WOUND HEALING

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

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

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

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

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

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

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

Incised Wound Cont.

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.

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.

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

Closed Wounds Simple fractures Simple fractures Torn ligaments Torn ligaments Blisters Blisters

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

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

Complicated Wound

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

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

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

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

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

Healing by First or Primary Intention

Healing by First or Primary Intention? Maybe not!

Wound Healing/Closure Secondary Intention/Second Intention Secondary Intention/Second Intention Trauma or Chronic wounds Trauma or Chronic wounds Wound is not closed Wound is not closed A. Wounds that cannot be re-approximated A. Wounds that cannot be re-approximated B. Infection risk too high to close by 1° intention 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 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 Healing occurs from the inside out and is prolonged as a result Tissue is lost Tissue is lost

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

Physiological Consequences Of A Wound Sympathetic Nervous System Response (Fight or Flight): Sympathetic Nervous System Response (Fight or Flight): ↑ HR hyperventilation ↑ HR hyperventilation ↑ BP ↑ mental status ↑ BP ↑ mental status ↑ clotting ↑ muscle tension ↑ 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 * 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

Wound Healing Natural and Spontaneous Phenomenon 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 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 May occur with sutures, stapling devices, clips, steri-strips, or topical adhesive (Derma-bond) (Derma-bond)

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

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

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

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

Tensile Strength Affects ability of tissue to withstand injury not how long it takes the wound to heal 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. 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 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 Until that plateau is reached, wound tissue requires extrinsic support, usually sutures to bring it back together

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

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

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

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

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

Other Wound Terms Cicatrix – normal scar formation Cicatrix – normal scar formation Collagen - The main structural protein found in animal connective tissue. Collagen - The main structural protein found in animal connective tissue. Serous - thin, watery liquid, usually clear 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) 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. Tensile strength – the pull-strength of tissue or suture.

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

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

Surgical Site Infections Incisional- at the site of incision Incisional- at the site of incision Deep Wound- within the tissue or in the cavity where the operation occurred Deep Wound- within the tissue or in the cavity where the operation occurred Nosocomial- acquired while in the hospital Nosocomial- acquired while in the hospital

Wound Care Aseptic Technique Aseptic Technique Prophyllactic antibiotics Prophyllactic antibiotics Antiseptics/antimicrobials used for skin prep Antiseptics/antimicrobials used for skin prep Adequate oxygenation of tissues by maintaining patient oxygenation Adequate oxygenation of tissues by maintaining patient oxygenation Closed wound drain systems when drains are used Closed wound drain systems when drains are used Sterile technique/supplies with dressing changes Sterile technique/supplies with dressing changes Dressings secured with clean tape or sterile packaged dressings (tegaderm/primapore) Dressings secured with clean tape or sterile packaged dressings (tegaderm/primapore)

Summary Definitions Definitions Physiological Consequences of a Wound Physiological Consequences of a Wound Wound Types Wound Types Mechanisms of Wound Healing Mechanisms of Wound Healing Stages of Wound Healing Stages of Wound Healing Factors Influencing Wound Healing Factors Influencing Wound Healing Surgical Site Infections Surgical Site Infections Wound Care Wound Care