What Are Open Wounds

Introduction

Open wounds are injuries where the skin's protective barrier is breached, exposing internal tissues to the environment. This category includes various wound types, such as incisions, lacerations, abrasions, and avulsions. In contrast, closed wounds involve tissue damage beneath the skin's surface, with no underlying tissues exposed to the external environment. Examples of closed wounds are bruises, blisters, contusions, and hematomas.

This article provides an overview of open wounds, including their classification, the wound-healing process, factors influencing healing, and critical aspects of wound treatment and care. It delves into the anatomical and physiological intricacies of the skin, evaluates risk factors and potential complications, and sheds light on established treatment protocols. This knowledge serves as a foundation for informed decision-making in the realm of open wounds, fostering optimal healing and risk mitigation. 

Skin layers and types of open wounds

Skin layers

The skin serves as a mechanical, thermal, and ultraviolet barrier consisting of three major layers: the epidermis, the dermis, and the hypodermis. 

The epidermis is the thinnest of these regions but contains five layers of its own. The essential cells in the epidermis region include:

• Keratinocytes: These cells form a tight barrier to prevent foreign substances from entering the body. They provide structural support to the skin, help modulate the immune system when needed, and produce keratin, which is involved in hair and nail formation.
• Corneocytes: These are dead ‘stiffened’ keratinocytes on the outermost layer of the epidermis. They protect deeper layers from abrasion, light, heat, and infections.¹
• Langerhans cells: They exist as a network of immune cells. They protect from foreign substances and direct the appropriate immune response.²

The dermis is the thickest layer of skin, where other important structures that need protection emerge, such as nerves, blood vessels, hair follicles, and sweat glands.³ It also contains two proteins called collagen and elastin, which respectively make your skin structurally strong and stretchy. In addition, the dermis has additional roles to help regulate body temperature and aid sensation.

The hypodermis, which consists mostly of fat cells, is the deepest layer that connects your skin to your muscles and bones. Aside from assisting in body temperature regulation and sensation, it also stores energy and acts as insulation, cushioning and lubricant between skin and muscles.

Types of wounds and their causes

Clinicians assess wounds in emergency settings by how the injury occurred and the observed damage to the skin, soft tissues (tissue below the dermis such as muscle), and bones.

In an open wound, the skin breaks in a way that exposes internal tissue to air. Whereas in a closed wound, the tissue damage and bleeding occur under the skin's surface, not exposed to air. This includes bruises, blisters, contusions and hematomas.

Open wounds are classified into different types based on affected tissues and the extent of the damage, as shown in the table below.⁴

Wound healing process

Stages of wound healing

Wound healing goes through four stages:⁵

1. Haemostasis (Day 0, immediately after wounding): Platelet cells in the blood form a clot to stop bleeding and release factors that attract inflammatory immune cells.
2. Inflammation (Days 1- 6): Once the bleeding is controlled, white blood cells remove debris and bacteria and move on to tissue repair.
3. Proliferation (Day 4 - Week 3): New tissue is formed, blood vessels grow, and collagen is produced to strengthen the wound.
4. Maturation (Week 3 - Years): Continuous tissue remodelling leads to the formation of scars and the strengthening and thinning of the skin over time. The blood vessels mature and regress.

Factors affecting wound healing 

Wound healing is a delicate and precise process. Therefore, successful wound healing requires that the abovementioned stages take place without interruption or prolongation. Otherwise, delays and complications may occur.

Factors that affect the wound healing process can be divided into two domains:⁶

1. Local factors affecting the wound itself include:
   • Oxygen and blood supply
   • Presence of infection
   • Presence of foreign bodies
   • Repeated trauma to the wound
   • Amount of drainage

2. Systemic factors that affect the whole body include:
   • Age and gender
   • Sex hormones
   • Stress
   • Diseases (diabetes, keloids, fibrosis, hereditary healing disorders, jaundice, uraemia)
   • Obesity
   • Medications (glucocorticoid steroids, non-steroidal anti-inflammatory drugs, and chemotherapeutic drugs)
   • Alcoholism and smoking
   • Immunocompromised conditions (AIDS, cancer, radiation therapy)
   • Nutrition

Treatment and care

Initial steps for managing open wounds

In a healthcare setting, the specific steps required to manage open wounds will be different, depending on the type and presentation of the wound and the patient's background and circumstances. For example, some wounds need cleaning and bandaging, while others require stitching. However, wound care should involve a logical sequence of actions based on international standards for effective treatment. These actions are:⁷

1. Comprehensive assessment and diagnosis: Comprehensive assessment of psychological and biological status, social needs, risk factors for delayed wound healing, and diagnosis of wound type.
2. Wound examination and evaluation: Examination of the wound for its location, size, depth, appearance, signs of infection, tissue damage, and other relevant factors.
3. Goal setting: Collaborate with patients in setting recovery or maintenance goals, creating a plan of care, and agreeing on methods and expected outcomes.
4. Addressing underlying issues: Action is taken to resolve any underlying health problems that may interfere with wound healing.
5. Standard wound care: Follow established procedures such as TIME (tissue, infection, moisture, and edge) for proper wound management.
6. Continuous monitoring: Ongoing observation of the progress of the wound healing process, with measurements of size, depth, appearance, signs of infection, tissue damage, and other relevant factors.
7. Modification of treatment: If necessary, the treatment plan is modified, and the specialist(s) may be consulted.

Education and support must be provided throughout to prevent recurrence and documented to obtain an accurate history.

Home care tips for minor open wounds

Small cuts and abrasions, despite being open wounds, can be treated at home. With less damage, the treatment steps are much simpler and are as follows:

1. Stop the bleeding
   • Apply pressure using a sterile bandage or cloth
   • If possible, reduce blood flow by raising the limb above the level of your heart

2. Clean and disinfect the wound
   • Wash your hands first. Wear gloves if available and clean the wound itself as well as the skin around the wound with water or sterile wipes
   • The antiseptic solution should not be applied directly to an open wound as this may lead to tissue damage

3. Apply sterile Bandage
   • Dry the wound using a clean cloth or gauze before applying the sterile bandage or plaster

4. Wound healing
   • Avoid risk factors that delay wound healing as much as possible
   • If blood seeps through the bandage, leave it in place, add another bandage, and continue to apply pressure on the wound
   • Change the bandage as often as necessary

Complications and risks

The wound healing process is a highly coordinated and complex process; thus, several physiological events and environmental influences can disrupt and ultimately divert the healing cascade, resulting in failure to progress through the normal stages of healing. This can leave the wound in a persistent state of inflammation.⁶ When an acute wound remains unhealed for longer than six weeks, it is known as a chronic wound.⁸ 

The risk factors mentioned in the section above can delay wound healing. For example, blocking blood flow can prevent the attraction of inflammatory and immune cells during the haemostasis stage (blood clotting phase). The more risk factors a patient has, the more likely it is that the wound will not heal.⁷ Therefore, reducing risk factors and eliminating local and systemic factors that contribute to delayed healing where possible will increase the chances and rate of wound healing.

Infection

Almost all wounds will grow a range of different microorganisms, but only some wounds are considered “infected” wounds, which contain bacterial populations that grow more rapidly and are more likely to lead to a significant and sustained level of infection.⁹ However, any wound is at risk of infection.⁹ Therefore, infection prevention is of paramount importance because with infection, treatment becomes more expensive and complex, healing is delayed, and the risk of other complications increases.⁷

Inflammation is an essential part of the healing process because it supplies the wound site with the cells necessary for decontamination by microbes such as infectious bacteria. However, when decontamination is not effective, inflammation can persist as microbes continue to contaminate the site. This prolongs the symptoms associated with inflammation, such as redness, swelling, pain, and odour.⁶  

A particularly risky situation can arise when complex bacterial communities gather in a protective layer known as a biofilm. This makes the bacterial infection more resistant to the body's usual immune response as well as to treatment with conventional antibiotics.⁶

The risk of infection increases in the following cases:

• The presence of contamination with dirt or body fluids
• The edge of the wound is rough
• The wound is longer than 5 cm
• The wound was caused by an animal or human bite

Signs of infection:

• Redness, swelling, and pain in the wound area
• The appearance of pus in or around the wound
• Fever of 38°C or higher
• Swollen glands under the chin, neck, armpits, or groin

Treatment includes a prescription short-course antibiotic.

When to seek medical attention

Sometimes it is not clear when to seek medical advice if there is an open wound. However, remaining cautious is the best option. If any of these signs appear, go to your nearest urgent treatment centre:

• The wound does not stop bleeding
• The wound is too large or too deep
• The bleeding is from an artery (bright red blood comes out in spurts with each heartbeat)
• There is a significant and persistent loss of sensation near the wound
• Moving body parts is very difficult
• Severe cut on the face
• The wound contains or may contain an object embedded in it
• The wound is very painful and cannot be cleaned
• The wound is near a major blood vessel 
• The wound is red and swollen, has pus, or has an odour
• The wound was caused by an animal or human bite

Summary

• The skin, which consists of the epidermis, dermis, and hypodermis, acts as a vital protective layer
• Open wounds breach the skin's protective layer and vary by the extent and tissue damage
• Effective wound treatment includes comprehensive assessment, goal setting, addressing health issues, standardised care, ongoing monitoring, adjustments as needed, and thorough documentation
• Early medical care is crucial for open wounds that show specific signs such as severe bleeding, deep or large wounds, embedded objects, intense pain, or signs of infection, ensuring minimised complications and faster healing