Wound infections

The following information about wound infections is taken from 3D Regional HealthPathways, accessed June 2020:

Assessment

1. Assess the wound using the General Wound Care pathway.
2. Diagnose infection clinically, based on signs and symptoms:
     • Localised wound infection
     • Spreading or systemic infection e.g., cellulitis, sepsis, or necrotising fasciitis.
3. Take a wound swab, or collect pus aspirate, only if there are clinical signs of infection and any of the following indications are present:
     • Spreading or systemic infection
     • The infection is not responding as expected to antimicrobial therapy
     • The wound is at high risk of resistant or unusual organisms e.g., methicillin-resistant Staphylococcus aureus (MRSA), post-surgical wounds, bite wounds, wounds sustained in water, contaminated wounds. Appropriate clinical details are very important, as they alert the laboratory to specifically look for unusual organisms.

Management

1. If there is suspected necrotising fasciitis or sepsis, arrange immediate transfer to the Emergency Department and request acute assessment from the appropriate specialty.
2. If there are symptoms or signs of spreading infection, follow the Cellulitis pathway.
   If patient has an underlying prosthesis, seek advice from the appropriate surgical specialty e.g., orthopaedics, before deciding on management.
3. Manage the wound. Good wound care is the most important factor in the management of localised wound infections, most of which do not require systemic antibiotic therapy in the first instance.
     • Draw around the erythema demarcation line. Ask the patient to monitor erythema spreading beyond the line. If antibiotics are being started, warn the patient that redness and swelling can take 24 to 48 hours to stop spreading, but to report any other clinical deterioration in that time e.g., fever, malaise.
     • If the infected wound is a surgical wound:
          ◊ If there is a collection of pus or exudate under suture line, consider removing one or alternate sutures to allow the pus to drain.
          ◊ If unsure about management, seek advice from the appropriate surgical specialty.
     • To control bacteria levels locally, use products for reducing bacterial load.
          ◊ When choosing products, consider allergies, level of exudate or slough, and necrosis.
          ◊ Change dressings frequently to absorb high exudate levels, help reduce the number of bacteria, and allow monitoring for signs of spread or deterioration.
     • Treat empirically with appropriate antibiotics only if indicated for certain wound types e.g., skin grafts or bite wounds, or if clinical signs of infection persist despite a reasonable trial of the above wound care measures.
     • See also individual wound care pathways for specific management of different wound types.
4. Provide regular monitoring:
     • Regularly check for wound progression and extension of erythema. Do not expect complete resolution of erythema at the end of treatment. It will often persist despite adequate treatment, especially if the patient has venous insufficiency or lymphoedema.
     • Consider swabbing or re-swabbing the wound if infection is not responding as expected to antimicrobial therapy.

Learn more

Antibiotics: choices for common infections BPAC, NZ
Microbiological assessment of infected wounds: when to take a swab and how to interpret the results BPAC, NZ
Wound infection in clinical practice: principles of best practice International Wound Infection Institute

References

1. Wound infections 3D Regional HealthPathways, NZ, 2020