Transmission-Based Precautions and Protective Environment

Infection control is one of the most frequently tested topics in nursing fundamentals. This note reviews the three categories of transmission-based precautions, the PPE and room requirements for each, and the protective environment used for immunocompromised patients.

Definition

• Transmission-based precautions are used in addition to standard precautions for patients with known or suspected infections.
• They are selected based on the route of transmission.
• The three types are contact, droplet, and airborne precautions.

Quick Comparison

Contact Precautions

• Used for infections spread by direct contact with the patient or indirect contact with contaminated surfaces.
• PPE: gloves and gown. Perform hand hygiene before donning and after removing PPE.
• Place patient in a private room or cohort with patients who have the same infection.
• Use dedicated, single-patient equipment (stethoscope, BP cuff, thermometer). Disinfect any shared equipment between patients.
• Minimize transport. If needed, cover the infected area and clean transport equipment afterward.
• High-yield infections: C. difficile, MRSA, VRE, RSV, scabies, norovirus.
• For C. difficile and norovirus, use soap and water for hand hygiene — alcohol-based hand rub does not kill the spores.

Droplet Precautions

• Used for infections spread by respiratory droplets (coughing, sneezing, talking) that travel about 3 feet.
• PPE: surgical mask; add eye protection if splashing is likely.
• Place patient in a private room or cohort. No special ventilation is required.
• Minimize transport; if necessary, place a surgical mask on the patient.
• Maintain at least 3 feet of separation between the infected patient and others.
• High-yield infections: influenza, COVID-19, pertussis, bacterial meningitis, mumps, rubella.

Airborne Precautions

• Used for infections spread by small droplet nuclei that remain suspended in air and travel long distances.
• PPE: N95 respirator — fit-testing is required.
• Place patient in an Airborne Infection Isolation Room (AIIR) with negative pressure. Air is exhausted outside or HEPA-filtered.
• The door must remain closed at all times.
• Avoid transport when possible. If required, place an N95 on the patient if tolerated, or a surgical mask.
• Non-immune healthcare workers should not enter rooms of patients with measles or varicella.
• High-yield infections: tuberculosis, measles, varicella (chickenpox), disseminated herpes zoster.
• Localized shingles requires standard precautions only.

Protective Environment (Reverse Isolation)

• Used for immunocompromised patients (stem cell transplant, chemotherapy, severe neutropenia).
• Goal: protect the patient from outside infection — not to prevent spread from the patient.
• Room has positive pressure with HEPA filtration; air flows out of the room.
• Standard precautions are used and may be enhanced with masks, gloves, and gowns for staff and visitors.
• No live plants or fresh flowers (harbor fungi).
• No nearby construction (dust carries pathogens).

Donning and Doffing PPE

• Remove PPE in this order: gloves → gown → eye protection → mask (last).
• Do not touch the front of the mask.
• Perform hand hygiene after removing all PPE.
• Never reuse gloves or gowns between patients.

Common Exam Traps

• Do not mismatch the precaution with the route of transmission.
• Do not use alcohol-based hand rub for C. difficile or norovirus — use soap and water.
• Do not use a surgical mask for airborne infections — use an N95.
• Do not place an airborne patient in a regular room — they require a negative-pressure AIIR.
• Do not confuse droplet (3-ft separation, surgical mask) with airborne (N95, negative pressure).
• Do not forget that disseminated shingles = airborne, while localized shingles = standard precautions only.

Key takeaways

• Contact = gloves + gown (C. diff, MRSA, VRE, RSV, scabies, norovirus); soap and water for C. diff and norovirus.
• Droplet = surgical mask, 3-foot separation (influenza, COVID-19, pertussis, meningitis).
• Airborne = N95 + negative pressure AIIR with door closed (TB, measles, varicella, disseminated shingles).
• Doff PPE in order: gloves → gown → eye protection → mask, then hand hygiene.
• Protective environment = positive pressure + HEPA for immunocompromised patients; no live plants or nearby construction.