Key Takeaways
- Medical asepsis (clean technique) reduces the NUMBER of microorganisms; surgical asepsis (sterile technique) eliminates ALL microorganisms
- The chain of infection includes 6 links: infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host
- Standard Precautions apply to ALL patients regardless of diagnosis and include hand hygiene, PPE, safe injection practices, and respiratory hygiene
- Transmission-Based Precautions include Contact, Droplet, and Airborne precautions used in addition to Standard Precautions
- Hand hygiene is the single most effective way to prevent the spread of infection in healthcare settings
- Sterilization methods include autoclave (steam under pressure, 121C/250F for 15-30 minutes), chemical sterilization, and gas sterilization
- Biological indicators (spore tests) verify that sterilization equipment is functioning properly and should be run weekly at minimum
- The correct order for donning PPE is: gown, mask/respirator, eye protection, gloves; removal is in reverse order
- Sharps must be disposed of in puncture-resistant, leak-proof, red biohazard containers at the point of use
Last updated: February 2026
Asepsis, Infection Control & Sterilization
The Clinical Procedural Tasks domain accounts for 18.6% of the RMA exam (approximately 39 questions). Infection control is one of the most critical and heavily tested topics in this domain.
Types of Asepsis
| Type | Definition | Examples |
|---|---|---|
| Medical asepsis (clean technique) | Reduces the NUMBER of microorganisms and prevents their spread | Hand washing, surface disinfection, wearing gloves for non-sterile procedures |
| Surgical asepsis (sterile technique) | Eliminates ALL microorganisms from an area | Autoclave sterilization, sterile field setup, surgical hand scrub |
Chain of Infection
The chain of infection describes the six elements required for infection to spread. Breaking any single link prevents transmission:
- Infectious agent: The pathogen (bacteria, virus, fungus, parasite)
- Reservoir: Where the pathogen lives and multiplies (humans, animals, fomites, water, food)
- Portal of exit: How the pathogen leaves the reservoir (respiratory secretions, blood, skin, GI tract, GU tract)
- Mode of transmission: How the pathogen travels to the new host
- Direct contact: Touching, kissing, sexual contact
- Indirect contact: Fomites (contaminated objects), vectors (insects), vehicles (food, water, air)
- Droplet: Large respiratory droplets (< 3 feet, coughing, sneezing)
- Airborne: Small particles suspended in air (> 3 feet, remain airborne for extended periods)
- Portal of entry: How the pathogen enters the new host (respiratory tract, breaks in skin, mucous membranes, bloodstream)
- Susceptible host: A person with insufficient immunity to resist infection
Standard Precautions (Apply to ALL Patients)
Standard Precautions are used for every patient encounter regardless of known or suspected infection status:
- Hand hygiene: Before and after every patient contact, after removing gloves
- Gloves: When touching blood, body fluids, mucous membranes, non-intact skin
- Masks, eye protection, face shields: When splashing or spraying of body fluids is anticipated
- Gowns: When contact with blood or body fluids may soil clothing
- Safe injection practices: Use single-use, single-patient vials; never reuse needles or syringes
- Respiratory hygiene/cough etiquette: Cover coughs/sneezes, offer masks to symptomatic patients
- Sharps safety: Use safety-engineered devices; dispose in sharps containers immediately after use
Transmission-Based Precautions
| Type | When Used | PPE Required | Examples |
|---|---|---|---|
| Contact | Diseases spread by direct/indirect contact | Gown + gloves (upon room entry) | MRSA, C. difficile, scabies, VRE |
| Droplet | Diseases spread by large respiratory droplets | Surgical mask (within 3-6 feet) | Influenza, pertussis, mumps, meningitis |
| Airborne | Diseases spread by small airborne particles | N95 respirator + negative pressure room | TB, measles, varicella (chickenpox), COVID-19 |
Hand Hygiene
Hand hygiene is the single most important measure to prevent healthcare-associated infections.
When to Perform Hand Hygiene (WHO "5 Moments"):
- Before touching a patient
- Before a clean/aseptic procedure
- After body fluid exposure risk
- After touching a patient
- After touching patient surroundings
Hand Washing with Soap and Water
- Required when hands are visibly soiled or contaminated with blood/body fluids
- Required after caring for patients with C. difficile or Norovirus (spore-forming organisms)
- Use warm water, apply soap, lather for at least 20 seconds, rinse, and dry with paper towels
- Use paper towel to turn off faucet
Alcohol-Based Hand Rub (ABHR)
- Preferred for routine hand hygiene when hands are NOT visibly soiled
- Apply enough product to cover all surfaces of hands and fingers
- Rub until dry (approximately 20 seconds)
- NOT effective against spore-forming organisms (C. difficile) -- use soap and water
Personal Protective Equipment (PPE)
Donning Order (Putting ON):
- Gown (tie at neck and waist)
- Mask or N95 respirator (fit snugly over nose and mouth)
- Eye protection (goggles or face shield)
- Gloves (extend over gown cuffs)
Doffing Order (Taking OFF):
- Gloves (peel off without touching exterior; discard)
- Eye protection (remove by headband, not lens)
- Gown (unfasten, pull away from body, fold contaminated side in)
- Mask/respirator (remove by elastic bands, not front)
- Perform hand hygiene immediately
Sterilization Methods
| Method | Conditions | Use |
|---|---|---|
| Steam autoclave | 121°C (250°F), 15-20 psi, 15-30 minutes | Most common; instruments, wrapped packs |
| Flash autoclave | 132°C (270°F), higher pressure, 3-10 minutes | Unwrapped instruments needed urgently |
| Chemical sterilization (cold) | Glutaraldehyde or similar solution, 8-10 hours | Heat-sensitive items (scopes, plastic) |
| Gas sterilization | Ethylene oxide (EtO) | Heat/moisture-sensitive items; requires aeration time |
| Dry heat | 160-170°C, 1-2 hours | Oils, powders, items damaged by moisture |
Sterilization Quality Assurance
| Indicator Type | What It Checks | Frequency |
|---|---|---|
| Process indicator (tape) | External: confirms item went through process (color change) | Every load |
| Chemical indicator (strip) | Internal: verifies temperature, time, and steam reached item | Every pack |
| Biological indicator (spore test) | Confirms sterilization actually killed organisms | At least weekly; also after repairs |
Autoclave Loading Guidelines
- Leave space between packs for steam penetration
- Place items on their sides with lids open (jars, containers)
- Do not overload the autoclave
- Use autoclave tape on the outside of each pack
- Include a chemical indicator strip inside each pack
- Allow items to dry completely before removal and storage
- Label sterilized items with date, initials, and contents
- Sterilized items are typically considered sterile for 30 days if packaging is intact
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Test Your Knowledge
The most effective way to prevent the spread of infection in a healthcare setting is:
A
B
C
D
Test Your Knowledge
The autoclave sterilizes instruments using steam under pressure at:
A
B
C
D
Test Your Knowledge
Which type of Transmission-Based Precaution requires an N95 respirator and a negative pressure room?
A
B
C
D
Test Your Knowledge
Biological indicators (spore tests) for autoclaves should be performed at least:
A
B
C
D
Test Your KnowledgeOrdering
Arrange the correct order for DONNING (putting on) PPE.
Arrange the items in the correct order
1
Gloves
2
Eye protection/face shield
3
Gown
4
Mask or N95 respirator
Test Your KnowledgeFill in the Blank
Standard Precautions apply to ___ patients, regardless of their diagnosis or infection status.
Type your answer below
Test Your KnowledgeMatching
Match each Transmission-Based Precaution type with the correct disease example.
Match each item on the left with the correct item on the right
1
Contact Precautions
2
Droplet Precautions
3
Airborne Precautions