This document provides guidelines on infection control and cleaning of anaesthetic airway equipment. It defines key terms like asepsis, antisepsis, decontamination, disinfection, and sterilization. Cleaning airway equipment involves decontamination, cleaning, and either disinfection or sterilization. Equipment is classified as critical, semi-critical, or non-critical depending on its contact with patients. Proper hand hygiene and cleaning, disinfection or sterilization of equipment after each use is essential to prevent spread of infection. Chlorine solution is commonly used for decontamination, and high-level disinfection or sterilization is recommended for critical equipment.

1. Anaesthetic Airway Equipment and
Infection control
University of Gondar
School of Medicine
Department of Anesthesia

2. Anaesthetic
Airway
Equipment and
Infection control

3. Definitions /terms
• Asepsis: the prevention of microbial contamination of living tissues or
sterile materials.
• Antisepsis: chemical destruction of vegetative pathogens on living
tissue
• Decontamination: the removal of micro-organisms and unwanted
matter from contaminated materials or living tissue.
• Disinfection: the inactivation of non- sporing organisms using either
thermal or chemical means.
• Sterilisation: complete destruction of all micro-organisms, including
spores.

4. Decontaminating
equipment
Cleaning
Disinfection
Sterilization

5. Cleaning airway equipment prior to reuse involves three/four
steps:
 Decontamination
 Cleaning
 Disinfection or
 Sterilization
• It is very important to perform all four steps to make equipment safe
for future patients and for the staff that handle the equipment.
• Equipment is easier to clean if blood/sputum is not allowed to dry,
so wipe equipment such as a laryngoscope blade after use with wet
gauze or soak it in water before decontaminating it.

6. 1. Decontamination
• To kill the most harmful bacteria and viruses
• This process kills bacteria and viruses including Hepatitis B,
Hepatitis C and HIV.
• The purpose of this step is to make the equipment safer when
handled, by reducing the risk of infection to the person cleaning
it.

7. 1. Decontamination
• Put equipment in a bucket full of 0.5% chlorine solution (sodium
hypochlorite 'bleach') for 10 minutes: the cheapest and most
rapid decontaminant.
• It can be used on most equipment but rubber and metal should not
soak for over 20 minutes otherwise they will discolour or rust
• Alternatives are:
 70% ethyl or isopropyl alcohol: It has similar uses to chlorine
• 0.5–3% phenolic compounds : these discolour plastic and rubber,
so are used for metals, such as laryngoscopes

8. 2. Cleaning
• A process to remove visible dirt including dust, soil, blood or
other body fluids.
• It also removes up to 80% of bacteria and viruses.
• Proper cleaning is vital otherwise disinfection or sterilisation
will be much less effective.

9.  Automatic cleaning Examples are: Ultrasonic cleaner and
washer-sterilizer , Effective May not be available due to
expense
 Manual cleaning
• Use soapy water and a brush until the equipment looks clean,
especially the small parts.
• Water temperature should be below 45oC to stop blood clotting
• When it is clean, rinse with clean water and air dry

10. • Disinfection
• The destruction of pathogenic and other kinds of microorganisms
by physical and chemical means.
• This eliminates 95% of microorganisms, all except some bacterial
spores, such as Clostridium, as they have a thick cell wall.

11.  Low Level Disinfection: kills most vegetative bacteria (except TB
and endospores), some fungi and some viruses using disinfectants
such as sodium hypochlorite, 70% alcohol and chlorhexidine.
 Intermediate level disinfectants Vegetative bacteria most viruses
and fungi. : TB
 High Level Disinfection :
• kill all microorganisms but not spores in less than 45min.
• With sufficient contact time (often several hours), these high level
disinfectants may produce sterilisation, e.g. the use of aldehydes,
peracetic acid and chlorine dioxide

12. Disinfection, How: Options include:
 Steaming: for 20 minutes
 Boiling should be at 100oC for 20 minutes
 Chemical
 Example immersing in: 2% glutar aldehyde for 20 minutes
(takes 60 minutes to kill TB) 0.3% bicarbonate must be added to
activate it .
 It is irritating to the skin so items must be rinsed three times in
sterile water and left to dry after using glutaraldehyde

13. Disinfection..
 Is that good enough?
• This is adequate for most airway equipment as it will usually only
be touching mucous membranes or broken skin, but not entering
normally sterile tissues.

14. • Solution
• The most commonly used agent is chlorine solution
(hypochlorite bleach).
• A chlorine solution of 0.5% is the most commonly used for
decontamination.
• It can be made by diluting household bleach (which is a 3-6%
chlorine solution) or adding chlorine tablets or powder to water.

15. How to Make A Chlorine Solution:
• Question : How do you make a 0.5% chlorine solution from a
5% chlorine solution? (That is, how much water do you need
to mix with 1 litre of 5% chlorine to make 0.5% chlorine?)

16. To make a 0.5% chlorine solution
 We need to make : 0.5% chlorine, which is 5 mg/ml
 We have : 5% chlorine solution, which is 50 mg/ml
 50 / 5 = 10. So the 5% chlorine must be diluted to a 1:10 dilution
 This means 1 part 5% chlorine solution to 9 parts water (not 10
parts )of water Or a useful calculation is:
 So for this answer: (5% / 0.5%) - 1 = 10 – 1 = 9 parts of water
needed

17. Common sterilizers and disinfectants
 Sterilizer
– Moist heat (>121 oC)
– Dry heat (> 160 oC)
– Ionizing radiation
• Disinfectant
– Physical
• Ultraviolet radiation
• Hydrostatic pressure

18.  Chemical
• Alcohols, Phenols
• Quaternary ammonium compounds, Glutaraldehyde
• Iodine and iodine compounds
• Chlorine species (free chlorine, chloramines, and
chlorine dioxide).

19. Mechanisms of sterilizers and disinfectants
 Sterilizer
– Moist and dry heat: protein desaturation, enzyme inhibition,
RNA and DNA breakdown
– Ionizing radiations: single or double-strand breakage in DNA
 Disinfectants
– UV radiation : thymine dimers
– Chemical disinfectants : protein denaturation, enzyme inhibition,
breakdown of nucleic acids

20. Mode of action of (chemical) disinfectants
• Adsorption on the microbes’ surface
• Diffusion through the surface
• Binding to the vulnerable sites (e.g. plasma membrane, cytoplasmic
proteins, nucleic acids, and so on)
• Injury and death of the microbes

22.  Semi-critical:
• the device will be in contact with intact mucous membranes or
may become contaminated with readily transmissible organisms
• these devices require high level disinfection or sterilisation.
 Non-critical: the device contacts intact skin or does not contact
patient directly – these devices require low level disinfection or
cleaning.

23. Classification of device, process, and products
Device
Process Product
Classification Examples
Critical Implant, surgical
instrument
Sterilization Sterilant/disinfectant
Semicritical Flexible endoscope,
laryngoscope,
endotracheal tube
High-level Sterilant/disinfectant
Thermometer,
hydrotherapy tank
Intermediate-
level
Hospital disinfectant
with tuberculocidal
activity
Noncritical Stethoscope,
tabletops, bedpans
Low-level Sterilant/disinfectant
without tuberculocidal
activity

24. Anaesthetic apparatus
• Items of anaesthetic equipment may become contaminated either by
direct contact with patients, indirectly via splashing, by secretions or
from handling by staff.
• Contamination is not always visible and all used pieces of
equipment must be assumed to be contaminated and disposed of or,
if reusable, undergo a process of decontamination.

25. • The Code of Practice has specific requirements for the
decontamination of surgical equipment and other equipment
used in patient care.
• There is a need to designate a person who is responsible for
ensuring equipment cleanliness.

26. Single-use equipment
• The balance between single-use items and re-usable
equipment will require local determination based on an
assessment of patient safety, the available facilities and
cost.

27. Anaesthetic face masks
• Normally in contact with intact skin, these items are frequently
contaminated by secretions and would be considered semi-
critical, requiring cleaning and thermal disinfection after use.

28. Laryngoscopes
• Laryngoscope blades are considered critical equipment
because they may penetrate skin or mucous membranes, and as
such, require sterilisation.
• Laryngoscope handles should be cleaned with detergent and
water between each patient use.
• If contaminated with blood, they should be washed and
disinfected.

29. • The laryngoscope handle should be cleaned the same way as the
blade, because the blade often touches the handle and
contaminates it with blood or secretions.
• First, disconnect the laryngoscope blade and handle.
• Some laryngoscope bulbs need removing before cleaning, so
check manufacturers instructions.
• Most laryngoscopes require removal of the batteries before
cleaning.

30.  Bougies
• Re-use of these items is associated with cross-infection.
• It is preferable that alternative single-use intubation aids are
employed when possible.

31. Anaesthetic breathing systems
• If visibly internally or externally contaminated, or used for known
high-risk infectious cases, the circuits should be changed between
patients unless a heat moisture exchange bacterial filter is used.
• The breathing bag is easily contaminated by hand contact during
induction and emergence from anaesthesia.
• Breathing bags should be cleaned with detergent and water between
each patient use or replaced if single use.

32. Anaesthetic machines
• Routine daily sterilisation or disinfection of internal components
of the anaesthetic machine is not necessary if a bacterial/viral
filter is used between patient and circuit.
• However, cleaning and maintenance policies should be followed
and bellows, unidirectional valves and carbon dioxide absorbers
should be cleaned and disinfected periodically.

33. Surfaces and monitors
• The surface of the anaesthetic machine and monitoring equipment
should be cleaned between each patient with detergent and water.
• This includes NIBP cuffs and tubing, pulse oximeter probes and
cables, stethoscopes, electrocardiographic cables, blood warmers etc,
and the exterior of anaesthetic machines and monitors.
• Items such as temperature probes should be single patient use.
• Touch screens and control knobs should also be cleaned.

34. Disposable airway equipment
• It is recommended that disposable airway equipment is used where
available
• If replacement equipment is not available, equipment should be
decontaminated, cleaned and either disinfected or sterilised.
• Sterilisation gets rid of the most micro-organisms and so is
recommended, but it is not essential for most airway equipment

35. • Equipment that must be disposed of after use on a patient
include:
– Bacterial filters
– Equipment that is too narrow bore to be cleaned properly,
– Needle cricothyroidotomy cannula and scalpel used for
surgical cricoththyroidectomy

36. Preparation
• It is useful to have two trolleys (carts) for airway equipment
for adults:
Routine Airway Equipment Trolley
Difficult Intubation Trolley
• With attached contents list

39. A daily check is done to ensure that airway trolleys
• Are stocked properly, including important spares such as batteries
• Any missing pieces of equipment should be replaced from a store room
• Do not contain equipment that does not work.
• If you find something is not working properly, get it repaired or
replaced
• New equipment such as facemasks and spare breathing circuits are best
kept in their packaging until they are ready to be used

40. Hand hygiene
• Hand hygiene is the most important infection control measure.
• The term “hand hygiene” encompasses the use of soap/solution
(non-antimicrobial or antimicrobial) and water, or a waterless
antimicrobial agent to the surface of the hands.
• Effective hand hygiene should be performed before and after
each patient contact

41. • Hand preparation increases the effectiveness of decontamination
• Keep nails short, clean and polish free
• Avoid wearing wrist watches and jewellery, especially rings with
ridges or stones
• Artificial nails must not be worn
• Any cuts and abrasions should be covered with a waterproof dressing.
• Remove wristwatch and any bracelets and roll up long sleeves before
washing hands (and wrists).

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44. Bad practice

45. Order of patients
• ‘Dirty cases’, i.e. patients likely to disperse microbes of particular
risk to other patients, should be identified before surgery and
theatre staff should be notified.
• These patients should be scheduled last on an operating list to
minimise risk.

46. Key Points
• Anaesthetists must ensure that good hand hygiene becomes an
indispensable part of their clinical culture
• Decontamination to remove Hepatitis B, C and HIV
• Cleaning to remove dirt so that disinfection and sterilisation will
work
• Disinfection to remove 95% of bacteria and viruses except spores, or
Sterilisation to remove all micro-organisms

47. Key points
• Many infection prevention and control measures are simple
and low-cost
– Hand hygiene
– Correct application of basic precautions during invasive
procedures
– Require staff accountability and behavioural change

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