Isolation Precautions & Use of Personal Protective Equipment (PPE)

Nursing Notes — Infection Prevention and Control

1. Introduction

1. Standard Precautions — applied to every patient, every time, regardless of diagnosis.
2. Transmission-Based Precautions — added on top of Standard Precautions for patients with a suspected/confirmed transmissible pathogen.

Transmission-based precautions are used in addition to, never in place of, standard precautions.

• Tintinalli's Emergency Medicine, p. 1137

2. Types of Isolation Systems (Historical → Current)

3. Standard Precautions

• Red Book 2021 (AAP), p. 274

Key Components (remember: "H-H-G-M-E-R-S-L")

• Red Book 2021, p. 274–275; Tintinalli's Emergency Medicine, p. 1137

4. Transmission-Based Precautions

A. Contact Precautions

• Route: Direct contact (skin-to-skin) or indirect contact (via contaminated surfaces/equipment/hands).
• PPE: Gown + gloves.
• Examples: C. difficile, MRSA, VRE, scabies, RSV, wound infections, multidrug-resistant organisms (MDROs).
• Room: Single-patient room preferred; dedicated/disposable equipment where possible.

B. Droplet Precautions

• Route: Large respiratory droplets (≥5–100 microns) propelled a short distance (<3 feet, generally) during coughing, sneezing, talking, suctioning; deposited on conjunctivae, nasal mucosa, or mouth. Does not stay suspended in air → no special air handling/ventilation needed.
• PPE: Surgical mask (+ eye protection, gown, gloves depending on exposure) — should be donned on room entry.
• Examples: Influenza, Neisseria meningitidis, Bordetella pertussis, mumps, group A Streptococcus, rhinovirus.
• Room: Single-patient room; door may remain open (no negative pressure needed).

C. Airborne Precautions

• Route: Small droplet nuclei (≤5 μm) that remain suspended in air for prolonged periods and travel long distances — inhaled by a susceptible host even outside the immediate room.
• PPE: Fit-tested N95 respirator (or PAPR), donned before room entry, removed after leaving room.
• Room requirements:
  • Single-patient Airborne Infection Isolation Room (AIIR)
  • 6–12 air changes/hour
  • Negative pressure relative to surrounding area
  • Air exhausted directly outside or through HEPA filter
  • Door kept closed at all times
• Examples: Mycobacterium tuberculosis, measles, varicella-zoster (chickenpox/disseminated zoster).
• Non-immune staff should not enter rooms of measles/varicella patients unless essential (and then must wear a respirator even if previously immunized, in the case of measles).
• COVID-19/SARS-CoV-2 and MERS-CoV → combined airborne + droplet + contact precautions (N95, eye protection, gown, gloves); AIIR prioritized for aerosol-generating procedures.
• Red Book 2021, p. 276–278; Harrison's Principles of Internal Medicine 22E, p. 303–304

Quick Comparison Table

5. Epidemiology & Infection Prevention — CDC Guidelines

• CDC's HICPAC develops and updates national isolation guidelines (available at cdc.gov/infectioncontrol).
• WHO's 5 Moments for Hand Hygiene: (1) before touching a patient, (2) before a clean/aseptic procedure, (3) after body fluid exposure risk, (4) after touching a patient, (5) after touching patient surroundings.
• Surveillance and epidemiologic tracking of healthcare-associated infections (HAIs) — e.g., catheter-associated bloodstream infections, ventilator-associated pneumonia — guide prevention bundles (aseptic insertion checklists, daily line-necessity review, chlorhexidine bathing).
• Infection control gains (declining device-related infection rates) were reversed during the COVID-19 pandemic, underscoring the importance of consistent adherence to precautions.
• Occupational exposure management: post-exposure protocols, vaccination status tracking (e.g., TB testing every 6–12 months for high-risk staff, MMR/varicella immunity documentation).
• Tintinalli's Emergency Medicine, p. 1137–1138; Harrison's Principles of Internal Medicine 22E, p. 303

6. Effective Use of PPE

Types of PPE and Purpose

CDC Donning Sequence (put on in this order)

1. Gown — fully cover torso (neck to knees, arms to wrist), tie at back of neck and waist
2. Mask or respirator — secure straps/ties; if N95, perform a seal check
3. Goggles or face shield
4. Gloves — pull over gown cuffs

CDC Doffing Sequence (remove in this order — most contaminated items handled last touching skin as little as possible)

1. Gloves — remove first (outside-in technique), discard
2. Goggles/face shield — remove by touching only the strap/band
3. Gown — untie, pull away from body rolling contaminated side inward, discard
4. Mask/respirator — remove last, touching only ties/straps
5. Perform hand hygiene immediately after removing each item and again after full doffing

Nursing point: The reason gloves go on last and come off first is that they are the most contaminated item after patient contact — this protects the nurse from self-contamination during removal.

General Principles for Effective PPE Use

• Perform hand hygiene before donning and after doffing.
• PPE should never be reused between patients (single-use, disposable items discarded after each use).
• Change gloves between "dirty" and "clean" tasks even on the same patient.
• Remove PPE before leaving the patient's room (respirator may be removed just outside/after leaving for airborne precautions per some protocols).
• Damaged, soaked, or physically compromised masks must be discarded and replaced.
• All PPE removal should occur in a designated area to avoid contaminating clean zones.
• Park's Textbook of Preventive and Social Medicine, p. 4238–4246; CDC PPE Sequence Guidance

Quick Revision Summary

• 2 tiers: Standard Precautions (always) + Transmission-Based Precautions (added per pathogen)
• 3 transmission routes: Contact, Droplet, Airborne
• PPE order: Don = Gown → Mask → Goggles → Gloves; Doff = Gloves → Goggles → Gown → Mask
• Hand hygiene bridges every step — before donning, after doffing, between all patient contacts
• Airborne = N95 + negative pressure room; Droplet = surgical mask; Contact = gown + gloves