Definition
of Terms in
• Aseptic
Techniques: Practices observed in the clinic/hospital setting (including the laboratory)
to protect patients and the staff from being infected with pathogenic
microorganisms and to prevent the contamination of people and their working
environment in general.
• Sepsis:
The presence of pathogenic bacteria in the tissues.
•
Antiseptics: Chemical compounds that inhibit growth pathogens.
•
Antisepsis: The term used to describe disinfection applied to living tissue
(such as a wound).
•
Disinfectants: Chemical compounds that kill micro-organisms but are too toxic
to be used in tissue.
•
Disinfection: The process of freeing an article from some or its entire burden
of
contaminating
microorganisms. Disinfection is a relative term, embracing a wide range of efficacy
against particular viruses, vegetative bacteria and fungi, but not usually
including bacteria spores.
o
Disinfection is applied in circumstances in which sterility is unnecessary or
sterilizing procedures are impracticable. Thus, in the absence of demonstrable
clinical need, it is uneconomical to sterilize bed-pans, eating utensils, bed
linens, and other items of everyday living which may spread infection within
hospitals.
•
Sterilization: The process of freeing of an article from all living organisms
including viruses, bacteria, and fungi and their spores. An article may be
regarded as sterile if it can be demonstrated that there is a probability of
less than one in a million of there being viable microorganism.
•
Decontamination: A process of completely killing or reducing microorganisms
from the contaminated articles.
o The
practice of aseptic techniques was developed after by Dr. John Lister
discovered in 1867 that bacteria were the cause of suppuration if they
contaminated living tissue in surgical wounds.
o The
incidence of sepsis was greatly reduced by covering operation wounds with
dressings
soaked in carbolic acid to kill any bacteria and to exclude others from entry, and
by disinfecting surgeon’s hands and instruments.
o The
current art of aseptic technique has advanced greatly and aseptic techniques
are practised to prevent hospital infection (i.e. nosocomial infection) which
may be exogenous or endogenous in origin.
• The
exogenous environment may be another source of infection in the hospital (cross
infection) or a contaminated item of equipment or building service
(environmental infection).
Micro-Organisms Responsible for Hospital/Laboratory Infections
• Urinary
Tract
o
Escherichia coli
o Klebsiella
spp
o Proteus
species
o Faecal
streptococcus
o Candida
albicans
•
Respiratory Tract
o
Streptococcus pneumoniae
o
Staphylococcus aureus
o
Enterobacteriaceae
o
Respiratory virus
o
Haemophilus influenza
• Wounds and
Skin Infection
o
Escherichia coli
o Proteus
species
o Anaerobes
o Faecal
streptococci
o
Staphylococcus aureus
•
Gastro-Intestinal Infections
o Viruses
o Salmonella
spp
o
Campylobacter spp
o Shigella
sonnei
o Parasites
Importance of Aseptic Techniques
• To provide
sterile equipment that should be used properly to exercise strict personal hygiene
on the part of the operator (hospital/laboratory staff)
• To prevent
health care workers and clients from being infected with pathogenic microorganisms
• To prevent
the environment (community) from being exposed to dangerous pathogens from
hospitals
Types of Aseptic Techniques
1. Cleaning and
Disinfection
• Cleaning
of general hospital environment general waste disposal, and laundry
• Use of
chemical disinfectants, especially when there is spillage of body fluids
•
Heat-disinfection of ward equipment (e.g. bedpans, mop-heads, and clothes) and
storing them in dry places after use
•
Pre-cleaning of contaminated instruments before disinfection or sterilization
2. Skin
Disinfection and Antiseptics
• Thorough
hand washing by hospital/ laboratory staff is essential after any procedure involving
close contact with the patient.
•
Pre-operative disinfection of patient’s skin and for surgical scrubs is
mandatory within the operating theatre.
• Regular
replacement of dilute ‘in-use’ antiseptic solutions so that they are not
colonized with gram-negative bacteria. Ideally, single-use preparations should
be used.
Prophylactic
Antibiotics
• Rational
use of antibiotic prophylaxis plays an important role in infection control.
• Specific
indications include:
o
Peri-operative prophylaxis in gastro-intestinal, gynaecological, and urological
surgery.
o An antibiotic policy which limits choice of broad-spectrum agents is important.
3. Personal
Protective Equipment
• Different
activities within the hospital or laboratory require different degrees of
protection
of staff and patients. For example, clinical coat, aprons, sterile
gowns,sterile gloves, headgear, goggles, boots and face-masks (to minimize shedding
of micro organisms).
• Plastic
aprons and gloves should be used for any ward procedures where there may be soiling,
or for barrier nursing of patients with infectious diseases.
4. Isolation
• It may be
necessary to isolate patients (source isolation) to protect others,( e.g.
keeping them in cubicles (cubicle isolation)).
Hospital and
Laboratory Designs
• Hospital
and laboratory buildings should be designed in such a way that they do not encourage
spread of micro-organisms.
• Floors,
benches, and other surfaces should permit easy cleaning.
• The
designs should consider minimizing potential hospital-acquired infections
especially in operating theatres, laboratories, and air-conditioning systems.
5. Equipment
Selection
• Any object
or item of equipment for clinical use should be assessed to determine the appropriate
method, frequency, and site of decontamination.
6. Personnel
Health Records
• Staff
should receive pre-employment screenings and appropriate immunizations (e.g. Hepatitis
B).
• All staff including students should receive general health protection.
0 Comments