Perfusion is the circulation of blood through an organ or a part of the body. Shock is the inadequate circulation of blood through an organ or a part of the body. Uncontrolled bleeding that leads to depleted blood volume is one cause of shock.
A wound is an injury to soft tissues. A closed wound occurs when the soft tissues under the skin are damaged but the surface of the skin is not broken (for example, a bruise). An open wound results when the skin surface is broken (for example, a cut or scrape).
Hemorrhage (also called major bleeding) is an extreme loss of blood from a blood vessel. It is a life-threatening condition that requires immediate attention. If it is not controlled, hemorrhage can lead to shock and potentially to death.
Hemophilia is a disorder in which the blood does not clot normally. A person with hemophilia may have major bleeding from minor injuries and may bleed for no apparent reason. Some medications or a serious injury may also prevent effective clotting.
Arterial bleeding is the most serious type of bleeding. The blood from an artery is bright red, oxygen-rich blood. When an artery bleeds, blood spurts from the wound because the arteries are under high pressure. A bleeding artery can quickly lead to the loss of a large amount of blood. Arterial bleeding can be difficult to control due to high pressure within the artery.
Bleeding occurs more often from veins than arteries because veins are closer to the skin's surface. Venous bleeding is usually easier to control than arterial bleeding because it is under less pressure. Blood lost from a vein flows as a steady stream and is dark red or maroon because it is oxygen-poor blood.
Capillary bleeding is common because the walls of the capillaries are fragile and many are close to the skin's surface. Bleeding from capillaries is usually dark red. When a capillary is torn, blood oozes slowly from the site of the injury because the pressure within the capillaries is low. Capillary bleeding often clots and stops by itself within a few minutes.
External bleeding is bleeding that you can see. The blood flows through an open wound, such as a cut, scrape, or puncture. Clotting normally occurs within minutes. However, external bleeding must be controlled with your gloved hands and dressings until a clot is formed and the bleeding has stopped.
As an Emergency Medical Responder, you must wear personal protective equipment (PPE) when you anticipate exposure to blood or other potentially infectious material. HIV and the hepatitis virus are examples of diseases to which you may be exposed that can be transmitted by exposure to blood. Remember to put on disposable gloves before physical contact with the patient. Eye protection, a mask, and gown should be worn if there is a large amount of blood. PPE should also be worn when the splashing of blood or body fluids into your face or eyes is likely.
Six methods may be used to control external bleeding:
Applying direct pressure to the wound
Applying direct pressure slows blood flow and allows clotting to take place.
Elevating the affected extremity
If an arm or a leg is bleeding, elevation may help control the bleeding. If possible, elevate the extremity above the level of the heart while continuing to apply direct pressure. Raising the extremity above the heart reduces pressure at the wound site by reducing blood flow to it. This action allows blood to pool and clot. Do not elevate the extremity if pain, swelling, or deformity is present.
Applying pressure to an arterial pressure point
If bleeding continues from an arm or a leg, pressure points (also called pulse points) may be used to slow severe bleeding.
Applying a splint to immobilize the extremity
A splint is a device used to limit the movement of an injured arm or leg and reduce bleeding. After applying the splint, make sure to check the patient's fingers (or toes) often for color, warmth, and feeling.
Applying a pressure splint (air splint)
A pressure splint (also called an air or pneumatic splint) can help control bleeding from soft-tissue injuries or broken bones. It can also help stabilize a broken bone. An air splint acts as a pressure bandage, applying even pressure to the entire arm or leg. After applying any splint, be sure to check the patient's fingers (or toes) often for color, warmth, and feeling.
The pneumatic antishock garment (PASG) is used in some EMS systems. (This garment is also called the Military Antishock Trousers [MAST].) This device can be used as an effective pressure splint to help control severe bleeding from the legs or pelvis.
Applying a tourniquet (only as a last resort)
A tourniquet is a tight bandage that surrounds an arm or a leg. It is used to stop the flow of blood in an extremity. A tourniquet is rarely needed to control bleeding. It should be used only as a last resort to control lifethreatening bleeding in an arm or a leg when you absolutely cannot control the bleeding in any other way. A tourniquet can cause permanent damage to nerves, muscles, and blood vessels, resulting in the loss of the affected extremity.
Internal bleeding is bleeding that occurs inside body tissues and cavities. A bruise is a collection of blood under the skin due to bleeding capillaries. A bruise is an example of internal bleeding that is not life-threatening.
Internal bleeding is difficult to assess because you cannot see it. You should suspect it based on the mechanism of injury or the nature of the illness as well as your patient's signs and symptoms. Suspect internal bleeding when the mechanism of injury suggests that the patient's body has been affected by severe force. Examples include penetrating trauma and blunt trauma, such as falls, motorcycle crashes, pedestrian impacts, automobile collisions, and blast injuries.
Shock is the inadequate flow of blood through an organ or a part of the body. Shock can be caused by failure of the body's pump (heart), fluid (blood), or container (blood vessels).
Cardiogenic shock can result if the heart beats too quickly or too slowly or if the heart muscle does not have enough force to pump blood effectively to all parts of the body. This type of shock can occur as a result of a heart attack, a heart rhythm that is too fast or too slow, an injury to the heart, or other conditions that affect the heart's ability to pump.
Shock can result if there is not enough blood for the heart to pump through the cardiovascular system. Shock caused by severe bleeding is called hemorrhagic shock. The bleeding may be internal, external, or both.
Blood is not the only type of fluid that can be lost from the body. For example, you can lose body fluid because of vomiting or diarrhea. You can lose plasma due to a burn. You can also lose fluid due to excessive sweating or urination. Shock caused by a loss of blood, plasma, or another body fluid is called hypovolemic shock.
Early shock is often difficult to recognize. Remember to look for it and to consider the patient's mechanism of injury or the nature of the illness when assessing your patient. The sooner shock is recognized and appropriate treatment is begun, the better your patient's chance for survival. Early shock is usually reversible if it is recognized and the patient receives emergency care to correct the cause of the shock.
Late (decompensated) shock results when the patient's systolic blood pressure drops to less than 90 mm Hg. In this phase of shock, the body's defense mechanisms lose their ability to make up for the lack of oxygenated blood. A patient in late shock looks very sick. The signs of late shock are more obvious than those of early shock, but late shock is more difficult to treat. It is still reversible if the cause of the problem is quickly corrected.
Irreversible shock is also called terminal shock. You will feel an irregular pulse as the patient's heart becomes irritable and begins to beat irregularly. As shock continues, the patient's heart rhythm becomes more chaotic and can no longer effectively pump blood. Permanent damage occurs to the vital organs because the cells and organs have been without oxygenated blood for too long. Eventually, the heart stops, breathing stops, and death results.
An evisceration occurs when an organ sticks out through an open wound. In providing care, do not touch or try to place the exposed organ back into the body. Carefully remove clothing from around the wound. Lightly cover the exposed organs and wound with a thick, moist dressing. Secure the dressing in place with a large bandage to keep moisture in and prevent heat loss.
An impaled object is an object that remains embedded in an open wound. Do not remove an impaled object unless it interferes with CPR or is impaled through the cheek and interferes with care of the patient's airway. Control bleeding and stabilize the object with bulky dressings, bandaging them in place. Assess the patient for signs of shock and treat if present.
In the case of an amputated body part, control bleeding at the stump. In most cases, direct pressure will be enough to control the bleeding. Ask an assistant to find the amputated part as it may be able to be reattached at the hospital. Put the amputated part in a dry plastic bag or waterproof container. Seal the bag or container and place it in water that contains a few ice cubes.
There are three categories of burns:
A superficial (first-degree) burn affects only the epidermis. It results in only minor tissue damage (such as sunburn). The skin is red, tender, and very painful. This type of burn does not usually require medical care and heals in 2-5 days with no scarring.
A partial-thickness (second-degree) burn involves the epidermis and dermis. The hair follicles and sweat glands are spared in this degree of burn. A partialthickness burn produces intense pain and some swelling. Blistering may be present. The skin appears pink, red, or mottled and is sensitive to air current and pressure. This type of burn usually heals within 5-35 days. Scarring may or may not occur, depending on the depth of the burn.
A full-thickness (third-degree) burn destroys both the epidermis and dermis and may include subcutaneous tissue, muscle, and bone. The color of the patient's skin varies from yellow or pale to black. The skin has a dry, waxy, or leathery appearance. Because the skin is so severely damaged in this type of burn, it cannot perform its usual protective functions. Rapid fluid loss often occurs. Be ready to treat the patient for shock.
The rule of nines is a guide used to estimate the affected body surface area. The rule of nines divides the adult body into sections that are 9% or are multiples of 9%. This guideline has been modified for children and infants. To estimate the extent of a burn using the rule of nines, add the percentages of the areas burned.
A dressing is an absorbent material placed directly over a wound. A bandage is used to secure a dressing in place. A pressure bandage is a bandage applied with enough pressure over a wound site to control bleeding. Dressings and bandages serve the following functions:
