Wound

• Wound


  An injury to living tissue caused by a cut, blow, or other impact, typically one in which the skin is cut or broken

  
• Causes of wounds


  • Objects
  • Falls
  • Chemicals
  • Heat/severe cold
  • Friction/pressure
  • Operations
  • Diseases/conditions
• Wound injuries by object

  • Sharp object
  • Blunt object
• Wound injuries by object

  • Falls
• Wound injuries due to chemicals

  • Gases
  • Burns
• Wound injuries due to friction/pressure

  • Friction
  • Pressure
• Wound injuries due to operations/disease

  • Operations
  • Disease/conditions

  
• Classification of wounds


  • Anatomical site
  • Depth
  • Degree of tissue lost
  • Integrity of integument
  • Time lapse
  • Degree of contamination

  
• Closed wound


  A wound on the skin's surface that does not break the skin, caused by blunt trauma resulting in swelling, pain & discoloration of skin bluish black or purplish red

  
• Types of closed wounds

  • Contusion (bruise)
  • Hematoma
• Contusion (bruise)


  A superficial injury due to impact to tissues under the skin, resulting in discoloration of skin, swelling & pain – no skin break, caused by blunt object

  
• Hematoma


  A localized collection of blood, usually clotted, in an organ, space, or tissue, due to a break in the wall of a blood vessel, caused by blunt injury
• Open wound


  An injury involving an external or internal break in body tissue, usually involving the skin

  
• Types of open wounds

  • Abrasion (graze)
  • Incision (surgical wound)
  • Laceration
  • Avulsion
  • Stab wound
  • Puncture wound
  • Gun shot wound

  
• Abrasion (graze)


  A small wound on the skin surface due to friction or scratches, common in sports injuries usually caused by a fall on a hard surface
• Incision (surgical wound)


  A cut produced surgically by a sharp instrument e.g. scalpel, a sterile wound to treat a disease or condition
• Laceration


  A tear of the skin with irregular and jagged edges, often contaminated with bacteria & debris from the object that caused the injury, caused by a sharp object

  
• Types of laceration


  • Superficial (skin/subcutaneous tissues)
  • Deep (blood vessels, muscle, organs)
• Stab wound


  A type of puncture by a sharp object e.g. knife, an emergency condition
• Puncture wound


  A wound/opening into skin & tissues made by piercing a pointed object e.g. nail, opening small, may not bleed much but can easily become infected
• Avulsion


  Part of the skin or tissues pulled/ripped off from underlying muscle, connective tissue or bone, caused by accidents e.g. machinery
• Gunshot wound


  Injury caused by a bullet into/through the body causing trauma to tissues, may have 1 wound or 2 wounds (entry & exit sites)
• Classification of wounds by time lapse

  • Acute
  • Chronic
• Acute wound


  Occurs suddenly, short duration, healing occurs by primary intention
• Chronic wound


  Difficult to treat, healing time is prolonged > 3 months, healing is by secondary intention
• Examples of chronic wounds

  • Diabetic ulcers
  • Pressure ulcers
• Classification of wounds by degree of contamination

  • Clean wounds
  • Infected/dirty wounds
• Clean wound


  An aseptically-made wound, e.g. surgical incisions, primarily sutured
• Dirty/infected wound


  Wounds containing dead tissues or with clinical infection e.g. purulent discharge, often left open to drain
• Types of wound exudate

  • Serous
  • Purulent
  • Sanguineous
  • Serosanguineous
  • Purulosanguineous
• Serous exudate


  Consist of serum derived from blood & serous membrane (e.g. peritoneum) of body, e.g. fluid in blister from burns, pleural effusion
• Purulent exudate


  Thicker/viscous, contain pus (dead & dying neutrophils & bacteria, cellular debris, fluid leaked from blood vessels), the process of pus formation is by suppuration, colour - tinge of blue, green or yellow
• Sanguineous exudate


  Consist of large amount red blood cell indicating damage to capillary & seen in open wound
• Serosanguineous exudate


  Consist of clear & blood tinge drainage exudate commonly seen in surgical incision
• Purulosanguineous exudate


  Consist of pus & blood seen in new wound that is infected
• Wound healing process


  1. Vascular response - hemostasis, clotting & scab formation

  2. Inflammation

  3. Rebuilding (proliferation/resolution)

  4. Maturation & reconstruction (strengthening)
• Vascular response phase


  • Blood vessels constrict to stop bleeding & reduce exposure to bacteria
  • Clotting process begins - platelets form clot & stop bleeding, plasma protein begin to form a fibrous meshwork
  • Platelet release various proteins & growth factors to stimulate healing
  • Capillaries dilate 10-30 minutes - plasma flow into wounded area
• Inflammation phase


  • Purpose - to limit effects of harmful bacteria or injury by destroying or neutralizing organism & limiting its spread
  • WBC become active to clean up wound & initiate further healing process
  • Neutrophils - first & most numerous arrive at injured area, line walls of capillaries then constrict (by histamine) to increase permeability of capillaries & allow neutrophils to pass through & enter site of injury to begin phagocytosis
  • Basophils secrete histamine
  • Eosinophils secrete antihistamine to control inflammatory response
  • Lymphocytes help macrophage become more effective
  • Mediators - mast cells, kinins, cytokines, complement
• Wound healing


  1. Dilute toxins secreted by organisms

  2. Transport oxygen & nutrients for repair

  3. Carry phagocytes into the area

  4. Area becomes warm & red

  5. Inflammatory phase begins
• Inflammation phase


  Begins at the moment of injury & may continue for 4-6 days depending on extent of injury<|>Purpose is to limit effects of harmful bacteria or injury by destroying or neutralizing organism & limiting its spread throughout the body