6.3 Infection Control, Contact Precautions, & Environmental Hygiene

Infection Control, Contact Precautions, & Environmental Hygiene

Infection control is a paramount responsibility in wound management. Patients with chronic wounds exhibit broken cutaneous barriers, compromised local tissue immunity, and frequent exposure to healthcare environments, rendering them highly susceptible to colonization and infection by opportunistic pathogens and multidrug-resistant organisms (MDROs). Implementing rigorous infection control practices—including hand hygiene, Transmission-Based Contact Precautions, correct Personal Protective Equipment (PPE) sequencing, environmental surface disinfection, and clean-to-dirty procedural workflows—is essential to eliminate healthcare-associated infections (HAIs).

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Epidemiological Transmission Routes & MDRO Threats

Pathogens enter chronic wounds through three main transmission modes:

1. Direct Contact Transmission: Direct physical transfer of microorganisms between a healthcare provider's contaminated hands or skin and the patient's wound bed.
2. Indirect Contact Transmission: Contact with contaminated inanimate objects (fomites), such as reusable Doppler probes, wound measuring guides, surgical scissors, dressing carts, or examination tables.
3. Droplet / Aerosol Transmission: Microscopic droplet generation during high-pressure wound irrigation ($>15\text{ psi}$), sharp debridement, or active bioburden aerosolization.

Major Multidrug-Resistant Organisms (MDROs) in Wound Care

• MRSA (Methicillin-Resistant Staphylococcus aureus): Resistant to beta-lactam antibiotics; highly transmissible via direct hand contact.
• VRE (Vancomycin-Resistant Enterococcus): Persistent environmental survivor on surfaces for weeks.
• MDR Pseudomonas aeruginosa & Acinetobacter baumannii: Gram-negative opportunistic bacilli capable of biofilm formation on necrotic wound tissue and moist equipment surfaces.
• CRE (Carbapenem-Resistant Enterobacteriaceae): High-mortality pathogens requiring strict contact isolation.
• Clostridioides difficile (C. diff): Spore-forming anaerobic bacillus causing severe diarrheal disease; spores resist standard alcohol sanitizers.

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Hand Hygiene Protocols & Clinical Mandates

Hand hygiene represents the single most effective intervention to prevent healthcare-associated pathogen transmission.

Alcohol-Based Hand Rub (ABHR)

• Formulation: Solutions containing 60% to 95% ethyl or isopropyl alcohol.
• Indication: Preferred standard for all routine clinical encounters when hands are not visibly soiled.
• Technique: Apply product to palm, rub all hand surfaces, fingers, thumbs, and wrists vigorously for 20 to 30 seconds until completely dry.

Soap & Water Washing

• Indications (Mandatory):
  1. When hands are visibly soiled with blood, pus, wound exudate, or fecal matter.
  2. After caring for patients with confirmed or suspected Clostridioides difficile or Norovirus (spores resist alcohol destruction).
  3. Before eating and after using restroom facilities.
• Technique: Wet hands with warm water, apply antimicrobial or non-antimicrobial soap, rub all surfaces vigorously creating mechanical friction for at least 20 seconds, rinse under running water, dry thoroughly with disposable paper towels, and use towel to turn off faucet handles.

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Standard versus Transmission-Based Contact Precautions

Center for Disease Control and Prevention (CDC) guidelines categorize isolation precautions into two tiers:

Tier 1: Standard Precautions

Applied to all patient encounters regardless of suspected or confirmed infection status. Includes hand hygiene, clean non-sterile gloves when contacting blood, body fluids, non-intact skin, or mucous membranes, and gown/face protection if splash or spray is anticipated.

Tier 2: Contact Precautions

Mandatory for patients known or suspected to be infected or colonized with epidemiologically important pathogens (MDROs such as MRSA, VRE, CRE, MDR Pseudomonas, C. difficile, or uncontained wound drainage).

• Room Placement: Single-patient private room. If unavailable, cohort with a patient infected by the exact same organism.
• PPE Mandate: Don clean gown and gloves upon room entry, regardless of whether direct patient contact is planned.
• Dedicated Equipment: Dedicate non-critical patient-care equipment (stethoscope, blood pressure cuff, pulse oximeter, Doppler probe) exclusively to the isolation patient. Equipment must remain in the room and undergo HLD/disinfection upon patient discharge.

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Personal Protective Equipment (PPE) Donning & Doffing Sequences

Adhering to strict PPE donning (putting on) and doffing (removing) sequences prevents accidental self-contamination of healthcare worker skin and clothing.

DONNING SEQUENCE (Before Entry):
1. Gown -> 2. Mask/Respirator -> 3. Goggles/Face Shield -> 4. Gloves (over cuffs)

DOFFING SEQUENCE (At Doorway / Exit):
1. Gloves -> 2. Goggles/Face Shield -> 3. Gown -> 4. Mask/Respirator -> 5. Hand Hygiene

Detailed Doffing Steps

1. Gloves: Remove gloves first as they are most heavily contaminated. Peel off left glove inside-out into right hand, slide ungloved finger under right wrist cuff, peel right glove off inside-out over left glove, discard in trash.
2. Goggles / Face Shield: Touch only ear pieces or headband from back of head; lift forward and away from face.
3. Gown: Unfasten neck and waist ties. Pull gown away from neck and shoulders touching only inside of gown. Turn gown inside-out, roll into a tight bundle, and discard.
4. Mask / Respirator: Remove outside room after closing door. Touch only bottom ties/elastics, then top ties/elastics, lift off face without touching front filter surface.
5. Hand Hygiene: Perform immediate hand hygiene with ABHR or soap and water.

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Environmental Hygiene & Equipment Decontamination

The Spaulding Classification System categorizes medical equipment based on infection risk to determine decontamination levels:

1. Critical Items: Devices entering sterile vascular systems or sterile tissue (e.g., surgical scalpels, debridement curettes). Must undergo full sterilization (autoclave steam or ethylene oxide).
2. Semi-Critical Items: Devices contacting non-intact skin or intact mucous membranes (e.g., reusable Doppler probes contacting open wound periwound skin). Require High-Level Disinfection (HLD) (glutaraldehyde, hydrogen peroxide plasma) or disposable single-use status.
3. Non-Critical Items: Devices contacting intact skin only (e.g., blood pressure cuffs, examination tables, dressing carts). Require Low- to Intermediate-Level Disinfection with EPA-registered hospital disinfectants (quaternary ammonium or sodium hypochlorite bleach wipes).

Wound Care Cart & Field Protocols

• Never bring mobile dressing carts directly into Contact Precaution isolation rooms. Leave carts in hallway; bring only necessary single-use supplies inside in a clean plastic tray.
• Discard all unused single-use dressing supplies brought into an isolation room upon patient exit; never return exposed supplies to general inventory carts.
• Clean and disinfect examination tables and Doppler probes between every patient encounter using EPA-registered disinfectant wipes, maintaining required wet contact times (typically 1 to 4 minutes).

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Procedural Workflows for Dressing Changes

Dressing changes must follow a strict Clean-to-Dirty progression:

1. Preparation: Clean bedside table surface, apply moisture-resistant blue pad, arrange sterile or clean supplies in logical order of use.
2. Old Dressing Removal (Dirty Phase): Don clean non-sterile gloves. Carefully peel off old dressing. Assess exudate and odor. Wrap old dressing in dirty glove, discard into biohazard receptacle.
3. Hand Hygiene Transition: Remove dirty gloves, perform hand hygiene immediately.
4. Wound Cleansing & Treatment (Clean Phase): Don fresh clean or sterile gloves. Cleanse wound bed with sterile saline or non-cytotoxic wound cleanser. Perform wound measurement using disposable paper tape. Apply topical agents and clean secondary dressings.
5. Cleanup: Secure dressing, remove gloves, perform final hand hygiene, document procedure.