factors affecting and complications of wound healing new

Views:
 
Category: Entertainment
     
 

Presentation Description

No description available.

Comments

Presentation Transcript

PowerPoint Presentation:

FAHEEM SHAHZAD KHAN DEPARTMENT OF IMMUNOLOGY UNIVERSITY OF HEALTH SCIENCES-LAHORE FOCTORS AFFECTING,COMPLICATIONS OF WOUND HEALING

PowerPoint Presentation:

SYSTEMIC FACTORS LOCAL FACTORS FOCTORS AFFECTING WOUND HEALING

PowerPoint Presentation:

Systemic factors Age Drugs Vitamins Trace Elements 5.  Nutrition 6. Illness / Immunity FOCTORS AFFECTING WOUND HEALING

PowerPoint Presentation:

Local Factors Infection Foreign Bodies Mechanical Stress/ Pressure Wound Hydration Temperature Ionizing Radiation Oxygen Tension FOCTORS AFFECTING WOUND HEALING

PowerPoint Presentation:

1-AGE intrinsic physiologic changes ? wound healing . increased incidence of diseases? incidence of wound healing problems . 6 SYSTEMIC FACTORS

PowerPoint Presentation:

2. DRUGS Antimetabolite drugs : ? inhibiting early cell proliferation and wound DNA and protein synthesis. STEROIDS:? Inhibit the inflammatory phase of wound healing. Reduce collagen synthesis and wound strength? Steroids reduces TGF- B and IGF-I production in wounds and that collagen deposition suffers by that mechanism. 7 SYSTEMIC FACTORS

:

2. DRUGS cont … Anti-neoplastic agents ? Decreased leukocyte and fibroblast proliferation. Decreased wound contraction and protein synthesis . D ecreased collagen secretion and increased activity of collagenases. NSAIDs ? Decrease collagen synthesis by 45% even at normal levels . SYSTEMIC FACTORS

PowerPoint Presentation:

3. NUTRITION Precise calorie requirements for optimal healing? Protein depletion - prolongs inflammatory phase, impairs fibroplasia. Methionine required for forming disulfide bonds in collagen synthesis . Arginine deficiency results in decreased wound-breaking strength and wound collagen accumulation. Carbohydrates - energy source for leukocytes. Fats ? no significant effects, but Fats are essential elements of all cell membranes. 9 SYSTEMIC FACTORS

SYSTEMICFACTORS:

4 -Vitamins VITAMIN C Co-factor for proline hydroxylation? Ascorbic acid hydroxylation of proline and lysine collagen. Hydroxyproline also stabilizes the collagen triple-helix structure . ascorbic acid enhances neutrophil function, increases angiogenesis, and functions as a powerful antioxidant . Vitamin c deficiency failure in collagen synthesis and cross-linking . SYSTEMICFACTORS

PowerPoint Presentation:

VITAMIN A Vitamin A is required for epithelial and bone tissue development, cellular differentiation and immune system function. vitamin A may increase both collagen cross-linkage and wound breaking strength. Supplemental vitamin A can reverse the inhibitory effects of corticosteroids and vit E on wound healing. 11 SYSTEMIC FACTORS

SYSTEMIC FACTORS:

VITAMIN E Systemic vitamin E inhibits the inflammatory response and collagen synthesis, thereby possibly impeding the healing process. SYSTEMIC FACTORS

PowerPoint Presentation:

5 -Trace Metals Zinc cofactor for collagen synthesis . Zinc is an essential trace mineral for DNA synthesis, cell division, and protein synthesis, all necessary processes for tissue regeneration and repair . deficiency decreased fibroblast proliferation, decreased collagen synthesis, impaired overall wound strength, and delayed epithelialization . Copper required for collagen crosslinking . 13 SYSTEMICFACTORS

:

6. Associated Illnesses/Immunity Cancer, infection, peripheral vascular diseases, hypoxia, obesity AND smoking – all negatively affect wound healing. Immuno -dysfunction leads to decreased chemotaxis , phagocytosis, intracellular killing and collagen synthesis. SYSTEMICFACTORS

PowerPoint Presentation:

1-INFECTION Probably the most common cause of delayed healing. The most common organisms responsible for wound infections in order of frequency are: Staphylococcus species, Streptococcus Enterococci Escherichia coli . 15 LOCAL FACTORS

1. INFECTION……:

1. INFECTION…… Bacteria prolong the inflammatory phase and interfere with epithelialization, contraction, and collagen deposition . Bacterial phospholipase C can disrupt normal reepithelialization by decreasing cell-cell contact and increasing cell migration . LOCAL FACTORS

:

2 -Foreign Bodies Clot, necrotic debris, dirt, suture, glass etc Prolong inflammatory phase. Lead to increased susceptibility for infection. Increased duration of re-epithelialization . LOCAL FACTORS

:

3. Mechanical Stress /Pressure A ffects quantity, aggregation and orientation of collagen fibers. Undue pressure may lead to ischaemia of the wound, therefore, all wounds, particularly chronic wounds, should be off-loaded. LOCAL FACTORS

:

4 . Wound Hydration M oist wound healing environment increases rate of re-epithelialization . LOCAL FACTORS

:

5 . Temperature E nvironment temperature greater than 30 o C increases tensile strength. LOCAL FACTORS

PowerPoint Presentation:

6. IONIZING RADIATION Causes endothelial cell injury fibrosis, and delayed tissue repair. Inhibit Angiogenesis. keratinocytes and fibroblasts are most sensitive to radiation . 21 LOCAL FACTORS

PowerPoint Presentation:

7. OXYGEN TENSION Low oxygen tension has a profoundly deleterious effect on all aspects of wound healing. Fibroplasia , although stimulated initially by the hypoxic wound environment, is significantly impaired by local hypoxia . Optimal collagen synthesis requires oxygen as a cofactor , for the hydroxylation steps. 22 LOCAL FACTORS

Summary of factors affecting different steps:

Summary of factors affecting different steps

PowerPoint Presentation:

Categories Deficient scar formation (wound dehiscence, ulceration), Excessive scar formation (keloid, hypertrophic scar), Contractures, and Exuberant granulations. Complications Of Wound Healing

1. Deficient scar formation:

Two types Wound dehiscence Ulceration 1. Wound dehiscence : Surgical complication in which a wound breaks open along surgical suture. Risk factors: age, diabetes, obesity, poor knotting ,trauma to the wound after surgery. 1. Deficient scar formation

PowerPoint Presentation:

Wound dehiscence 1. Deficient scar formation….

1. Deficient scar formation….:

2. Ulceration An ulcer is a discontinuity or breach in the epithelium of the skin or mucous membrane 1. Deficient scar formation….

PowerPoint Presentation:

Ulcerations 1. Deficient scar formation….

PowerPoint Presentation:

Caused by differing amounts of collagen over-expression called SCARING Two types HYPERTROPHIC SCARS Keloid HYPERTROPHIC SCARS : overproduction of collagen, which causes the scar to be raised above the surrounding skin.(red, raised, itchy and tender) Keloid: excessive stiff collagen bundled growth over-extending the tissue.(surgery, accident, acne) How to differentiate b/w HYPERTROPHIC SCARS and Keloid ? Hypertrophic scar : their lack of growth outside the original wound area - keloid : can carry on growing indefinitely 2. Excessive Formation Of The Repair Components

Hypertrophied scars:

Hypertrophied scars

KELOID :

KELOID

3. WOUND CONTRACTURE:

Wound contracture is a process that may occur during wound healing when an excess of wound contraction. A normal healing process , may lead to physical deformity and functional limitations . May be seen after serious burns. 3. WOUND CONTRACTURE

CONTRACTURE :

CONTRACTURE

:

Exuberant granulations is excessive proliferation of granulation tissue in healing wounds. 4. EXUBERANT GRANULATIONS

Exuberant granulations:

Exuberant granulations

PowerPoint Presentation:

DISCUSSION A 25-year-old woman sustains a deep, open laceration over her right forearm in a motorcycle accident. The wound is cleaned and sutured. Which of the following cell types mediates contraction of the wound to facilitate healing? (A) Endothelial cells (B) Fibroblasts (C) Macrophages (D) Myofibroblasts (E) Smooth muscle cells During the next 3 months, the wound heals with formation of a linear scar. Which of the following nutritional factors is required for proper collagen assembly in the scar tissue of the patient described in Question 4? (A) Folic acid (B) Thiamine (C) Vitamin A (D) Vitamin C (E) Vitamin E

PowerPoint Presentation:

The answer is D: Myofi broblasts. The myofi broblast is the cell responsible for wound contraction as well as the deforming pathologic process termed wound contracture. These cells express a-smooth muscle actin, desmin, and vimentin, and they respond to pharmacologic agents that cause smooth muscle to contract or relax. Myofi broblasts exert their contractile effects by forming syncytia, in which the myofi broblasts are bound together by tight junctions. By contrast, fibroblasts (choiceB) tend to be solitary cells, surrounded by collagen fibers. Endothelial cells (choice A) respond to growth factors and form capillaries, which are necessary for the delivery of nutrients and inflammatory cells. Neither macrophages (choice C) nor smooth muscle cells (choice E) mediate wound contraction.

PowerPoint Presentation:

The answer is D: Vitamin C. Vitamin C (ascorbic acid) is a powerful, biologic reducing agent that is necessary for the hydroxylation of proline residues in collagen. Most of the clinical features associated with vitamin C deficiency (scurvy) are caused by the formation of an abnormal collagen that lacks tensile strength. Patients with vitamin C defi ciency exhibit poor wound healing. Dehiscence (bursting open) of previously healed wounds may also occur. None of the other choices are required for collagen assembly.

authorStream Live Help