January 27, 2007
Soft Tissue Emergencies
Most trauma involves some sort of injury to the soft tissues. Soft tissue injuries cause significant pain for the victim. These injuries may also cause considerable problems such as bleeding, source of infection and even pose a risk of vascular compromise to limbs. An organized patient assessment with appropriate treatment will reduce the likelihood of these complications.
ANATOMY AND PHYSIOLOGY
The skin, or integumentary system, is the largest organ of the human body. In the average adult, the skin has a surface area of about 22 square feet. The skin is divided into different layers. They are the epidermis, dermis, and subcutaneous layers. Each of these layers contain certain components which provide a specific function to the overall wellbeing of the organism.
The epidermal layer is the outermost layer of the skin and is composed of epithelial tissue. The epidermis can further be divided into 5 layers, or strata. The stratum germinativum is the basal layer and is the area of cell division. Continuing outward are the stratum spinosum, the stratum granulosum, the stratum lucidum, and the outermost being the stratum corneum. The stratum corneum consists of entirely dead, keratinized cells.
The new cells growing deep in the epidermis are continually pushing up older dying cells towards the surface. The dead cells on the surface will be sloughed off eventually as new cell growth continues. These dead cells are able to provide protection to the body by providing a watertight barrier on the outside of the body. The waterproofing protein in the epidermis is called keratin. The cells are bathed in an oily substance called sebum, produced in the dermal layer, which helps them remain lubricated and pliable.
Within the epidermis are cells called melanocytes which produce a brown-black pigment called melanin. Melanin contributes to the coloring of the skin and helps protect against solar radiation. The more melanin produced, the higher the tolerance to exposure to the sun.
The dermal layer is composed of dense connective tissue. Collagen and elastin are the two proteins that give the dermis strength, elasticity, and the ability to stretch (extensibility).
The dermis contains many structures. Near the surface of the dermal layer are the nerve endings which are responsible for sensations such as light pressure, deep pressure, heat/cold sensory, and pain. At the base of the dermal layer you will find hair follicles which allow for hair to grow through the dermis and epidermal layers. Channeling in with the hair follicle shaft is the sebaceous gland which produces sebum.
Also attached to each hair shaft is the arrector pili muscle. These tiny muscles are responsible for literally making our hair stand on end. Sweat (sudoriferous) glands and ducts are also located in this layer. The ducts allow for sweat to be pushed to the skin and aid in cooling the individual by evaporation.
Small blood vessels such as arterioles, venules, and capillaries may also be found in this layer. These blood vessels can dilate or constrict in response to environmental or emotional factors. Arteries, arterioles, veins, and venules are composed of three layers. The outer layer is called the tunica externa, the middle layer which is composed of smooth muscle is called the tunica media, and the inner layer is called the tunica intima. The center of the blood vessels through which blood flows is called the lumen. Capillaries are tiny vessels whose walls are only one cell thick.
Produced in the dermis is another pigment that contributes to the color of the skin, the yellow-orange pigment carotene. The hemoglobin in the blood is responsible for the pinkish color of pale skin.
The subcutaneous layer, or hypodermis, is composed of areolar and adipose (fatty) tissue. It contains the larger vessels and fat that provide a base for the dermis. The subcutaneous layer is separated from the muscles by fascia.
Functions of the Skin
The skin has many functions which are necessary to support our life. The skin provides a barrier of protection against bacteria and other pathogens which could cause infection. The skin also protects the body by giving a layer of protection against trauma. It also provides a mechanism for temperature regulation by shunting blood to or from the surface of the skin and releasing sweat to aid in cooling the body. As mentioned earlier, the skin provides sensory information to let us detect touch, pain, temperature, and pressure. The skin also synthesizes Vitamin D when exposed to sunlight. Vitamin D is necessary for bone strength and the uptake of calcium from the intestines.
Injury to the skin may cause disastrous side effects. Loss of temperature control or acute fluid loss may lead to death.
SOFT TISSUE INJURIES
An abrasion occurs when an injury abrades or scrapes away a portion of the epidermal and dermal layers. This injury causes slow minimal bleeding since only capillaries and small vessels are injured. Large abrasions may lead to a potential source of infection. Abrasions are often quite painful. Care for an abrasion includes control of hemorrhage and reducing the chance of infection. This can be accomplished by placing a sterile dressing over the wound and applying pressure.
A laceration is a wound which cuts more deeply into the dermis. This injury may cause injury to larger vessels. If the laceration occurs in certain places there may be other structures or organs injured. Injury to tendons and nerves are a potential complication. A laceration may bleed profusely. You should apply a sterile dressing and control bleeding with direct pressure.
Lacerations may be described as linear, where the wound ends are regular, or stellate, if the wound is irregular in shape. An incision is a smooth laceration that is caused by very sharp objects such as knives, broken glass, or scalpels.
A contusion is an injury where blunt trauma causes rupture of small blood vessels in the dermis. The epidermis remains intact. This allows for an accumulation of blood within the tissues. Initially, the area will have a reddened color, or erythema. As the blood in the tissues loses oxygen, the area will turn purple, then blue. This bruising effect is called ecchymosis. Bleeding will be self limiting. If the patient has a clotting disorder or is taking certain medications such as anti-coagulants, you may need to apply direct pressure to stop subcutaneous hemorrhaging.
A hematoma is a lump caused by collection of blood beneath the skin. Like a contusion, the epidermis remains intact. A larger amount of tissue is damaged in a hematoma than in a contusion. If larger vessels are damaged, the patient may lose as much as a liter of blood in a confined space.
An avulsion occurs when a section of skin is flapped or torn free. This may allow for significant bleeding as well as a potential source of infection. There may also be nerve involvement. Application of a moist, sterile dressing will reduce the likelihood of contamination and increase the chances of healing. If a section of skin is completely avulsed, transport it like an amputated part by wrapping it in moist, sterile dressings and keeping it cool. If bleeding continues then you should apply direct pressure.
A puncture wound is caused by a sharp, pointed object which penetrates the skin barrier. The wound may appear superficial, however, an external assessment may be very misleading. These wounds allow for introduction of significant pathogens into the body. Puncture wounds to the chest or abdomen could cause potentially lethal injuries such as a pneumothorax, hemothorax, ruptured aorta or other great vessel, or a ruptured solid or hollow organ.
They must be assessed and cared for in an appropriate manner by a physician. You can care for the patient by applying a sterile dressing and control any active bleeding.
Impaled objects should not be removed in the pre-hospital environment unless they are isolated to the tissue part of the cheek. These are removed only on the basis that they may bleed severely, and may interfere with airway control and involve no major structure that the rescuer could severely injure during removal. All other impaled objects should be immobilized in the position found.
An amputation is the partial or complete severance of a limb or digit. There are three types of amputations: complete, partial (greater than 50% of the limb or digit is severed), and degloving. A degloving injury is an injury where skin and adipose is torn away, but underlying tissue remains intact. These type of injuries are usually caused by machinery.
These injuries are extremely traumatic for the patient and, in many cases, for the provider. The caregiver must remember to keep their assessment priorities focused to the whole patient and not the obvious injury. Very few amputations are immediately life-threatening, but failure to detect airway compromise often has great consequences. Once life-threatening priorities are dealt with we will then turn our attention to this injury.
A priority for care is cessation of continued blood loss. Many amputations actually no not bleed significantly due to a vasoconstriction of vessels involved. Those that are actively bleeding can usually be controlled by direct pressure to the site. Application of a bulky sterile dressing should be performed.
If possible, the amputated part should be located and prepared for transport as well. One common suggestion for preparation includes covering the amputated part with a moist, sterile dressing and then placing it within a plastic bag. This bag should then be placed in another plastic bag which contains ice. This prevents direct contact of the amputated part with the ice which could cause frostbite thus preventing potential reimplantation.
Only a vascular surgeon in conjunction with other reimplantation surgeons can predict potential success of reattachment. It is important to remain positive with the patient but it is wise not to give a false sense of hope. Reimplantation is much more successful than in years past but still has its limitations. In many cases when the entire part cannot be reimplanted portions may still be utilized such as skin. Treat all amputated parts as though they are viable.
Crush injuries are caused by extreme external forces that crush both tissue and bone. The skin remains intact, but severe damage may occur to underlying tissues and organs. Common causes of crush injuries are industrial or construction accidents, motor vehicle accidents, and also prolonged application of MAST or improperly applied splints. Crush injuries can have systemic effects such as electrolyte and acid-base abnormalities, hypovolemia, and destruction of skeletal muscle with release of myoglobin into the blood can lead to kidney failure and possibly death.
CONTROL OF BLEEDING
Some soft tissue injuries may cause significant bleeding. There are four suggested ways to control hemorrhaging. They are:
Application of direct pressure
Elevation of bleeding extremity
Application of direct pressure with your gloved hand and a sterile dressing will be effective in most cases. However, elevation of the extremity above the level of the heart will help to slow blood flow to the area and aid in your efforts. Some authors have advocated that if direct pressure with a bulky dressing is ineffective you may remove the dressing one time to look to see if you can isolate the direct area of the "bleeder." This would allow you pinpoint exactly where your pressure should be directed. After this single look you should never remove your dressing in direct contact with the wound as this may remove the body's products of wound closure that are hopefully working at the site.
If bleeding still persists, then you may apply pressure to an artery that supplies the injured extremity to slow blood flow as well. You must apply pressure to the artery proximal to the wound for it to be effective. For example, you may apply pressure to the radial and ulnar arteries of the forearm to slow blood supply to the hand. The brachial artery of the upper arm will slow blood to the forearm. Pressure applied to the femoral artery in the inguinal portion of the groin will limit blood flow to the respective leg. You may apply pressure to the temporal artery in front and above the level of the ears for scalp lacerations. You should never apply pressure to the carotid artery as this may cease blood flow to the brain leading to further complications.
As a last resort, you may be forced to apply a tourniquet. A tourniquet causes a cessation of all blood flow to the extremity. This should only be done as a last resort. You should clearly mark the time of tourniquet application as it may affect the manner and speed of tourniquet removal by the physician. Do not remove a tourniquet once it is in place.
MANAGEMENT OF SOFT TISSUE INJURIES
Management of soft tissue injuries include each of the following:
Ensure scene safety.
Assess the patient. Perform the initial assessment, the detailed assessment, obtain a SAMPLE (Signs and Symptoms, Allergies, Medications, Last oral intake, Events leading up to the injury), perform ongoing assessment as needed.
Utilize cervical spine precautions as necessary.
Administer high-flow oxygen.
Dress wounds with sterile dressings and appropriate bandaging materials.
Rapid, safe transport to the hospital
Initiate vascular access with a large bore catheter
Notify medical control and/or receiving hospital
REVIEW OF BANDAGING AND DRESSING MATERIALS
A dressing is any material that covers a wound. Dressings help prevent further contamination and help control bleeding. Sterile dressings are used when infection is a concern. Sterile dressings come in all shapes and sizes.
The multi-trauma, or universal, dressing is made of thick, absorbent material and is used to cover large wounds such as abrasions or burns. It can also be used as a pressure dressing over long open wounds and as padding for splints. The 4 X 4 gauze dressing is a small dressing that can be used for smaller wounds. An occlusive dressing is used when you want to prevent air from going through the dressing. Petroleum gauze, sterile aluminum foil, or sterile plastic wrap are all occlusive dressings.
A bandage is material used to secure a dressing in place. Bandages help provide pressure to control bleeding. The roller bandage is the most common type of bandage used in pre-hospital care. It is a slightly elastic gauze that is wrapped around a dressing on an extremity or the head. The triangular bandage is a versatile bandage. It can be used for rapid application of direct pressure over a wound, as a cravat bandage, as a sling, or as a tourniquet. Adhesive tape and bandaids are other types of bandaging materials.
There are some special things to consider regarding soft tissue injuries. Many of these patients may not wish to travel to the hospital by ambulance or otherwise. It may be helpful to explain to the victim that lacerations of the hand and feet may involve not only the soft tissue but tendons and nerves as well. These types of injuries are usually not handled by a general practitioner. These types of injuries may involve the use of hand surgeons, orthopedic specialists, nerve and vascular surgeons or a combination of the above. Encourage these patients to seek medical attention early.
Some lacerations cannot be safely closed after a certain time period. There is a story in which a man goes to the Emergency Department of a large hospital immediately after cutting his hand. After the patient was triaged, he was asked to sit in the waiting area. When he was finally called to his room some ten hours later and then seen by the physician an hour after that he was told that it could not be "sewed up" since it occurred more than six hours ago. Physicians have different time lines that they will use in deciding which wounds may be closed and which may not. This is usually based on the risk of infection and the availability of skin with good vasculature that can be used to close the wound. Do not inform patients that a wound can or cannot be closed based on time. Rather, encourage them to seek medical attention immediately to have the best chance of appropriate wound closure.
Patients who have breaks in their integumentary system are also at significant risk of infection or introduction of diseases such as tetanus. Current recommendations are that Tetanus immunizations are "good" for ten years. However, most physicians will suggest an update if there is a significant exposure between the fifth and tenth year. Antibiotics may be necessary for some wounds especially those involving animal or human bites. Only a physician can decide if antibiotic therapy is indicated and if so which antibiotics will work against the bacteria suspected. Do not let patients assume that since they have "some left over antibiotics" that they will work for their current exposure.
For those patients who refuse transport and who will not obviously seek medical care on their own it is important to go over the risks versus benefits of refusing medical care. The risks include continued hemorrhaging, delay causing prevention of wound closure, infection, loss of function, loss of limb, and even death in some cases. The obvious benefits are early evaluation by a physician including care by specialists if necessary.
For those who still refuse care, you should encourage them to keep the wound clean with a mild soap and water and then kept covered with a dry, sterile dressing. The suggested use of topical antimicrobial agents should only be made by a licensed physician as some agents may be toxic to the area tissues. Any pain, pus, or purulent drainage should be evaluated immediately by a physician.
Treatment of soft tissue injuries can be easily managed in the pre-hospital environment. Wound management is geared towards prevention of pathogen entry and controlling all bleeding. These wounds may appear very severe but with a basic understanding of wound development and complications you should feel confident in your ability to treat the patient.
Soft Tissue Injuries Quiz
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