Wound Ppt Final

Dr Tejus MNModerator: Dr Ramesh TS

Skin Largest organ of the bodyPrimary function is protectiveComposed of several layers

Outer EpidermisDermis, containing the capillary network

Subcutaneous layer (hypodermis, adipose layer)

To be regenerated

Cell egeneration

ECM regeneration

vascular Regeneration

Wound A wound can be defined as “A cut or break in the continuity of any tissue, caused by injury or

operation”

Wounds can be classified according to their nature:• Abrasion• Incision• Laceration• Open• Penetrating• Puncture• Septic etc……

Types of healingHealing by primary intention

Healing by secondary Intention

Delayed primary healing

Healing by primary intention

• Two opposed surfaces of a clean, incised wound are held together.

• No significant degree of tissue loss

Healing by secondary intention

If there is significant tissue loss, healing

will begin by the production of granulation tissue

Granulation results in a broader scar Healing process can be slow due to

presence infection Daily dressing with debridment to

allow granulation tissue formation

Delayed primary healing

If there is high infection risk – patient is given antibiotics and closure is delayed

for a few days e.g. bitesDelayed primary closure or secondary

sutureThe wound is initially cleaned, debrided

and observed The wound is purposely left open

Phases of healingAll wounds heal following a specific

sequence of phases which may overlap

The phases are:

Inflammatory phaseProliferative phaseRemodelling or maturation phase

Phases of healing

Inflammatory phaseHEMOSTASIS In the inflammatory phase clotting

takes place in order to obtain hemostasis INFLAMMATION various factors are released to attract

cells that phagocytose debris, bacteria, and damaged tissue and release factors that initiate the proliferative phase of wound healing

Inflammatory phaseDay 0 – 5The inflammatory phase is

characterised by heat, swelling, redness, pain and loss of function at the wound site

Early (haemostasis)Late (phagocytosis)This phase is short lived in the

absence of infection or contamination

Proliferative phaseAngeogenesis Epithelialization Extracellular matrix

Angiogenesis Collagen first detected at day 3 and

rapidly increases for approx. 3 weeks

Fibroplasia (fibroblast proliferation and synthesis) continues in parallel with re-vascularisation

Angiogenesis Endothelial cells from the side of

vessels closest to the wound begin to migrate in response to angiogenic stimulus forming capillary buds

VEGF, TGF

Granulation Day 3 – 14Granulation tissue consists of a

combination of cellular elements including:

Fibroblasts, inflammatory cells, new capillaries embedded in a loose extra-cellular collagen matrix

Epithelialization The epidermis immediately adjacent

to the wound edge begins to thicken within 24hrs after injury

They migrate to the wound breaking collagen in healing wound

Maturation Can last up to 2 yearsNew collagen forms, changing the shape

of the wound and increasing the tensile strength

Scar tissue, however is only ever approx. 50-80% as strong as the original tissue

During the remodelling process there is a gradual reduction in cellularity and vascularity of the tissue

Contraction When there is unacceptable tissue

loss and an unsatisfactory cosmetic result

Wound contraction usually begins from day 5 and is complete at approx. day 12 - 15

Factors affecting Immune statusBlood glucose levels (impaired white

cell function)Hydration (slows metabolism)Nutrition Oxygen and vascular supplyCorticosteroids (depress immune

function)

Growth factors EGFPDGFFGFTGF-BInterlukinsInterferons

WOUND ASSESSMENT

Size, depth & location

Wound bed:

• necrosis

• granulationSurrounding skin: colour, moisture,

Wound edge

Odour or exudate

Signs of infection

Wound dressing Non-adherent wound contact

materials Films Hydrogels Hydrofibre dressings Hydrocolloids Foams Alginates Miscellaneous

Film dressings

Semi-permeable primary or secondary dressings Clear polyurethane coated with adhesiveConformable, resistant to shear and tearDo not absorb exudateExamples: Tegaderm, Op-site

Hydrocolloids

Pectin, gelatin, carboxymethylcellulose and

elastomers Environment for autolysis in sloughy

or necrotic wounds Occlusive --> hypoxic environment to encourage angiogenesis Waterproof e.g. Urgotul

Foam dressings

Advanced polymer technologyHighly absorptiveSemi-permeableVarious types Adhesive and non-adhesive

Hydrogels

Sheets or gelsStarch and polyacrylamide (94%

water)Low exudate, shallow woundsRe-hydrates necrotic tissueSecondary dressing neededMay cause skin maceration

Alginates

Seaweed dressingsForm a gel over the woundModerate to high exudate woundsEasily removedCan cause painHelp to debride a wound