Asepsis and infection control notes

Asepsis
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state of being free from disease-causing micro-organisms such as bacteria,
viruses, fungi, and parasites.
• preventing contact with microorganisms.
• practices that 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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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
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The invasion and multiplication of microorganisms such as bacteria, viruses, and
parasites that are not normally present within the body.
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 that 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
Resident flora of the large intestine
Peristalsis
Low pH of the vagina
Urine flow through the urethra
NANDA Diagnosis
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Risk for Infection
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State in which an individual is at increased risk for being invaded by
pathogenic microorganisms
Risks factors
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Inadequate primary defenses
Inadequate secondary defenses
Related Diagnoses
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Potential Complication of Infection: Fever
Imbalanced Nutrition: Less than Body Requirement
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Acute Pain
Impaired Social Interaction or Social Isolation
Anxiety
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.
Ways of 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
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 Tlymphocytes and B-lymphocytes
3. Cell mediated immunity: T-lymphocytes are responsible for cellular
immunity
▪ When fungi , protozoa, bacteria and some viruses activate
T-lymphocytes, 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
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Active immunity is produced when the immune system is
activated either naturally or artificially.
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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A. Altered immune function (specifically,
decreased phagocytosis by the neutrophils and
by the macrophages)
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B. Decreased bladder muscle tone resulting in
urinary retention
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C. Diminished cough reflex, loss of elastic recoil
by the lungs leading to inability to evacuate
normal secretions
D. Gastrointestinal changes resulting in
decreased swallowing ability and delayed
gastric emptying.
Heredity: some people have a genetic predisposition or
susceptibility to some infectious diseases
Cultural practices: healthcare beliefs and practices, as well as
nutritional and hygiene practices, can influence a person’s
susceptibility to infectious diseases
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
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
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
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.
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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
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
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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
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
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