Chapter 4 Flashcards
Nosocomial Pneumonia
Associated with factors that promote colonization of the pharynx with gram negative bacteria.
Most nosocomial PNA occurs in…
Patients having chest or abdominal surgery.
- Normal swallowing and clearance mechanisms impaired.
- The presence of artificial airway increase likelihood of developing nosocomial PNA
Who has a greater risk for nosocomial PNA following major surgery.
COPD, Smokers, Obesity, advanced age
Colonization
presence of microorganisms in a host
Pathogen
microorganisms capable of producing disease in humans
infection
when microorganisms cause cell or tissue damage (microorganisms overcomes barriers of hose)
What does getting an infection depend on?
Virulence or microorganism, host’s resistance
Nosocomial infection
infections acquired in the hospital
Asepsis
Absence of disease-producing microorganisms (Bacteria, mycoplasmas, fungi, and viruses)
Sterile
Complete absence of all forms of microorgisms
Cross-contamination
transmission of microorganisms between places and/or persons
What does the spread of infection require?
- source of pathogen
- Susceptible host
- Route or transmission
Source of infections (in hospitals)
- people (patients, personal, and visitors)
* Contaminated objects
Susceptible Host
resistance to infection varies greatly from one person to the next
Host factors the increase the change of infection
- poorly controlled diabetes
- increased age
- chemotherapy
- placement of tubes and catheters (artificial airways)
Transmission routes
- contact
- Droplet
- airborne
- common vehicle
- vectorborne
Contact Transmission
The most common mode of transmission.
*Direct Contact- Microorganism is transferred directly from one infected person to another without a contaminated intermediate object (fomite) or person
Indirect Contact: Transfer of infectious agent through a contaminated intermediate object or person (Dirty hands)
Droplet Transmission
Respiratory droplets, greater then 5 microns that travel relatively short distances through the air, generally considered 3 feet or less.
- generated by coughing, sneezing, and or talking from an infected individual
- These large droplets do not remain suspended in the air, do not require special air handling procedures
Airborne Transmission
Airborne dissemination by droplet nuclei or small respirable particles (less then 5 microns)
*easily dispersed by air currents
Requires Negative pressure room and N-95 Masks
Droplet Nuclei
Residue of evaporated liquid droplets (TB and Measles form droplet nuclei)
Vehicle
Exposure to pathogens in contaminated food or water, not common in the hospital setting
- Salmonella and Hepatitis A are common examples of food borne
- Cholera is a common example of waterborne
Vectorborne Transmission
Occurs when an animal (usually insect) transfers an infectious agent from one host to another
*examples, malaria-mosquito; Lyme-tick
infection control strategies
Break the chain of events
- decrease host susceptibility
- Eliminating source of pathogen
- interrupting routes of transmission
decreasing host susceptibility
Least feasible approach, main focus is on employee immunization (influenza, Hepatitis B, Tetanus)
Interrupting routes of Transmission (three major approaches)
- Specialized equipment handling procedures
- Barrier/isolation precautions
- Single patient use disposable equipment
Barrier Measures and Isolation percautions
Hand washing is the single most effective method to prevent the spread of infection.
*PPE (Gloves, Mask, Gown, Goggles)
Standard Percautions
Primary strategy for preventing transmission of infectious agents among patients and health care workers, Assumes that any body fluids are infectious, decisions about PPE determined by type of clinical interactions with pt
Expanded Precautions
Applied with patients who have Known or Suspected infections the require additional control measures (Contact, Droplet and Airborne)
Gloves
Used when touching blood, body fluids, secretions, excretions, contaminated items, for touching membranes and non intact skin
Gowns
Use during procedures and patient care activities when contact of clothing/ exposed skin with blood/body fluids, secretions, or excretions is anticipated
Mask and goggles or a face shield
Use during patient care activities likely to generate splashes or sprays of blood, body fluids, secretions, or excretions
Contact Percautions
Gown and Gloves
Droplet Percautions
Surgical Mask
Airborne infection isolation
N95 mask
Protective environment isolation
Engineering approach to protect highly immunocomprised patients
General Sanitation
Reducing pathogens to a safe level
- Sanitary (Laundry management, Food preparation, house keeping)
- Environmental control of air and water
Equipment processing
Decontaminating equipment (my wash all equipment first, getting all the organic material off first) then disinfection and sterilization, it is impossible to eliminate all pathogens
Equipment Categories
Based on the risk of infection in equipment is contaminated
Critical equipment
Equipment that enters sterile tissues or vascular systems (should be purchased sterile or sterilized before use)
Semi-Critical equipment
Equipment that contacts mucous membranes or non intact skin (most respiratory equipment, requires at least high-level sterilization)
Non-Critical equipment
Equipment that come in contact with intact skin, decontamination where they are used (bed rails)
Equipment processing
- Cleaning (Step one) Removing dirt and organic material. Failure to clean properly will render subsequent processing ineffective. Designate dirty and clean areas, completely disassemble and wash in hot soapy water (when applicable) dry completely.
- If equipment cannot be immersed in water clean and disinfect surface (70% ethyl alcohol or 90% isopropyl alcohol)
- disinfect or sterilize (most equipment must also be disinfected or sterilized)
Disinfection
Destroys vegetative form of pathogen but cannot kill bacterial spores
Sterilization
complete destruction of all forms of microbial life (Sporadical)
