Overview of Lacerations and First Aid

Our skin is the body’s largest and most exposed organ, and it includes nails, toenails, hair, body hair, and subcutaneous fat. The skin is broadly composed of two layers, the epidermis and dermis, and beneath the skin is a layer of subcutaneous fat.

The skin prevents external irritation and the invasion of pathogens, protects the body from chemicals and sunlight, and regulates body temperature. When it is cold, it contracts to prevent body temperature from dropping, and when it is hot, it relaxes to promote sweating and prevent body temperature from rising, thereby helping maintain a constant body temperature. In addition, it functions in sensation, respiration, facial expression, excretion, and the production of vitamin D.

Skin wounds are broadly divided into abrasions, contusions, incisions, puncture wounds, and lacerations. Among these, a laceration refers to a wound caused by tearing of the skin. Lacerations often have irregular, uneven edges, and because a damaged space is created in the skin, the skin loses its protective function.

Wound Healing Process

Wound healing occurs gradually over time. It can be divided into the hemostasis and inflammatory stage, the proliferative stage, and the maturation stage.

1. Hemostasis and inflammatory stage (Day 0 to Day 3)

From the time a wound occurs until day 3, the hemostasis and inflammatory stage begins. Vasoconstriction, fibrin deposition, and thrombus formation at the wound site stop the bleeding. As cells and blood vessels are damaged and blood comes into contact with the injured blood vessel wall, clotting factors in the blood are activated, inducing platelet action. As a result, a mass of fibrin forms and adheres to the wound site, and once it hardens, the hemostatic stage is complete, preventing further loss of blood and fluid.

1. Vascular response

After the initial vasoconstriction, the release of a substance called histamine from the damaged blood vessel begins the process of vasodilation, increasing blood flow and vascular permeability. Through plasma movement, plasma proteins, white blood cells, and others seep out of the blood vessels and exudate accumulates at the injured site.

2. Cellular response

As exudate increases, various inflammatory cells such as white blood cells increase in the tissue. White blood cells phagocytose and remove dead tissue and bacteria and induce blood vessel formation, helping wound healing. In addition to the immune response to foreign substances, inflammatory cells are also involved in collagen synthesis and production, forming a fibrin network that lays the foundation for wound healing.

2. Proliferative stage (Day 4 to 2 weeks)

From day 4 to 2 weeks is the proliferative stage. Fibroblasts that migrate along the fibrin network at the wound site proliferate and form a collagen complex that creates new tissue, strengthening the newly formed tissue and leading to the formation of granulation tissue. During the proliferative stage, granulation tissue may overgrow and rise above the surrounding skin. In addition, epithelial cells on the surface of the skin differentiate and proliferate, moving along the gaps between the scab and covering the wound area. This re-epithelialization progresses quickly enough that, if the wound edges are not separated, it can be completed within 48 hours of the injury.

3. Maturation stage (2 weeks and onward)

When about 2 weeks have passed and the maturation stage begins, inflammatory cells disappear, blood vessel formation stops, and fibrosis also stops. In this stage, collagen synthesis increases to its maximum, forming a scar that initially appears red and raised. After about 6 months, collagen fibers gradually rearrange and decrease, blood vessels are compressed, the scar becomes thinner, and its color fades until the original skin tone reappears.

First Aid

1. Hemostasis

When a laceration occurs, bleeding is present in most cases. The first thing to do is stop the bleeding. First, remove or cut away the clothing over the wound to visually confirm the bleeding. Then apply direct pressure to the laceration using a clean towel or gauze.

◆ Caution ◆

· Unless there is no other way, avoid touching the wound with bare hands as much as possible.

· Apply steady pressure to the wound, not too weakly.

· If the bleeding does not stop within 10 minutes after applying pressure, the pressure may have been too weak or the pressure point may have been incorrect.

Apply pressure again for more than 10 minutes with a wider pressure area and stronger force.

· Once the bleeding has stopped and treatment is finished, be sure to wash your hands thoroughly with soap.

· In cases of eye injury, visible foreign bodies at the wound site, or skull fracture, direct pressure may cause greater damage.

· Applying ointments or powder-type medications that are easily available on the market to a laceration for hemostasis does not help stop bleeding and may instead interfere with drainage of wound secretions and removal of contaminants.

※ Severe bleeding

If the blood from the wound changes in rhythm with the heartbeat or spurts out, it is likely arterial bleeding. If bleeding does not stop even after applying pressure for more than 10 minutes, call 119 immediately and receive treatment from medical personnel. At this time, removing the gauze covering the wound to check whether bleeding has stopped may stimulate the barely controlled wound and cause rebleeding, so it is better to keep adding gauze and pressing on the wound while waiting for medical personnel.

2. Wound cleansing

Once hemostasis has been achieved to some extent, wash the wound under running tap water so that as little dirt or other contaminants remain as possible. If there is no tap water nearby, potable water may be used to disinfect it. If an appropriate cleansing solution cannot be obtained, apply pressure with a dry towel and go to the hospital immediately.

◆ Caution ◆

· Leaving a wound submerged in standing water does not help with disinfection.

· If there is no tap water, wash the wound with clean potable water.

· Sucking out the wound with the mouth is not recommended because the many bacteria in the mouth can increase the risk of wound infection.

· Betadine solution (red medicine), alcohol, and similar products are helpful for disinfecting the area around the wound, but if the concentration is strong, they can kill normal cells inside the wound. Therefore, it is better not to spray disinfectant directly onto the wound site.

· Wrapping a wound repeatedly with small adhesive bandages increases the chance that germs will get onto the wound site and cause infection.

※ Wounds that require hospital treatment

· When bleeding does not stop

· When the wound extends to muscle or bone

· When the wound is on a bending area such as the elbow or knee

· When the wound is on the palm or thumb

· When the wound is large and deep

· When a foreign object is deeply embedded in the wound

· When a foreign object remains even after wound cleansing

· When caused by a bite from a person or animal

· When a noticeable scar may remain

· When the wound is wide and gaping

· When the eyelid is wounded

· When the lip is wounded

So far, we have covered the overview of lacerations and first aid.

In the next part, we will look at treatment for lacerations.

Source: Korea Disease Control and Prevention Agency, National Health Information Portal