MDRAO Infection Prevention and Control 2 — Questions and Answers
Question 1: What is the Spaulding Classification system, and how does it determine the level of disinfection or sterilization required for medical devices?
- A system that classifies microorganisms by their resistance to disinfectants
- A three-tier classification (critical, semi-critical, non-critical) that categorizes medical devices by their risk of infection transmission based on intended use (Correct answer)
- A ranking system for cleaning chemical effectiveness
- A grading scale for assessing sterile processing department performance
Correct answer: A three-tier classification (critical, semi-critical, non-critical) that categorizes medical devices by their risk of infection transmission based on intended use
The Spaulding Classification categorizes medical devices into critical, semi-critical, and non-critical based on their intended use and associated infection risk, determining whether sterilization or different levels of disinfection are required.
Developed by Dr. Earle Spaulding in 1968, the Spaulding Classification is the foundational framework for medical device reprocessing. It classifies devices into three categories: Critical items enter sterile tissue or the vascular system (e.g., surgical instruments, implants) and require sterilization. Semi-critical items contact mucous membranes or non-intact skin (e.g., flexible endoscopes, laryngoscope blades) and require at minimum high-level disinfection. Non-critical items contact only intact skin (e.g., blood pressure cuffs, stethoscopes) and require only low-to-intermediate level disinfection. Ontario PIDAC guidelines and CSA Z314 are built upon the Spaulding framework, and all reprocessing decisions must be made with reference to this classification.
Question 2: What is the distinction between sterilization and high-level disinfection (HLD)?
- Sterilization and HLD achieve the same result — both completely eliminate all microorganisms
- Sterilization kills ALL microorganisms including bacterial spores; HLD kills most microorganisms but may not eliminate all bacterial spores (Correct answer)
- HLD is more effective than sterilization for heat-sensitive devices
- Sterilization is used only for non-critical devices while HLD is for critical devices
Correct answer: Sterilization kills ALL microorganisms including bacterial spores; HLD kills most microorganisms but may not eliminate all bacterial spores
Sterilization achieves complete elimination of all viable microorganisms including bacterial spores. High-level disinfection kills most microorganisms including Mycobacterium tuberculosis and viruses, but may not eliminate all bacterial spores.
The critical distinction between sterilization and high-level disinfection (HLD) lies in their spectrum of antimicrobial activity. Sterilization — whether by steam, EO, hydrogen peroxide plasma, or other validated methods — achieves destruction of all forms of microbial life including the most resistant bacterial endospores, achieving a SAL of 10⁻⁶. High-level disinfection (using agents such as glutaraldehyde, ortho-phthalaldehyde (OPA), hydrogen peroxide, or peracetic acid) kills vegetative bacteria, mycobacteria, most fungi, and most viruses, but may not reliably eliminate high concentrations of bacterial spores. This is why critical devices (those entering sterile tissue) require sterilization, while semi-critical devices (contacting mucous membranes) may be processed with HLD per the Spaulding Classification.
Question 3: What does 'standard precautions' mean in the context of the CSSD decontamination area?
- Precautions taken only when staff know a patient has a known infectious disease
- A minimum set of infection prevention practices (including hand hygiene, PPE, safe sharps handling) applied to ALL patients regardless of infection status (Correct answer)
- Special isolation procedures reserved for immunocompromised patients only
- Sterilization procedures applied as a standard to all instrument sets
Correct answer: A minimum set of infection prevention practices (including hand hygiene, PPE, safe sharps handling) applied to ALL patients regardless of infection status
Standard precautions are the minimum level of infection prevention applied to all patients/all instruments regardless of known or suspected infection status — based on the assumption that all blood, body fluids, and instruments are potentially infectious.
Standard precautions (formerly known as 'universal precautions') are the foundation of infection prevention in healthcare settings. They are based on the principle that all blood, body fluids, secretions, excretions (except sweat), non-intact skin, and mucous membranes are potentially infectious, regardless of the patient's known or suspected diagnosis. In the CSSD decontamination area, standard precautions mean that staff must apply full PPE (gloves, gown, face protection) when handling ALL returned instruments — not just those from patients with known infections. This approach protects staff from unrecognized bloodborne pathogens and other infectious agents and forms the minimum baseline for safe instrument handling per Ontario PIDAC guidelines.
Question 4: What is the role of hand hygiene in preventing healthcare-associated infections (HAIs) in the sterile processing department?
- Hand hygiene is important only in clinical patient care areas — it is less critical in the CSSD
- Hand hygiene is the single most effective measure to prevent cross-contamination and the spread of HAIs in all healthcare settings including CSSD (Correct answer)
- Hand hygiene is only required when handling soiled instruments, not after removing gloves
- Gloves completely eliminate the need for hand hygiene in CSSD
Correct answer: Hand hygiene is the single most effective measure to prevent cross-contamination and the spread of HAIs in all healthcare settings including CSSD
Hand hygiene remains the most effective measure to prevent HAIs and must be practiced at all the 4 Moments in all healthcare areas including CSSD — including after removing gloves, as gloves may have microscopic defects.
Hand hygiene is universally recognized as the single most effective measure to prevent the transmission of healthcare-associated infections (HAIs). In the CSSD, hand hygiene is required: before and after touching instruments or PPE (at all 4 Moments of Hand Hygiene per WHO/Ontario PIDAC guidelines), after removing gloves (gloves may have undetected microperforations and hands can become contaminated during glove removal), when moving between the contaminated and clean zones, and before handling clean or sterile items. Alcohol-based hand rub (ABHR) is effective for most situations; soap and water is required when hands are visibly soiled, before and after working with Clostridioides difficile, and after restroom use. Hand hygiene compliance in CSSD is a key quality and patient safety indicator.
Question 5: Which of the following transmission-based precautions requires the use of an N95 respirator by healthcare workers?
- Contact precautions for MRSA
- Droplet precautions for influenza
- Airborne precautions for active pulmonary tuberculosis (TB) (Correct answer)
- Enteric precautions for C. difficile
Correct answer: Airborne precautions for active pulmonary tuberculosis (TB)
Airborne precautions — required for diseases transmitted by airborne nuclei such as active pulmonary TB, measles, and varicella — mandate N95 or higher respirators rather than standard surgical masks.
Transmission-based precautions are used in addition to standard precautions for patients with known or suspected infections requiring additional safeguards. Airborne precautions are required when pathogens can remain suspended in the air on small particles (<5 microns) over long distances — as is the case with Mycobacterium tuberculosis (active pulmonary TB), measles, and varicella. N95 respirators filter ≥95% of airborne particles and are the minimum required protection. Surgical masks (which healthcare workers wear for droplet or contact precautions) do not provide adequate protection against airborne pathogens. In CSSD, staff may encounter instruments from patients under airborne precautions and should be aware of requirements for handling such instruments per Ontario PIDAC guidance.
Question 6: What is a prion, and why do prion-contaminated instruments present a unique challenge for standard reprocessing protocols?
- Prions are a type of fungal spore that requires extended steam sterilization cycles
- Prions are misfolded proteins that cause fatal neurodegenerative diseases (e.g., CJD) and are extraordinarily resistant to all standard sterilization and disinfection methods (Correct answer)
- Prions are antibiotic-resistant bacteria requiring specialized HLD protocols
- Prions are heat-stable viruses that require EO gas sterilization
Correct answer: Prions are misfolded proteins that cause fatal neurodegenerative diseases (e.g., CJD) and are extraordinarily resistant to all standard sterilization and disinfection methods
Prions are abnormal misfolded proteins that cause fatal neurodegenerative diseases such as Creutzfeldt-Jakob disease (CJD). They are uniquely resistant to standard sterilization, disinfection, UV radiation, and even incineration in some cases.
Prions (proteinaceous infectious particles) are abnormal isoforms of normal cellular proteins that cause a group of fatal progressive neurodegenerative diseases called transmissible spongiform encephalopathies (TSEs), including Creutzfeldt-Jakob disease (CJD), variant CJD (vCJD), and Gerstmann-Sträussler-Scheinker syndrome. Unlike bacteria, viruses, and fungi, prions contain no nucleic acid and cannot be destroyed by standard sterilization methods, many disinfectants, formaldehyde, radiation, or ethylene oxide. Instruments used in neurosurgery, ophthalmology, or procedures on high-risk tissues in patients with known or suspected CJD require specialized high-concentration NaOH or sodium hypochlorite pre-treatment before sterilization, or instruments may need to be quarantined or destroyed. Ontario Public Health and CSA Z314 have specific protocols for managing prion risk.
MDRAO Infection Prevention and Control 2
What is the Spaulding Classification system, and how does it determine the level of disinfection or sterilization required for medical devices?