L13 - Prophylaxis

Question 1

What ‘soils’ can act as reservoirs of pathogens?

Answer 1

bodily fluids

dust

Question 2

Definition of cleaning?

Answer 2

process in which substantial amount of any material that is not part of an item is removed

Question 3

Definition of disinfection?

Answer 3

any process in which the potential of an item to cause infection is removed by reducing the number of microorganisms present

Question 4

Definition of Sterilisation?

Answer 4

process used to render an object free from ALL living organisms?

Question 5

desirable properties of chemical disinfectants?

Answer 5

wide spec of microbicidal activity

rapid action

not be inactivated by (in)organic matter

non-corrosive

not irritant

cheap

Question 6

What disinfectants do be normally used in environments?

Answer 6

chlorine-based disinfectants

sodium hypochlorite, chlorine dioxide

Question 7

What disinfectants do we normally used in kitchens and near patients?

Answer 7

Quaternary ammonium compounds (QACs)

Question 8

What bacteria an used QACs as a carbon source?

Answer 8

pseudomonas

Question 9

How do chlorine-based disinfectants work?

Answer 9

disrupt membrane

Question 10

How do QACs work?

Answer 10

membrane damage

Question 11

What are 2 problems with disinfection?

Answer 11

re-contamination of surfaces can be RAPID

Poor education/cost cutting = cleaners spread pathogens through hospital

Question 12

Why do repeat used medical instruments pose a problem?

Answer 12

they have to be cleaned and reused

some cannot be autoclaved

Question 13

How are medical instruments sterilised?

Answer 13

washer disinfectors

equipment packaged and autoclaved

check for prion contamination

Question 14

What pathogens sometimes are not killed by autoclave?

Answer 14

Bovine spongiform encephalopathy - C, J, D

Question 15

What are 4 alternatives to autoclaving?

Answer 15

Ethylene oxide
Glutaraldehye
Peracetic acid
Ionising radiation

Question 16

how does ethylene oxide work?

Answer 16

alkylation of protein/DNA/RNA

Question 17

How does Glutaraldehyde work?

Answer 17

crosslinking of macromolecules

Question 18

How does peracetic acid work?

Answer 18

oxidation

Question 19

How does ionising radiation work?

Answer 19

ROS production - dsDNA breaks, carbonylation of proteins, peroxidation of lipids

Question 20

What are CRE?

Answer 20

carbapenem-resistant eneterbacteriaceae

Question 21

What are duodenoscopes prone to contaminated by?

Answer 21

UPPER GI organisms

Question 22

How does air filtration help prevent infection during surgery?

Answer 22

pass through HEPA

removes 99.97% of all particles >0.3um

Question 23

What are the 3 ways a HEPA filter stops particles

Answer 23

INTERCEPTION - adhere to surface of fiber

IMPACT - do not move fast enough, disintegrate

DIFFUSION - changes movement within HEPA filter - creating increase for impact and interception

Question 24

What 2 areas are disinfected before surgery?

Answer 24

skin in surgical field

hands/arms of surgeon

Question 25

What 2 chemicals used for antisepsis?

Answer 25

Iodophor | Chlorhexadine

Question 26

Definition of anti-septic?

Answer 26

a chemical disinfection compatible with use on skin

Question 27

Mode of action of Iodophor?

Answer 27

inactivation of proteins by binding to thiols - denature

Question 28

Mode of action of Chlorhexadine?

Answer 28

disrupt membrane integrity

Question 29

What alcohol is used in hand gel?

Answer 29

isopropanol

Question 30

benefits of alcohol gel vs. handwashing?

Answer 30

less time accessible location don't dry hands (moisturisers contaminated) not sporocidal

Question 31

What is antibiotic prophylaxis?

Answer 31

use of antibiotics before, during or after a diagnostic, therapeutic or surgical procedure to PREVENT infection

Question 32

Which surgeries require antibiotic prophylaxis?

Answer 32

S.aureus colonised (10-40%) GI, respiratory UT surgeries open wounds fracture bones (debridement) acute inflammation/pus areas

Question 33

Is bone infection easy to clear?

Answer 33

NO - VERY DIFFICULT TO TREAT

Question 34

How are patients tested for S.aureus carrier?

Answer 34

Swab | plate onto selective indicator mediu (MSA, CHROMagar)

Question 35

How are patients carrying S. aureus decolonised?

Answer 35

Mupirocin

Question 36

Post-exposure prophylaxis?

Answer 36

use antimicrobial chemotherapy to prevent disease arising in individuals that have been exposed to pathogen

Question 37

Why is organ transplant prophylaxis needed?

Answer 37

stops body rejecting transplanted organ/tissue

Question 38

How are burn wounds prevented from infection?

Answer 38

remove necrotic tissue apply dressing containing antimicrobial (silver)

Question 39

Why are nano-silver compounds now used?

Answer 39

silver nitrate was painful

Question 40

What is immunisation?

Answer 40

treatment to produce immunity to a disease - typically by inoculation

Question 41

What is passive immunisation?

Answer 41

antibody containing preparations PASSIVE IMMUNITY receive serum containing antibodies SHORT TERM PROPHYLAXIS

Question 42

What is active immunisation?

Answer 42

antigen containing preparations ACTIVE IMMUNITY patient produces antibodies LONG TERM PROPHYLAXIS