5.1 Infection Control & Prevention
Key Takeaways
- Standard precautions apply to ALL patients regardless of diagnosis: hand hygiene, gloves, gown, mask/eye protection as the task dictates
- Contact precautions: gown + gloves for MRSA, VRE, C. diff, scabies, RSV; use dedicated single-patient equipment
- Droplet precautions: surgical mask within 3-6 feet for influenza, pertussis, mumps, meningococcal disease, COVID-19 (minimum)
- Airborne precautions: fit-tested N95 respirator + Airborne Infection Isolation Room (negative pressure, 6-12 air changes/hour) for TB, measles, varicella
- VAP bundle: HOB 30-45 degrees, daily sedation interruption, daily extubation-readiness assessment, DVT prophylaxis, stress-ulcer prophylaxis, chlorhexidine oral care
- Hand hygiene is the single most effective measure to prevent healthcare-associated infections
- Alcohol-based hand rub is preferred EXCEPT when hands are visibly soiled or C. diff/Norovirus is suspected (use soap and water)
- Do NOT change ventilator circuits routinely; routine changes raise VAP risk -- change only when visibly soiled or malfunctioning
Infection Control & Prevention
Infection-control items live in the Troubleshooting and Infection Control content area of the NBRC Therapist Multiple-Choice (TMC) exam -- the 160-question (140 scored, 20 unscored), 3-hour test you must pass to earn the Certified Respiratory Therapist (CRT) credential and qualify for the Clinical Simulation Exam on the path to the Registered Respiratory Therapist (RRT) credential. Respiratory therapists handle equipment connected directly to the airway, so disciplined technique is non-negotiable.
Standard Precautions (Apply to ALL Patients)
Standard precautions assume that all blood, body fluids, secretions, excretions (except sweat), non-intact skin, and mucous membranes are potentially infectious. They apply to every encounter, even when no organism is known.
| Measure | When to use |
|---|---|
| Hand hygiene | Before and after every contact; before aseptic tasks; after body-fluid exposure; after touching the patient's surroundings |
| Gloves | Contact with blood, body fluids, mucous membranes, non-intact skin, or contaminated equipment |
| Gown | When clothing may contact body fluids or during splash-prone procedures |
| Mask + eye protection | Aerosol- or splash-generating procedures: suctioning, intubation, bronchoscopy, nebulizer setup |
| Respiratory hygiene | Cover cough/sneeze; perform hand hygiene after contact with secretions |
| Sharps safety | Drop into a puncture-resistant container immediately; never recap needles |
The My 5 Moments for Hand Hygiene (World Health Organization) is a useful TMC framework: before patient contact, before an aseptic task, after body-fluid exposure risk, after patient contact, and after touching patient surroundings.
Transmission-Based Precautions
Layer these on top of standard precautions based on how the organism spreads. The TMC loves to test the pathogen-to-precaution match.
| Type | Protection | Room | Common pathogens |
|---|---|---|---|
| Contact | Gown + gloves; dedicated single-patient equipment | Standard room; may cohort | MRSA, VRE, C. difficile, scabies, RSV, draining wounds |
| Droplet | Surgical mask within 3-6 feet | Standard room; private preferred | Influenza, pertussis, mumps, meningococcal disease, H. influenzae meningitis |
| Airborne | Fit-tested N95 (or PAPR) | Airborne Infection Isolation Room: negative pressure, 6-12 air changes/hour, door closed | Tuberculosis, measles (rubeola), varicella (chickenpox), disseminated zoster |
Memory aid -- "My Chicken Hez TB": Measles, Chickenpox (varicella), and TB are the classic airborne triad. A surgical mask is useless against airborne droplet nuclei (<5 microns); only a fit-tested respirator protects you.
Hand Hygiene -- the #1 Prevention Measure
Alcohol-based hand rub (ABHR) is preferred for routine hygiene: apply enough to keep all surfaces wet, rub for 20-30 seconds until dry, no rinsing. ABHR fails against C. difficile spores and Norovirus -- use soap and water with friction for at least 20 seconds when those are suspected, when hands are visibly soiled, before eating, and after the restroom. A common TMC trap: choosing ABHR for a C. diff patient. Spores resist alcohol; you must physically wash them off.
Ventilator-Associated Pneumonia (VAP) Bundle
| Intervention | Rationale |
|---|---|
| Head of bed 30-45 degrees | Reduces aspiration of gastric contents |
| Daily sedation interruption (SAT) | Earlier extubation; fewer ventilator days |
| Daily extubation-readiness (SBT) assessment | Shortens duration of ventilation |
| DVT prophylaxis | Prevents venous thromboembolism |
| Stress-ulcer prophylaxis | Prevents GI bleeding (PPI or H2 blocker) |
| Chlorhexidine oral care | Lowers oropharyngeal colonization |
| Subglottic secretion drainage | Clears pooled secretions above the cuff |
Cuff pressure should stay roughly 20-30 cmH2O: too low lets secretions leak past the cuff (aspiration, VAP); too high risks tracheal mucosal ischemia.
Equipment Reprocessing (Spaulding Classification)
| Level | Kills | Used for |
|---|---|---|
| Sterilization | All microbes, including spores (autoclave, ethylene oxide) | Critical items entering sterile tissue |
| High-level disinfection | All microbes except high spore loads (glutaraldehyde, OPA) | Semi-critical: bronchoscopes, reusable circuits |
| Intermediate | Bacteria, fungi, most viruses, mycobacteria (alcohol, bleach) | Stethoscopes, ventilator surfaces |
| Low-level | Most bacteria, some viruses/fungi (quats) | Non-critical surfaces, counters |
Worked scenario: A bronchoscope contacts mucous membranes -- a semi-critical device. The minimum acceptable reprocessing is high-level disinfection, not low-level wipe-down. Circuit rule: do not change ventilator circuits on a schedule; routine changes increase VAP risk. Swap heat-and-moisture exchangers (HMEs) every 48 hours or sooner if soiled/clogged, and drain heated-humidifier condensate away from the patient.
Healthcare-Associated Infections (HAIs) the RT Must Know
Beyond VAP, the TMC expects familiarity with the broader healthcare-associated infection (HAI) family because RTs touch lines, drains, and airways:
- VAP -- pneumonia developing more than 48 hours after intubation; the strongest RT-controllable HAI.
- CLABSI -- central line-associated bloodstream infection; reduced by full barrier insertion, chlorhexidine skin prep, and prompt line removal.
- CAUTI -- catheter-associated urinary tract infection; reduced by removing catheters early.
- SSI -- surgical site infection.
For any aerosol-generating procedure (open suctioning, bronchoscopy, intubation, extubation, manual ventilation, nebulizer therapy, non-invasive ventilation, high-flow nasal cannula), add eye protection and consider a respirator even when the underlying precaution is only droplet or contact, because the procedure can aerosolize organisms into fine particles.
Donning and Doffing -- Sequence Matters
The TMC tests the order of putting on and removing personal protective equipment (PPE), because most self-contamination happens during removal.
| Step | Donning (put on) | Doffing (take off) |
|---|---|---|
| 1 | Gown | Gloves |
| 2 | Mask / respirator | Goggles / face shield |
| 3 | Goggles / face shield | Gown |
| 4 | Gloves | Mask / respirator (last, outside the room) |
Remove gloves first because they are the most contaminated, and remove the mask or respirator last, after leaving the patient room, performing hand hygiene at the transitions. A new N95 must be fit-tested and seal-checked before each use; facial hair under the seal voids protection and is a common exam distractor.
A patient is admitted with suspected active pulmonary tuberculosis. Which precautions are required?
When must soap and water be used instead of alcohol-based hand rub?
Which intervention is a core component of the VAP prevention bundle?
Match each pathogen to its transmission-based precaution level.
Match each item on the left with the correct item on the right
How often should ventilator circuits be changed to minimize VAP?
A reusable bronchoscope that contacts mucous membranes requires at minimum which level of reprocessing?
Which of the following belong to the VAP prevention bundle? (Select all that apply)
Select all that apply