Introduction

The first issue encountered when studying chronic wounds is the definition. Many publications lack a clearly defined definition, and those that do present one share a common component: disrupted healing [1-3]. However, there is no consensus on the time frame; some publications use the term “expected timeframe”, while others often use a range of 4-12 weeks [1-8]. For this publication, we define a chronic wound as one that fails to heal within 30 days despite proper treatment or is not expected to heal within 4-6 weeks.

Studies report that chronic wounds are a global problem, affecting around 2-6% of the world population [1], although the percentage may vary across different populations. Additionally, it is necessary to keep in mind the heterogeneous nature of the problem, as chronic wounds vary in terminology, underlying disease, and regional distribution [2]. Nevertheless, chronic wounds are reported to be most common in older patients, as well as in patients with diabetes or chronic venous insufficiency [1-3].

Given the large population affected and the prolonged treatment period for chronic wounds, the high cost of treatment for healthcare institutions is also a major problem [9-11]. Another important aspect is that the patient’s quality of life is negatively affected. They often suffer from loss of productivity, psychological distress, and reduced life expectancy [5].

Because of the wide spectrum of chronic wounds, the literature lacks treatment standardization. The aim of this article is to present a practical treatment algorithm to address this problem.

Pathophysiology of chronic wounds

Normal wound healing consists of 4 phases: hemostasis, inflammation, proliferation, and remodeling. Chronic wounds are associated with interruption of this process. In their pathophysiology, the inflammatory phase is often prolonged. In that state, protease activity is excessive, matrix formation is impaired, growth factor signaling is reduced, and epithelial migration is reduced [2, 8].

Local and systemic factors then reinforce one another. Poor arterial inflow limits the supply of oxygen and nutrients. Venous hypertension and edema impair tissue mechanics and oxygen diffusion. Neuropathy removes protective pain sensation. In addition, hyperglycemia, renal disease, malnutrition, smoking, immunosuppression, and medication may also negatively influence wound healing [1, 2].

Another concern worth addressing is biofilm, especially in wounds that appear clean enough to dress yet still fail to heal. Bacteria within biofilms are embedded in an extracellular matrix and may be less responsive to host defenses and antimicrobial treatment than planktonic bacteria [2, 8, 12]. In clinical practice, biofilm should be suspected when necrosis recurs rapidly after wound debridement, when the wound condition repeatedly worsens, or when healing progresses slowly despite seemingly adequate treatment. In such cases, it is usually recommended to perform repeat debridement, remove necrotic tissue from the wound, and prepare the wound bed, rather than simply prolonging systemic antibiotic therapy [1, 10, 12, 13].

Initial patient and wound assessment

The first step in treating a patient with a chronic wound is to assess the patient before focusing on the wound surface. Document diabetes, vascular disease, malnutrition, renal failure, immunosuppression, smoking, pain, mobility, and prior treatment and medication history. The next step is to focus on the wound itself. Describe it in a way that allows changes to be monitored over time: location, duration, dimensions, depth, tissue type, exudate, odor, pain, wound edge, surrounding skin, and signs of infection [1, 2, 11, 14, 15].

For lower-limb wounds, vascular assessment should be performed early. Pulse examination is useful, but objective testing is often needed. The ankle-brachial index, Doppler waveform assessment, transcutaneous oxygen measurement, and vascular imaging may all play a role, depending on the patient and local practice [1, 2]. If arterial insufficiency is clinically significant, referral for vascular assessment is part of wound treatment.

The underlying cause should be treated concurrently. Venous ulcers require compression when arterial inflow permits. Diabetic foot ulcers require offloading, and for plantar neuropathic ulcers, this is often the most important intervention [16]. Pressure injuries require pressure redistribution and a realistic repositioning plan. Edema, malnutrition, pain, and poor glycemic control require active management. Without addressing the root cause, local wound care will not yield significant benefits [1, 9, 14, 15].

The TIME strategy

The TIME strategy is a widely known approach to wound care. It is not a complete wound diagnosis but a practical bedside framework. It consists of 4 parts: tissue management and debridement; inflammation and infection control; moisture management; and edge management. It allows for proper preparation of the wound for healing [1, 9]. Recent studies indicate the need to expand the concept to include a broader perspective on the healing of chronic wounds. This has led to the inclusion in the strategy of the role of factors supporting regeneration and repair processes, such as proper nutrition, as well as the role of social factors related to the patient and family. Consequently, the letters R (regeneration and repair) and S (social) have been added to the acronym, and therefore, the use of the acronym TIMERS is recommended [1]. The TIMERS strategy is shown in Figure 1.

Biofilm, infection, and microbiology

One of the most important factors influencing the healing of a chronic wound is the presence of a biofilm. If a biofilm is present, standard approaches, such as antibiotic therapy, may be ineffective because the cellular matrix serves as a protective layer within the biofilm [17]. Biofilms are structured communities of microorganisms suspended in an extracellular polymeric matrix [18]. The matrix is composed of polysaccharides, proteins, and nucleic acids. It plays a crucial role in protecting microorganisms from adverse environmental factors, such as the host’s immune system or antibiotics. To disrupt a biofilm, it is necessary to use appropriate techniques, primarily debridement and topical antibiotic therapy, though techniques such as laser therapy and ultrasound are also being explored [19].

Chronic wounds often harbor bacteria, but colonization does not equal infection. This distinction is crucial for antimicrobial management. The clinician should differentiate as clearly as possible among contamination, colonization, local infection, spreading infection, and systemic infection. Antibiotics are justified when there is a clinical infection.

Microbiological testing should be used when it can change management. Conventional culture methods remain widely used, but they may not capture the complexity of mixed bacterial communities, anaerobic bacteria, spatial variability, and biofilm behavior. Recent studies have examined molecular diagnostics, fluorescence imaging, biosensors, and other methods, but there is no unambiguous evidence. Therefore, it is difficult to translate them into routine care [1, 8, 10].

In practice, sample collection is most useful when infection is suspected, the wound condition has deteriorated, treatment has failed, or when targeted systemic therapy is being considered. In the case of a wound whose healing has stalled and where biofilms are suspected, the first step is often mechanical and local intervention: debridement, removal of necrotic tissue, disruption of the biofilm, protection of the surrounding skin, and assessment of the response [1, 8, 10].

Dressing selection

The dressing choice should follow the wound, not the other way around. The dressing should maintain a moist healing environment, manage exudate, protect peri-wound skin, reduce pain during dressing changes, and allow reassessment. An example of a dressing selection chart is shown in Figure 2 [1, 9]. Antimicrobial and bioactive dressings can be useful, but they should be used for a clear reason and discontinued or changed if the expected response is not seen.

Negative pressure wound therapy and advanced options

Negative pressure wound therapy (NPWT), also referred to as vacuum-assisted closure (VAC) therapy, is a versatile wound care system that promotes healing by applying subatmospheric pressure through specially designed wound dressings. It reduces inflammatory exudate and promotes granulation tissue formation [20].

Studies report that NPWT reduces edema and seroma formation, promotes granulation tissue formation, and is believed to lower the risk of surgical wound dehiscence in high-risk sites [21].

NPWT is an effective tool for deep wounds, wounds with heavy exudate, postoperative wounds healing by secondary intention, wounds being prepared for grafting, or wounds where exudate control and mechanical stabilization are important. A negative-pressure system may also be connected to saline or antibiotic instillation to increase delivery of these therapies to the wound bed [1, 3, 21].

It should be used as an adjunct to treatment; therefore, debridement, vascular assessment, infection control, or offloading should not be omitted. Before initiating NPWT, the wound bed should be prepared so that no structures are at risk of injury from negative pressure. The pressure should be set appropriately for the planned therapy site. Newer approaches, including the combination of NPWT with topical oxygen therapy (TOT), have shown promising results and may be helpful in selected cases [3, 21].

Other advanced treatments, including hyperbaric oxygen in selected indications, topical oxygen therapy, collagen matrices, skin substitutes, larval therapy, and growth-factor approaches, may have a place after the wound bed and underlying cause have been addressed. In most cases, escalation should be triggered by a poor healing trajectory rather than by the availability of a product [1, 3, 6].

Surgical and conservative treatment

In chronic wound care, surgery extends beyond final closure. It includes sharp or operative debridement, drainage, excision of nonviable tissue, management of osteomyelitis, revascularization, correction of venous disease, offloading procedures, grafting, flaps, and, when limb salvage is no longer safe or realistic, amputation [1, 7].

Debridement is a crucial part of wound care because it removes devitalized tissue and may promote the formation of healthy granulation tissue and wound healing. Additionally, it helps reduce biofilm and minimize the risk of infection, thereby supporting the healing process [22]. There are many debridement methods, including autolysis, enzymatic, mechanical, biological, and sharp/surgical debridement. Selecting the best method is challenging because adequate pain control, the patient’s underlying condition, comorbidities, social factors, and wound-healing ability classification must be considered. A three-group classification of wounds as healable, maintenance, or non-healable is especially useful. The first is healable, defined as a wound with an adequate blood supply and an underlying cause that is addressed; in this case, active surgical debridement may be considered. The second is maintenance, defined as a wound with impaired healing due to patient-related or other health factors; conservative debridement may be applied. The third category comprises non-healable wounds, in which insufficient blood supply cannot be reversed, as in advanced chronic disease or the dying process [22, 23].

Early surgical or specialist review should be considered when there is extensive necrosis, deep infection, exposed bone or tendon, suspected malignancy, failure of conservative treatment, or a clean wound that is too large to close by epithelialization alone. In these situations, waiting for another series of dressings may delay the care the patient actually needs [1, 7].

Proposed clinical algorithm

The presented algorithm is intended to help healthcare workers in their daily practice with chronic wound management (Fig. 3).

Monitoring and risk prediction

The follow-up should be objective. Wound area, depth, tissue quality, exudate, pain, peri-wound condition, and photographs should be recorded consistently. A wound that does not decrease by roughly 20% to 30% over 4 weeks warrants reassessment [5, 11, 15]. The correct response is not always a more advanced dressing; it may be a new vascular test, better offloading, debridement, infection review, or a revised diagnosis.

Prediction models are likely to become more useful as wound databases improve. Existing work suggests that wound-level features such as size, depth, location, and etiology can be important predictors of healing [5, 11]. However, such tools should support clinical judgment rather than replace it. They also need validation in the population where they will be used.

Discussion

The main problem in chronic wound care is often timing. A treatment can be reasonable, but it may be applied too late, too early, or to the wrong wound. A patient with untreated ischemia will not heal because the dressing is newer. A wound with ongoing pressure will not close because an antimicrobial product is added. A biofilm-dominated wound will not reliably improve with systemic antibiotics alone. This is why the proposed pathway keeps returning to cause, perfusion, pressure, infection, moisture, and progress [1, 2, 9, 12, 15].

Several promising newer approaches have been reported. Honey dressings, topical oxygen, NPWT combinations, advanced diagnostics, biomaterials, and prediction models may improve care for selected patients [3, 6, 10-12]. The difficulty is that chronic wound studies often include diverse wound types, endpoints, and local care protocols. For now, these therapies are best presented as targeted additions to good-to-standard care, not as replacements for it.

The strength of this review is its practical orientation. The limitation is that it is a narrative synthesis rather than a formal guideline or a systematic review. A next step would be prospective validation of an algorithm-based pathway, with outcomes including healing time, recurrence, antimicrobial exposure, cost, hospitalization, and patient-reported quality of life [4, 9, 11].

Table 1 summarizes key publications cited in this article, showing how chronic wounds are defined across the literature and how selected studies support the main elements of the proposed management algorithm, including wound assessment, wound bed preparation, infection and biofilm control, offloading, NPWT, and treatment escalation [1, 2, 4, 8, 9, 12-16, 22, 24].

Conclusions

Chronic wound management works best when it is both structured and flexible. TIME is a useful foundation, but it must be embedded within a broader clinical algorithm that begins with the patient, the wound’s cause, vascular status, pressure or load, systemic barriers, and realistic goals of care. Biofilm-oriented wound hygiene, careful antimicrobial use, dressing selection based on wound needs, timely escalation to NPWT or other advanced therapies, and early surgical or vascular referral are all part of the same pathway. The proposed algorithm requires validation in real-world settings to determine its usefulness and applicability in clinical practice.

Disclosures

This research received no external funding.

Institutional review board statement: Not applicable.

The authors declare no conflict of interest.

References