Can a traditional Negative Pressure Wound Therapy (NPWT) be placed on an infected wound?

Can Traditional NPWT Be Placed on an Infected Wound?

Yes, traditional NPWT can be safely placed on infected wounds, but only after adequate surgical debridement has been performed to remove all necrotic tissue and control the source of infection. 1

Critical Prerequisite: Complete Debridement First

The most important principle is that NPWT should never be applied to infected wounds until complete surgical removal of necrosis has been accomplished. 1 The 2018 WSES/SIS-E consensus guidelines explicitly state that NPWT should be considered "for wound care after complete removal of necrosis in necrotizing infections." 1

Algorithmic Approach:

1. Initial surgical debridement: Perform radical debridement of all infected and necrotic tissue, continuing into healthy-looking tissue 1
2. Obtain cultures: Take tissue and fluid cultures during initial debridement to guide antibiotic therapy 1
3. Apply NPWT: Once necrosis is removed, NPWT can be safely initiated 1
4. Combine with antibiotics: Use NPWT synergistically with appropriate antibiotic therapy 2

Physiologic Benefits in Infected Wounds

After adequate debridement, NPWT provides multiple therapeutic benefits for infected wounds:

• Increases local blood flow and tissue perfusion, which enhances antibiotic delivery to the wound bed 1, 2
• Removes wound exudates and inflammatory fluids, reducing bacterial load and edema 1, 2
• Promotes granulation tissue formation by removing bacterial contamination and creating a stable wound environment 1
• Inhibits infection spread by managing wound drainage and preventing fluid accumulation 1

Evidence Supporting Use in Infected Wounds

Necrotizing Soft Tissue Infections

The 2018 WSES/SIS-E guidelines provide a conditional recommendation (1C) to consider NPWT for wound care in necrotizing infections after complete debridement. 1 While the evidence quality is not strong enough to prove superiority over conventional dressings, NPWT is widely accepted as safe and effective in this context. 1

Acute Contaminated Wounds

A large retrospective study of 86 patients with 97 Class IV contaminated wounds (91% meeting sepsis criteria) demonstrated that NPWT is safe and effective, with 92% durability of wound closure and only 7% mortality (none related to NPWT). 3 This represents the largest known cohort supporting NPWT use in acute, contaminated wounds. 3

Complex Infected Orthopedic Wounds

Recent evidence shows successful wound closure in 65% of complex infected orthopedic wounds treated with NPWT, with average treatment duration of 5.2 days. 4 A separate study of 43 patients with infected lower limb wounds treated with NPWT after debridement showed complete healing in an average of 5 weeks with no complications. 2

Important Caveats and Contraindications

When NOT to Use NPWT:

• Before adequate debridement: Never apply NPWT to wounds with residual necrotic tissue or uncontrolled infection 1
• Non-surgical diabetic foot ulcers: The 2024 IWGDF guidelines provide a strong recommendation against using NPWT for non-surgically related diabetic foot ulcers due to lack of evidence 1
• Wounds with exposed vessels or organs: Use extreme caution in anatomically vulnerable areas 5

Common Pitfalls to Avoid:

• Inadequate initial debridement: The most critical error is applying NPWT before complete source control 1
• Expecting NPWT to replace debridement: NPWT does not eliminate the need for repeated surgical debridements when necessary 1
• Assuming bacterial reduction is the primary mechanism: Evidence suggests that reduction of bacterial bioburden is not a major mode of action of NPWT 5
• Intermittent disconnection: NPWT requires continuous application to maintain the therapeutic wound environment; planned disconnections compromise efficacy 6

Practical Considerations

Pressure Settings:

• Standard pressure of 125 mmHg is typically used 5
• Lower pressures (75-80 mmHg) may be appropriate for vulnerable anatomic areas 6

Dressing Changes:

• Average of 5 dressing changes required for optimal granulation 2
• Changes typically performed every 2-3 days 6
• Mean time to wound closure ranges from 10-17 days depending on wound complexity 3

Monitoring for Infection Control:

• Five studies in diabetic foot wounds showed no difference in new infection rates between NPWT and control groups 1
• NPWT with instillation (NPWTi) may provide additional benefits for complex infected wounds through cyclic cleansing mechanisms 4