What are the proper methods for sterilisation and disinfection in a healthcare setting to prevent hospital-acquired infections?

Sterilization and Disinfection in Healthcare Settings

Classification-Based Approach to Instrument Processing

All critical instruments that penetrate sterile tissue or the vascular system must be heat-sterilized before each use, while semicritical items contacting mucous membranes require high-level disinfection, and noncritical items touching intact skin need intermediate-level disinfection. 1

Critical Instruments (Penetrate Sterile Tissue)

• Sterilize using steam autoclaving at 121-132°C, ethylene oxide gas, low-temperature gas plasma, or immersion in liquid chemical sterilants 1
• Examples include surgical instruments, needles, urinary catheters 1
• Never sterilize implantable devices unwrapped 1
• Do not store critical instruments unwrapped 1

Semicritical Instruments (Contact Mucous Membranes)

• Require high-level disinfection using wet pasteurization at 70°C for 30 minutes, 2% glutaraldehyde, 0.55% ortho-phthalaldehyde, or 7.5% hydrogen peroxide 1
• Examples include laryngoscopes, endoscopes 1
• Heat-sterilize semicritical items when possible as preferred method 1

Noncritical Instruments (Touch Intact Skin Only)

• Clean and disinfect with EPA-registered hospital disinfectant with low-level (HIV/HBV claims) to intermediate-level (tuberculocidal claim) activity 1
• Use intermediate-level disinfectant if visibly contaminated with blood 1
• Examples include stethoscopes, blood pressure cuffs 1

Mandatory Pre-Processing Steps

Thoroughly clean all visible blood and organic contamination from instruments with soap and water before any sterilization or disinfection procedure—this is non-negotiable 1

• Use automated cleaning equipment (ultrasonic cleaner or washer-disinfector) to improve effectiveness and decrease worker blood exposure 1
• Wear puncture- and chemical-resistant heavy-duty utility gloves during cleaning 1
• Wear mask, protective eyewear, and gown when splashing anticipated 1

Sterilization Monitoring Requirements

Use mechanical, chemical, and biological monitors according to manufacturer's instructions for every sterilization cycle 1

• Place internal chemical indicator inside each package; if not visible externally, also use external indicator 1
• Monitor each load with mechanical indicators (time, temperature, pressure) 1
• Allow packages to dry completely in sterilizer before handling to avoid contamination 1

Instrument Processing Area Organization

Physically or spatially divide the processing area into four distinct zones: (1) receiving/cleaning/decontamination, (2) preparation/packaging, (3) sterilization, and (4) storage 1

• Never store clean instruments where contaminated instruments are held or cleaned 1
• Minimize handling of loose contaminated instruments; transport in covered containers 1

Environmental Surface Disinfection

Use EPA-registered hospital disinfectants following manufacturer's instructions; never use liquid chemical sterilants/high-level disinfectants for environmental surfaces 1

Clinical Contact Surfaces

• Use surface barriers on difficult-to-clean surfaces (dental chair switches) and change between patients 1
• Clean and disinfect non-barrier-protected surfaces with EPA-registered hospital disinfectant after each patient 1

Blood/Body Fluid Spills

• Don PPE (puncture-resistant gloves, protective clothing, eyewear, mask) before approaching any spill 2
• Remove visible organic material first, then decontaminate with EPA-registered hospital disinfectant with low-level activity for small spills on non-porous surfaces 2
• Use intermediate-level disinfectant (tuberculocidal claim) for large spills, porous surfaces, or any spill with visible blood 1, 2

Storage and Packaging

Store sterile items and dental supplies in covered or closed cabinets 1, 3

• Label packages with sterilization date and sterilizer identification to facilitate retrieval if sterilization failure occurs 1
• Examine wrapped packages before opening to ensure barrier wrap not compromised during storage 1
• Reclean, repack, and resterilize any compromised package 1

Critical Pitfalls to Avoid

• Never reuse single-use disposable instruments—use once and dispose correctly 1
• Do not use liquid chemical sterilants as holding solutions or for environmental disinfection 1
• Preferentially use sterile water for rinsing reusable semicritical equipment after chemical disinfection; if unavailable, use filtered water or tap water followed by isopropyl alcohol rinse and forced-air drying 1
• Unwrapped sterilized instruments must be used immediately or aseptically transferred to sterile container 1

Personnel Training Requirements

Train all healthcare workers handling instruments in proper cleaning, disinfection, and sterilization procedures according to their level of responsibility 1

• Inform staff of OSHA guidelines for chemical agent exposure 1
• Train personnel handling medical waste in appropriate disposal methods and health/safety hazards 2