Wound Healing Flashcards
Think of 5 Functions of the skin
Regulates body temperature Protection Sensation Excretion Immunity Blood reservoir Synthesis of Vitamin D
What is healthy skin? Think of 5 signs
Pink Well perfused Free from blemishes No cracks Warm Not dry or flaky Not sweaty No oedema
What causes skin changes? Think of 5 things
Ageing Smoking Malnutrition Diabetes Infection Medications Disease eg: eczema, psoriasis
What are the effects of ageing on the skin?
Collagen fibres breakdown
Skin loses elasticity
80% of ageing is due to sun damage
What are the effects of smoking on the skin?
Smoking reduces skin cell replication through vascular constriction
Decreased oxygen in blood - thickens blood reducing collagen
Skin thickness and health is reduced by up to 40%
Think of 5 characteristics of abnormal skin
Skin may have Cuts Abrasions Redness Pallor Lumps Bruises Swelling Dryness Profuse sweating Cellulite Rashes Wounds
What is an acute wound? give 3 examples of causes and 3 examples of wounds.
An acute wound occurs when healthy tissue is damaged by trauma, such as surgery, heat, electricity, chemicals or abrasion. Continuity of the skin surface is lost. Eg Burns Donor sites Abrasions Incisional\surgical wounds Trauma
What is a chronic wound? Give 3 examples
Chronic wounds are in principle acute wounds where the healing process has stopped or has been interrupted somewhere in the normal sequence. Arterial and venous leg ulcers Pressure ulcers Neuropathic ulcers Malignant ulcers
4 Stages of Wound Healing
1 Haemostasis Phase
2 Inflammatory Phase
3 Proliferative Phase
4 Maturation
Haemostasis: What are its 3 phases, and how quickly does it occur?
The process of the wound being closed by clotting; starts when blood leaks from the body.
First step is vasoconstriction
Next, platelets stick together to seal the break in the wall of the blood vessel. Finally, coagulation occurs and reinforces the platelet plug with threads of fibrin which are like a molecular binding agent. The haemostasis stage of wound healing happens very quickly. The platelets adhere (stick) to the sub-endothelium surface within seconds of the rupture of a blood vessel’s epithelial wall. After that, the first fibrin strands begin to adhere in about 60 seconds.
Inflammation phase?
The second stage of wound healing, begins straight after the injury when the injured blood vessels leak transudate (made of water, salt and protein) causing localised swelling. Inflammation both controls bleeding and prevents infection. The fluid engorgement allows healing and repair cells to move to the site of the wound. During the inflammatory phase, damaged cels, pathogens, and bacteria are removed from the wound area.
Proliferative Phase
Third phase of wound healing. The proliferative phase of wound healing is when the wound is rebuilt with new tissue made up of collagen and extracellular matrix. In the proliferative phase, the wound contracts as new tissues are built. In addition, a new network of blood vessels must be constructed so that the granulation tissue can be healthy and receive sufficient oxygen and nutrients. Myofibroblasts cause the wound to contract by gripping the wound edges and pulling them together using a mechanism similar to that of smooth muscle cells. In healthy stages of wound healing, granulation tissue is pink or red and uneven in texture. Moreover, healthy granulation tissue does not bleed easily. Dark granulation tissue can be a sign of infection, ischemia, or poor perfusion. In the final phase of the proliferative stage of wound healing, epithelial cells resurface the injury.
Maturation Phase
Also called the remodelling stage of wound healing, the maturation phase is when collagen is remodelled from type 3 to type 1 and the wound fully closes. The cells that had been used to repair the wound but which are no longer needed are removed by apoptosis, or programmed cell death. When collagen is laid down during the proliferative phase, it is disorganised and the wound is thick. During the maturation phase, collagen is aligned along tension lines and water is reabsorbed so the collagen fibers can lie closer together and cross-link. Cross-linking of collagen reduces scare thickness and also makes the skin area of the wound stronger. Generally, remodelling begins about 21 days after an injury and can continue for a year or more. Even with cross-linking, healed wound areas continue to be weaker than uninjured skin, generally only having 80% of the tensile strength of unwounded skin.
3 Wound closure types
Primary Wound Closure
Secondary Closure
Delayed Primary Closure
Think of 5 Factors influencing the healing process
- Advanced age
- Diseases (diabetes, PVD, cardiovascular diseases)
- Poor nutrition
- Medications (steroids, cytostatica)
- Smoking
- Inactivity
- Poor mental health
- Systemic infections (Infections that are in the blood stream)
- Infected or highly colonised wound
- Devitalised/necrotic tissue/ haematoma -
- Foreign bodies, (Sutures, dressing debris)
- Moisture balance
- Reduced wound temperature
- Pressure, friction, shearing forces
- Inappropriate wound management
- Location of wound