WOUND HEALING

1. WOUND HEALING

2. Wound: Any disruption of cells, be it tissue or skin • Wound Healing: Restoration of that disruption

3. Types of Wounds • Surgical Wounds (intentional) • Traumatic Wounds (accidental) • Chronic Wounds (persistent) - result of underlying condition

4. Surgical Wounds • Patient sustains this type of wound any time a surgeon cuts into the skin to perform a surgical procedure • Are classified according to the CDC: Class 1 (clean) -Carries low risk of infection <5% - Conditions are ideal (aseptic without prior break in skin) - Primary closure - Drains placed in wound are closed systems -No respiratory, alimentary, oropharyngeal, or genitourinary systementry -Does include blunt trauma that is non-penetrating

5. Surgical Wounds Continued Class 2 (clean-contaminated) - infection risk 8-11% - respiratory, alimentary, or genitourinary tracts are entered under aseptic, controlled conditions - no infection or break in aseptic technique - drains placed in wound are closed systems - examples: biliary, appendix (prior to rupture), vagina, oropharynx.

6. Surgical Wounds Continued Class 3 (contaminated) - infection risk 15-20% - traumatic, fresh, open wounds < 4 hours old - inflammation may be present - injury could have resulted in spilling of organ contents -Includes spillage of GI tract content or break in sterile technique intra-operatively

7. Surgical Wounds Continued Class 4 (dirty/infected) - infection risk 27-40% - infection was present before the surgical procedure - includes traumatic wounds > 4 hours old - can be a ruptured or perforated organ (ex. ruptured appendix) - tissue may appear necrotic, (dead), have a purulent (pus) drainage, and foul odor

8. Traumatic Wounds • Chemical, thermal, physical, or outside force that has caused injury to the body tissue • Types of traumatic wounds: abrasion laceration avulsion perforation chemical puncture contusion thermal crushed

17. Incised Wound Cont.

18. Chemical Wound/Burn The chemical burn is a part or an entire destruction of the molecules, the cells or the structure of the skin due to an irritant or corrosive chemical product. The importance of the tissue modification will characterize the degree of the burn.

19. Thermal Burn This patient received a thermal burn to the buttocks, and there was complete destruction of the skin and some of the underlying fat. This shows the exposed fat after the MD debrided the necrotic skin. Normal fat appears yellow.

20. Traumatic Wounds Continued • Classifications of: Closed - outside skin intact, tissue under skin is not Open – outside skin broken Simple Complicated Clean Contaminated

21. Closed Wounds • Simple fractures • Torn ligaments • Blisters

22. Open Wounds • Simple • Skin interruption without loss or destruction of the underlying tissue • Lacerations

23. Open Wounds • Complicated • Skin and underlying tissue injury or destroyed • Burns • Crushing injury • Foreign object (bullet or foreign object that is present such as knife or nail)

24. Complicated Wound

25. Complicated Wound cont. Pt. from Nigeria. Machete wound to the scalp. Patient survived wound and surgery.

26. Open Wounds • Clean • Object or conditions surrounding injury were clean • Wound cared for within 6 hours of injury • Heals by primary intention • Cut that happens when loading a dishwasher

27. Open Wounds • Contaminated • Conditions surrounding injury not clean or care given 6 hours after injury • Heals by 2° or 3° intention • Injury occurs when handling feces from an animal or person

28. Chronic Wounds • An underlying condition of the patient is causing their wound to not heal • Delayed healing results from persistent infection or disease processes: • Diabetes (gangrenous ulcer) • PVD • MRSA/VRSA • Pressure sores • Immuno-compromised (Cancer/chemotherapy/AIDS/steroid therapy)

29. Wound Healing/Closure • Types of: Primary Intention/First Intention - Surgical wound - Edges are closely approximated - Closed by suture, staples, or adhesive tapes/gels - No tissue lost

30. Healing by First or Primary Intention

31. Healing by First or Primary Intention? Maybe not!

32. Wound Healing/Closure Secondary Intention/Second Intention • Trauma or Chronic wounds • Wound is not closed A. Wounds that cannot be re-approximated B. Infection risk too high to close by 1° intention • Must remove dead or necrotic tissue by process of debridement prior to allowing healing by this means • Healing occurs from the inside out and is prolonged as a result • Tissue is lost

34. Wound Healing/Closure Tertiary Intention/Third Intention • Surgical, Trauma, or Chronic wound • Closure by primary intention must be delayed due to swelling, inflammation, contamination, or patient’s condition (unstable) • May require debridement before closure • Closure delayed 4 to 6 days

36. Physiological ConsequencesOf A Wound • Sympathetic Nervous System Response (Fight or Flight): ↑ HR hyperventilation ↑ BP ↑ mental status ↑ clotting ↑ muscle tension * Results in vasoconstriction and decrease in blood being delivered to the abdominal organs as bleeding is attempted to be minimized by the body and delivered to vital organs

37. Wound Healing • Natural and Spontaneous Phenomenon • If cannot occur naturally, must remove dead tissue or foreign bodies, treat for infection, and re-approximate the tissue until healing can take place • May occur with sutures, stapling devices, clips, steri-strips, or topical adhesive (Derma-bond)

38. Tissue • Collection of cells that are similar as well as the intercellular substance around them • Four Tissues of the Body: • Epithelium • Connective tissue (blood vessels, bone, and cartilage) • Muscle • Nerve

39. Stages of Normal Wound Healing • Lag (Inflammatory) Phase • Healing (Proliferative) Phase • Maturation (Remodeling) Phase

40. Lag/Inflammatory Phase • Lasts 1 to 4 days • Fluid called exudate, containing blood, fibrin, and lymph accumulates in wound • Clotting begins as the exudate binds the wound edges together • Inflammation, a vascular and cellular reaction gets rid of bacteria, foreign matter, and dead tissue • Inflammation causes site to be red, swollen, warm, and painful • Scab (dry, protective layer) forms • Wound strength limited at this time

41. Healing/Proliferative Phase • Begins day 5, lasts two weeks • Epithelialization, new cell formation • Strength of wound increases due to collagen fibers that are produced • Directly related to tensile strength of the wound • Edges of wound continue to be brought closer together

42. Tensile Strength • Affects ability of tissue to withstand injury not how long it takes the wound to heal • This is the term referring to the pull strength of a wound or the ability to resist rupture. • As collagen forms, tissue strength rapidly increases, but it may take months for a plateau to be reached • Until that plateau is reached, wound tissue requires extrinsic support, usually sutures to bring it back together

43. Remodeling/Maturation Phase • Begins after 2nd week of wound and lasts about 4 weeks and can last over a year if the wound is extensive • Scar tissue forms (collagen formation becomes dense) • Scars have limited vascularization, hence they are pale in color • Ultimate strength of wound is 80% of the nonwounded tissue

44. Physiological Consequences Of A Wound Continued • Contamination/Potential Infection • Hemorrhage and Excessive Clot Formation • Complete or total loss of organ function • Cell or Tissue Death

45. Factors Influencing Wound Healing • Wound Type • Patient’s Physical Condition • Type of Operation

46. Wound Complications • Adhesions – abnormal attachments • Debridement – the process of removing devitalized tissue • Dehiscence – the breakdown of suture lines • Evisceration – the spillage of bowel from the abdominal cavity. • Fistula – pathway between two normally separate surfaces • Gangrene - Localized death and decomposition of body tissue, resulting from either obstructed circulation or bacterial infection. • Granulation - new connective tissue and tiny blood vessels that form on the surfaces of a wound during the healing process • Hematoma - A solid swelling of clotted blood within the tissues • Hemorrhage – MASSIVE blood loss (((regular)) blood loss comes from a paper cut)

47. Wound Complications • Herniation - the protrusion of an organ or the fascia of an organ through the wall of the cavity that normally contains it. • Infection • Ischemia – loss of blood flow to an area • Keloid – abnormal scar formation • Necrosis – tissue death • Proud Flesh - the swollen tissue around a healing wound or ulcer • Sinus – cavity with only an exit

48. Other Wound Terms • Cicatrix – normal scar formation • Collagen - The main structural protein found in animal connective tissue. • Serous - thin, watery liquid, usually clear • Sero-sanguinous -A serum-like exudate which is blood-stained (i.e. Pink fluid) Sanguinous – fluid containing mostly blood (i.e. Red fluid) • Tensile strength – the pull-strength of tissue or suture.

49. Smoking Circulation Age Nutritional status Obesity Immunologic status Pre-existing diseaseprocesses: Respiratory Diabetes Drug therapies Cancer Anemia Cardiovascular Patient’s Physical Condition

50. Type of Operation • Aseptic technique • Handling of tissue involved • Methods of achieving hemostasis • Security of the wound • How the wound was approximated • Where the wound is anatomically