Wound dressing performance: - BAP Medical

ContentsForewordKeith F Cutting03Performance parameters for modern wound dressings should take into account more thanjust exudate absorption. Other factors to consider are the dressing’s ability to promote amoist wound environment, bind matrix metalloproteases and bacteria, and prolong theintervals between changes. This will not only promote healing, but also improve quality of lifeWound dressings: 21st century performancerequirementsKeith F Cutting04 – 09A wide range of wound dressing performance parameters exist. This paper discusses dressingattributes that, within the constraints of current technology, favourably influence thebiological actions/processes that may occur within the wound so that they actively contributeto the healing processMoist wound healing, exudate, and clinicalmanagement of the wound bedRichard J. White10 – 13This paper reviews the current state of thinking and evidence on moist wound healing, andpresents a new wound dressing technology that enables the purported ‘optimum’ moistenvironment to be maintained without risk of desiccation or macerationSorbion sachet S: clinical application and resultsMartyn Butcher14 – 18Sorbion sachet S was designed to bestow a range of clinical advantages across a number ofindications, particularly in moderately to highly exuding wounds. This paper explores thecurrent evidencePublisher: Anthony KerrAssociate Publisher/Editor: Tracy CowanSub-editor: Andy EscottDesigner: Laura HawkinsPublishing Director: Matt CianfaraniCover picture: Corbis2J O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 0

Wound dressings: 21st centuryperformance requirementsA wide range of wound dressing performance parameters exist. This paper discussesthose dressing attributes that, within the constraints of current technology, favourablyinfluence the biological actions/processes that may occur within the wound so thatthey actively contribute to the healing process.Keith F Cutting, Visiting Professor, Buckinghamshire New University, Uxbridge, UKJSampson Gamgee’s (1828–1886) view thatwound dressings should be dry, firm, absorbentand disturbed as infrequently as possible madehim a revolutionary clinician of his time. 1 Gamgeefound that placing absorbent cotton wool betweenlayers of absorbent gauze resulted in a firm butabsorbent dressing that perfectly suited his surgicalpractice. 1 Dressing changes were also less frequent.Following the advent of the concept of moistwound healing, 2 the focus shifted to a dressing’sability to maintain a moist wound/dressing interfaceand create an optimal environment that will supporthealing and improve scar cosmesis. Over thepast 40 years, there has been a transition from providingsimple protection, to the developmentof hi-tech synthetic or natural dressing materialsthat are biocompatible and actively support thehealing process.Wound dressing performanceparametersIn the past, natural materials were used to protectthe wound from the external environment. Woundswere cleansed with water or milk and often dressedwith honey, lard or butter, which was kept in placewith leaves and/or grass and, later, with wool orlinen. 3 It appears that some of the ancients used treeresin to cover and protect the wound surface. Theresin would harden, providing a natural barrier orseal. 3 Resin does not decompose when the bark iscut, but oozes naturally from the surface. It is possiblethe ancients drew an analogy from this.In 1985, performance parameters were developedto ensure that a dressing will create a microenvironmentthat supports healing. 4 To comply with these,the dressing must:• Remove excess exudate and toxic components• Maintain high humidity at the wound/dressing interface• Allow gaseous exchange• Provide thermal insulation• Protect against secondary infection• Be free from particulate or toxic contamination• Not cause tissue trauma during removal.This inventory was extended by Morgan 5 in 1998but, surprisingly, was not extensively modified untilThomas 6 published the performance requirementsof the ideal dressing in 2008 (Table 1).Interestingly, the moist wound dressings availablein 1985 would easily have met all of Turner’s criteria.However, not only is the 2008 list more complex butno single dressing currently available complies withall of the parameters. Clearly, dressing performanceparameters have become more sophisticated as ourknowledge has increased, and the gap between therequirements of the ideal dressing and the capabilityof modern dressing technology to meet them all in asingle dressing has widened.This might have been the stimulus for the developmentof a range of durable medical devices, suchas negative pressure wound therapy (NPWT) andelectrical stimulation. While no single durable medicaldevice can fulfil all of the requirements of theideal wound dressing, these devices do appear to fillthe technology gap resulting from our dependenceon textiles as the foremost wound dressing modality.Nevertheless, it may be worth exploring whetherthere are any areas of overlap in performancebetween durable medical devices and textile-basedwound dressings.When seeking the ideal dressing for a particularwound in the 21st century, the decision should bebased not on one main function or one woundfactor, but should embrace the patient, his or herwound and the associated multifactorial needs. 7Advanced wound care products have beendesigned with a specific function or functions inmind. These are governed largely by the properties4J O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 0

Table 1. Performance requirements of the ideal dressing 6 (Thomas 2008)6Primary requirementsType of feature1 Free of toxic or irritant extractables Design feature2 Does not release particles or non-biodegradable fibres into the wound Design feature345Forms an effective bacterial barrier (effectively contains exudate or cellulardebris to prevent the transmission of microorganisms into or out of thewound)If self-adhesive, forms an effective water-resistant seal to the periwound skin,but is easily removed without causing trauma or skin strippingMaintains the wound and the surrounding skin in an optimum state ofhydration (this implies it is able to function effectively under compression)Design featureDesign featureDesign/wound related6 Requires minimal disturbance or replacement Design/wound related78Protects the periwound skin from potentially irritant wound exudate andexcess moistureProduces minimal pain during application or removal as a result of adherenceto the wound surfaceDesign/wound relatedDesign/wound related9 Maintains the wound at the optimum temperature and pH Design/wound relatedSecondary requirements10Possesses antimicrobial activity — capable of combating localisedinfection11 Has odour-absorbing/combating propertiesType of featureDesign featureDesign feature12 Able to remove or inactivate proteolytic enzymes in chronic wound fluid Design feature13 Haemostatic propertiesDesign feature14 Exhibits effective wound cleansing (debriding) activity Design/wound relatedof the dressing ‘ingredients’. This has led to a popularclassification of wound dressings based primarilyon their principal constituents such as films, hydrogelsand hydrocolloids. In other areas of health care,products are chosen or grouped on the basis of theirfunction e.g. orthotics, bronchodilators, mucolyticsand antifungals. van Rijswijk rightly points out thatthe focus on dressing ingredients, rather than ontheir function, appears outmoded or even counterproductiveto the development and clinical use ofadvanced dressing technology. 8Optimal wound management is dependent onacquisition of the necessary resources, plus the skillsof the attending clinician. Since the characteristicsof the ideal wound dressing remain at a superlativelevel, only dressing attributes that address widespreadneeds, especially those found in chronicwounds, are discussed here.Exudate managementEfficient exudate management is a vital ingredientof good wound care and an essential dressing per-J O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 05

LymphvesselExtracellular matrix(ECM)LymphformationArteriole – Capillary – VenuleFluid andsubstanceshifts alonghydrostaticand osmoticgradientsFig 1: Diagrammatic representation of the generation ofexudate (based on Bishop 11 and Vowden and Vowden 34 )WoundTissue pressure = Exudate formationformance parameter. The fluid-handling mechanismsof the chosen medical device are therefore of primeimportance as it must be able to respond to the idiosyncraticbehaviour of the wound.What is exudate?Exudate is a generic term used to describe moistureor liquid emanating from the wound. It is derivedfrom extracellular fluid, which naturally bathes thecells, protecting these delicate structures from desiccationand providing them with nutrients anddiffused oxygen. It occurs when the epidermal barrieris breached. Although principally composed ofwater, normal acute wound fluid is rich in proteinsand contains many biological chemicals and cells. 9Wound exudation is a consequence of the naturalinflammatory response. 10 Its volume, consistencyand chemical composition vary considerably fromperson to person and, even within an individual, itsmake up and volume will change as a result ofwound events and the stage of the healingprocess. 10The delicate balance of tissue hydration is maintainedby the interplay between the interstitial fluidpressure, the capillary filtration pressure and the rateof lymphatic drainage 11 within the extracellularmatrix (ECM). Damage to the epidermis disruptsthis balance, causing fluid to move into the surroundingtissues and then the environment (Fig 1).This process is intensified by the presence ofinflammatory mediators such as histamines, whoserelease at injury causes capillary dilation, raising theflow of fluid into and out from the wound. 12CompositionIn acute wounds, exudate appearsto stimulate production of fibroblastsand endothelial cells. 13Polymorphonuclear leucocytes(PMNs) engulf dysfunctional protein(collagens and elastin) andbacteria in the wound by phagocytosis12 and help prepare thewound for remodelling and repair.This process is known as autolysis.Monocytes then differentiate intomacrophages, which also breakdown proteins by phagocytosisand release proteases, which arehighly regulated by tissue inhibitorsof metalloproteases (TIMPs). 12A myriad of biochemical and cellularinteractive events take place, which govern thehealing process. 12Chronic wound exudate has a different composition.Here, abnormally high levels of proteases canhave a destructive influence on tissue generationand the integrity of periwound tissues. 9 Proliferationof keratinocytes, fibroblasts and endothelial cells isslowed or completely blocked, growth factors can bedenatured, making them ineffective stimulants forcell generation and healing, and high levels of proinflammatorycytokines promote a chronicinflammatory response. 9 All of these factors contributeto delayed healing and the destruction ofhealthy tissues.The ECM canabsorb and releasewater in a dynamicfashion. When itscapacity is exceededoedema forms.Effects on healing outcomesFailure to maintain the optimum level of moisture atthe wound interface can have marked effects onhealing outcomes. As Winter demonstrated, 2 a moistwound interface enables rapid re-epithelialisationand therefore rapid wound closure when comparedwith wounds exposed to air.The type of exudate involved has a significanteffect on healing outcomes. Bishop et al. describedchronic wound exudate as ‘corrosive biologicalfluid’. 11 The high levels of proteases present inchronic wound exudate break down regeneratingtissue and cause further damage to the previouslymacerated periwound epidermis. The clinician thereforeneeds to ensure that there is no excess exudatein the wound or on the periwound skin. 11Moist wound healingThe objective of chronic wound management is toprocure conditions that will maintain a moist woundenvironment, thereby promoting an ‘optimal’ heal-6J O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 0

ing environment (see second article in thissupplement). While ‘optimal’ in this context has yetto be fully defined, it is vital that the chosen dressingnot only provides a relatively constant level of moistureat the wound-dressing interface but also absorbsand binds any excess exudate. Contemporaryapproaches offer distinct advantages over conventionaldressing technology, which was unable toachieve this.Fluid-handling mechanismsAbsorbencyBecause of the heterogeneous nature of wounds(and exudate), dressing selection should correlatenot only to the size and type of wound, but also tothe nature, volume and viscosity of the exudatepresent. 14 The management of highly exuding pressureulcers poses two additional problems:• Prevention of secondary damage caused by highpoints of pressure between the support surface/dressing interface and underlying soft tissues• The binding of the fluid within the dressingmatrix when the dressing is place undercompression.The first problem requires the careful selection ofmaterials that can conform and spread the pressureload while retaining their integrity.Excess exudation can have serious consequencesfor wound healing. Once the absorbent capacity ofany dressing used has been reached, fluid may leakthrough or around the dressing material. Thisallows exudate to spread further from the woundand provides a route for bacterial ingress, increasingthe risk of infection to the patient or the spreadof bacteria to other individuals. For the sufferer,sodden, soiled dressings are embarrassing and canlead to chronic social isolation as she/he shies awayfrom even family and friends. This social exclusioncan have negative impacts on healing outcomes. 15The selected dressing should be able to absorb ahigh volume of fluid in relation to its physicaldimensions. This is particularly important if it is tobe used on moderately to highly exuding wounds,which typically produce approximately 5ml per10cm 2 per 24 hours. 16It has been suggested that polyurethane foams,alginates and Hydrofiber are suitable for highlyexuding wounds. 17 Nevertheless, limitations existin their clinical performance. In my clinical experience,polyurethane foams are unable to absorb andretain large volumes of exudate for extended periodsand appear to be more relevant for low tomoderate levels. Despite their popularity, one publicationstates that polyurethane foams have notshown any advantages over gauze in healing times,patient satisfaction, costs or length of hospital stay,and there is no proof in the literature of a consistentadvantage over other non-gauze dressings. 18Alginates are derived from brown seaweed. Theircomposition influences the degree of alginate fibregelling that takes place 19 and, hence, maintenanceof the overall dressing integrity. Although they canabsorb up to 20 times their weight in wound fluid,absorption capacity is limited as a 10x10cm alginatedressing weighs a mere 1g. Absorption capacityis further reduced under compression. 19Hydrofiber is a fibrous material made fromsodium carboxymethylcellulose, which forms a gelwhen in contact with wound exudate and plays avaluable role in avoiding/reducing wound deadspace. 20 Anecdotal evidence suggests that there maybe a loss of dressing integrity with Hydrofiber whenused under compression and that it has only aslightly higher absorbent capacity in relation to itsown weight than alginate.Polyurethane foams, alginates and Hydrofiberdressings promote a moist wound environment andso have a role to play in wound management, butlike all dressings limitations in performance exist.Retention of fluidCochrane (1990) stated that skin should be keptclean and dry to prevent maceration. 21 An importantdressing performance parameter that extendsbeyond the mere volume absorbed is the dressing’sability to retain the exudate within its matrix. 11,22A sponge is able to readily take up fluid but isunable to hold it when compressed. A product thatcan expertly manage and retain ‘excess’ exudate isrequired. By preventing further moisture loss andthus desiccation, it will enhance re-epithelialisationand autolytic debridement. It must be possibleto use the product with other therapies, such ascompression bandaging, without compromisingefficacy or posing additional problems such aslocalised pressure damage. Finally, the productshould also be able to lock-in a significant volume(in the region of 100ml) of exudate without losingits structural integrity. A dressing that can absorband retain wound fluid will avoid the risk of overhydrationand/or maceration. 6Prevention of macerationProlonged exposure to excessive chronic woundexudate or its protease content will lead to wounddeterioration and potential skin breakdown. 23Excess moisture can lead to problems: over-hydrationof the surrounding skin results in macerationJ O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 07

— the formation of white, oedematous tissue frequentlyfound around highly exuding wounds.This tissue no longer offers a barrier to bacterialingress, and instead forms a microclimate in whichmoisture-loving bacteria can proliferate. 23 The tissuesbecome weakened and the wound increases insize. 23 Judicious care, and use of appropriate dressings,can avoid maceration and delayed healing.Vertical wickingVertical wicking occurs when exudate is taken upand held by the dressing within the wound areaimmediately above the wound, avoiding lateralspread to the periwound skin. (Lateral wickingoccurs when exudate is taken up by the dressingand spreads laterally across the dressing surfacebeyond the borders of the wound margin.)Bioburden management anddebridementWounds are contaminated with a variety of bacteria,so the potential for infection is always present. 24The warm, moist environment, together with aready supply of nutrients, offers an ideal setting forbacterial proliferation. Reducing bioburden is thereforean important aspect of wound management.The immobilisation of bacteria and the modulationof matrix metalloproteases (MMPs) is anindispensable performance parameter. This shouldnot affect the product’s absorption capacity, or itsretention properties and absorption kinetics. Thecombined effect is anti-inflammatory, which aidsdebridement and the progression towards healing.Concern has been raised about a possible associationbetween bacterial resistance and the widespreadand sometimes indiscriminate use of antimicrobials.25,26 Therapeutic management of woundbioburden through non-antimicrobial (passive)methods such as bacterial sequestration has notbeen vigorously pursued, despite the inherentadvantage of avoiding antibiotic resistance.It is widely recognised that an accumulation ofslough is consistent with slow/impaired woundhealing. To promote healing, this should be removedat regular intervals (debridement), even thoughthere are no clinical data to support this. 27 Approachesto debridement include autolytic, enzymatic, irrigation,larvae, sharp/surgical and wet to dry methods.The focus here is autolysis. Debridement may welltake on more significance as we learn more about itsbeneficial effects for healing.Matrix metalloprotease modulationWound repair and remodelling is influenced byMMP expression. Excess production of MMPs, inconjunction with reduced levels of TIMPs, results inan unbalanced destruction of the ECM and delayshealing. 28 Proteases produced by wound bacteriacompound the problem of tissue breakdown. MMPregulation is therefore important, and topical interventionshave proved beneficial in this respect. 29,30,31Impact on quality of lifeAdvanced wound dressings have improved the qualityof life of many patients. However, in somequarters these advances have not been fully accepted,and the lack of objective scientific evidence is oftencited as a reason for this.Horkan et al. examined 13 systematic reviews/meta-analyses that explored the effects of moderndressings on wound healing by secondary intention.32 His stark conclusion was that there appears tobe no consistent evidence that any one moist woundhealing dressing is better than another.Where does this leave the quest for advancedproducts and their use? Some clinicians appear socomfortable with outmoded practices, in spite ofabundant evidence, both empirical and objective,that they may not deliver optimal outcomes. Inorder to make a case for dressings that will achieve21st century outcomes, it is useful to consider therequirements of 21st century wounds.The health economics of highlyexuding woundsTraditional attempts to cope with highexudate levels required the use of high absorbencydressings. Simple cotton or cellulose-based productshave limited absorptive capacity. Once fibres areloaded with fluid, uptake is halted andleakage occurs.Later management techniques introduced the useof higher absorbency materials. Products such asalginates and Hydrofibers have the potential toabsorb higher volumes of fluid, but they also havea higher unit cost and generally require asecondary dressing, adding to the overall cost. Themanagement of heavy exudate can therefore beexpensive; frequent changing of saturated dressingsis required.In my experience, some clinicians may use simplewound interface materials, changing outer absorbentmaterials as required. However, this requiresfrequent health-care interventions. Dressings thatpromote a moist wound healing environment havebeen associated with faster healing rates and reducedpain and scarring. These features have improvedpatient satisfaction and decreased treatment costs. 338J O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 0

Other management techniques include the use ofNPWT. While effective in handling large volumes offluid, they can limit patient movement, require highlevels of expertise, have limited availability in thecommunity and are costly to operate.ConclusionTo perform the sum of absorbency, retention, preventionof maceration, vertical wicking, bioburdenmanagement, MMP modulation and debridement,an amalgamation of technologies specificallydesigned for collective maximum performanceis required.The efficient management of wounds, especiallyexudate output and its associated chronic inflammation,remains a challenge. However, this can be metif careful consideration is given to the overall woundcharacteristics, dressing selection and dressing performance.Finally, the product must be readilyavailable to clinicians in all health-care sectors at anaffordable unit price, with no hidden costs in theform of extra health-care interventions.References1 Kapadia, H.M. SampsonGamgee: a great BirminghamSurgeon. J R Soc Med 2002;95: 2, 96-100.2 Winter, G. Formation of thescab and the rate ofepithelialization of superfi cialwounds in the skin of theyoung domestic pig. Nature1962; 193: 293-295.3 Forrest, R.D. Early history ofwound treatment. J R Soc Med1982; 75: 3, 198-205.4 Turner, T.D. Semi-occluive andocclusive dressings. In: Ryan, T.J. (ed). An Environment forHealing: The role of occlusion.Royal Society of Medicine,1985.5 Morgan, D.A. The application ofthe ‘ideal dressing’ theory topractice. Nursing Scotland1998; July, 16-18.6 Thomas, S. The role of dressingsin the treatment of moisturerelatedskin damage. WorldWide Wounds, 2008. Availableat: www.worldwidewounds.com/2008/march/Thomas/Maceration-and-the-role-ofdressings.htmlAccessed 23February 2010.7 Reddy, M., Kohr, R., Queen, D.et al. Practical treatment ofwound pain and trauma: apatient-centered approach. Anoverview. Ostomy WoundManage 2003; 49: (4 Suppl),2-15.8 van Rijswijk, L. Ingredient-basedwound dressing classifi cation: aparadigm that is passé and inneed of replacement. J WoundCare 2006; 15: 11-14.9 Trengove, N.J., Stacey, M.C.,Macauley, S. et al. Analysis ofthe acute and chronic woundenvironments: the role ofproteases and their inhibitors.Wound Repair Regen 1999; 7:6, 442-452.10 Cutting, K.F. Wound exudate:composition and functions. Br JCommunity Nurs 2003; 8:(Suppl. 9), 4-9.11 Bishop, S.M., Walker, M.,Rogers, A.A., Chen, W.Y.Importance of moisturebalance at the wound-dressinginterface. J Wound Care 2003;12: 4, 125-128.12 Broughton, G. 2nd, Janis, J.E.,Attinger, C.E. The basic scienceof wound healing. PlastReconstr Surg 2006; 117:(Suppl. 7), 12S-34S.13 Katz, M.H., Alvarez, A.F.,Kirsner, R.S. et al. Humanwound fl uid from acutewounds stimulates fi broblastand endothelial cell growth. JAm Acad Dermatol 1991; 25:(6 Pt 1), 1054-1058.14 Kennedy, J.F., Bunko, K. Theuse of ‘smart’ textiles forwound care. In: Rajendran, S.(ed). Advanced Textiles forWound Care. WoodheadPublishing, 2009.15 Woodall, R.D. Tissue viability.Living with leg ulcers: apatient’s personal experience.Nurs Stand 1996; 10: 45, 52.16 Lamke, L.O., Nilsson, G.E.,Reithner, H.L. The evaporativewater loss from burns and thewater-vapour permeability ofgrafts and artifi cial membranesused in the treatment of burns.Burns 1977; 3: 3, 159-165.17 Alexander, S. Malignantfungating wounds: managingmalodour and exudate. JWound Care 2009; 18: 9, 374-382.18 Vermeulen, H., Ubbink, D.T.,Goossens, A. et al. Systematicreview of dressings and topicalagents for surgical woundshealing by secondary intention.Br J Surg 2005; 92: 6: 665-672.19 Thomas, S. Alginate dressingsin surgery and woundmanagement: part 3. J WoundCare 2000; 9: 4, 163-166.20 Snyder, R.J. Managing deadspace: an overview —eliminating these unwantedareas is a key to successfulwound healing. PodiatryManage 2005; 24: 8, 171-174.21 Cochrane, G. The severleydisabled. In: Bader, D.L. (ed.).Pressure Sores: Clinicalpractice and scientifi capproach. Macmillan, 1990.22 White, R.J., Cutting, K.F.Modern exudate management:a review of wound treatments.World Wide Wounds, 2006Available at: www.worldwidewounds.com/2006/september/White/Modern-Exudate-Mgt.html Accessed 12December 2009.23 Cutting, K.F., White, R.J.Maceration of the skin andwound bed. 1: Its nature andcauses. J Wound Care 2002;11: 7, 275-278.24 Bowler, P.G., Duerden, B.I.,Armstrong, D.G. Woundmicrobiology and associatedapproaches to woundmanagement. Clin MicrobiolRev 2001; 14: 2, 244-269.25 Russell, A.D., Tattawasart, U.,Maillard, J.Y., Furr, J.R. Possiblelink between bacterialresistance and use ofantibiotics and biocides.Antimicrob Agents Chemother1998; 42: 8, 2151.26 Tambe, S.M., Sampath, L.,Modak, S.M. In vitro evaluationof the risk of developingbacterial resistance toantiseptics and antibiotics usedin medical devices. JAntimicrob Chemother. 2001;47: 5, 589-598.27 Bradley, M., Cullum, N.,Sheldon, T. The debridementof chronic wounds: asystematic review. HealthTechnol Assess 1999; 3: 17,iii-iv, 1-78.28 Ma, C., Tarnuzzer, R.W.,Chegini, N. Expression ofmatrix metalloproteinases andtissue inhibitor of matrixmetalloproteinases inmesothelial cells and theirregulation by transforminggrowth factor-beta1. WoundRepair Regen 1999; 7: 6, 477-485.29 Chin, G.A., Thigpin, T.G.,Perrin, K.J. et al. Treatment ofchronic ulcers in diabeticpatients with a topicalmetalloproteinase inhibitor,Doxycycline. Wounds 2003;15: 10, 315-323.30 Kakagia, D.D., Kazakos, K.J.,Xarchas, K.C. et al. Synergisticaction of protease-modulatingmatrix and autologous growthfactors in healing of diabeticfoot ulcers: a prospectiverandomized trial. J DiabetesComplications 2007; 21: 6,387-391.31 Vin, F., Teot, L., Meaume, S.The healing properties ofPromogran in venous legulcers. J Wound Care 2002;11: 9, 335-341.32 Horken, L., Stansfi eld, G.,Miller, M An analysis ofsystematic reviews undertakenon standard advanced wounddressings in the last 10 years. JWound Care 2009; 18: 7,298-304.33 Metzger, S. Clinical and fi nancialadvantages of moist woundmanagement. Home HealthcNurse 2004; 22: 586-590.34 Vowden, K., Vowden, P.Understanding exudatemanagement and the role ofexudate in the healing process.Br J Comm Nurs 2003; 8: 11(Suppl), 4-13.All dressings should bechanged in line with themanufacturer’s instructionsfor use and clinicians shouldbe pragmatic aboutperformance expectationsJ O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 09

Moist wound healing, exudate andmanagement of the wound bedThis paper reviews the current state of thinking and evidence on moist wound healing,and presents a new wound dressing technology that enables the purported ‘optimum’moist environment to be maintained without risk of desiccation or macerationMartyn Butcher, Independent Tissue Viability Consultant, Plymouth, UKIn the past 40 years, the wound care communityhas embraced the concept of moist wound healingand the need for exudate management, butit still has not identified exactly how these conceptscan be used to create the so-called ‘optimum’ environment.While numerous wound dressings purportto ‘effectively’ handle varying moisture levels,there is no robust evidence on what the ‘ideal environment’actually is in terms of moisture content.As a result, clinicians use empirical measures togauge their success in providing a moist woundenvironment. Effective exudate management, particularlyin relation to heavily exuding wounds,remains a clinical challenge.The ‘moist wound healing’ mantraIn modern times, it has been accepted that the optimumenvironment for the repair and restoration oftissue function is one in which the wound bed iskept moist. By providing a moist wound environment,it is possible to increase macrophage andfibroblast activity, re-epithelialisation and the productionof collagen. It has also been postulated thatmoisture is important in maintaining endogenousbioelectric fields, which orchestrate cell movementby galvanotaxis and the expression of specificgenomes that are important in the repair process. 1The presence of a moist wound environment,therefore, is an essential component of naturalwound healing. However, the definition of the optimalmoist environment lacks clarity, beingdescribed as ‘not too wet, not too dry’. 2 In ‘normal’acute wound healing models, the body’s owndefence system provides moisture in the form ofwound exudate. When exposed to the atmosphere,exudate dries to form a scab. This impairs re-epithelialisationas the migrating tissue has to movethrough or under the physical barrier presented bythe dry eschar. 3,4According to Fonder et al. 5‘One of the great misconceptions in wound care is thata wound heals best when permitted to form a dry scab.By contrast, moisture has repeatedly been shown tosignificantly accelerate wound healing. Emergency physiciansand other acute care providers are encouraged toincorporate occlusive moisture-retentive dressings intotheir regular practice to expedite healing, reduce painand scarring, improve wound care convenience andpatient compliance, and minimise wound contaminationand infection’.Managing exudate: its meaning inthe healing regimenAs evident in wound management tools such aswound bed preparation and TIME, expert exudatemanagement is a key component of a structuredapproach to wound care. Clinicians face thedilemma of keeping the wound bed hydrated, whilealso eliminating any excess wound exudation.Excess exudation caused by systemic or regionalfactors, such as oedema or venous hypertension,needs to be addressed and, wherever possible,reversed. If the high levels of exudation persist,then complications can occur. This applies even tothe use of graduated compression bandages, whichcan rapidly become soiled; applying additionallayers of absorbent materials underneath themalters the limb circumference, thereby changingthe pressures achieved.Managing exudate:practical considerationsExudate production is not a linear event: exudatelevels rise and fall as a result of both internal andexternal influences. For example, the onset of infectionis often heralded by an increase in exudate 6 aslocal inflammation increases periwound capillarypermeability and, in turn, the volume of exudateproduced. In addition, the effects of gravitationalforces of venous pressure, when the individual is1 0J O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 0

upright or the affected limb isdependent, may also increase exudateproduction. It is possible toreduce capillary pressures by elevatingthe leg, but many people findthis impractical. Similarly, significantproblems are experienced with leakageand strikethrough when walkingor standing for periods of time.The wound location is thus highlysignificant, with lesions on the lowerlimb generally causing more exudate-relatedproblems than thosehigher up the torso. This is especiallysignificant when dealing with ulcerson the plantar surface of the foot. Chronic woundsin this area often have a diabetic neuropathic orneuroischaemic aetiology. Plantar ulcers pose additionalproblems for patients, who are invariablydependent, and management is difficult if mobilityis to be maintained.Managing exudate:the clinician’s dilemmaFailure to check a dressing’s fluid-handling propertiesbefore application can cause problems. Forexample, a high absorbency product mistakenlyused on a low to moderately exuding wound willresult in a dry (desiccated) wound bed, to which theproduct will adhere. Clinicians should therefore basedressing selection on the wound status and theirown clinical objectives. Consideration of exudatelevels plays a crucial role in this.In some instances — particularly in larger wounds— one area of the wound might have high levels ofexudation, while another part might be dry. Traditionally,one option for the clinician has been tocover the entire wound with a hydrogel dressing inorder to rehydrate the hardened eschar, whiletrying to prevent the exudation from other parts ofthe wound having a deleterious effect on healing.Conversely, the clinician may have decided to usean absorbent dressing, which could further desiccateany dry areas of the wound bed. This mighthave led the clinician to use multiple wound-careproducts on the same wound.This phenomenon, whereby layer upon layer ofdressings are applied, each with a desired outcomein wound management, complicates managementand increases costs. While hydrogels may rehydratedry eschar, many clinicians will have had littleunderstanding of whether they are of benefit whenused in conjunction with an alginate, which isintended to absorb excess exudate. Indeed, manyclinicians will have had limited understanding ofthe potential interaction of such a hybrid dressing,or whether one dressing will nullify the action ofanother. An unduly complicated and ultimatelycostly intervention would result, with little evidencethat it delivers any clinical benefit.Hydration response technologySorbion sachet S is constructed of selected andmechanically treated cellulose fibres within whichpolymer gelling agents are embedded (Fig 1). In theFig. 2Fig. 1presence of moisture, these compoundsinteract with and lock upfluid. The dressing’s actionensures maximum fluid-handlingwithout the risk of desiccation atone extreme or maceration at theother. 7 The manufacturer hasnamed this ‘hydration responsetechnology’ (HRT) and indicatesthis is a potential advancementin the management of woundfluid and the creation of an ‘optimalmoist wound environment’.The dressing is double-faced, soJ O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 01 1

Lateral wicking – when exudate, together with itscomponents, is taken up by the dressing andspreads laterally across the dressing surfacebeyond the borders of the wound marginVertical wicking – when exudate is taken up bythe dressing but is held in the area within thewound margin, avoiding exudate contact with theperi-wound skincan be placed on the wound either way up. The outerpolypropylene contact surface is sealed ultrasonically,which eliminates the need for adhesives, andthe possibility of contact-sensitivity reactions. This isclaimed to help maintain its structural integrity,holding the absorbent inner core in place (Fig 2).The specification of the cut, knitted, mechanically-treatedand surface-maximised cellulosecomponents results in the physical stability of thedressing form, even when the gelling agents havebound a significant volume of wound fluid. This iseasily tested by exposing a sample to differentamounts of liquid and feeling the stability of theinner product layers.One clinical parameter that depends on a dressing’sability to stay in place and retain its internalshape is protection of the wound edges. Loss ofexternal and/or internal structure can lead to a shortageof active material, resulting in maceration of theperiwound skin in heavily exuding wounds. In aproduct evaluation involving 53 patients (discussedmore fully later in this article), the condition of theperiwound skin improved in most cases, evenwhen severe maceration was present at baseline. 8The wound edge protection properties emphasisethe absorbent and retentive properties of the dressing,together with a primarily vertical wickingaction, which prevents exudate from reaching thewound edges.HRT technology was created to generate a dressingthat specifically meets the challenge of woundsthat produce moderate to high levels of exudate. Ittherefore possesses properties that take it beyondmere absorption.As with all absorbent dressings, care must betaken to avoid application on dry wounds, whichwould risk dressing adherence.Managing wounds using HRTThe product is designed to assist wound bed preparation,including exudate management, and toutilise this exudate to create and maintain a moistenvironment, without provoking maceration.This notion is supported by the preliminary clinicalevidence published in the literature to date. 7-12This ‘optimum’ moist environment is intended tofacilitate re-epithelialisation and promote autolyticdebridement.Managing exudateSorbion Sachet S is able to absorb and bind a largevolume of fluid: a 10 x 10cm dressing can easilyretain about 100ml within the dressing matrix, andthis can be easily demonstrated in a simple test.The dressing’s ability to absorb and retain exudate,and thus maintain a moist environment, resultsfrom the combined effect of its high-specificationcellulose components and the performance of itsgelling agents. These allow for the bonding of a significantvolume of wound fluid, while maintainingthe dressing’s physical integrity. These characteristicspersist even when the dressing is used undercompression.This is evident in a small clinical report byRomanelli et al., 7 who treated 10 patients withvenous leg ulcers with a HRT dressing plus compression.(All patients had been treated withcompression before starting treatment with Sorbionsachet S.) In all cases, there was an improvementin the condition of the wound and periwound skinas measured by reduction in wound size, the woundbed characteristics, exudate pH and transdermalwater loss. This gives an indication of the dressing’seffectiveness under compression.In a product evaluation involving 53 patientswith 42 highly-exuding wounds, the condition ofthe periwound skin improved in most cases, evenwhen severe maceration was present at baseline. 8At baseline, 25 wounds (60%) were macerated,eight wounds (19%) were dry/eczematous and nine(21%) had healthy/normal periwound skin. 8At week 4, the periwound skin of 30 wounds (71%)had no maceration, 11 (26%) had minimal macerationand one wound (2%) was severely macerated(mitigating circumstances were noted in thisinstance).In addition, no periwound excoriation wasreported in any of the 53 patients. These findingsindicate that the dressing’s absorption propertiesand retention capability appear to protect thewound margins.MMP modulationModulation of proteolytic enzymes, such as MMPs,promotes healing by avoiding the denaturing ofendogenous growth factors and, possibly, by reducingthe production of damaging free radicals. 13 An1 2J O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 0

unpublished laboratory report found that HRTdressing samples bound inflammatory proteases,including MMP-2. 14 This is supported by furtheranecdotal evidence suggesting that the dressingcore enables the product to regulate excess matrixmetalloproteinase (MMP) activity, 7 which has beenimplicated as a key factor in wound chronicity. 15Indeed, Sorbion sachet S has been placed in theprotease modulating matrix category of the UKDrug Tariff.Bacterial sequestration and debridementSequestration of bacteria by the dressing componentshelps to lower the wound bioburden. Initialclinical data indicate that the dressing can managewound infection without resorting to antimicrobialadjuncts. 10,11Bacterial sequestration and regulation of thewound climate have been attributed to use of thedressing. Romanelli et al. 7 and Chadwick 12 havereported on its debriding properties, which resultedin the generation of a clean and granulating woundbed through the removal of slough.It has recently been proposed that there is astrong association between slough and biofilminfection. 16 Although this standpoint requires validation,empirical observation informs us thatwound healing is delayed as the bioburden increasesand that healing is more likely to occur with regulardebridement of devitalised tissue.It has been proposed that slough is a thrivingaccumulation of bacteria that requires regular andfrequent debridement. 16Impact on quality of lifeIn a clinical evaluation, 51 patients with 40 highlyexuding wounds and 11 moderately exudingwounds were recruited. 9 Despite the high level ofexudate production at baseline, 41 patients reportedan improvement in periwound skin after fourweeks, eight patients reported no change and twopatients reported a deterioration. The latter twopatients had multiple comorbidities and one wasnon-concordant with treatment.Over the four weeks of the study, the frequency ofdressing changes reduced in 32 patients and remainedthe same in 18. Data were not recorded in 18 patients.Forty-six patients reported that the level of comfortassociated with the dressing was ‘good’ or‘excellent’.These results indicate that the patients’ quality oflife improved following application of the dressing.It is reasonable to assume that if a patient finds thata dressing improves their wellbeing, then concordanceis more likely to occur. This may explain theexcellent results reported.ConclusionThe development of HRT and its incorporation intoan easy-to-use dressing may represent a significantadvancement in our ability to create an ‘optimal’moist wound environment. It is hoped that this willresult in the improved management of exudingwounds of all aetiologies. These properties are uniqueto this dressing and distinguish it from a growinggroup of products that continue to focus on absorptionalone.References1 Zhao, M., Song, B., Pu, J. et al.Electrical signals control woundhealing throughphosphatidylinositol-3-OHkinase-gamma and PTEN.Nature 2006; 442: 7101, 457-460.2 Bishop, S.M., Walker, M., Rogers,A.A., Chen, W.Y. Importanceof moisture balance at thewound-dressing interface. JWound Care 2003; 12: 4, 125-128.3 Hinman, C.D., Maibach, H. Effectof air exposure and occlusionon experimental human skinwounds. Nature 1963; 200:377-378.4 Winter, G. Formation of the scaband the rate of epithelializationof superfi cial wounds in the skinof the young domestic pig.Nature 1962; 193: 293-295.5 Fonder, M., Mamelak, A.,Lazarus, G., Chanmugam, A.Occlusive wound dressings inemergency medicine and acutecare. Emerg Med Clin NorthAm 2007; 25: 1, 235-242.6 Cutting, K.F., Harding, K.G.Criteria for identifying woundinfection. J Wound Care 1994;3: 4, 198-199.7 Romanelli, M., Dini, V., Bertone,M. A pilot study evaluating thewound and skin careperformances of the HydrationResponse Technology dressing:a new concept of debridement.J Wound Technology 2009; 5:1-3.8 Cutting, K.F. Managing woundexudate using a superabsorbentpolymer dressing: a53-patient clinical evaluation. JWound Care 2009; 18: 5, 200-205.9 Cutting, K.F., Acton, C., Beldon,P. et al. Clinical evaluation of anew high absorbency dressing.Poster presented at EWMAconference 2008, Lisbon,Portugal.10 Sharp, C.A. Managing thewound environment withHydration ResponseTechnology. Wounds 2010 (inpress).11 Evans, J. Hydration ResponseTechnology and managinginfection. J Community Nursing2010; 24: 1, 15-16..12 Chadwick, P. The use of sorbionsachet S in the treatment of ahighly exuding diabetic footwound. Diabetic Foot J 2008;11: 4, 183-186.13 Cullen, B., Watt, P.W.,Lundqvist, C. et al. The role ofoxidised regenerated cellulose/collagen in chronic woundrepair and its potentialmechanism of action. Int JBiochem Cell Biol 2002; 34: 12,1544-1556.14 Abel, M., Wiegand, C., Ruth, P.,Hipler, U-C. Polyacrylatesuperabsorbersbindinfl ammatory proteases in vitro.Available at: http://freedownloadbooks.net/wiegand2-pdf.html15 Moore, K. Compromisedwound healing: a scientifi capproach to treatment. In:White, R.J. (ed). Trends inWound Care, volume 3. QuayBooks, 2004.16 Cutting, K.F., Wolcott, R.,Dowd, S.E., Percival, S.L.Biofi lms and signifi cance towound healing. In: Percival, S.(ed). Microbiology of wounds.CRC Press, 2010.J O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 01 3

Sorbion sachet S: clinicalapplication and resultsSorbion sachet S was designed to bestow a range of clinical advantages across anumber of indications, particularly in moderately to highly exuding wounds. Thispaper explores the evidenceMartyn Butcher, Independent Tissue Viability Consultant, Plymouth, UKThe large volume of exudate generated by manychronic wounds, and the ensuing fluid-handlingchallenges, are discussed in the two precedingpapers. Management can be problematic,with fluid harbouring bacteria 1 and containingharmful compounds such as matrix metalloproteases(MMPs), 2 which contribute to wound chronicity. 3-5Exudate can also damage periwound skin, causingmaceration 6,7 and subsequent wound extension.To effectively manage exudate, a dressing shouldtherefore protect the wound edges, remove harmfulcompounds and microbes from the wound surface(via MMP modulation and bacterial sequestration)and promote autolytic debridement, all the whileproviding a moist, healing environment. This will, inturn, improve the patient’s quality of life.Sorbion sachet S is specifically designed to achieveall of these goals as a primary dressing, as Whiteexplains in the previous paper. The theoretical argumentsfor its use in managing both acute and chronicwounds are compelling. However, practitioners musthave the opportunity to appraise the clinical evidenceif its use is to be integrated into clinical practice. It isworth considering the key performance indicators ofthe product: exudate management, wound edge protection,MMP modulation, bacterial sequestration,debridement and impact on the patient’s quality oflife. In many cases, the multiplicity of product actionsis clearly demonstrated through the results obtained.Managing exudate and protectingthe wound edgeOne valuable function of Sorbion sachet S is its effectivemanagement of wound exudation. Throughoutnumerous case studies and clinical evaluations, frequentreference has been made to its ability to rapidlydraw excess fluid away from the wound surface, lockingit into the dressing matrix. This prevents soilingof outer dressings and bandages, reduces the need forfrequent dressing changes and prevents macerationof the periwound tissues.A case study by Sharp demonstrates the benefits ofthe product in the management of wound exudate. 8She describes an elderly, obese gentleman withgrossly oedematous legs and virtually circumferential,bilateral ulcerations, who had been admitted forwound assessment and management.These ulcers had been present for three years andwere highly exuding. Wound management had beena major problem: dressing changes took at least onehour to complete, often requiring the assistance of asecond nurse. The highly absorbent dressings previouslyused, including gauze, foams, non-adherentpads and a non-specific ‘super-soaker’, had beenineffective, and extensive excoriation of the periwoundskin had been observed.Sorbion sachet S dressings were applied frombelow the knees to toes and kept in place with crepebandages as compression bandaging could not beused. The first dressing applied needed changingafter 48 hours and, on removal, the periwound skinmaceration was noticeably reduced and appearedless red and inflamed. The exudate had been efficientlyabsorbed and retained within the dressings.By day 4, the dorsum of each foot was free ofexcess moisture and within 14 days the wounds hadmade such good progress that the dressing was nolonger clinically indicated. The reduction in dressingchange frequency meant that nursing time wasalso reduced.Cutting , in a product review of Sorbion sachet S,cited the case of an 80-year-old female with longstandingvenous leg ulcers (VLUs) that had failed torespond to foam dressings under graduated compressionbandages. 9 Despite twice weekly dressingchanges, she had extensive excoriation and macerationof the medial ankle and foot.Four weeks of treatment with Sorbion sachet Sresulted in a vast improvement of the periwoundskin, which was no longer macerated, and improvementsin the condition and size of the ulcer (reducedfrom 3.5 x 2cm to 3.0 x 1.5cm).1 4J O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 0

Fig 1: Poor exudate control has resulted in an increase inthe wound size and periwound macerationA 10-patient study of the use of Sorbion sachet Sto achieve wound bed preparation was undertakenin the US. 10 The average age was 66.3 years (range:33–92). A total of 16 lesions were treated with theproduct: nine pressure ulcers, four VLUs, two casesof wound dehiscence and one case of pyodermagangrenosum. The average wound duration was24.5 months (range: 1–96). On enrolment, the averagesurface area was 131.1cm 2 (range: 2.86–624).Patients were treated with the Sorbion dressingfor a mean of 23.1 days, during which 164 dressingprocedures were performed. Dressing performancecriteria investigated included pain, debridement,wound reduction and healing. During the study,exudate handling was scored as excellent or goodin 91% of all cases, adequate in 8% and poor in0.5%. There was a regular and sustained reductionin maceration and in 100% of all dressing changesSorbion sachet S was considered easy to remove.A case study taken from this evaluation demonstratedthe success of this product. A 94-year-oldfemale enrolled into the trial had a non-specificulcer on the left medial ankle of three years’ duration.The ulcer had been triggered by a traumaticinjury and was complicated by rheumatoid arthritis.Treatment with absorbent dressings (alginates,Hydrofiber, foams), external compression and thedaily use of an external pneumatic compressiondevice failed to promote healing. In fact, the ulcerhad increased in size, with a surface area of 25cm 2 ,Table I. Wound aetiology and durationFig 2: Resolution of maceration and complete ulcerhealing 12 weeks after initiation of Sorbion sachet Sand the periwound skin was compromised (Fig I).Management with Sorbion sachet S was initiatedto control exudation and minimise periwoundmaceration. The dressing was combined with supportstockings and vasopneumatic compression,both of which had been used beforehand. The ulcerand periwound skin improved rapidly and, at 12weeks, the wound had completely re-epithelialised(Fig 2).Chadwick reported on the treatment of a 64-year-old patient with a highly exuding diabeticulcer following a forefoot amputation. 11 The woundhad been present for nearly one year. Here, thechallenge was not only to manage exudate levelsand prevent periwound maceration and excoriation,but also to find a product capable of retainingthe fluid taken up, even during weight-bearing.Although the patient was fitted with total contactcasts and total contact insoles, it was impossible tocompletely eliminate load from the wound area.This, combined with limb dependency and excessiveexudation, made management difficult andcaused rapid soiling of his orthotic devices.Changing the dressing regimen to Sorbion sachetS brought about major changes to the patient’swound status. Soiling ceased to be a problem, exudatelevels were well managed and it was possibleto reduce the frequency of dressing reapplicationfrom daily to twice weekly. By week 12 the woundhad healed completely and it remains healed.Woundduration(weeks)Wounds with high level of exudate on enrolmentAbdominaldehiscenceDiabetic footulcerVenous legulcerPressure ulcerVein graftdonor site0–6 1 - 2 2 - 56–12 - - - 1 - 1>12 - 2 28 5 1 36Total 1 2 30 8 1 42J O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 01 5

As eluded to in the previous paper, Cutting’s findingsin a clinical evaluation of 53 patients treatedwith Sorbion Sachet S on a variety of wound aetiologies(Table I) provide good evidence of the dressing’sfluid-handling capability. Most of the wounds werehighly exuding and had periwound maceration atbaseline. 12After four weeks of treatment with Sorbion sachetS, the exudation was well contained and skin healthrestored. This not only supports the findings of theearlier case studies but also shows that these are notisolated instances of success. This is of significanceto clinicians who need to be assured that productperformance can be maintained in a number of differentcircumstances.DebridementThe debridement of devitalised tissue and slough isan essential component of successful wound management.Just as exudate management is an essentialcomponent of wound bed preparation and the TIMEapproach to wound management, so debridement isneeded to remove tissue that would act as a potentiallocus for infection and prolong woundinflammation. While sharp debridement is the fastestmethod of removing devitalised tissue, it is notalways practical or possible. Safe sharp debridementrequires a high level of dexterity and technical skillsas well as an in-depth knowledge of anatomicalstructures. This may be possible within the safety ofa controlled clinical environment but is far more difficultto achieve within the community setting. Inaddition, the absence of a clearly defined plane ofviability between viable and non-viable tissue maymake such debridement difficult to achieve safely. 13,14In such cases, a gentler, yet still effective, method ofdebridement is called for.Interventions such as larval debridement therapycan be indicated, but these too can have limitationsin terms of availability, patient acceptance and logistics.Standard approaches to the promotion ofautolysis involve the maintenance of a moist woundbed and yet, as seen in the previous case studies,even the presence of high levels of exudate does notnecessarily result in successful wound debridement,and the addition of moisture to an already wetwound can be counterproductive. A product with adifferent mechanism of action is therefore indicatedin these circumstances.Romanelli et al. reported on a 10-patient studyundertaken to determine the influence of Sorbionsachet S on wound bed preparation. 15 The primaryobjective of this four-week evaluation of VLUs wasto find out if use of this dressing supports the body’sautolytic debridement process, as indicated by a significantreduction in slough and reduction of woundpH to more physiological levels (a high pH is anindicator for poor wound healing). 16The patients’ age ranged from 18 to 80 years andthe average ulcer duration was two years (range: fourmonths to four years). Despite standard therapy(described simply as moist wound healing and shortstretchcompression bandaging), all wounds hadfailed to progress. Following recruitment, eachpatient had Sorbion sachet S added to their existingwound care regimen as a primary dressing. Dressingchanges were performed twice weekly.The wound pH was measured using a handheldpH meter (Hanna Instruments). In addition, transepidermalwater loss (TEWL) was measured at thewound edge (using a VapoMeter, Delfin Technologies,Kuopio, Finland), and wound size and tissuedistribution were analysed using a Silhouette portable2D and 3D laser scanning device (ARANZMedical).In all patients, significant and positive changes intissue type were observed. Romanelli et al. reportedthat ‘a stark reduction of presence of slough wasseen which was in relation to the removal of wetnecrosis’. 15 The results show that slough was eithercompletely or significantly eliminated in all but onepatient by the end of week 4. There were no reportsof adverse events, including bandage-related pressuredamage.When Professor Romanelli presented these resultsat the Wounds UK conference in Harrogate in 2009,he explained: ‘at dressing removal, debris lifted offthe wound surface easily and revealed a wound surfacecovered in fine, highly vascular granulationtissue’. He described this process as ‘soft debridement’,and said he felt it contributed significantly tothe healing outcomes.Bacterial sequestration andMMP modulationAs described in the previous papers in this supplement,excess MMPs are thought to play a significantrole in wound chronicity. They are not only derivedendogenously, but also can be manufactured in largevolumes by wound pathogens and result in thebreakdown of essential wound proteins. Their management(by reduction of bacterial bioburden andsafe binding within the dressing matrix) is an essentialcomponent of the promotion of woundhealing.Evans reported a case study that appears to confirmthe ability of Sorbion sachet S to facilitatebacterial sequestration. 17 She cites the case of a 92-1 6J O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 0

Fig 3: Before initiation of Sorbion sachet S, theperiwound skin is heavily macerated and the woundbed has 85% slough coverageyear-old woman who developed a wound on her lefthallux after hip surgery. The wound was infectedwith meticillin-resistant Staphylococcus aureus(MRSA), which failed to respond to a combination ofappropriate systemic antibiotic therapy and topicalantimicrobial dressings (silver-based) administeredfor over three weeks. The wound and periwoundarea had deteriorated and exudate levels becamehigh. The topical antimicrobial was discontinuedand the wound was dressed with Sorbion sachet S.Within one week, exudate levels had fallen andsubsequent laboratory analysis of swabs from thewound revealed the MRSA had been eliminated.Sorbion sachet S was continued for three weeks untilno longer indicated. During this time cultures of thewound remained negative.In a case study presented by Cutting, bacterialsequestration may also have played a significant partin the successful treatment of a patient — a 66-yearoldmale presenting with a large VLU on theanterolateral aspect of his right leg. 9 The ulcer washighly exudating and the periwound skin showedsigns of serious maceration. Increasing exudatelevels are a classic sign of increased bacterial burden.Approximately 85% of the wound bed was coveredwith slough (Fig 3). As the high bacterial load wasconsidered a mitigating factor, the wound had beentreated every second day with a primary antimicrobialdressing (Inadine, Systagenix, UK), which washeld in place with Jelonet (Smith & Nephew, UK).However, this did not contain the bacterial load,with exudate levels remaining highand the ulcer increasing in size.Sorbion sachet S was applied with anon-adherent primary dressing.Within the first week of application,exudate levels improved and thedressing change frequency reducedto twice weekly. Maceration of theperiwound skin resolved and theulcer started to reduce in size. Afterfour weeks, slough levels had reducedto cover just 30% of the wound surface(Fig 4). The patient rated thedressing comfort as excellent.In the previously quoted study byRomanelli et al., monitoring of thewound-bed acid/alkali balance wasmeasured as an indicator for healing.15 Chronic wounds have beenfound to have a neutral or alkaline pH when comparedwith the surrounding intact skin, andacidification increases the healing rate. 18 Proteaseactivity is highly dependent on pH. A weak acidenvironment decreases proteolytic activity andinhibits bacterial proliferation. 19,20 Conversely, highpH levels may be an indicator of manipulation ofthe wound environment by bacterial colonies. 19As stated above, in the Romanelli et al. study, 15wound pH levels were initially high, but returned tomore physiological levels following use of SorbionSachet S. 15 This may indicate a reduced level of bacterialload and would appear to suggest that proteaseactivity had reduced.Impact on quality of lifeAll wounds affect quality of life. With chronicwounds, the negative effects such as social isolation,pain, soiling, malodour, loss of independence andfinancial considerations become a daily reality, andoften there seems to be no end in sight. This canaffect the patient’s physical and psychological wellbeing,potentially reducing concordance withtreatment. Quality-of-life issues are of significance toboth the patient and health-care provider.Patient comfort and satisfaction are obvious indicatorsof quality of life. The study previouslyhighlighted by White in the second article in thissupplement 21 showed that patient comfort washighly rated (46 patients reporting good or excellentcomfort) with the Sorbion dressing. This finding ismirrored throughout the case studies and evaluationsFig 4: Periwound skin has improved and slough levelshave reducedJ O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 01 7

previously cited. 9,12,15 However, other indicators ofquality of life need to be considered, especially if specificquality-of-life questionnaires have not been usedwithin an evaluation or case study.Pain has a serious negative effect on quality of life.It is therefore fair to assume that lack of pain shouldbe considered a performance indicator that can havepositive effects on perceived quality outcomes.Romanelli reported that the use of Sorbion was associatedwith improved comfort and all patientspreferred it to the previously used dressing products,including Hydrofibre and foams. 15 Similarly, theabsence of wound malodour, as described by Sharp, 8skin sensitivities, trauma at dressing change asobserved by Evans, 17 and absence of malodour 8 canall be seen as positive wound-related outcomes thataffect patient satisfaction and hence quality of life.Not only does the frequency of care interventionsaffect the individual’s ability to continue normalactivities of living, but they are also a major influenceon the cost of wound management. Frequent dressingchanges stop patients living a normal lifestyle andcan prevent them from returning to work. Throughoutthe case studies and evaluations mentioned here,reductions in dressing frequency were observed asexudate management was optimised, bacterial colonisationwas reduced and the toxic effect of exudateon the periwound skin was relieved.ConclusionFor the clinician faced with the dilemmas of exudatemanagement, finding a successful resolution canoften take a long time. All too often products purportedto handle fluid have proven ineffective whenused in the clinical situation, and clinicians are leftto seek further therapy options. High exudate levelsand their all too frequent sequelae of bacterial andnecrotic burden, malodour, pain, periwound macerationand proteolytic degradation can incur massivecosts and reduce quality of life. The development ofa smart technology that is easy to use, readily availableand has been proven to improve clinicaloutcomes, therefore, is long overdue.The existing evidence for Sorbion sachet S comprisespreliminary clinical data. The most robust andsupportive clinical evidence, in terms of the samplesize, is Cutting’s study, which recruited 53 patients.This non-comparative clinical evaluation providedpositive outcomes linked to multiple case studies.Without doubt, further studies are required, includingcomparative designs. However, initialnon-comparative results are very promising.From the evidence available, therefore, hydrationresponse technology in the form of Sorbion Sachet Snot only provides theoretical benefits in woundmanagement but also matches these claims withreal-life clinical outcomes.References1 Bowler, P.G., Duerden, B.I.,Armstrong, D.G. Woundmicrobiology and associatedapproaches to woundmanagement. Clin MicrobiolRev 2001; 14: 2, 244-269.2 Trengove, N.J., Stacey, M.C.,MacAuley, S. et al. Analysis ofthe acute and chronic woundenvironments: the role ofproteases and their inhibitors.Wound Repair Regen 1999; 7:6, 442-452.3 Saarialho-Kere, U.K. Patterns ofmatrix metalloproteinase andTIMP expression in chroniculcers. Arch Dermatol Res1998; 290: Suppl, S47-54.4 Neely, A.N., Clendening, C E.,Gardner, J., Greenhalgh, D.G.Gelatinase activities in woundsof healing-impaired mice versuswounds of non-healingimpairedmice. J Burn CareRehabil 2000; 21: 5, 395-402.5 Mulder, G.D., Vande Berg, J.S.Cellular senescence and matrixmetalloproteinase activity inchronic wounds. Relevance todebridement and newtechnologies. J Am Podiatr MedAssoc 2002; 92: 1, 34-37.6 White, R.J., Cutting, K.F.Interventions to avoidmaceration of the skin andwound bed. Br J Nurs 2003;12: 20, 1186-1201.7 Gray, M., Weir, D. Preventionand treatment of moistureassociatedskin damage(maceration) in the periwoundskin. J Wound OstomyContinence Nurs 2007; 34: 2,153-157.8 Sharp, C.A. Effi cient managementof the wound environmentusing Hydration ResponseTechnology (HRT). Posterpresentation at Tissue ViabilitySociety conference 2009,Telford, UK.9 Cutting, K.F. Optimal exudatemanagement in a dressing. JCommunity Nursing 2008; 22:11, 33-34.10 Kwon Lee, Maloney S, HermansMHE. (2009) data on fi leSorbion AG, Ostbevern,Germany.11 Chadwick, P. The use of sorbionsachet S in the treatment of ahighly exuding diabetic footwound. The Diabetic FootJournal 2008; 11:4 183-186.12 Cutting, K.F. Managing woundexudate using a superabsorbentpolymer dressing: a53-patient clinical evaluation. JWound Care 2009; 18: 5, 200,202-205.13 Vowden, K.R., Vowden, P.Wound debridement. Part 2:Sharp techniques. JWC 1999; 8:5, 237-24014 Tissue Viability NursesAssociation Conservative SharpDebridement.Procedures,Competencies and Training.TVNA, 2005. http://tinyurl.com/yzj3w4w15 Romanelli, M., Dini, V., Bertone,M. A pilot study evaluating thewound and skin careperformances of the HydrationResponse Technology dressing:a new concept of debridement.J Wound Technology 2009; 5:1-3.16 Leveen, H.H., Falk, G., Borek, B.et al. Chemical acidifi cation ofwounds: an adjuvant to healingand the unfavorable action ofalkalinity and ammonia. AnnSurg 1973; 178: 6, 745-753.17 Evans, J. Hydration ResponseTechnology and managinginfection. J Community Nursing2010; 24: 1, 15-16.18 Wilson, I.A, Henry, M., Quill, R.D., Byrne, P.J. The pH ofvaricose ulcer surfaces and itsrelationship to healing. Vasa1979; 8:4 339-342.19 Shukla, V.K., Shukla, D., Tiwary,S.K. et al. Evaluation of pHmeasurement as a method ofwound assessment. J WoundCare 2007; 16: 7, 291-294.20 Schultz, G., Mozingo, D.,Romanelli, M., Claxton, K.Wound healing and TIME: newconcepts and scientifi capplications. Wound RepairRegen 2005; 13 (Suppl 4): SI-SII.21 Cutting, K.F., Acton, C.,Dunwoody, G. et al. Clinicalevaluation of a new highabsorbency dressing. Posterpresentation at EuropeanWound ManagementAssociation (EWMA)conference, Lisbon, 2008.1 8J O U R N A L O F W O U N D C A R E S O R B I O N S U P P L E M E N T 2 0 1 0

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