Medical Asepsis, Infection Control, and Safety
What the domain tests
This domain tests how you break the chain of infection, choose the right precautions, and protect yourself and others from bloodborne pathogens, sharps, and environmental hazards. Expect sequencing questions (is the mask donned before or after gloves?) and judgment questions about the first action after an exposure.
Core rules
- The chain of infection runs: infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host. Hand hygiene is the single most effective intervention at every link.
- Medical asepsis reduces organisms (clean technique); surgical asepsis eliminates them (sterile technique) and is required for invasive procedures and dressing changes on sterile sites.
- Wash with soap and water for at least 20 seconds when hands are visibly soiled or after caring for a patient with C. difficile or norovirus; use alcohol-based rub when hands are not visibly soiled.
- Donning order: gown, mask or respirator, eye protection, gloves. Doffing order: gloves, eye protection, gown, mask. Perform hand hygiene after removing each item and at the end.
- Standard Precautions apply to every patient regardless of diagnosis. Transmission-based precautions add contact (gown and gloves, dedicated equipment), droplet (surgical mask, private room), or airborne (fit-tested N95 or higher, negative-pressure room) measures.
- After a needlestick, wash the site with soap and water, do not squeeze or scrub, report immediately, and follow the exposure control plan for source testing and post-exposure prophylaxis.
- Fire response uses RACE (rescue, alarm, contain, extinguish) and PASS (pull, aim, squeeze, sweep). Never use water on an electrical fire.
Worked example
You sustain a needlestick from a used lancet while testing a glucose. Reasoning: the priority is immediate wound care and reporting, not finishing the task. Wash with soap and water, flush any mucous membrane splash, report to the supervisor at once, complete the incident report, and follow the exposure protocol for source testing and prophylaxis. Looking up the source patient's HIV status yourself or delaying the report are wrong answers.
Traps that cost marks
- Wearing gloves instead of performing hand hygiene.
- Letting a mask dangle under the chin during doffing, contaminating the face.
- Recapping needles with two hands or bending them before disposal.
- Assuming a patient with no known diagnosis needs no precautions.