PMY3304- WOUND MANAGEMENT

What are the stages in wound healing?

1) haemostasis stage

2)inflammatory phase

3) proliferative phase

4)remodelling/ maturation phase

what is the haemostasis stage?

• aim is to prevent blood loss

• in this stage vasoconstriction occurs, platelet activation (form clots) and coagulation cascade

what is the inflammatory phase?

• clot formation and inflammation, this is intended to clean the wound

• macrophages at the site will release cytokines, attract other immune cells and clear pathogens

what happens in the proliferative stage?

• in this stage dermal repair and epidermal regeneration occurs as fibroblasts produce collagen and other matrix components

• granulation is the formation of new connective tissue and blood vessels

what is the remodelling/ maturation phase?

scar formation and wound strengthening

what factors affect the wound healing process?

• wound will not heal unless it is red and clean, must be warm and moist with adequate supplies of nutrition and oxygen

• delayed healing may be patient related (intrinsic) or wound related (extrinsic)

what are examples of intrinsic factors to wound healing?

nutrition, blood supply, age, concurrent disease, pharmacological agents, smoking

what are examples of extrinsic factors to wound healing?

moisture, temperature, oxygenation, pH, infection, particulate contamination/ irritants

what are characteristics of necrotic wounds?

• dead or devitalised (non-viable) tissue

• poor blood supply 

• impeded wound healing

what are characteristics of a sloughy wound healing?

white or yellow layer of dead tissue which sometimes has a foul odour

how does a granulating wound look?

• wound in the process of healing which is characterised by granulating tissue (bright red, bumpy, moist tissue)

what characterises an epithelialising wound?

final stage in wound healing, when new skin cells (epithelial cells/keratinocytes) cover the wound surface

how is a clean wound classified?

uninfected and minimal inflammation usually a surgical wound

how is a clean-contaminated wound classified?

contact with the normal flora but no overt infection

how is a contaminated wound classified?

open, traumatic wounds with no major break in asepsis

how is a dirty/infected wound classified?

contains dead tissue and pathogens

what are the potential classifications of cut by depth?

• superficial

• partial thickness

• full thickness

what are the potential causes of wounds?

• bite

• burn

• puncture

• incision

• laceration

• abrasion

what are the usual duration of wounds?

• acute (traumatic wounds, burns and scalds, surgical wounds)

• chronic

what is a traumatic wound?

• the body is subject to a force which exceeds strength of skin or underlying tissues

• these wounds are not immediately life threatening unless a major blood vessel is penetrated

what is an important factor in the management of traumatic wounds?

• meticulous irrigation 

• debridement of dead tissue and foreign bodies

why are dressings used on healing wounds?

protect injured tissue and create optimal conditions for healing

what kind of wounds are tetanus prone wounds?

penetrating wounds like rusty nail n foot, devitalised tissue, contact with soil, clinically infected wounds

what are the three zones with a burn or scald?

1) zone of coagulation

2)zone of stasis

3)zone of hyperaemia

what is the zone of coagulation with a burn/scald?

• centre of burn contains coagulated blood vessels

• if this zone is in or deeper than the dermal layer, the tissue will die or slough off

what is the zone of stasis in burns/scalds?

• surrounding the burn centre, blood supply is sluggish due to aggregation of WBC’s, this tissue has the potential to recover

what is the zone of hyperaemia with burns/scalds?

• burn border that appears red due to inflammatory process, this tissue should recover completely 

how is the extent of burn injury expressed?

in terms of depth and TBSA which is calculated as a % of body surface area

how do you treat a burn?

• immerse in cold running water for at least 20 mins

• remove any jewellery or clothing, unless stuck to the burn, before the area starts to swell

• when the burn has cooled cover the area with clingfilm, loosely to give room for swelling 

• elevate injured limbs, particularly hands

• don’t apply cream, ointments, oils

• don’t apply adhesive or cotton wool

• wrap patient in blanket to prevent hypothermia and shock

what should be done with blisters from a burn/scald?

• small painless blisters should be left intact, large problematic blisters should be deroofed

what should the ideal burn dressing do?

• control bacterial colonisation

• promote rapid granulation and epithelialisation

• be non-adherent

• manage exudate (fluid that travels to the wound, like water/electrolytes)

• not hinder movement

• not compromise circulation

how are surgical wounds characterised?

most are categorised as acute and should heal without complication in an expected time frame however healing can be affected by surgical site infections

what are the choices for surgical wound closure?

stitches, steri strips, staples

what is the difference between primary, secondary and tertiary intention?

primary intention produces a hairline scar

secondary intention produces a large scar

tertiary intention produces a closure with a wide scar

how do we lower the risk of infection post surgery? (peri and intraoperative care)

• identify risk e.g. MRSA screening

• patient should shower prior to surgery

• skin should be disinfected before incision made, aseptic technique and dressing change 

• antibiotic prophylaxis

• keep dressing changes to a minimum at first, wait 48 hourss  unless signs of complications

what are characteristics of the ideal post op dressing?

• effective barrier to contamination

• waterproof

• gaseous exchange

• monitoring of wound 

• low adherence 

what are examples of chronic wounds?

includes pressure ulcers, leg ulcers, diabetic foot ulcers, fungating malignant wounds

why do chronic wounds occur?

disrupted healing process during one or more of the healing phases for example:

• alterations in the amount of growth factors, cytokines, proteases

• oxidative damage by free radicals

• condition specific factors e.g. neuropathy (loss of feeling) in diabetes

• accumulation of necrotic tissue or slough

• infection and biofilm formation

how do biofilms contribute to the occurrence of chronic wounds?

biofilm will protect the bacteria from antibiotics, low oxygen in biiofilms, stops woundhealing, can impair migration of immune cells

where do pressure ulcers usually occur?

mainly on bony prominences of the body

what are pressure ulcers?

• localised areas of tissue damage from sustained mechanical loading of the skin and its underlying structures

• the tissue becomes depleted of blood flow therefore there is no oxygen or nutrient supply to the wound and no removal of waste products from the wound

how can pressure ulcers be prevented?

repositioning

what is a leg ulcer?

area of loss of skin below the knee on the leg or foot which takes more than 6 weeks to heal

what are the potential causes of leg ulcers?

usually vascular aetiology, can also b autoimmune, malignancy or infection cause

what age group has the highest prevalence of leg ulcers?

in the 80+ age group as there are usually lots of comorbidities in this age group

how are leg ulcers treated?

• goal of management is to reduce venous hypertension

• compression bandaging

• graduated compression bandaging has been shown to heal many leg ulcers within 12 weeks

why are diabetic patients predisposed to foot ulcers?

• due to peripheral neuropathy and vascular insufficiency

• specialist assessment should be conducted by a podiatrist

what are the potential complications with diabetic foot ulcers?

delayed or inadequate treatment can lead to complications like osteomyelitis, gangrene, amputation

how are diabetic foot ulcers managed?

• good metabolic control

• inspect feet daily

• wash and dry feet carefuly daily

• use of emollients to stop dry skin from cracking

• ensure shoes fit properly

• cut toenails straight across to prevent ingrowth

• debridement

• reduction of pressure

what is a fungating malignant wound?

• cancerous infiltration of the skin

• ulcerating and proliferative growth, and is named by appearance as it isn’t caused by fungi

what is the difference between exophytic and endophytic fungating malignant wounds?

exophytic- cauliflower like

endophytic- appearance of ulcer or crater

how can fungating or malignant wounds be healed?

tumour growth must be arrested

how are most dressings classified?

as medical devices as there is much less of a requirement to prove clinical effectiveness

what are the ideal characteristics of a dressing?

• manages excess exudate

• allows gaseous exchange

• impermeable to microorganisms

• insulates wounds from low temperatures

• allows removal without trauma

• maintains a moist environment

• comfort of dressing

• cosmetic effect

• malodour

• pain

• body image

whats the difference between the primary and secondary dressing?

the primary dressing is in direct contact with the wound whereas the secondary dressing if required is used to secure the primary dressing or absorb exudate

what are alginate dressings produced from?

sodium and calcium salts of alginic acid, a natural polymer derived from seaweed

what is the function of alginate dressings and what form can they come in?

they absorb exudate and they can come in flat sheets or packing for cavity wounds

what are the indications for alginate dressings?

• sloughy or clean wounds that produce moderate to heavy exudate

• ribbon/rope for packing cavities

• sheet for shallow wounds

what are alginate dressing C/I for?

• dry wounds

• diabetic foot ulcers if underlying infection

why are honey dressings used? what is the downside?

• contains an enzyme that produces hydrogen peroxide (slow release antibacterial and antiseptic effect)

• deodoriser

• maintans a mosit environment and is claimed to stimulate tissue growth

• however needs to be sterilised

what are the indications for honey dressings?

• malodourous wounds

• dry or sloughy wounds

• necrotic wounds

what are honey dressing C/I for?

• allergy to bee venom

• caution in diabetes due to potential of glucose and fructose absorption

what is the active ingredient in cadexomer dressings?

iodine

how do cadeoxomer dressings work?

• spherical starch microbeads that form a 3D lattice- iodine is trapped in this lattice at conc of 0.9%

• starch has a high absorption capacity- (swells)

• releases iodine for up to three days, iodine has an anti-microbial effect against gram negative bacteria, fungi and yeasts, protozoa and viruses

• this paste is sandwiched in a protective gauze backing

what are cadexomer dressings indicated for?

• absorption of high levels of exudate

• infected wounds and prevention of infection

what are cadexomer dressings c/i for?

• dry wounds

• history of thyroid dysfunction

• severely impaired renal function

• potential interaction with lithium 

• secreted into milk-avoid in breastfeeding

what is the active ingredient in povidone dressings?

iodine

what are povidone dressings?

knitted viscose fabric containing 10% iodine in a PEG base

what are the indications for povidone dressings?

• prophylaxis and treatment of wounds where likely bacterial,  fungal or protozoal infection

when are povidone dressing c/i?

• sensitivity to iodine

• breastfeeding or pregnancy risk (risk of elevated serum iodide)

what are hydrocolloid dressings and how do they work?

• microgranular suspension of gelatin, pectin and sodium carboxymethylcellulose in an adhesive matrix

• the granules are hydrophilic and capable of absorbing some exudate- forms a  gel

• matrix  is hydrophobic and prevents wound from dessication

• waterproof- so patient can shower or bath with dressing in place

what are the indications for hydrocolloid dressings?

• dry to moderately exuding wounds

• sloughy or necrotic wounds- prevents loss of water vapour and hydrates dead tissue  encouraging autolysis

what are the C/I of hydrocolloid dressings?

contain gelatin

when would hydrocolloid fibrous dressings be used?

• may be used in similar situations to algnates, but greater capacity for retaining exudate

• converts from a dry dressing to a soft coherent gel sheet

what are the indications for hydrocolloid fibrous dressings?

• heavily exuding wounds

• infected wounds, must be changed daily

what are the c/i for hydrocolloid fibrous dressings?

• dry wounds

what is a semi permeable film?

• thin, comfortable, hypoallergenic sheets of polyurethane coated with a layer of acrylic  adhesive

• permeable to water vapour and gases, but no liquid water or microorganisms

what are the indications for semi permeable film?

• can be applied as secondary dressing, to cover shallow wounds, or to protect the skin

• securing venous catheters, surgical drains (remove fluid from surgical sites)

• suitable for showering as waterproof

when are semi permeable films c/i?

• fragile skin, can cause trauma on removal

how do silver dressings work?

• silver readily ionises in contact with body fluids to become reactive

• antibacterial mechanisms of silver are poorly understood as they can bind to and damage bacterial cells at different sites

what kind of wounds should silver dressings be used with caution?

• in epithelialising wounds as silver is potentially toxic to the monolayer of epithelial cells resurfacing the wound

what are the indications for silver dressings?

used to decrease the bacterial count when critical colonisation is suspected

what are the c/i for silver dressings?

pregnancy and breastfeeding

what are the enhanced novel therapies being used for wound managment?

• topical negative pressure (TPN)

• 3D printed sensor dressings

• larval therapy

how does topical negative pressure (TNP) work?

• uses negative pressure applied directly to the wound bed to promote healing 

• a vacuum unit capable of providing controlled levels of sub-atmospheric pressure is required

works by continuous wound cleansing and stimulation of granulation tissue:

• fluid removal

• increased blood flow

• reduced oedema

what kind of dressings are used with TNP?

Foam dressings or gauze are used with this system 

how do 3D- printed sensor dressings work?

• can sense when bacteria are growing and change colour, based on the CO2 produced by respiring bacteria 

• xylenol blue dye changes from blue to green to yellow with CO2

how does larval therapy work?

• common greenbottle maggots are used, grow from 2-3mm to 8-10mm

• when applied to the wound they produce proteolytic enzymes that degrade necrotic tissue

• also remove odour by ingesting bacteria in the wound 

• classified under the European medicines directive as a medicine