ASMAA Ehab

• Epidermis


  Composed of several thin layers: stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum
• Epidermis


  • Contains melanocytes which produce melanin, a pigment that gives skin its color and protects it from UV radiation
  • Contains keratinocytes which produce keratin, a water-repellent protein that gives the epidermis its tough, protective quality
• Dermis


  Thick layer of skin that contains collagen and elastic fibers, nerve fibers, blood vessels, sweat and sebaceous glands, and hair follicles
• Subcutaneous Tissue


  Fatty layer of skin that contains blood vessels, nerves, lymph, and loose connective tissue filled with fat cells
• Functions of Integument


  • Protection
  • Thermoregulation
  • Fluid and Electrolyte Balance
  • Vitamin D Synthesis
  • Sensation
  • Psychosocial
• Classification of Wounds


  • Clean Wound
  • Clean/Contaminated Wound
  • Contaminated Wound
  • Infected Wound
• Wound Closure


  • Healing by Primary Intention
  • Healing by Secondary Intention
  • Healing by Tertiary Intention
• Wound Healing


  1. Inflammation

  2. Proliferative phase

  3. Maturation phase
• Surgical Wound Infection


  • Incisional infections identified by purulent or culture positive drainage isolated from any structure above the fascia in proximity to the initial wound
  • Deep infections characterized by purulent drainage from subfascial drains, wound dehiscence, or abscess formation and involve adjacent sites manipulated during surgery
• Risk Factors for Surgical Wound Infection


  • Patient-related factors
  • Surgery-related factors
  • Wound-related factors
• Optimal antibiotic for surgical prophylaxis


  • Effective against suspected pathogens
  • Does not induce bacterial resistance
  • Effective tissue penetration
  • Minimal toxicity
  • Minimal side effects
  • Long half-life
  • Cost effective
• Appropriate antibiotic use for prevention of surgical wound infection


  • Appropriate timing of administered agents and repeated dosing
  • Appropriate selection based on procedure performed
  • Appropriate duration to avoid infection and decrease potential for development of resistance
• Potential pathogens by body site


  • Nose
  • Skin
  • Mouth/pharynx
  • Urinary tract
  • Colon
  • Biliary tract
  • Vagina
  • Upper respiratory tract
• Antibiotic selection based on wound classification


  • Clean: Cefazolin
  • Clean/contaminated: Cefazolin vs broad spectrum
  • Contaminated: Broad spectrum
  • Dirty: Therapeutic antibiotics
• Fetal Wound Healing


  • Proceeds without fibrosis or scar formation
  • Mediated in part through a fetal wound extracellular matrix rich in hyaluronic acid
  • Fewer neutrophils and more monocytes during inflammatory period
  • Different concentrations of cytokines
  • Greater proportion of type III collagen
• Transforming growth factor-β (TGF-β)


  Plays a central role in scar formation, with low levels of TGF-β1 and TGF-β2 and high levels of TGF-β3 in fetal wounds
• Staging of Pressure Ulcers

  • Stage I: redness and warmth
  • Stage II: shallow ulcer with distinct edges
  • Stage III: full-thickness loss of skin
  • Stage IV: involvement of fascia, connective tissue, muscle and bone
  • Stage V: area covered with black eschar
• Hypertrophic Scars


  Raised and thickened lesions that do not extend beyond the boundary of the incision/scar
• Keloids


  Raised and thickened lesions that extend beyond the boundary of the incision
• Burn Classification


  • First-degree: involve epidermis, erythema and minor changes, no scar, heals in 10 days
  • Second-degree: involve epidermis and part of dermis, blister formation or reddish/non-viable whitish appearance
  • Third-degree: full thickness burns, white non-viable skin, may involve muscle
• Burn Resuscitation (Parkland Formula)


  4x % Burn x Weight in kg for 24 hours, Lactated Ringer's. Give the first half in first 8 hours and the next half in the next 16 hours.
• Urine output for burn/trauma patients

  At least 1-1.5 ml/kg/hour
• Topical antibacterial agents for burns


  • Silver sulfadiazine
  • Silver nitrate
  • Mafenide
• Urine output


  Normally 0.5ml/kg, but for burns and trauma patients is at least 1-1.5 ml/kg/hour
• Initial treatment of the actual burn


  1. First debridement of the denuded skin with moist gauze

  2. Coverage with topical antibacterial agents is necessary
• This additionally aids in estimating volume of burn
• Topical antibacterial agents for burns


  • Silver sulfadiazine
  • Silver nitrate
  • Mafenide
• Silver sulfadiazine


  Wide spectrum, moderate eschar penetration. May cause leucopenia
• Silver nitrate


  Mild spectrum, non-painful. Does not penetrate eschar, causes staining. Sodium, calcium, and potassium wasting
• Mafenide


  Wide spectrum penetrates eschar. Painful. Causes metabolic acidosis
• Initial coverage can include culture skin and skin substitutes. Split thickness skin grafts for burns of small percentage (<25%) can be utilized.

  
• Seborrheic keratoses


  Superficial, non-invasive tumors that originate in the epidermis
• Seborrheic keratoses


  • Typically appear in older people as multiple slightly elevated yellowish, brown or brownish-plaque rounded plaques, and are found typically on the shoulders, trunk, scalp, and face
• Treatment of seborrheic keratoses

  Shave excision
• Involuting hemangiomas


  Most common tumors that occur in childhood, 95% of all hemangiomas that are seen in childhood. Typically present at birth or during 2-3 weeks of life, grow at a rapid rate for 4-6 months, then involution begins and is complete by 5-7 years of age
• Types of involuting hemangiomas


  • Strawberry nevus
  • Nevus vasculosus
  • Capillary hemangioma
  • Cavernous hemangioma
• Treatment is not usually indicated for involuting hemangiomas, only if the lesions impair vision (eyelid), a condition that can lead to amblyopia
• Non-involuting hemangiomas


  Most of these lesions are present at birth. They grow in proportion to the growth of the infant, and persist into adulthood. Unlike involuting, these are not true neoplasms, but malformations of arterial and/or veins
• Types of non-involuting hemangiomas


  • Port wine stains
  • Cavernous hemangioma
• Port wine stains


  Most common, mainly occur on face or neck. Best to observe, or laser surgery