Chapter 10 · 2012-12-13 · © Paradigm Publishing, Inc. 4 Terms to Remember germ theory of disease the idea that microorganisms cause diseases

© Paradigm Publishing, Inc. 1

Chapter 10

Infection Control


Identifying and Controlling the Source of Infection

• The development of the germ theory of disease

• Microorganisms and disease • Asepsis and sterilization


The Development of the Germ Theory of Disease

• The cause of infectious diseases was not fully understood until recently.

• Disease was attributed to evil influences.

• Knowledge of infectious disease progressed slowly over the centuries.


Terms to Remember

germ theory of disease the idea that microorganisms cause diseases



• Pasteur developed a heating process to kill bacteria and mold in milk (pasteurization).

• Pasteur proposed that disease could be prevented by not allowing microorganisms to enter the body.


Terms to Remember

pasteurization a sterilization process designed to kill most bacteria and mold in milk and other liquids



English surgeon Joseph Lister built on Pasteur’s work:

– He knew that carbolic acid killed bacteria, so he used it to disinfect surgical dressings.

– He developed other antiseptic methods for surgery.

– His sterile surgical techniques reduced post-surgical infections and saved thousands of lives.



• Robert Koch defined a series of steps (Koch’s Postulates) that could prove that a certain disease was caused by a certain microorganism (1876).

• He conducted research on cattle infected with anthrax: – Cultured bacteria in the lab – Infected healthy animals with it – Found the same bacteria in the blood of the

infected animals


Microorganisms and Disease • Bacteria – single-celled

microorganism • Three main forms


Terms to Remember

bacterium a small, single-celled microorganism that can exist in three main forms, depending on type: spherical (cocci), rod-shaped (bacilli), and spiral (spirochetes)


Microorganisms and Disease

Bacteria cause a variety of illnesses: – Food poisoning – Strep throat – Ear infections – Rheumatic fever – Meningitis – Pneumonia – Tuberculosis – Pinkeye – Acne



• Virus – a microorganism consisting of genetic material encased in protein

• Needs a living host in order to reproduce • Causes many illnesses

– Colds and influenza – Mumps and measles – Chickenpox – Hepatitis – HIV


Terms to Remember

virus a minute infectious agent that does not have all of the components of a cell and thus can replicate only within a living host cell



• Fungus – a parasite that reproduces slowly by means of spores

• Can occur as – Molds – Mildews – Mushrooms


Terms to Remember

fungus a single-celled organism similar to human cells; marked by the absence of chlorophyll, a rigid cell wall, and reproduction by spores; feeds on living organisms (or on dead organic material)



• Molds can be beneficial – source of penicillin

• Can also cause conditions such as – Athlete’s foot – Ringworm – Vaginal yeast infections – More serious systemic fungal infections

in the hospital


Microorganisms and Disease • Protozoa – a microscopic organism

consisting of one cell or a group of identical cells

• Live in water or inside other creatures as parasites

• Examples include paramecia and amoeba

• Can cause dysentery, malaria, and sleeping sickness


Terms to Remember

protozoa a single-celled organism that inhabits water and soil


Asepsis and Sterilization Before scientific control of harmful microorganisms, epidemics and pandemics killed millions of people:

– Bubonic plague killed 137 million Europeans. – European diseases such as smallpox

decimated Native American populations. – One quarter of delivering mothers died of

infections carried by hands and instruments of nurses and physicians.

– Influenza epidemic of 1918 killed over 25 million people worldwide.


Asepsis and Sterilization

• Asepsis is the absence of disease-causing microorganisms.

• Sterilization is any process that destroys microorganisms.

• There are several types of sterilization: – Heat – Dry heat – Mechanical – Gas – Chemical


Terms to Remember

asepsis the absence of disease-causing microorganisms

sterilization a process that destroys the microorganisms in a substance, resulting in asepsis



• Boiling kills vegetative forms, many viruses, and fungi in about 10 minutes.

• More time is needed to kill fungus spores and the hepatitis virus.



• An autoclave sterilizes with heat (270° F) and pressure (15 psi).

• Most known organisms are killed in about 15 minutes.


Terms to Remember

autoclave a device that generates heat and pressure to sterilize



Dry heat (such as direct flaming) kills all organisms:

– Impractical for many substances – Used for disposal of contaminated

objects



• Mechanical sterilization is achieved by means of filtration.

• It is used for heat-sensitive materials: – Culture media – Enzymes – Vaccines – Antibiotic solutions



Gas sterilization is used for materials subject to destruction by heat:

– Uses ethylene oxide – Requires special equipment and

aeration – Used only in large institutions and

manufacturing facilities


Asepsis and Sterilization • Chemical sterilization usually does not

produce complete sterility. • It reduces microbial numbers to safe levels. • Chemicals used for sterilization are known

disinfectants. • Commonly used topical disinfectants

include – Iodine – Isopropyl alcohol (IPA) – Chlorinated bleach


Terms to Remember

disinfectant a chemical applied to an object or topically to the body for sterilization purposes, such as rubbing alcohol


Contamination

• Prevention of contamination in the preparation of IV products is crucial.

• Contaminated IV solution can cause serious infection or death.

• Contamination can occur by – Touch – Air – Water


Touch

• Millions of bacteria live on the skin and hair and under the nails.

• Touching is the most common means of contamination and the easiest to prevent.


Touch

Hand washing and use of gloves and head coverings minimize touch contamination.


Air

• Microorganisms are found in the air, dust particles, and moisture droplets.

• Sterile materials should be prepared in an area designed to keep contaminants to a minimum.

• Special equipment is used to control airflow and minimize contamination.


Water

• Tap water contains microorganisms. • Moisture droplets (especially from a

sneeze or cough) contain harmful microbes.

• Sterile materials must not be exposed to contaminated water.


The Centers for Disease Control and Prevention

• CDC is a federal agency that provides guidelines and recommendations on infection control.

• A major focus of the CDC has been to prevent transmission of infectious diseases in the hospital.

• CDC updates and publishes guidelines to protect patients and healthcare workers from infectious diseases.


Hand Hygiene

• Hand washing and hand hygiene are the most important practices to prevent touch contamination.

• Hand washing involves using plain or antiseptic soap and water.

• Hand hygiene involves using special alcohol-based rinses, gels, or foams that do not require water.


Terms to Remember

hand washing the use of plain or antiseptic soap and water with appropriate time and technique

hand hygiene the use of special dry, alcohol-based rinses, gels, or foams that do not require water


Hand Hygiene

• Effectiveness of hand hygiene depends on – Technique – Presence of artificial fingernails and

jewelry (both can harbor microorganisms)

• Proper hand hygiene technique is used only about 40% of the time.


Gloves • CDC recommends the use of gloves

for workers in the IV area. • Gloves are important because hand

washing alone may not prevent the transmission of microorganisms.

• Gloves are usually made of latex or vinyl, but because some people are sensitive to latex, an alternative should always be available.


Vaccination

• CDC recommends that healthcare workers get an annual flu shot.

• Flu shots protect the workers, their families, and the patients.

• Flu shots are between 70% and 90% effective.

• Only about 40% of healthcare workers get a flu shot each year.


USP Chapter 797 Standards

• USP developed first official and enforceable requirements for sterile preparation compounding (2004).

• Requirements were updated and approved in 2008.

• USP Chapter 797 focuses on sterility and stability.


Terms to Remember

compounded sterile preparation (CSP)

a sterile product that is prepared outside the pharmaceutical manufacturer’s facility, typically in a hospital or compounding pharmacy


USP Chapter 797 Standards

Standards for sterile compounding are more stringent than for nonsterile compounding:

– Must work in a defined clean-room environment – Additional rules for garbing – Personnel training and testing in aseptic

techniques – Specifications for environmental quality – Rules for disinfection of gloves and surfaces


Environmental Quality and Standards

• Compounding facilities are designed and controlled to minimize airborne contaminants.

• 797 standards use the ISO classification system for defining the amount of particulate matter allowed in room air.



Sterile compounding area is divided into three main parts:

– Ante area – Buffer area – Direct

compounding area (DCA)


Terms to Remember

ante area (ante means before) the area of the IV room used for hand washing and donning protective garments, among other high-particulate-generating activities


Terms to Remember

buffer area the area of the IV room used for the storage of components and supplies (such as IV bags and administration sets) that are used for compounding CSPs; also area for hand hygiene and donning protective gloves


Terms to Remember

direct compounding area (DCA) the sterile, compounding area of the IV room, in which the concentration of airborne particles is controlled with a HEPA filter providing ISO Class 5 air quality



• Ante area activities – Personnel hand washing and garbing – Staging of components – Order entry – CSP labeling

• Ante area air quality should be at ISO Class 7 or 8.



• Buffer area is where CSP supplies are stored.

• Buffer area air quality should be no more than ISO Class 7.



• Staging area outside the compounding workbenches should have an air quality of ISO Class 5.

• Compounding is performed in the most sterile area (the DCA) under laminar airflow workbenches (LAFW).



• The buffer area and the direct compounding area together comprise the clean room.

• Air quality is controlled with a high-efficiency particulate air (HEPA) filter system.

• The clean room is physically segregated from the rest of the pharmacy.


Terms to Remember

clean room an area that includes the buffer and staging areas and the sterile, direct compounding area (DCA) of the IV compounding lab


Terms to Remember

high-efficiency particulate air (HEPA) filter

a device used with laminar flow hoods to filter out most particulate matter to prepare parenteral products safely and aseptically



• No food, drink, or chewing gum is permitted in the compounding lab.

• No long-term storage is permitted in the clean room.

• Only specific items needed for sterile compounding can be taken into the DCA.


Special Equipment

• Laminar airflow workbenches (LAFW) are crucial for maintaining air quality in the clean room.

• Horizontal laminar airflow workbench is used to prepare nonhazardous CSPs.

• Vertical laminar airflow workbench is use to prepare hazardous CSPs.


Special Equipment

• In a horizontal LAFW, air flows from the back of the hood, across the work surface, and out into the room.

• Air is filtered with a HEPA filter, which removes 99.97% of particles 0.3 microns or larger.


Terms to Remember

horizontal laminar airflow workbench (LAFW)

a special biological safety cabinet used to prepare IV drug admixtures, nutrition solutions, and other parenteral products aseptically


Special Equipment In a vertical LAFW, air flows from the top of the hood down through a prefilter and a HEPA filter, onto the work surface, and is then circulated through another HEPA filter and vented outside.


Terms to Remember

vertical laminar airflow workbench (LAFW)

a special biological safety cabinet used to prepare hazardous drugs, such as cancer chemotherapy drugs, aseptically

Safety Note


Special Equipment

Coughing and talking should be directed away from the hood and workbench.


Special Equipment

Technicians using a vertical LAFW should wear eye protection, a mask, and proper apparel.


Special Equipment

• Routine cleaning of LAFWs is an important responsibility of the IV technician.

• The entire LAFW should be cleaned with 70% IPA daily.


Special Equipment

The technician should wear full protective clothing while cleaning LAFWs.


Personnel Cleansing and Garb

• Personnel must remove all outerwear before entering the ante area.

• Cleansing process starts with hand washing and putting on protective garb.

• Process continues with hand hygiene in the buffer area.

• Gloves are the last step. • For hazardous materials, extra protection

includes eye protection and double gloving.


Contamination Risk Levels

• Risk levels are assigned to each CSP based on the probability of microbial, chemical, or physical contamination.

• Risk level can be – Low – Medium – High



• Low-risk CSPs include sterile products that have been handled using aseptic techniques.

• Low-risk CSPs also include the transfer, measuring, and mixing of CSPs containing three or fewer ingredients.



• Medium-risk CSPs include multiple sterile products combined using automated devices or transferred from multiple sterile containers into one final sterile container.

• Examples include TPN solutions containing more than three electrolytes or vitamins.


Contamination Risk Levels • High-risk CSPs include

– Products that have been compounded from nonsterile ingredients

– Sterile products without preservatives – Sterile products exposed to inferior air quality

• All high-risk CSPs must be sterilized by using – A 0.22 micron filter – Autoclaving – Dry heat


Terms to Remember

expiration date the date after which a manufacturer’s product should not be used


Training Required to Work with CSPs

• Extensive skills and training are necessary to practice in a clean room.

• Written tests and skill assessments must be passed.

• The technician may be encouraged or required to acquire additional certifications for sterile compounding.


Terms to Remember

infection control committee (ICC) a committee of the hospital that provides leadership in relation to infection control policies


Terms to Remember

nosocomial infection an infection caused by bacteria found in the hospital from any source that causes a patient to develop an infectious disease; also called healthcare-associated infection (HAI)


Infection Control Committee

• Primary role is to prevent, identify, and control nosocomial infections as well as infections brought into the hospital from the community.

• Committee plays a major role in ensuring that the hospital is in compliance with Joint Commission, CDC, and USP Chapter 797 standards.



Sets infection control policy and is involved in planning, monitoring, evaluating, updating and educating

– Surveillance of nosocomial infections – Antibiotic and other product evaluations – Investigation of infection outbreaks and

infection clusters – Development of infection control procedures – Patient education regarding medical waste

management



• Hospital is also responsible for protecting workers from contracting infectious diseases from patients.

• ICC educates all hospital employees about the importance of following procedures to minimize employee exposure.

• Universal precautions are procedures followed in all healthcare settings to prevent infection.


Terms to Remember

sharp a used needle, which can be a source of infection


Terms to Remember

universal precautions procedures followed in healthcare settings to prevent infection as a result of exposure to blood or other bodily fluids



Documents

Chapter 10 · 2012-12-13 · © Paradigm Publishing, Inc. 4 Terms to Remember germ theory of disease the idea that microorganisms cause diseases