Wounds, Principles of Wound Healing, Contaminated Wounds, Dog Cat and Human Bites

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There are 3 stages of wound healing - Inflammatory, Proliferative and Remodelling stages. 


Factors that influence wound healing:

  1. Mechanical (local trauma, tension)
  2. Blood supply (ischemia / circulation)
  3. Temperature
  4. technique and suture materials
  5. hematoma and seroma (increase infection rate)
  6. tissue irradiation
General 
  1. Age - the older the worse the prognosis
  2. Nutrition (Protein, Vit C, O2)
  3. Smoking 
  4. Chronic illness (DM, cancer, CVD)
  5. venous hypertension
  6. immunosuppression (steroids, chemotherapy, radiotherapy)
  7. peripheral vascular disease
  8. collagen vascular disease



Abnormal Healing:

  • Hypertrophic Scar - scar remains roughly in the boundaries of of the original injury - (keeps the line)
    • red raised, widened, frequently itchy (pruritic)
    • Usually on the back, shoulder and sternum (thank god not the face)
    • treatment - conservative - time and TLC - do not do surgery - try silicon sheets
  • Keloid scar - scar extends beyond the boundaries of the original injury
    • pruritic, PAINFUL, collegen in whorls (rather then bundles)
    • Sternum, deltoid, earlobe, more common in blacks (darker skinned people) 
    • pressure dressings - silicon sheets, topical steroids, intralesional steroids, radiation therapy
  • Chronic wounds - fails to heal in 3/12 
    • Marjolin's ulcer - Squamous cell Ca arising in a chronic wound 
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  • Marjolin's ulcer

    • First described by Jean Nicholas Marjolin in 1828
    • Marjolin's ulceration is a squamous cell carcinoma arising at sites of chronic inflammation
    • Recognised underlying causes include:
      • Chronic venous ulceration
      • Burns
      • Osteomyelitis sinuses
    • Usually a long-period between injury and malignant transformation
    • This period my be 10-25 years
    • 40% occur on lower limb
    • Malignant change is usually painless
    • Nodal involvement is uncommon
    • Diagnosis is confirmed by biopsy of the edge of the ulcer
    • Management involves adequate excision and skin-grafting or amputation
    Marjolin's ulcer

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Arterial Ischemic Ulcer (Courtesy of Dr. A. Freiberg)PL5.jpg

Diabetic Foot Ulcer
PL6.jpg

Venous Stasis Ulcer (Courtesy of Dr. A. Freiberg)

PL4.jpg

Pressure Sores


Stage 1 - Nonblanchable erythema of intact skin.

Stage 2 - Partial thickness superficial skin loss involving epidermis and/or dermis that usually presents as an abrasion, blister, or shallow crater.

Stage 3 - Full thickness skin loss with damage or necrosis of subcutaneous tissue that may extend down to, but not through, underlying fascia, presenting as a deep crater with or without undermining of adjacent tissue.

Stage 4 - Full thickness skin loss with extensive destruction, tissue necrosis, or damage to muscle, bone, or supporting structures (e.g. tendon or joint capsule), and may be present with undermining and sinus tracts.

PLFULL 14.jpg




Contaminated Wounds : >100, 000 bacteria per gram



  • Acute < 24 hours
    • Irrigate the wound with NS or RL
    • debridement - remove foreign tissue and devitalised tissue and old blood
    • evaluate the underlying structure - vessels, nerves, tendons, dislocations, bone fractures - {patella, finger, elbow, knee)
    • control the active bleeding
    • systemic antibiotics
    • tetanus toxoid - 0.5ml IM 
    • postexposure management - HBC,Hepatitus C, HIV
    • reevaluate in 48 hours for sighns of deep infection
  • Chronic contaminated wounds
    • Irrigation and debridement - surgical or mechanical (wet to dry dressings)
    • Topical antibacterial creams - bacitracin and Neosporin
    • Systemic antibiotics
Bites

  • Dog and Cat bites- Dogs and cats may be your pets but leave a nasty bite -
    • Pasturella mulocidia, Steph aureus and Strep viridans
    • Augmentin q8h po
    • Rabies prophylexis - if animal is symptomatic
    • debridement
    • Secondary closure with drains
  • Human Bites: 
    • Usually a bite to the hand
    • Xrays - to rule out foreign body - broken teeth, or fractured bones
    • cultures
    • Treatment - surgical exploration of joint, drainage and debridement of infected tissue
    • Augmentin  ( Clindymycin + Cipro 500mg if Pen allergy)

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