Wounds PDF

# WOUNDS ## DR. HUSSEIN EL-ANANY ## Skin - Covers entire surface of body - Consists of three layers - Epidermis: thin outer layer - Dermis: thick underlying layer - Hypodermis: fatty layer **Image:** A diagram of a normal skin with three layers: epidermis, dermis and subcutaneous. #...

# WOUNDS ## DR. HUSSEIN EL-ANANY ## Skin - Covers entire surface of body - Consists of three layers - Epidermis: thin outer layer - Dermis: thick underlying layer - Hypodermis: fatty layer **Image:** A diagram of a normal skin with three layers: epidermis, dermis and subcutaneous. ## Epidermis - Thin granular layer - Translucent layer - Outermost layer - Sloughs off dead keratinocytes ## Epidermis - Consists of five sub-layers - Basal cell layer - Squamous cell layer - Stratum granulosum - Stratum lucidum - Stratum corneum ## Dermis - Thickest of the three layers - Main functions are: - Stores much of the body’s supply of water - Supplies nutrients to the epidermis - Regulates body temperature ## Dermis - Contains specialized cells and structures - Blood vessels - Lymph vessels - Hair follicles - Sweat glands - Sebaceous glands - Nerve endings - Collagen ## Hypodermis - Network of fat and collagen - Functions as: - Shock-absorber for body - Insulator - Stores fat as energy reserve ## Aim of study: to maintain and restore the tissue integrity ## Wounds means: loss of continuity of epithelial surface # Wound classification - according to the causative agent - according to chronicity - according to level of infections. - according to clinical appearance ## 1- according to the causative agent ### Closed - hematoma - contusions ### Open - incised - Lacerated - Penetrating - punctured - Avulsion - Gun shots - bite wounds - abrasion - crushed ## 1- Hematoma means: - collection of blood in an specific area, - it depend on its sit: knee, intramuscular, subcutaneous, retroperitoneal. - It may be: - spontaneous as in hemophilic patients - induced as in blunt trauma - It may be: - painful and causing neural deficit (with large hematomas ## 2- contusions: - soft tissue injury without skin injury as sports injury, bone fractures, strain, sprain, torn tendon or muscle - It accompanied by: - Injury of skin small blood vessels (tiny burst), - Skin discoloration because the blood gets trapped below the skin - It may be unnoticed or accompanied with little pain ## 3- abrasions - its damage of epidermal skin layer - usually not accompanied by scar formation except in deep one - its painful as the dermal nerve endings are expose - Infection can occur - Bleeding is limited due to rupture of small veins and capillaries **Image:** A diagram of a skin abrasion on a human leg. ## 4- Incised (cut) wounds - Caused by: sharp objects (clean) as glass, knife, razor - It have a sharp edges, less contaminated - Length of it more than depth - common examples: sharp trauma and surgical wounds **Image:** A diagram of a skin incision on a human leg. ## 5- Penetrating wounds - Caused by long sharp objects knifes as in stab injury - It depth more than length - Usually accompanied by internal organ injury and or internal hemorrhage ## 6- Lacerated wounds - irregular jagged tear-like wounds caused by blunt trauma, RTA, fall on a stone - It may be superficial or deep, accompanied by hematoma, bruising or necrosis, tissue loss - Its often contaminated **Image:** A diagram of a skin laceration on human arm. ## 7- punctured wounds - Caused by sharp pointed objects as needle-stick - Its contaminated and carry a danger of tetanus infection - Plain X-ray examination should be carried out, in order to out retained foreign bodies - External bleeding limited - Internal damage may cause bleeding **Image:** A diagram of a skin puncture mark on a human arm. ## 8- Crushing wounds - Caused by blunt trauma due to run over by vehicle, wall collapse, earthquakes or industrial accidents - These wounds more dangerous as they cause severe hemorrhage, death tissue and blood vessels crushing ## 9- bites wounds - It may be punctured or avulsion as animal and or human bites - More common in children ## 10- avulsion wound - Means forcibly detachment of an body organ or part of it - Avulsion of skin called Degloving - Avulsion may be induced surgically as in amputation procedures - Or - it may be caused by bites, blunt trauma - Usually accompanied by severe bleeding, tissue loss, severe pain - It may be life threatening injury ## 11- gun shot wounds - it has inlet and exit accompanied by damage of nearby structures - most common cause of death: bleeding, hypoxia, and pnumothorax - Caliber: bullet diameter in hundredths of an inch - Magnum: extra gunpowder in the shell causing a 20 to 30% increase in bullet energy - Dumdums: bullets that expand & flatten upon impact - bullet velocity speed of bullet per second by feets(fps) - High velocity: bullet with muzzle velocity greater than 2000-2500 feet per second (fps) or 800 meters per second - Cavitations: cavity in tissue created by bullet passage **Image:** A diagram of several bullets. # Classification of Wounds - This classification important for surgeons and it’s a cornerstone of antibiotic usage with operative procedures ### Clean Wound: - Clean incised wounds, no signs of infection, they often involve skin, vascular and eye surgery ### Clean/Contaminated Wound: - No signs of infection, but it accompanied by high risk of infection - It often involve the respiratory, gastrointestinal, genital, and/or urinary tract procedures ### Contaminated Wound: - open, traumatic wounds - or surgical wounds with contaminated skin ### dirty contaminated Wounds: - old, traumatic wounds containing dead tissue and wounds with evidence of a clinical infection or wounds exposed to fecal matter # General classification - Tidy wounds: Incised, clean, healthy tissue and seldom associated with tissue loss - Untidy wounds: Crushed or avulsed, contaminated, devitalised tissues and often with tissue loss # Acute wounds - Characterised by: - No underlying aetiology i.e. Stab, RTA - it can happen anywhere on the body and vary from superficial scratches to deep wounds damaging blood vessels, nerves, muscles, or other body parts. - It may be traumatic or surgical - Short duration - Normal inflammatory phase - Heal and do not breakdown **Image:** A diagram of a simple skin cut on a human head. # Chronic wounds - Characterised by: - Underlying pathology e.g. venous insufficiency (leg ulcers, pressure sores) - Prolonged duration - Hyperactive state - Persistent state of inflammation **Image:** A diagram of a deep wound on a human leg. ## Leg ulcers: - Aetiology: its either: venous, arterial, traumatic, infectious or neoplastic ## Pressure sores - Tissue necrosis resulting from prolonged pressure of tissue against hard areas as occipital and sacral areas in bedridden patients # Compartmental syndrome - It means increased pressure in closed area (more than 30 mmHg) - The most common examples lower limb - The leg has a 3 compartment (anterior – posterior and peroneal) - It’s a life threatening condition that occurs when perfusion pressure falls below tissue pressure in a closed anatomical compartment. - If left untreated -tissue necrosis release of vasoactive and toxic materials to circulation especially myoglobin and finally death - vasoactive material = increase endothelial permeability - Myoglobin = myoglobinuria = glomeruler blockage and renal failure - Severe pain which increased with passive movement - Disruption or absence of distal pulse - Need emergency release of pressure (fasciotomy) # Development of acute CS - In an enclosed muscle (osteofascial) compartment: - Increase in volume of contents and/or Reduction in size of compartment - increased pressure within the compartment - compression of muscles, nerves & vessels - impaired blood flow - ischemia & necrosis **Image:** An illustration depicting the effect of compartment syndrome on muscle, nerves and vessels. # Acute Anterior Compartment Syndrome - Paresthesia - Paresis (foot drop) - Pain on stretch (site of pain) - Pressure (palpable, painful tenseness of compartment) - Pink color - Pulse present - Six Ps, often early manifestations of compartment syndrome **Image:** An illustration of acute anterior compartment syndrome symptoms. # Wound healing - It means restore and maintain the tissue integrity # Factors affecting wound healing - General factors - age - General conditions - Chronic diseases - Medications - Immune diffecency - smoking - Specific or local factors - site and type of wound - structures involved - FB - tissue loss - blood supply **Image:** A diagram depicting the factors affecting wound healing. # Aging - Healing in children more faster - In old age: delayed proliferative phase and decrease of dermal collagen contents # Chronic diseases - It usually accompanied by vitamin C and zinc deficiency, polytrauma and hepatic cirrhosis. - diabetes - Malignancy - Uremia - Liver impairments # Diabetes mellitus - Tissue hypoxia: arthrosclerosis, microangiopathy - Repetitive trauma due to neuropathy - Susceptible to infection due to high glucose level - Impaired phagocyte, lymphocyte, and leukocyte activity - Increased collagen degradation and decreased deposition # Drugs - Anticoagulant - Steroids - Phenytoin - Chemotherapy - Radiation therapy - anti-inflammatory # Chemotherapeutic drugs - Decrease cell proliferation - Reduce number of platelets - Reduce the growth factors - Decrease wound strength # Ionizing radiation - Endothelial injury with endarteritis - Tissue atrophy and fibrosis # Nutrition - Malnutrition delay the wound healing in all phases. - The most important nutrition are - Protein and albumen level - Vitamin C important for synthesis and maintain of collagen - Vitamin K - Minerals – zinc, copper - Zinc rare to becoming deficient but observed in severe # Infection - collagenolyssis adverse effects of wound strength - Bacteria - prolong the inflammatory phase - interfere with epithelization, contraction and collagen deposition - Endotoxin - collagen degradation and destruction of surrounding previously normal tissue # Technical Factors - Surgical techniques: - tissue handling - Direction, length and site of incision - adequate homeostasis, and Careful apposition of wound edges - Bad homeostasis - Suture materials: type, diameter # Normal wound healing - Phases of wound healing # 1- inflammatory phase: - It start immediately after wounding and lasts 2-4 days - The body’s defenses are aimed at limiting the amount of damage and preventing further injury - vascular vasoconstriction start immediately after wounds, - thrombus formation platelet plugs - Platelets stick to the damaged endothelial lining and release of ADP, which induce thrombocytic aggregations - release of inflammatory mediators which increase vascular permeability mainly histamine, serotinine - kinin and prostaglandin (chemotactic role for WBCs and fibroblast cells - PNL: play important role in removing of dead and necrotic tissues - platelet derived growth factors (PDGF) and transforming growth factor beta (TGFβ) # Proliferative (collagen) phase - Between third and 5th day: the PNL decreased in number, and monocytes increased - 1- Fibroblast activity is a cornerstone of this phase, which appear between 5th and 6th day production of protocollagen which converted to collagen by prtocollagen hydroxylase enzyme - Formation of ground substances which is mucopolysacchrides (proteoglycans and glycosaminoglycans) so the wound becoming fibre + gel + fluids - fobroblast need vitamin C to produce protocollagen - 2- Angiogenesis: Formation of new vessels - 3- Epithelialization by migration of epithelial cells mainly from the edge of the wound and from the base of wound # Remodeling phase - Start within 4th day and is usually completed by 14 days - Maturation of collagen (type III to type I= 4-1 - Decreased of wound vascularity - Wound contraction by fibromyoblast cells - wound contraction reduce with corticosteroids, radiation, chemotherapy and in wounds over the tibia - Connective tissue formation # Scar formation phase - In which: - Fibroplasia - Lying of collagen increased - Decrease of vascularization - Epithelialization continues - Remolding of collagen and cicatrisation **Image:** A diagram depicting the different phases of wound healing; inflammatory, proliferative, maturation, and remodeling. **Image:** A diagram depicting the different cells involved in wound healing like; platelets, neutrophils, macrophages, lymphocytes, fibroblasts, epithelial cells, smooth muscle cells, endothelial cells. # HEALING RESPONSES - Hemostasis - 1. Stop bleeding - Inflammation - 2. Chemotaxis - 3. Epithelial migration - Connective tissue regeneration - 4. Proliferation - 5. Maturation - Contracture - 3. Contraction - 4. Scarring - 5. Remodeling of scar **Image:** A diagram depicting the classification of wound healing by intention: primary, secondary and tertiary. # Complications of wound healing - Infection: is the most important one, the source of bacteria mainly endogenous - Ugly scar - Contracture deformity - Keloid formation - Hyertrophic scar formation - Pigmentation - Marjolins ulcer # Hypertrophic Scar - It is overgrowth of epithelial cells that remains within boundaries of original wound and tend to regress spontaneously - It rises above the skin - Not teneder not vascular - Itching is not common - More common with scar crossing normal skin crease, over sternum, joints and young persons - treated by: excision, silicon applications **Image:** A hypertrophic scar on a human back. # Keliod - overgrowth of dense fibrous tissue beyond the wound limit. They do not regress spontaneously. - Accompanied by severe itching, tender margin, vasculer, red - Claw like process - Common in black race, tuberculous patients, vaccination sites, injection sites piercing sites - Familial and hereditary tendency - Common over the sternum and ear lobe - Equal in both sex - Complicated by ulceration, infection - Treated by: Steroid injection, chemotherapeutic agents (5 flurouracil), silicon aplications and intramarginal excision **Image:** A keloid scar on a human ear. # Comparison of hypertrophic and keliod | feature | Hypertrophic scar | Keliod scar | |---|---|---| | Genetic | Not familial | May be familial | | Race | Not related | Black > white | | Borders | Remains whithin wound | Outgrows wound area | | Natural history | Subsides with time | Rarely subsides | | Site | Flexor surface | Sternum, shoulder, face | | Etiology | Related to tension <br> Related to poor surgical technique. | Unknown | | Affect of pregnancy | Not affacted | Inc: risk in pregnancy and puberty | | collagen | Electron microscope shows thin organized collagen bundles. | Electron microscope shows thick, disorganized collagen. | | immunological | Some immunological abnormalities | Not related to immunological abnormalities | # Treatment of hypertrophic and keliod scars - cortisone injections - Radiotherapy - Cryotherapy - Laser treatment - interferon - Cytotoxic drugs - Other therapies: - vitamin supplementation - Surgical