Skin & Soft Tissue Injuries - Lecture Slides.pdf

Medical & Traumatic Emergencies Week 2 – Lines of Defence, Soft Tissue Injuries & Diseases PARA 1503 Rohan Shammi Factors Influencing Susceptibility to Disease  Genetic VS Environmental ...

Medical & Traumatic Emergencies Week 2 – Lines of Defence, Soft Tissue Injuries & Diseases PARA 1503 Rohan Shammi Factors Influencing Susceptibility to Disease  Genetic VS Environmental  Causal VS Non-causal  A causal association means we have evidence to say ‘this’ directly leads to ‘that’  Non-causal means there is no direct link, but data suggests ‘this’ increases risk for ‘that’ even if the link is not understood  Modifiable VS Non-Modifiable  Modifiable risk factors can be controlled & largely refer to ‘lifestyle’ factors (ie: diet, exercise, etc.)  Non-modifiable risk factors cannot be controlled (ie: gender, race, family history, age, etc.)  Measures of Societal Impact Incidence Rate - # of new cases in a given time period Prevalence Rate - % of the population with a given disease Mortality Rate - # of deaths divided by the total population with the disease Types of Disease & Deficiencies  Refers to a failure of the body’s organ systems, self-defence mechanisms, etc. to function at their normal capacity  These deficiencies can be:  Congenital - Meaning present at birth  Acquired – via Infection, Cancer, Immuno- suppressive drugs, Aging  As emergency healthcare providers we are more likely to encounter patients with these kinds of complex issues Body’s Self-Defense Mechanisms  First Line – External Barriers  Including skin, mucous membranes of the respiratory, digestive, and genitourinary (GU) tract  Provides a barrier to the entry of foreign substances & a hostile environment for pathogens  Pathogens are micro-organisms that cause disease including bacteria, viruses, fungi, etc.  Second Line – Inflammatory Response  Cellular & vascular response to trauma, infection, or injury  Third Line – Immune Response  Destruction & removal of foreign substances Inflammatory Response  May seem counterintuitive but inflammation is an adaptive response to disease or injury  However, if too widespread or prolonged there can & will be negative consequences  Inflammation is intended to localize & remove any ‘injurious agent’ whatever those may be  Allows for greater blood flow and easier entry for immune & repair cells to the site of injury  Inflammation occurs in response to a wide variety of triggers including:  Physical – Cuts/wounds, extremes of heat/cold  Chemical – Exposure to acids/bases  Others – Including ischemia, allergic reactions, infection, etc.  3 Basic Stages of Inflammation / Healing  Acute Phase – Vasodilation increases blood flow, macrophages consume foreign materials/pathogens  Proliferation Phase – Tissue rebuilding occurs  Remodelling Phase – Repaired tissue is strengthened  Redness (rubor), Swelling (tumor), Pain (bolar), Warmth (calor) Immune Response  Natural/Passive Immunity VS Acquired Humoral Immunity  Passive immunity involves antibodies that are produced in someone else’s body other than your own (ie: mother)  Neonates have passive immunity from antibodies transferred from mother to child through the placenta  Acquired immunity involves antibodies produced within your own body  Either from exposure to the disease itself or from a dose of vaccine  Antibodies / Immunoglobulins (IgG, IgM, IgA, IgD, IgE)  Antibodies are produced by B-cells of the immune system  They are special proteins that recognize & help fight specific infectious pathogens (ie: bacteria, viruses, etc.)  Antibodies bind to antigens (found on foreign cells) & promote their destruction  IgG antibodies are the most common, IgE are involved in allergic reactions  Antigens & Immunogens  Refers to any substance that causes your immune system to produce antibodies  Typically harmful pathogens elicit this response, but may be maladaptive in the case of allergic reactions)  Complement System – Enhances the ability of antibodies & phagocytic cells  Part of the innate immune system, it is present at all times in the blood, but is not adaptable like antibodies are (ie: cannot learn new tricks)  Cell Mediated immunity – T-cells  White blood cells (WBCs) that identify & attack any cells infected by pathogens or otherwise identified as harmful or non-self (ie: cancer) Anatomy of the Skin  Integumentary system is the set of organs forming the outermost layer of the body  Includes ‘appendages’ like hairs, nails, etc.  Represents 12-15% of TBW  Epidermis – Strong, superficial layer, barrier to infection & first line of protection  Basement Membrane – Thin sheet of fibers separating epidermis & dermis, contains cytokines + growth factors  Dermis – Layer below the epidermis, contains connective tissue and cushions the body from stress/strain, harbours receptors for heat/touch  Subcutaneous Layer – Not part of the skin, lies below the dermis (hypodermis), attaches the skin to the underlying bone/muscle, contains blood vessels/nerves  3 Main Functions: Protection, Regulation, Sensation  Physical barrier & immunological barrier (low pH)  Regulates body temperature, maintains water balance  Contains mechanoreceptors, nociceptors, & thermoreceptors Soft Tissue Injuries & Healing Process  Wound = Disruption in tissue integrity  Deeper injuries that penetrate to the muscle tissue, skeletal system, or inner organs = complicated wound  Wound Healing has distinct phases:  Hemostasis – Wound closure through clotting  Vessels constrict, platelets stick together to form seal, coagulation occurs to reinforce platelet plug with fibrin  Inflammation  Chemical mediators result in localized swelling, helps to control bleeding and prevent infection. Allows for healing/repair cells to get to site  Proliferative Phase  Wound is rebuilt with new tissue made up of collagen (released by fibroblasts). Wound contracts as new tissues are built, new vessels ensure granulation tissue stays healthy  Granulation tissue is new connective tissue and microscopic blood vessels that form on the surfaces of a wound during the healing process. Granulation tissue typically grows from the base of a wound and is able to fill wounds of almost any size  Remodeling Stage  Collagen remodeled from type III to I, wound fully closes, scar tissue forms. Repair cells are no longer needed and are removed by apoptosis (programmed cell death) Wound Classification Closed Wounds  Typically caused by blunt trauma, associated with less external blood loss, though internal bleeding may be significant  Contusions  Vessel disruption below epidermis  Hematomas  Blood collection beneath the skin  Abrasions  Partial thickness injury, epidermis scraped away Open Wounds  Caused by either blunt or penetrating trauma  Associated with greater external blood loss and infection  Lacerations - Tear, split, or incision of the skin  Punctures/Impaled - Type of laceration due to sharp/pointed object  Never remove impaled object (unless it interferes with airway management or chest compressions)  Gun Shot Wounds (GSWs)  Path the bullet travels is unpredictable, ALWAYS assess for both the entrance & exit wound!  The wound itself may look minor/superficial, but the damage to internal structures & tissues may still be significant  Medium Velocity = Handguns/shotguns, High Velocity = Rifles, etc.  Injection Injuries - Type of puncture wound where substance is introduced into body  Avulsions - Full thickness skin loss in which wound edges cannot be approximated  Often involve ear lobes, nose tip, finger tips, toes  Degloving Injuries - Avulsion where shearing forces separate skin from underlying tissue  Amputations - Complete or partial loss of a limb due to blunt/penetrating trauma  Bites - Combination of puncture, laceration, avulsion, and crush injury  Highly likely to be infected Surgical Wound Classifications  There are 4 surgical wound categories & they are classified based on their risk for developing an infection, with Class IV wounds at highest risk  Clean Wounds (Class I) - These wounds show no signs of infection or inflammation and are primarily closed  Additionally, a clean wound does not typically enter any internal organs, and there is no break in the sterile operative technique  Clean-Contaminated Wounds (Class II) – Includes wounds that are mostly closed, are clean, and have no contamination present  A clean-contaminated wound is one where an internal organ has been entered but without any significant spillage of the organ’s contents  Contaminated Wounds (Class III) – Are typically open wounds that show obvious signs of contamination  Examples of contaminated wounds are penetrating traumatic injuries, wounds with spillage from the gastrointestinal tract but are less than four to six hours old  Dirty/Infected Wounds (Class IV) – Open, infected wounds that may have a foreign object in the wound bed (debris, fecal matter, etc.)  Examples of dirty-infected wounds are wounds that present with an abscess or present with a perforated bowel with possible pus and/or stool within the abdominal cavity Wounds Requiring Hospital Treatment  Important for paramedics to know what soft tissue injuries are likely to require physician treatment  Wounds deeper than 6mm/0.25in and/or longer than 19mm/0.75in, especially with jagged edges or wounds that gape open  Deep wounds that go down to the fat, muscle, bone, or other deep structures  Wounds over a joint, especially if the wound opens when the joint is moved or if pulling the edges of the wound apart shows fat, muscle, bone, joint structures, etc.  Wounds on the face, lips, or any area where scarring would be an issue (for cosmetic reasons)  Wounds that continue to bleed after 15 minutes of direct pressure  Wounds that appear contaminated/infected 3 Main Categories of Wound Healing Techniques  Primary Intention – A wound is closed using staples, stitches, sutures, Wound glues, etc.  You can close a wound in this way because there is a low risk for infection as well Healing as little concern for the wound’s edges separating (dehiscing) due to tension on the incision line Techniques  Primary intention lowers the risk for infection, leaves minimal scarring, and helps the wound heal faster  Secondary Intention - When a wound is NOT surgically closed, either completely or partially  This happens when a wound has a large amount of tissue loss or the edges cannot be safely brought together surgically  Over time with secondary healing, you will see the wound bed filling in with more viable tissue, such as granulation tissue  As this occurs, less non-viable tissue, such as slough or eschar, will be less present and ultimately, you will observe the epithelial covering of the wound bed, indicating the end stages of wound healing  Tertiary Intention – Used when there is a need to delay wound closing, also called delayed primary intention  Typically required due to risk of trapping infectious pathogens if closed prematurely, the wound may require draining prior to closing  With this type of closure, there is a planned period where the superficial layers of the wound are left open  If the situation allows, later, these layers are closed in a similar fashion to what is performed with primary intention, but in this case, the process is more prolonged  Tertiary intention might include closing the wound bed using a skin graft, a skin flap, or a skin substitute Complications of Healing  Loss of Function - Results from the loss of normal cells and the lack of specialized structures or normal organization in scar tissue  If scar tissue replaces normal skin, that area will lack hair follicles, glands, and sensory nerve endings  Contractures - Scar tissue is nonelastic and tends to shrink over time  This process may restrict the range of movement of a joint and eventually may result in fixation and deformity of the joint  Hypertrophic Scar Tissue - An overgrowth of fibrous tissue consisting of excessive collagen deposits may develop  Leads to hard ridges of scar tissue or keloid formation, which result in masses of tissue that are disfiguring and often cause contractures  Keloid Scar – Excessive accumulation of scar tissue that extends beyond original wound border  Hypertrophic Scar – Excess accumulation of scar tissue within the original wound border Pressure Sores  Also known as bedsores or decubitus ulcers they are extremely common in patients who are bedridden or otherwise immobile  Pressure sores develop when blood supply to the skin is cut off for more than 2 to 3 hours  As the skin dies, the bedsore first starts as a red, painful area, which eventually turns purple  Left untreated, the skin can break open and the area can become infected  Although they start superficial, they can extend into the muscle and bone  They most often occur on the buttocks area (tailbone/hips), heels of the feet, shoulder blades, back of the head, backs & sides of the knees  Once a bedsore develops, it is often very slow to heal  Depending on the severity of the bedsore, the person's physical condition, and the presence of other diseases (such as diabetes), bedsores can take days, months, or even years to heal. They may need surgery to help the healing process.  Limited pre-hospital treatment, prevention is critical  Patient should be turned/repositioned every 2 hours, provide soft padding, keep skin clean and dry (but moisturized), ensure good nutrition, etc.  4 Stages with Stage 1 being the least severe and Stage 4 the most  Stage 1 - The area looks red and feels warm to the touch. With darker skin, the area may have a blue or purple tint. The person may also complain that it burns, hurts, or itches.  Stage 2 - The area looks more damaged and may have an open sore, scrape, or blister. The person complains of significant pain and the skin around the wound may be discolored.  Stage 3 - The area has a crater-like appearance due to damage below the skin's surface.  Stage 4 - The area is severely damaged and a large wound is present. Muscles, tendons, bones, and joints can be involved. Infection is a significant risk at this stage.  Can broadly be classified into non-freezing cold injuries (NFCI) & frostbite  Of the two, frostbite tends to be more devastating and require more aggressive treatments Environmental  attention Soft Tissue NFCIs include frostnip, chilblains, & trench foot still have the potential for significant disability and require prompt medical Although pediatric & geriatric patients have greatest risk for this type of injury, it is most common in adult Injuries  males, aged 30-49  This is typically due to behavioural risk factors (homelessness, inadequate clothing or shelter, ETOH/drug use, psychiatric illness, etc.)  Physiological risk factors include impaired peripheral/distal circulation (diabetes) / Hands & feet are the most common locations for environmental soft tissue injury  Frostnip is the least severe and typically affects the distal extremities after prolonged exposure to cold, but non-freezing temperatures  Ice crystal formation and profound vasoconstriction are common in the superficial tissues and patients frequently complain of a dull throbbing pain du ring rewarming, this is a precursor to frostbite  Chilblains involve the formation of inflammatory skin lesions after repeated intermittent exposure to anon- freezing, but cold & wet environment  Although chilblains can affect any area of the body, the face, dorsal surfaces of the hands and feet, and pretibial tissues are the most commonly involved. Permanent tissue damage secondary to vascular inflammation and tissue bed hypoxia may develop  Trench foot develops after prolonged exposure to persistently wet conditions, both warm & cold, although the cold typically results in more severe tissue injury  The long-term exposure to moisture induces tissue edema and inflammation, whereas the prolonged cold exposure leads to direct tissue injury and can lead to full-thickness tissue loss  Immersion foot is most commonly seen in the homeless population  Frostbite involves the freezing of tissues and can result in significant tissue loss and long-term disability  Ice crystal formation within the extracellular space can induce intracellular dehydration, enzymatic dysfunction, and cellular death  Microvascular occlusion secondary to profound vasospasm and intraluminal thrombosis further the severity of tissue loss  Circulating tissue inflammatory markers frequently exacerbate the intensity of tissue injury and complicate the reperfusion of warmed tissue  Remove patient from cold/wet environment ASAP  Frostnip has mild blanching of the skin, superficial frostbite has waxy/white skin but still supple, deep frostbite has cold, hard, wooden skin  If shivering is absent and/or LOC is markedly altered assume core temp is