Wound Healing Flashcards
Sequence of body’s defense mechanism:
1) Stop the blood loss (Hemostasis)
2) Clean up pathogens and debris in the wound
3) Seal the wound against infection
4) Regenerate the natural epidermal covering
5) Repair deeper tissue damage
3 phases of wound healing:
1) Inflammation phase
2) Proliferation phase
3) Remodeling phase
Inflammation phase includes
Starts immediately after an incision is made and lasts for first 6 days
Hemostasis
Phagocytosis
Edema
Proliferation phase includes
Starts the second day after the incision is made and continues until the 22nd day
Epitheliazation
Neovascularization
Collagen synthesis
Contraction
Remodeling phase includes
Starts 21 days after the incision and may continue for 2 years
Collagen remodeling
Tensile strength
Three ways in which wounds heal
Primary union/First intention
Granulation/Second intention
Delayed primary closure/third intention
Primary/First intention features
Ideal conditions, clean incision with wound edges approximated by suture, staples, etc
Minimal tissue loss and no dead space is left as a potential for site infection
Wound margins are approximated with little drainage
Granulation/Second intention features:
Wound is debrided, cleansed and occluded- allowed to fill with granulation tissue
Infection, excessive trauma, tissue loss, or imprecise approximation of tissues causes healing by second intention
Significant tissue loss, may require grafting
Wound is left open and allowed to heal from the inner layer to the outer surface
Delayed primary closure/third intention features:
Method of repair for contaminated, dirty, infected traumatic wounds with extensive tissue loss and a high risk for infection
Suturing is delayed to wall off area of gross infection- wound is kept open to monitor!
Closed on day 3-5
Examples of primary union/first intention wounds:
Surgical incision
Simple lacerations
Examples of granulation/second intention wounds:
infected wounds, drains, trauma, tissue loss
Examples of delayed primary closure/third intention wounds:
Compartment syndrome, burns, debridement, wound disruption, excessive trauma
Characteristics of Class I clean wounds:
No inflammation encountered
No breaks in sterile technique
No hollow viscous entered
Respiratory, alimentary, genital or infected urinary tracts are not entered
Examples of class I clean wounds include:
Thyroidectomy
Mastectomy
Ganglion excision
Herniorrhaphy
Laminectomy
Characteristics of Class II clean contaminated wounds:
Nontraumatic wounds
No inflammation encountered
No breaks in sterile technique
HOLLOW VISCOUS ENTERED
RESPIRATORY, ALIMENTARY, GENITAL or URINARY TRACTS ARE ENTERED UNDER CONTROLLED CONDITIONS!
Examples of class II clean contaminated wounds:
Cholecystectomy
Hysterectomy, abdominal or vaginal
C-section
Colon resection
Tracheostomy
Appendectomy
Cystoscopy
Characteristics of class III contaminated wounds:
Open, fresh, accidental wounds
Major break in technique occurred
Entrance into genitourinary or biliary tracts with infection
Examples of class III contaminated wounds include:
Inflamed but unruptured appendix or gall bladder, open fractures, or penetrating wounds
Procedures performed with unsterile instruments
Characteristics of Class IV dirty wounds:
Old wounds with retained devitalized tissue
Perforated viscera (perforated appendix)
Chronic infected wounds
Example of class IV dirty wounds:
Incision and drainage of an abscess
Patient specific risk factors that delay wound healing
Older age
Inadequate oxygenation
Obesity
Malnutrition
Alcohol consumption
Medications
Chronic diseases
Smoking
Preoperative skin prep
Preoperative stress
Existing infection
Medications that can impair wound healing
Steroids (Suppresses inflammatory response but delays contraction and collagen synthesis)
Anticoagulants (affects hemostasis and should be stopped 2 TO 7 DAYS before surgery)
- stop ASA and COUMADIN 7 DAYS before surgery
- Stop NSAIDS (Ibuprofen( 48 hours before surgery
Chemotherapeutics (Inhibits protein synthesis, delays wound repair)
Radiation (large doses decrease blood supply to affected area)
Intraoperative factors in postoperative wound infection
Length of surgery
Location of the wound (injuries in areas of mobility (elbows, knees) delay healing; wounds in highly vascular areas heal more quickly)
Complications (hemorrhages, break in aseptic technique, poor surgical technique, tissue trauma) may delay healing
Foreign bodies in the wound (hardware, implants, artificial heart valves)
Elimination of dead space (
Passive or Mechanical Hemostatic Agents
Agents that are applied at the bleeding site and provide a barrier to stop blood flow
Collagens
Cellulose (Surgicel)
Gelatins (Gelfoam)
Polysaccharide spheres
Active Hemostatic agents
Agents contain thrombin and products mixed with THROMBIN!
Enhance clotting at the bleeding site
Flowables
Combinations of passive and active hemostatic agents
Work by mechanically obstructing the flow of blood and converting fibrinogen into fibrin at bleeding site
Do not contain fibrinogen and require direct contact with blood to make this conversion work
FLOSEAL!!
Fibrin sealants
Promote blood clotting by increasing the amounts of fibrinogen and thrombin at the bleeding site
Example: tisseel
Types of SSI:
Superficial incisional
Deep incisional
Organ or space
Traditional methods if hemostasis
Holding pressure
Suturing
Electrocautery
Blood/blood products
