2Aims and objectivesTo understand the underlying structures of the skinTo gain a basic understanding of the process of wound healing.To be able to identify different tissue types in areas such as the wound bed, wound edge and surrounding skin
6Largest and most visible organ Made up of two main layers: Epidermis – very thin layer and is firmly attached to the dermis at the dermo- epidermal junction.Dermis- made up of two layers comprising of fibrous proteins, collagen and elastin which give skin its strength and elasticity.Below dermis is subcutaneous layer , this provides support to the dermis and stores fat which protects the internal structures.Epidermis is outer layer and varies in thickness 0.1mm-on eyelids and 1mm thick on Palms and solesAcidic= PH 5.5Has five layers corneum,lucidium,granulosum,spinosum, basaleDermis – deeper layer composed of collogen fibres and elastin fibres( skins elasticity and stregnth)
10Acid PH helps to prevent infection Protection of internal structures – physical barrier to microorganisms and foreign matter.Acid PH helps to prevent infectionDamage to skin impairs ability to carry out these functions. Ordinary washing = 45 mins. to restore skin PhProlonged exposure = up to 19 hours
11Sensory perception-Allows you to feel pain, pressure heat this helps us to identify potential dangers and avoid injury
12Thermoregulation- Blood vessels constrict or dilate to raise or lower body temperature. Sweat production promotes cooling
13Excretion –Transmits small amounts of water and body waste via sweatHelps to prevent dehydration.
14Metabolism-Photochemical reaction in the skin produces Vitamin D essential for metabolism of calcium
15Absorption-Some substances can be absorbed directly into blood stream
17Functions of the skin that declines with age. Flattening of the dermal-epidermal junction, increased susceptibility to friction/ shearing forces resulting in blistering.Decreased sensitivity to pain perceptionEpidermis becomes thinner and flatter , uneven distribution of melanocytes leading to uneven pigmentation.Skin becomes wrinkled due to depletion of elastic fibres.Skin becomes dry as a result of atrophy of sebaceous glandsBaraboski (2003) and Beldon (2006)
19Classification of wound healing Wounds that heal by primary intention e.g. incisional woundsWounds that heal by secondary intention e.g. pressure ulcersWounds that heal by tertiary intention e.g. delayed suture
20Wounds characterised by whether they are acute or chronic
21Acute wounds Characterised by: No underlying aetiology i.e. trauma Short durationNormal inflammatory phaseHeal and do not breakdown
22Chronic wounds Characterised by: Underlying pathology e.g. venous insufficiencyProlonged durationHyperactive statePersistent state of inflammation
24Normal Wound Healing Response ProteoglycansFibroblastsCollagenAngiogenesisCollagen remodellingScar maturationNeutrophilsMacrophagesLymphocytesMATURATIONPROLIFERATIONPlateletsFibrin0 – 3 days: The first phase of wound healing occurs immediately at the time of injury. During this phase, there is increased blood supply to the area, platelets aggregate to form a temporary plug & fibrin which forms a mesh as the body attempts to clot off any bleeding vessels allowing haemostasis to occur. This blood clot or scab is part of a natural covering mechanism creating a new barrier for the broken skin to protect the underlying tissues from harmful bacterial invasion.1 – 6 days: Following this the natural inflammatory response occurs. It consists of widespread vasodilation, oedema formation and the migration of cells such as neutrophils (whose function is the phagocytosis of bacteria), macrophages (which also destroy bacteria but are also a rich source of biological regulators that are essential for the normal wound healing process) & lymphocytes (white blood cells involved in the immune response).3 – 24 days: During the proliferation phase the extracellular matrix (the supporting structure of new tissue) is formed and remodelled, with angiogenesis (new blood vessel development), epithelisation (new skin cells) & wound contraction taking place. During this phase fibroblasts play an important role in the manufacture of collagen (protein responsible for holding the body together, skeleton included), along with other substances such as proteogylcans to form the ECM, which fills the wound space and provides a scaffold for the new tissue.24 – 365 days: The maturation phase can last for many months after skin cover has been achieved. The initially formed ECM is remodelled, while collagen increases the tensile strength of the wound.NB Stages overlapINFLAMMATIONHAEMOSTASISMINUTESDAYSWEEKSMONTHS / YEARS(whru)
25Haemostasis Starts immediately after injury. Blood vessel contraction (vasoconstriction)Vasoconstriction minimises blood loss
26Inflammatory phase Occurs between 0-3 days Vascular permeability increases and serrous fluid ( comprising of cell and plasma protein) accumulates in surrounding tissue causing swellling redness and warmth
27Proliferation0-24 daysDuring this phase growth factors prompt fibroblasts to migrate to the wound. They make new fibres and ground substnaces (ECM) provides support to cellsFibroblasts start at wound edge then spread over surface. – require o2 to perform this task
28Maturation 20 days – 2 years Closure of wound and re-epithelisation. Scar maturation
29What factors may affect wound healing? ASK AUDIENCE
30Factors Affecting Healing Systemic AgeAnaemiaNutritionMedications e.g.: Anti inflammatory, Cytotoxic drugs, steroidsChronic health conditions eg :Diabetes MellitusSystemic infection (Bowler & Davies, 1999)OxygenationSmokingPsychological factorsTemperatureAge – in old age the inflammatory response, proliferation phase and maturation are diminished.Anaemia – lack of red blood cellsAnti-inflammatory – suppress the normal inflammatory response to injury.Cytotoxic drugs – interfere with cell proliferation and severely impair healing. Also neutropenia makes the patient more susceptible to infection. Nausea / vomiting leads to poor nutritional intake and dehydration.Diabetes – many factors are thought to impair wound healing, though no single factor alone is responsible.Hormones -Jaundice - excess of bilirubin (bile) from the liver Nutritional status – despite malnutrition healing has been demonstrated to take place, improved nutrition would reduce the complications and length of hospital stay. There are discrepancies in the literature relating to obesity and wound healing. Problems such as performing surgery are very high.Temperature - Any substance used should be at body temperature as it takes 40 mins for the wound to return to normal body temp after cleansing and Mitotic cell division can be delayed for up to 3 hoursUraemia – excess of urea (waste products from the kidneys in the urine)Vitamins – Vit A deficiency inhibits the keratinisation process; Vit C deficiency causes wound dehiscence, reduces tensile strength and adversely affects angiogenesis.Zinc is essential in fibroblast epithelialisation, cofactor for protein synthesis & for metalloproteinase production in the ECM.Stress & anxiety can affect the immune system, can disturb sleep, which is important for healing and tissue repair. Altered body image due to disfiguring wounds or surgery can adversely affect patients’ psychological state.
31Factors affecting healing Local Factors Blood supplyDenervationHaematomaLocal InfectionDurationWound bed conditionAnatomical siteSize of woundClassic infection – clearly infected, red, hot, smelly and bleeding. 5th toe already amputated. 4th toe sausage shaped. NeuropathyEventually had a below knee amputation.Denervation – interruption of the nerve supply to the muscles and skin.
32Assessment of a wound is the responsibility of the qualified member of staff You should ensure that this has been undertaken and a treatment plan has been established.
33RememberThe selection of dressings or bandages without accurately undertaking a wound assessment taking into account underlying factors that may delay wound healing may result in costly treatments that are inappropriate and are not successful!
34Clinical appearance of wound bed Colour Physiological StateBlack NecroticYellow SloughyRed GranulatingPink EpithelializingGreen Infected?
35Characteristics of granulation tissue Healthy tissueBright redMoistShinyDoes not bleedUnhealthy tissueDark redDehydratedDullBleeds easilyS