Asepsis and Infection Control
Asepsis
Asepsis is the state of being free from disease-causing contaminants (such as
bacteria, viruses, fungi, and parasites) or, preventing contact with
microorganisms. The term asepsis often refers to those practices used to
promote or induce asepsis in an operative field in surgery or medicine to
prevent infection.
Medical asepsis
1. Includes all practices intended to confine a specific microorganism to a
specific area
2. Limits the number, growth, and transmission of microorganisms
3. Objects referred to as clean or dirty (soiled, contaminated)
Surgical asepsis
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4.
Sterile technique
Practices that keep an area or object free of all microorganisms
Practices that destroy all microorganisms and spores
Used for all procedures involving sterile areas of the body
Principles of Aseptic Technique Only sterile items are
used within sterile field.
1. Sterile objects become unsterile when touched by unsterile objects.
2. Sterile items that are out of vision or below the waist level of the nurse are
considered unsterile.
3. Sterile objects can become unsterile by prolong exposure to airborne
microorganisms.
4. Fluids flow in the direction of gravity.
5. Moisture that passes through a sterile object draws microorganism from
unsterile surfaces above or below to the surface by capillary reaction.
6. The edges of a sterile field are considered unsterile.
7. The skin cannot be sterilized and is unsterile.
8. Conscientiousness, alertness and honesty are essential qualities in
maintaining surgical asepsis
Infection
Signs of Localized Infection
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Localized swelling
Localized redness
Pain or tenderness with palpation or movement
Palpable heat in the infected area
Loss of function of the body part affected, depending on the site and
extent of involvement
Signs of Systemic Infection
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Fever
Increased pulse and respiratory rate if the fever high
Malaise and loss of energy
Anorexia and, in some situations, nausea and vomiting
Enlargement and tenderness of lymph nodes that drain the area of
infection
Factors Influencing Microorganism’s Capability to Produce Infection
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Number of microorganisms present
Virulence and potency of the microorganisms (pathogenicity)
Ability to enter the body
Susceptibility of the host
Ability to live in the host’s body
Anatomic and Physiologic Barriers Defend Against Infection
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Intact skin and mucous membranes
Moist mucous membranes and cilia of the nasal passages
Alveolar macrophages
Tears
High acidity of the stomach
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Resident flora of the large intestine
Peristalsis
Low pH of the vagina
Urine flow through the urethra
NANDA Diagnosis
Risk for Infection
 State in which an individual is at increased risk for being invaded by
pathogenic microorganisms
 Risks factors
 Inadequate primary defenses
 Inadequate secondary defenses
Related Diagnoses
 Potential Complication of Infection: Fever
 Imbalanced Nutrition: Less than Body Requirement
 Acute Pain
 Impaired Social Interaction or Social Isolation
 Anxiety
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Interventions to Reduce Risk for Infection
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Proper hand hygiene techniques
Environmental controls
Sterile technique when warranted
Identification and management of clients at risk
Chain of Infection
1. The chain of infection refers to those elements that must be present to
cause an infection from a microorganism
2. Basic to the principle of infection is to interrupt this chain so that an
infection from a microorganism does not occur in client
3. Infectious agent; microorganisms capable of causing infections are
referred to as an infectious agent or pathogen
4. Modes of transmission: the microorganism must have a means of
transmission to get from one location to another, called direct and indirect
5. Susceptible host describes a host (human or animal) not possessing
enough resistance against a particular pathogen to prevent disease or
infection from occurring when exposed to the pathogen; in humans this
may occur if the person’s resistance is low because of poor nutrition, lack
of exercise of a coexisting illness that weakens the host.
6. Portal of entry: the means of a pathogen entering a host: the means of
entry can be the same as one that is the portal of exit (gastrointestinal,
respiratory, genitourinary tract).
7. Reservoir: the environment in which the microorganism lives to ensure
survival; it can be a person, animal, arthropod, plant, oil or a combination
of these things; reservoirs that support organism that are pathogenic to
humans are inanimate objects food and water, and other humans.
8. Portal of exit: the means in which the pathogen escapes from the reservoir
and can cause disease; there is usually a common escape route for each
type of microorganism; on humans, common escape routes are the
gastrointestinal, respiratory and the genitourinary tract.
Asepsis and Infection Control
Breaking the Chain of Infection
Etiologic agent
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Correctly cleaning, disinfecting or sterilizing articles before use
Educating clients and support persons about appropriate methods to
clean, disinfect, and sterilize article
Reservoir (source)
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Changing dressings and bandages when soiled or wet
Appropriate skin and oral hygiene
Disposing of damp, soiled linens appropriately
Disposing of feces and urine in appropriate receptacles
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Ensuring that all fluid containers are covered or capped
Emptying suction and drainage bottles at end of each shift or before full or
according to agency policy
Portal of exit
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Avoiding talking, coughing, or sneezing over open wounds or sterile fields
Covering the mouth and nose when coughing or sneezing
Method of transmission
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Proper hand hygiene
Instructing clients and support persons to perform hand hygiene before
handling food, eating, after eliminating and after touching infectious
material
Wearing gloves when handling secretions and excretions
Wearing gowns if there is danger of soiling clothing with body substances
Placing discarded soiled materials in moisture-proof refuse bags
Holding used bedpans steadily to prevent spillage
Disposing of urine and feces in appropriate receptacles
Initiating and implementing aseptic precautions for all clients
Wearing masks and eye protection when in close contact with clients who
have infections transmitted by droplets from the respiratory tract
Wearing masks and eye protection when sprays of body fluid are possible
Portal of entry
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Using sterile technique for invasive procedures, when exposing open
wounds or handling dressings
Placing used disposable needles and syringes in puncture-resistant
containers for disposal
Providing all clients with own personal care items
Susceptible host
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Maintaining the integrity of the client’s skin and mucous membranes
Ensuring that the client receives a balanced diet
Educating the public about the importance of immunizations
Modes of Transmission
1. Direct contact: describes the way in which microorganisms are transferred
from person to person through biting, touching, kissing, or sexual
intercourse; droplet spread is also a form of direct contact but can occur
only if the source and the host are within 3 feet from each other;
transmission by droplet can occur when a person coughs, sneezes, spits,
or talks.
2. Indirect contact: can occur through fomites (inanimate objects or
materials) or through vectors (animal or insect, flying or crawling); the
fomites or vectors act as vehicle for transmission
3. Air: airborne transmission involves droplets or dust; droplet nuclei can
remain in the air for long periods and dust particles containing infectious
agents can become airborne infecting a susceptible host generally through
the respiratory tract
Course of Infection
1. Incubation: the time between initial contact with an infectious agent until
the first signs of symptoms the incubation period varies from different
pathogens; microorganisms are growing and multiplying during this stage
2. Prodromal Stage: the time period from the onset of nonspecific symptoms
to the appearance of specific symptoms related to the causative pathogen
symptoms range from being fatigued to having a low-grade fever with
malaise; during this phase it is still possible to transmit the pathogen to
another host
3. Full Stage: manifestations of specific signs & symptoms of infectious agent;
referred to as the acute stage; during this stage, it may be possible to
transmit the infectious agent to another, depending on the virulence of the
infectious agent
4. Convalescence: time period that the host takes to return to the pre-illness
stage; also called the recovery period; the host defense mechanisms have
responded to the infectious agent and the signs and symptoms of the
disease disappear; the host, however, is more vulnerable to other
pathogens at this time; an appropriate nursing diagnostic label related to
this process would be Risk for Infection
Inflammation
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The protective response of the tissues of the body to injury or infection;
the physiological reaction to injury or infection is the inflammatory
response; it may be acute or chronic
Body’s response
1. The “inflammatory response” begins with vasoconstriction that is followed
by a brief increase in vascular permeability; the blood vessels dilate
allowing plasma to escape into the injured tissue
2. WBCs (neutrophils, monocytes, and macrophages) migrate to the area of
injury and attack and ingest the invaders (phagocytosis); this process is
responsible for the signs of inflammation
3. Redness occurs when blood accumulates in the dilated capillaries; warmth
occurs as a result of the heat from the increased blood in the area,
swelling occurs from fluid accumulation; the pain occurs from pressure or
injury to the local nerves.
Immune Response
1. The immune response involves specific reactions in the body to antigens
or foreign material
2. This specific response is the body’s attempt to protect itself, the body
protects itself by activating 2 types of lymphocytes, the T-lymphocytes and
B-lymphocytes
3. Cell mediated immunity: T-lymphocytes are responsible for cellular
immunity
 When fungi , protozoa, bacteria and some viruses activate Tlymphocytes, they enter the circulation from lymph tissue and seek out
the antigen
 Once the antigen is found they produce proteins (lymphokines) that
increase the migration of phagocytes to the area and keep them there
to kill the antigen
 After the antigen is gone, the lymphokines disappear
 Some T-lymphocytes remain and keep a memory of the antigen and
are reactivated if the antigen appears again.
4. Humoral response: the ability of the body to develop a specific antibody to
a specific antigen (antigen-antibody response)
 B-lymphocytes provide humoral immunity by producing antibodies that
convey specific resistance to many bacterial and viral infections
 Active immunity is produced when the immune system is activated
either naturally or artificially.
3.
 Natural immunity involves acquisition of immunity through
developing the disease
4.
 Active immunity can also be produced through vaccination by
introducing into the body a weakened or killed antigen (artificially
acquired immunity)
5.
 Passive immunity does not require a host to develop antibodies,
rather it is transferred to the individual, passive immunity occurs
when a mother passes antibodies to a newborn or when a person
is given antibodies from an animal or person who has had the
disease in the form of immune globulins; this type of immunity only
offers temporary protection from the antigen.
Types of Immunity
Active Immunity
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Host produces antibodies in response to natural antigens or artificial
antigens
Natural active immunity
 Antibodies are formed in presence of active infection in the body
 Duration lifelong
Artificial active immunity
 Antigens administered to stimulate antibody formation
 Lasts for many years
 Reinforced by booster
Passive Immunity
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Host receives natural or artificial antibodies produced from another source
Natural passive immunity
 Antibodies transferred naturally from an immune mother to baby
through the placenta or in colostrums
 Lasts 6 months to 1 year
Artificial passive immunity
 Occurs when immune serum (antibody) from an animal or another
human is injected
 Lasts 2 to 3 weeks
Nosocomial Infection
1. Nosocomial Infections: are those that are acquired as a result of a
healthcare delivery system
2. Iatrogenic infection: these nosocomial infections are directly related to the
client’s treatment or diagnostic procedures; an example of an iatrogenic
infection would be a bacterial infection that results from an intravascular
line or Pseudomonas aeruginosa pneumonia as a result of respiratory
suctioning
3. Exogenous Infection: are a result of the healthcare facility environment or
personnel; an example would be an upper respiratory infection resulting
from contact with a caregiver who has an upper respiratory infection
4. Endogenous Infection: can occur from clients themselves or as a
reactivation of a previous dormant organism such as tuberculosis; an
example of endogenous infection would be a yeast infection arising in a
woman receiving antibiotic therapy; the yeast organisms are always
present in the vagina, but with the elimination of the normal bacterial flora,
the yeast flourish.
Risks for Nosocomial Infections
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Diagnostic or therapeutic procedures
 Iatrogenic infections
Compromised host
Insufficient hand hygiene
Factors Increasing Susceptibility to Infection
1. Age: young infants & older adults are at greater risk of infection because of
reduced defense mechanisms
 Young infants have reduced defenses related to immature immune
systems
 In elderly people, physiological changes occur in the body that make
them more susceptible to infectious disease; some of these changes
are:
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 Altered immune function (specifically, decreased phagocytosis by
the neutrophils and by the macrophages)
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 Decreased bladder muscle tone resulting in urinary retention
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 Diminished cough reflex, loss of elastic recoil by the lungs leading
to inability to evacuate normal secretions
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 Gastrointestinal changes resulting in decreased swallowing ability
and delayed gastric emptying.
2. Heredity: some people have a genetic predisposition or susceptibility to
some infectious diseases
3. Cultural practices: healthcare beliefs and practices, as well as nutritional
and hygiene practices, can influence a person’s susceptibility to infectious
diseases
4. Nutrition: inadequate nutrition can make a person more susceptible to
infectious diseases; nutritional practices that do not supply the body with
the basic components necessary to synthesized proteins affect the way
the body’s immune system can respond to pathogens
5. Stress: stressors, both physical and emotional, affect the body’s ability to
protect against invading pathogens; stressors affect the body by elevating
blood cortisone levels; if elevation of serum cortisone is prolonged, it
decreases the anti-inflammatory response and depletes energy stores,
thus increasing the risk of infection
6. Rest, exercise and personal health habits: altered rest and exercise patterns
decrease the body’s protective, mechanisms and may cause physical
stress to the body resulting in an increased risk of infection; personal
health habits such as poor nutrition and unhealthy lifestyle habits increase
the risk of infectious over time by altering the body’s response to
pathogens
7. Inadequate defenses: any physiological abnormality or lifestyle habit can
influence normal defense mechanisms in the body, making the client more
susceptible to infection; the immune system functions throughout the body
and depends on the following:
 Intact skin and mucous membranes
 Adequate blood cell production and differentiation
 A functional lymphatic system and spleen
 An ability to differentiate foreign tissue and pathogens from normal
body tissue and flora; in autoimmune disease, the body has a problem
with recognizing its own tissue and cells; people with autoimmune
disease are at increased risk of infection related to their immune
system deficiencies.
8. Environmental: an environment that exposes individuals to an increased
number of toxins or pathogens also increases the risk of infection;
pathogens grow well in warm moist areas with oxygen (aerobic) or without
oxygen (anaerobic) depending on the microorganism, an environment that
increases exposure to toxic substances also increases risk
9. Immunization history: inadequately immunized people have an increased
risk of infection specifically for those diseases for which vaccines have
been developed.
10. Medications and medical therapies: examples of therapies and
medications that increase clients risk for infection includes radiation
treatment, anti-neo-plastic drugs, anti inflammatory drugs and surgery
Diagnostic Tests Used to Screen for Infection
1. Signs and symptoms related to infections are associated with the area
infected; for instance, symptoms of a local infection on the skin or mucous
membranes are localized swelling, redness, pain and warmth
2. Symptoms related to systemic infections include fever, increased pulse &
respirations, lethargy, anorexia, and enlarged lymph nodes
3. Certain diagnostic tests are ordered to confirm the presence of an
infection.
Category-specific Isolation Precautions
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Strict isolation
Contact isolation
Respiratory isolation
Tuberculosis isolation
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Enteric precautions
Drainage/secretions precautions
Blood/body fluid precautions
Disease-specific Isolation Precautions
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Delineate practices for control of specific diseases
 Use of private rooms with special ventilation
 Cohorting clients infected with the same organism
 Gowning to prevent gross soilage of clothes
Universal Precautions (UP)
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Used with all clients
Decrease the risk of transmitting unidentified pathogens
Obstruct the spread of bloodborne pathogens (hepatitis B and C viruses
and HIV)
Used in conjunction with disease-specific or category-specific precautions
Body Substance Isolation (BSI)
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Employs generic infection control precautions for all clients
Body substances include:
 Blood
 Urine
 Feces
 Wound drainage
 Oral secretions
 Any other body product or tissue
Standard Precautions
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Used in the care of all hospitalized persons regardless of their diagnosis
or possible infection status
Apply to:
 Blood
 All body fluids, secretions, and excretions except sweat (whether or
not blood is present or visible)
 Nonintact skin and mucous membranes
Combine the major features of UP and BSI
Transmission-based Precautions
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Used in addition to standard precautions
For known or suspected infections that are spread in one of three ways:
 Airborne
 Droplet
 Contact
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May be used alone or in combination but always in addition to standard
precautions
Managing Equipment Used for Isolation Clients
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Many supplied for single use only
Disposed of after use
Agencies have specific policies and procedures for handling soiled
reusable equipment
Nurses need to become familiar with these practices
Bloodborne Pathogen Exposure
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Report the incident immediately
Complete injury report
Seek appropriate evaluation and follow-up
Identification and documentation of the source individual when feasible
and legal
Testing of the source for hepatitis B, C and HIV when feasible and
consent is given
Making results of the test available to the source individual’s health care
provider
Testing of blood exposed nurse (with consent) for hepatitis B, C, and HIV
– please check these to match style used in book – fairly certain it should
be caped antibodies
Postexposure prophylaxis if medically indicated
Medical and psychologic counseling
Puncture/Laceration
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Encourage bleeding
Wash/clean the area with soap and water
Initiate first aid and seek treatment if indicated
Mucous membrane exposure (eyes, nose, mouth)
Flush with saline or water flush for 5 to 10 minutes
Postexposure Protocol (PEP) for HIV
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Start treatment as soon as possible preferably within hours after exposure
For “high-risk” exposure (high blood volume and source with a high HIV
titer), three drug treatment is recommended
For “increased risk” exposure (high blood volume or source with high HIV
titer), three-drug treatment is recommended
For “low risk” exposure (neither high blood volume nor source with a high
HIV titer), two-drug treatment is considered
Drug prophylaxis continues for 4 weeks
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Drug regimens vary and new drugs and regimens continuously being
developed
HIV antibody tests should be done shortly after exposure (baseline), and 6
weeks, 3 months, and 6 months afterward
Postexposure Protocol (PEP) for Hepatitis B
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Anti-HBs testing 1 to 2 months after last vaccine dose
HBIG and/or hepatitis B vaccine within 1 to 7 days following exposure for
nonimmune workers
Postexposure Protocol (PEP) for Hepatitis C
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Anti-HCV and ALT at baseline and 4 to 6 months after exposure