Emergency bleeding control describes the steps or actions taken to control bleeding from a patient who has suffered a traumatic injury or who has a medical condition which has led to bleeding. Many bleeding control techniques are taught as part of first aid throughout the world, although some more advanced techniques such as tourniquets, are often taught as being reserved for use by health professionals, or as an absolute last resort, in order to mitigate the risks associated with them, such as potential loss of limbs. In order to manage bleeding effectively, it is important to be able to readily identify both types of wounds and types of bleeding.
Wounds are normally described in a variety of ways. Descriptions may include wound size (length) and thickness; plainly visible wound characteristics such as shape and open or closed; and origin, acute or chronic. The most common descriptors of wounds are these:
Incision: Straight edges to the wound margins, as if sliced with a knife. These can vary in size, and may be caused by a variety of objects, including a scalpel, a knife, any piece of straight, sharp metal, or a piece of glass. Tissue is rarely missing from the wound site, and the margins of the wound may be easily matched from one side of the wound to the other for the purposes of closure.
Laceration: Jagged edges to the wound margins, more closely resembling a tear than a slice. The direction of the wound is random rather than straight, and it may have multiple branches. Most often caused by an object with a broken or serrated edge, such as a piece of broken glass or metal, but may also be caused by a blow from a blunt object to tissue with bone immediately behind it.
Puncture: Sharp object penetrates the tissue and travels inward, but does not move laterally in any direction from the point of entry. Such wounds can be misleading, as they may appear quite small on surface examination, but extend quite deeply into the body, even damaging nerves, blood vessels, or internal organs. They may cause substantial internal bleeding or secondary injuries, such as a collapsed lung, which may not be readily evident during primary assessment. Occasionally, the object causing the injury will remain in the wound as an impaled object. A stab wound from a knife or other sharp object, or a bullet wound, would be examples of this type of injury. Medical professionals usually refer to this type of wound as penetrating trauma.
Abrasion: A scraping or scratching. Generally quite superficial, and affecting only the surface layers of the epidermis. No internal organs, nerves, or blood vessels other than capillaries, are affected. This may be the result of a fall, or of sliding (friction) against rough surfaces. The road rash often suffered by falling motorcyclists is an example of this type of wound.
Contusion: Simple bruising. In this type of injury, the capillaries in the epidermis and dermis are damaged, without breaking the skin. Blood oozes out of these vessels into the spaces between cells or interstitial space, causing swelling and discoloration. Blood loss is generally limited, and not of serious consequence. It may, however, act as a signpost, pointing to more serious injuries.
Avulsion: A full thickness laceration-type wound, often semi-circular in shape. This creates a flap which, when lifted, exposes the deeper tissues to view, or extrudes them from the wound itself. Avulsions often occur in mechanical accidents involving fingers (sometimes referred to as degloving), or, more seriously, may affect the orbit of the eye or the abdominal cavity, exposing the internal viscera. Avulsions are difficult to repair, and no avulsion should ever be considered a minor injury.
Amputation: Similar to, but distinct from, an avulsion. Whereas an avulsion is characterized by a "flap" of skin being removed, an amputation is characterized by a complete loss of a limb. This can occur at any point on the extremity, and is usually followed by significant arterial bleeding. However, as serious as this injury is, an amputated limb that is cooled and transported to the hospital can sometimes be surgically reattached.
Types of wounds
External bleeding is generally described in terms of the origin of the blood flow by vessel type. The basic categories of external bleeding are:
Arterial bleeding: As the name suggests, blood flow originating in an artery. With this type of bleeding, the blood is typically bright red to yellowish in colour, due to the high degree of oxygenation. Blood typically exits the wound in spurts, rather than in a steady flow. The amount of blood loss can be copious, and can occur very rapidly.
Venous bleeding: This blood is flowing from a damaged vein. As a result, it will be blackish in colour (due to the lack of oxygen being transported) and will flow in a steady manner. Caution is still indicated; while the blood loss may not be arterial, it can still be quite substantial, and can occur with surprising speed without intervention.
Capillary bleeding: Capillary bleeding usually occurs in superficial wounds, such as abrasions. The colour of the blood may vary somewhat (distal portion of circulation with oxygenated and unoxygenated blood mixing), and will generally ooze in small amounts, as opposed to flowing or spurting.
Internal wounds (usually to the torso) are harder to deal with than external wounds, although they often have an external cause. The key dangers of internal bleeding include hypovolaemic shock (leading to exsanguination), causing a tamponade on the heart or a haemothorax on the lung. The aortic aneurysm is a special case where the aorta, the body's main blood vessel, becomes ruptured through an inherent weakness, although exertion, raised blood pressure or sudden movements could cause a sudden catastrophic failure. This is one of the most serious medical emergencies a patient can face, as the only treatment is rapid surgery.
In the event of the bleeding being caused by an external source (trauma, penetrating wound), the patient is usually inclined to the injured side, in order to ensure that the 'good' side can continue to function properly, without interference from the blood inside the body cavity.
The treatment of internal bleeding is beyond the scope of simple first aid, and should be considered by any first aider to be potentially life-threatening. The definitive treatment for internal bleeding is always surgical treatment, and medical advice must be sought urgently for any victim of internal bleeding.
