Chapter 27 Asepsis and Infection Control

Components of the Infection Cycle Infectious agent—bacteria, viruses, fungi Reservoir—natural habitat of the organism Portal of exit—point of escape for the organism Means of transmission—direct contact, indirect contact, airborne route Portal of entry—point at which organisms enter a new host Susceptible host—must overcome resistance mounted by host’s defenses

The Infection Cycle

Infectious Agents Bacteria—most significant and most prevalent in hospital settings Virus—smallest of all microorganisms Fungi—plantlike organisms present in air, soil, and water

Classification of Bacteria Spherical (cocci), rod shaped (bacilli), corkscrew shaped (spirochetes) Gram positive or gram negative—based on reaction to Gram stain Aerobic or anaerobic—based on need for oxygen

Factors Affecting an Organism’s Potential to Produce Disease Number of organisms Virulence Competence of person’s immune system Length and intimacy of contact between person and microorganism

Possible Reservoirs for Microorganisms Other humans Animals Soil Food, water, milk Inanimate objects

Common Portals of Exit Respiratory Gastrointestinal Genitourinary tracts Breaks in skin Blood and tissue

Laboratory Data Indicating Infection Elevated white blood cell count—normal is 5000 to 10,000/mm3 Increase in specific types of white blood cells Elevated erythrocyte sedimentation rate Presence of pathogen in urine, blood, sputum, or draining cultures

Aseptic Technique Includes all activities to prevent or break the chain of infection Two categories Medial asepsis—clean technique Surgical asepsis—sterile technique

Factors Predisposing Patients to Nosocomial Infections Use of invasive medical devices Antibiotic-resistant organisms developed in hospitals

Measures to Reduce Incidence of Nosocomial Infections Constant surveillance by infection-control committees and nurse epidemiologists Written infection-prevention practices for all agency personnel Hand hygiene recommendations Infection control precaution techniques Keeping patient in best possible physical condition

Bacterial Flora Transient—attached loosely on skin, removed with relative ease Resident—found in creases in skin, requires friction with brush to remove

Stages of Infection Incubation period—organisms growing and multiplying Prodromal stage—person is most infectious, vague and nonspecific signs of disease Full stage of illness—presence of specific signs and symptoms of disease Convalescent period—recovery from the infection

Body’s Defense Against Infection Body’s normal flora Inflammatory response Immune response

Factors Affecting Host Susceptibility Intact skin and mucous membranes Normal pH levels Body’s white blood cells Age, sex, race, hereditary factors Immunization, natural or acquired Fatigue, climate, nutritional and general health status Stress Use of invasive or indwelling medical devices

Personal Protective Equipment and Supplies Gloves Gowns Masks Protective eye gear Hair bonnets Shoe covers

Evolution of Specialized Infection Control Precautions Early CDC guidelines Specific isolation techniques Disease-specific isolation Universal precautions OSHA regulations for universal precautions Body substance precautions Current CDC guidelines

Current CDC Guidelines Standard precautions—used in care of all hospitalized patients Apply to blood, body fluids, secretions, excretions, non-intact skin, mucous membranes Transmission-based precautions—used in addition to standard precautions for patients with suspected infection Include airborne, droplet, or contact precautions Box 27-4 pg 717

Current CDC Guidelines (cont’d) Neutropenic precautions-use for a patient whose immune system is compromised Examples: one recovering from a transplantation surgery or receiving chemotherapy Standard precautions are needed (as with all patients) Provide a healthy caregiver Restrict visits from friends or family members with colds or contagious illnesses Avoid standing collections of water in the room

Type N95 Particulate Respirator

Use of Surgical Asepsis Operating room, labor and delivery areas Certain diagnostic testing areas Patient bedside e.g., for procedures that involve insertion of urinary catheter, sterile dressing changes, or preparing and injecting medicine

Patient Teaching for Medical Asepsis at Home Wash hands before preparing or eating food Prepare foods at high enough temperatures Use care with cutting boards and utensils Keep food refrigerated Wash raw fruits and vegetables Use pasteurized milk and fruit juices Wash hands after using bathroom Use individual care items

Evaluating Patient Goals Use techniques of medical asepsis Identify health habits and lifestyle patterns promoting health State signs and symptoms of an infection Identify unsafe situations in the home environment

What is the most important thing to remember about Infection Control?

Skills Handwashing Don and Doff PPE