decontamination revision lecture

Question 1

define decontamination

Answer 1

a combination of processes including cleaning, disinfection and sterilisation which, together, render a reusable medical device free from contaminants and safe for reuse

Question 2

what are the most resistant types of bacteria?

Answer 2

prions and endospores of bacteria (prions more so)

Question 3

name 5 types of SICP

Answer 3

hand hygiene, PPE, safe disposal of waste and sharps, environmental cleanliness and occupational exposure management

Question 4

what is the purpose of SICPs?

Answer 4

to protect yourself and others

Question 5

What is COSHH and what is its purpose?

Answer 5

Control of Substances Hazardous to Health, purpose is to protect yourself and others

Question 6

give 3 statements from COSHH

Answer 6

employers must:
assess health risks from hazardous substances in the workplace
prevent employees from being exposed to hazardous substances or, if unavoidable, control their risk
prepare procedures to deal with any incidents

Question 7

what must a practitioners policy for acquiring medical devices include?

Answer 7

review of manufacturer’s instructions and decontamination processes before purchase

documented specifications for the device

requirement for medical devices purchased to have the appropriate CE mark

requirement for new devices to meet current standards and be acceptable to both practitioners and decontamination staff

requirement for the correct medical devices to be purchased that can withstand repeated exposures to decontamination processes

Question 8

what is the purpose of a batch code?

Answer 8

allows faulty devices to be traced back to a batch for recall

Question 9

what is the purpose of a serial number?

Answer 9

it is a device’s unique identifier

Question 10

when may single use instruments be favoured?

Answer 10

when there is a high risk of infection, when a reusable item is difficult to clean or when it is more economical or practical

Question 11

what is the manufacturer’s device directive?

Answer 11

defines the info manufacturers are required to provide for users of their products

Question 12

what does a CE mark indicate?

Answer 12

that a medical device satisfies the requirements of the MDD, making it fit for use

Question 13

what is the first stage of the decontamination process?

Answer 13

cleaning

Question 14

what is the aim of cleaning?

Answer 14

to remove all physical contamination as debris may interfere with sterilisation, increase the risk of infection for staff handling the instruments or damage the surface of the instruments therefore affecting the functionality of the device

Question 15

why is automated cleaning favoured?

Answer 15

it is reproducible and more effective

Question 16

why are 3 sinks required for manual cleaning?

Answer 16

sinks for washing, rinsing and hand washing must be kept separate

Question 17

why should CHx or hibiscrub not be used for cleaning of steel instruments?

Answer 17

these agents make proteins stick to steel

Question 18

what kind of brush should be used for manual cleaning?

Answer 18

long handled, soft bristle brush, not metal

Question 19

what do enzymatic detergents do?

Answer 19

they contain molecules which break down proteins, fats and starch

Question 20

why should instruments be immersed in water rather than run under a tap?

Answer 20

to prevent aerosols

Question 21

what type of lid should an ultrasonic cleaner have?

Answer 21

an interlocking lid to prevent aerosols and opening mid-cycle

Question 22

what other features should an ultrasonic cleaner have?

Answer 22

chamber tap drain, time and temperature controls, printer

Question 23

how often should washing solution be changed in an ultrasonic cleaner?

Answer 23

every 4 hours or more frequently if contaminated

Question 24

what tests can be run on an ultrasonic cleaner to check its effectiveness?

Answer 24

foil ablation test and residual soil test

Question 25

describe the principle of a foil ablation test

Answer 25

determines the pattern of erosion on aluminium foil strips suspended in the cleaner

Question 26

what is the second stage of decontamination?

Answer 26

disinfection

Question 27

define disinfection

Answer 27

carried out after all visible soil has been removed and aims to reduce the number of viable microorganisms on a device

Question 28

why are washer-disinfectors favoured?

Answer 28

they are automated and validated, they require minimal human contact, reduce the risk of sharps injuries and are reproducible

Question 29

what are the 5 stages of washer-disinfection?

Answer 29

flush, wash, rinse, thermal disinfection, dry

Question 30

what is an automatic control test for washer-disinfectors?

Answer 30

a cycle run before use to ensure everything is operating correctly

Question 31

why is thermal disinfection preferred over chemical disinfection?

Answer 31

it leaves no harmful residue and some chemicals may have a weakening effect on metals

Question 32

when is visual inspection carried out?

Answer 32

after washing and disinfection

Question 33

what must happen to a device that fails visual inspection?

Answer 33

sent to the start of the cleaning process, sent fro repair or disposed of and replaced

Question 34

how would you carry out visual inspection?

Answer 34

under an illuminated magnifier check for cleanliness, dryness, damage and functionality

Question 35

define functionality

Answer 35

all loving parts can move freely and any blades are aligned and sharp

Question 36

defines sterilisation

Answer 36

the destruction/removal o all living organisms and spores

Question 37

why is debris on the instruments detrimental to the sterilisation process?

Answer 37

they will prevent the stem from contacting all surfaces of the instrument, protect microorganisms, increase the risk of corrosion and prevent the instrument from functioning correctly

Question 38

if a washer-disinfector with a drying cycle is not available what is the alternative?

Answer 38

drying with low-linting paper towels

Question 39

why is drying before sterilisation necessary?

Answer 39

moisture may encourage the growth of microorganisms, contaminate the steam in the steriliser or cause corrosion of the instruments

Question 40

what is the difference between devices packaged before and after sterilisation?

Answer 40

those packaged prior to sterilisation can be labelled sterile afterwards but those packaged afterwards must be labelled sterilised but cannot be labelled sterile

Question 41

what are the requirements of pre-sterilisation packaging?

Answer 41

allows steam penetration, allows steam to circulate instruments, withstands sterilisation, prevents recontamination, maintains sterility, made of non-shedding material, allows placement of adhesive labelling

Question 42

what are the requirements of post-sterilisation packaging?

Answer 42

contains the instrument and keeps it clean during transport and storage

Question 43

what info should a label on a sterilised device offer?

Answer 43

whether contents are sterile or sterilised, cycle number, method of sterilisation, contents info including individual identifier and name of clinic

Question 44

can instruments be used for invasive procedures if packaged after sterilisation?

Answer 44

no, instruments must be sterile at point of use

Question 45

what type of microorganisms are not destroyed by sterilisation?

Answer 45

prions

Question 46

what is the recommended method of sterilisation for dentistry?

Answer 46

high temperature steam sterilisation

Question 47

define sterile

Answer 47

when the theoretical probability of a viable microorganism being present in or on a device following a validated sterilisation process is less than one in a million

Question 48

what are the three key factors for successful sterilisation?

Answer 48

high temperature, sufficient time and air removal

Question 49

what are the standard values for sterilisation in dentistry?

Answer 49

2.25 bar at 134-137 degrees C for 3 minutes

Question 50

what is a type B steriliser?

Answer 50

vacuum type, for packaged, solid, hollow and porous materials, with active air removal

Question 51

what is a type N steriliser?

Answer 51

downward displacement type, for unwrapped solid or lumened handpieces, with passive air removal

Question 52

what is a type S steriliser?

Answer 52

active air removal for wrapped or unwrapped instruments but rarely used in dentistry

Question 53

what are some advantages of steam sterilisation?

Answer 53

practical, cost-effective, non-toxic and readily controlled/monitored

Question 54

what is an FIFO system?

Answer 54

a first in first out system for storage of medical devices to allow for stock rotation

Question 55

what 3 qualities should steriliser water have?

Answer 55

low mineral, pathogen free, endotoxin free

Question 56

why an tap water not be used for sterilisation?

Answer 56

it is high mineral and would cause scaling of the heating element and chamber

Question 57

what should sterilisation records include?

Answer 57

details of daily ACT and steam penetration tests, details of each steriliser cycle and documented evidence that the steriliser was working correctly

Question 58

why is traceability important?

Answer 58

for defence against allegation of an HAI and for procedures with medium or high vCJD risk

Question 59

what would result from having no operational policies in place?

Answer 59

difficulty in providing evidence in a public health investigation that correct practice was followed after an adverse incident, loss of patient confidence and possible legal action