropenem for adults with severe burns: a population pharmacokinetic study with Monte Carlo simulations

Objectives To develop a population model to describe the pharmacokinetics (PK) of intravenous meropenem in adult patients with severe burns and investigate potential relationships between dosage regimens and antimicrobial efficacy. Patients and methods A dose of 1 g every 8 h was administered to adult patients with total body surface area burns of ≥15%. Doses for subsequent courses were determined using results from the initial course and the patient's clinical condition. Five plasma meropenem concentrations were typically measured over the dosage interval on one to four occasions. An open, two-compartment PK model was fitted to the meropenem concentrations using NONMEM and the effect of covariates on meropenem PK was investigated. Monte Carlo simulations investigated dosage regimens to achieve a target T>MIC for ≥40%, ≥60% or ≥80% of the dose interval. Results Data comprised 113 meropenem concentration measurements from 20 dosage intervals in 12 patients. The parameters were CL (L/h) = 0.196 L/h/kg × [1 − 0.023 × (age − 46)] × [1 − 0.049 × (albumin − 15)], V1 = 0.273 L/kg × [1 − 0.049 × (albumin − 15)], Q = 0.199 L/h/kg and V2 = 0.309 L/kg × [1 – 0.049 × (albumin − 15)]. For a target of ≥80% T>MIC, the breakpoint was 8 mg/L for doses of 1 g every 4 h and 2 g every 8 h given over 3 h, but only 4 mg/L if given over 5 min. Conclusions Although 1 g 8 hourly should be effective against Escherichia coli and CoNS, higher doses, ideally with a longer infusion time, would be more appropriate for empirical therapy, mixed infections and bacteria with MIC values ≥4 mg/L.</p