Safety and Infection Control
Core concepts
Understand the chain of infection (infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host) and how to break each link. Know standard precautions apply to all patients regardless of diagnosis, while transmission-based precautions (contact, droplet, airborne) apply to specific pathogens. Know the sequence for donning and removing PPE: don gown, mask/respirator, goggles, then gloves; remove gloves first, then goggles, gown, and mask last, performing hand hygiene after. Understand medical asepsis vs. surgical asepsis, sterilization vs. disinfection, and the difference between cleaning and sanitizing. Know body mechanics, fire safety (RACE, PASS), and fall precautions.
Traps in questions
- Order of PPE removal: gloves come off first and the mask/respirator last - distractors scramble this.
- Precaution type: airborne (e.g., tuberculosis, measles, varicella) requires an N95 and negative-pressure room; droplet (e.g., influenza) requires a surgical mask; contact (e.g., C. difficile, MRSA) requires gown and gloves.
- Hand hygiene timing: before and after patient contact and after glove removal; gloves do not replace hand hygiene.
- Sharps and spills: never recap a needle by hand; use the safety device or a recapping station.
- Fire response: RACE (rescue, alarm, contain, extinguish) and PASS (pull, aim, squeeze, sweep) are frequently reversed in distractors.
Rule of thumb
Standard precautions for everyone; add transmission-based precautions only when the pathogen requires it. When a stem describes a specific organism, identify its transmission route first, then choose the precaution.
Worked example
Stem: 'A patient is suspected of having active tuberculosis. What precautions are required?' TB is transmitted by airborne droplet nuclei, so use an N95 respirator and a negative-pressure (airborne infection isolation) room - not just a surgical mask.