Infection Prevention and Control
Colonization, critical colonization, infection
All open wounds carry bacteria. Critical colonization is a localized, covert problem; spreading infection is overt and may involve deeper structures. Biofilm, an organized microbial community adherent to the wound bed, resists antibiotics and antiseptics and should be suspected when a wound stalls despite otherwise appropriate care. Warning signs include increasing size, new breakdown, warmth, induration, purulence, friable red granulation, pocketing at the base, foul odor, and probe-to-bone.
Screening frameworks
NERDS (Nonhealing, Exudate, Red friable tissue, Debris, Smell) suggests superficial critical colonization that may respond to topical antimicrobial therapy. STONEES (Size increase, Temperature elevation, Os probe to bone, New breakdown, Erythema or edema, Exudate, Smell) suggests deeper or spreading infection and warrants escalation for systemic evaluation.
Prevention practice
Hand hygiene is the single most important measure. Use standard precautions, add contact precautions for multidrug-resistant organisms, and choose clean versus sterile technique based on setting and wound severity. Cleanse with saline or potable tap water at adequate pressure. Avoid routine antiseptics because of cytotoxicity to fibroblasts and keratinocytes; reserve them for short courses when critical colonization is present.
Cultures and stewardship
The gold standard is tissue biopsy. A Levine swab, rotated over about one square centimeter of cleansed viable wound bed, is the accepted swab method; do not culture pus or superficial drainage. Do not culture or prescribe antibiotics without clinical signs of infection, since treating colonization drives resistance.
Rule of thumb
Redness plus warmth plus enlarging size means escalate and evaluate, not merely switch dressings.