Before any form of tissue injury whether acute or chronic can be successfully treated, wound care providers must be able to accurately diagnose, and categorize the type of wound they are dealing with. In this article, we will discuss the diagnostic and treatment techniques involved in handling complex wounds. 

What Is a Complex Wound?

A complex wound is an acute or chronic injury to human skin tissues that does not respond to conventional treatments in a timely manner. Complex wounds often cause extensive damage to both the epidermal, and dermal layers of the skin as well as the underlying subcutaneous tissues. 

The following characteristics are common to complex wounds:

• A slow healing time, usually greater than three months
• The presence of a superimposed infection
• Co-existence with chronic medical disorders
• Evidence of compromised blood flow to wound area with tissue necrosis

While not every complex wound is chronic in duration, the terms are often used interchangeably. These forms of tissue damage often result in serious deformity, and disability if left unchecked. In addition to the clinical difficulties involved in providing care for patients with complex wounds, these injuries contribute significantly to the overall financial burden on the healthcare industry. 

Types of Complex Wounds

There are different categories of complex wounds based on their duration and etiology. Complex wounds include the following types:

• Pressure wounds due to prolonged immobilization, e.g., limb fractures, surgery, etc
• Venous and arterial wounds from peripheral blood vessel diseases
• Moisture-associated wounds
• Diabetic foot wounds from poorly controlled diabetes mellitus
• Iatrogenic/complicated surgical wounds like fistulas
• Wounds with mixed etiology

Categorizing complex wounds is crucial to their treatment as the management plans will differ according to the causative factors.

Risk Factors

The major factors that predispose patients to developing complex wounds are:

• Extensive tissue injury/loss
• Wound infection
• Prolonged wound duration
• Presence of comorbidities and other wound-related conditions

Extensive Tissue Injury/Loss

Generally, the more extensive the initial damage sustained by a patient, the more likely it is for the wound to become a chronic one. Loss of large areas of skin and subcutaneous tissue will close more slowly, requiring more time to cycle through the phases of wound healing. 

Wound Infection

Bacterial and fungal colonization of wound sites will result in the breakdown of healing tissues, with delayed granulation, and wound closure. In many cases, an abscess will form within wound sites creating a barrier to tissue closure and providing a medium for further colonization by pathogenic microorganisms. 

Prolonged Wound Duration

Wounds lasting greater than three months in duration are typically considered to be complex wounds. This is due to a higher chance of pathological transformation from physical trauma and infectious processes.

Presence of Comorbidities/Other Wound Related Conditions

Many chronic medical conditions as well as their treatment modalities, predispose affected patients to complex wounds. Diabetes mellitus, peripheral vascular disease, immunosuppressive states, medications, and radiotherapy all increase the risk of developing complex wounds via the following mechanisms:

• Constriction or total blockage of oxygen-rich blood to wounded tissues
• Negative metabolic alterations resulting in tissue death
• Physical changes in moisture, pressure, and temperature at the wound site

Also, the presence of other wound-related conditions, e.g., Osteomyelitis, peri-wound dermatitis, hematomas (bleeding within tissues), and edema (fluid retention within tissues) will negatively affect wound repair resulting in complex wounds.

Clinical Features

The clinical features present in a patient with a complex wound will vary according to the etiology however the most common signs and symptoms include:

• Fever (typically high)
• Erythema
• Pain around the wound site
• Tissue ulceration
• Malodorous discharge from the wound site
• Tissue loss/amputation

In some cases of complex wounds, the clinical picture presented by the patient will be enough to arrive at a definitive diagnosis. However, for the majority of patients with complex wounds, further laboratory, and radiological investigations will be required to gain better understanding of how to treat the wounds.

Diagnostic Process for Complex Wounds

The diagnosis of a complex wound requires a combination of the following processes:

• Documenting a comprehensive patient history
• Clinical examination of wound/periwound lesions
• Laboratory investigations using blood samples, wound swabs, and biopsy samples
• Radiological diagnostic techniques (CT, MRI, wound ultrasonography, etc)

Coupled with an extensive knowledge base, wound care experts may use the aforementioned strategies to accurately diagnose most complex wounds.

General Treatment Principles

While the strategies used in treating complex wounds will differ between the various categories, general principles guide their implementation. Regardless of etiology, wound care professionals should include the following steps in managing complex wounds:

• Pain management using appropriate analgesia and adjunctive therapies
• Local wound care including wound cleansing, debridement, and dressing
• Infection control with antibiotic, antifungal preparations
• Treatment of comorbid medical states using medications or surgery as appropriate
• Dietary modifications/nutritional support
• Psychological support, e.g., grief counseling, and management of treatment expectations
• Physical or occupational rehabilitation to aid post-recovery integration into normal daily activities

Prevention Strategies

The prevention strategies for complex wounds require wound care experts to educate patients on the risk factors for developing them. Optimization of the health of patients living with chronic medical conditions, lifestyle (e.g., smoking cessation and reduction in alcohol consumption), and dietary modifications are all crucial to preventing the onset of complex wounds in individuals.