Chemical sterilisation and disinfection Student PPT.pptx

ppt presentation

1. Sterilization and Disinfection Competency Covered MI 1.4, 1.5

2. At the end of the session, the students will be able to understand: What is chemical sterilization, disinfection - high-level disinfectant, intermediate-level disinfectant, low-level disinfectant Types of Cleaning Agent and Environmental Cleaning Methods to Test Efficacy of Disinfectant C SSD

3. Level of sterilant/ disinfectants according to their microbicidal action

4. Spaulding’s Classification of Medical Devices

5. Chemo sterilisation Chemical agents Chemosterilant Ethylene Oxide(ETO) P lasma gas

6. Ethylene Oxide(ETO) Highly penetrative, non-corrosive, microbicidal gas Kills the microorganisms by broad spectrum activity Highly toxic, inflammable, explosive and irritant gas This will kill all types of microbes including bacterial spores provided it is used with suitable humidity, at correct temperature and for sufficient time Used at 10% concentration by mixing with inert gases like CO 2 or N 2 to reduce the risk of explosion Duration – 2 hours

7. Application of ETO Used as chemosterilant Effective for heat and moisture sensitive materials Used to sterilize the instruments – Heart lung machine components, respiratory ventilators, heat sensitive endoscopes Sterilize single use disposable articles like syringes, needles, catheters, sutures, gloves, face masks etc. Precautions Mutagenic/carcinogenic – potential risk to both operator and patients Strictly monitored for safety and effectiveness

8. Gas Plasma Sterilisation This system uses a completely new technology applying radio frequency emissions to the hydrogen peroxide substrate. Gas plasmas have been referred to as the fourth state of matter. A gas plasma is created by the electric field. To facilitate maximum dispersion of the hydrogen peroxide vapor around the equipment, a deep vacuum is generated which also helps to avoid using excessive heat. It does not produce any harmful substances; water and oxygen being the end products.

9. This method effectively used to sterilize glass items, plastics, polyvinyl chloride (PVC), metal items, electric and fiber optic cables as well as rigid endoscopes, Unsuitable for cellulosic material like linen, cotton, and paper. The cycle does not need aeration and equipment can be used immediately. It is less expensive as compared to ETO, but needs special compatible supplies like wraps and trays. No toxic residues remain on the sterilized items after completion of gas plasma sterilisation. The heat and moisture sensitive instruments can be sterilized by this process in about one hour.

10. CLASSIFICATION OF DISINFECTION DISINFECTANT PHYSICAL AGENT HEAT RADIATION HALOGENS SURFACE ACTIVE SUBSTANCES CHEMICAL AGENT FILTERATION BIGUANIDE ALCOHOL PHENOL AND PHENOLIC COMPOUNDS

11. Disinfection Disinfection means the destruction or removal of all pathogenic organisms, or organisms capable of giving rise to infection Process that destroys or removes most if not all pathogenic organisms but may or may not destroy bacterial spores. Achieved by a physical agent or a chemical agent. Used only on inanimate objects, not on body surfaces.

12. Disinfectants – chemicals used for disinfection Disinfectant are mainly applied to inanimate objects Antiseptics - the chemical disinfectants which can be safely applied on the skin or mucous membrane to prevent infection Sepsis - is presence of pathogenic organisms in living tissue Asepsis - is absence of significant contamination Antisepsis - is prevention of infection, usually by inhibiting the growth of bacteria in wounds or tissues Aseptic techniques - are the measures used to prevent contamination during any invasive procedure

13. Chemical disinfectants Factors influencing disinfection by chemical disinfectants Concentration Time of action pH of the medium Temperature Nature of organisms Presence of organic matters – pus, blood, fats etc.

14. Mode of action Protein coagulation Disruption of cell membrane Removal of free sulphydryl groups that are essential for the functioning of the enzymes and thus the life of the cell

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16. Alcohols Ethanol and Isopropyl alcohol At 60-70% concentration in water used as Skin antiseptics Disadvantage – relatively inactive against spores and fungi, inflammable Methanol – used to disinfect the surface of clean inanimate objects – incubator, inoculating hood, trolley tops Can’t be used as skin antiseptics because toxic

17. Aldehydes 1. Formaldehyde 40% of water solution of formaldehyde is formalin Has bactericidal, sporicidal and viricidal effect Applications - Formalin is used to fumigate (disinfect) OT, ICU, hospital wards, inoculating hood, incubators etc. Formaldehyde gas is used in special machines for decontamination of anesthetic equipment Toxic and irritant to skin and eyes

18. 2. Gluteraldehyde Superior over formaldehyde being less toxic and irritant Effective against TB, fungi and viruses Application At 2% concentration used to disinfect fibre optic endoscopes, anesthetic tubes, haemodialysers

19. Dyes Two groups 1. Aniline dyes – malachite green, crystal violet Used as selective agents in culture media 2. Acridine dyes – acriflavine , proflavine Used as skin and wound antiseptics

20. Halogens 1. Iodine Highly active against vegetative form of bacteria and has some action on fungi, viruses and spores Tincture of iodine and Iodophores – most widely used skin antiseptics

21. 2. Chlorine Mainly used in the form of sodium hypochlorites Active against all bacteria including spores, viruses and fungi Used to purify water supplies, food and dairy industries Hypochlorite solution 0.5% used for blood spillage in general

22. Phenolics A group of compound also known as coal tar derivatives obtained by distillation of coal tar 1. Phenol – is the parent compound of this group also known as ‘carbolic acid’ Effective against many bacteria- TB, viruses but not spores Used at 5% concentration to disinfect floors, working bench 2. Cresol - 2% solution to disinfect the floors

23. 3. Lysol – Cresol + soap solution - disinfection of instruments, furniture 4. Chloroxylenol (Dettol) – chlorine, cresol, terpineol and alcohol - antiseptic and deodorant

24. Gaseous substances 1. Formaldehyde 2. Ethylene oxide – chemosterilant 3. Betapropiolactone ( BPL ) - Condensation product of Ketone and formaldehyde More efficient for fumigation purposes than formaldehyde- rapid bactericidal action Used for fumigation of rooms

25. Surface active agents These are substances that reduces surface tension. Mainly used as detergents, emulsifiers and wetting agents 4 main groups Anionic Cationic – E.g. Quaternary ammonium compounds most important antibacterial agents Nonionic Amphoteric

26. Metal salts Mercuric chloride, silver nitrate As wound antiseptics

27. Oxidising agents KMnO 4 - as water purifier H 2 O 2 – to clean septic wounds

28. Biguanides Chlorhexidine – Savlon Uses – as antiseptic for skin and mucous membrane, preoperative skin preparation, preoperative scrub for surgeons, local antisepsis in urethra before catheterisation Chlorhexidine + alcohol + glycerine – for rapid antisepsis in busy IC and neurological units

29. Testing of disinfectants Chemical disinfectants used in hospitals and laboratories must be tested periodically to ascertain its potency and efficacy. Various methods are available: Rideal and Walker test or Phenol coefficient test Chick Martin test Capacity (Kelsey-Sykes) test In-use (Kelsey-Maurer) test The liquid phase of disinfectant solutions in actual use in hospital practice is examined quantitatively for viable organisms

30. TYPES OF DISINFECTANTS 1. HIGH LEVEL DISINFECTANTS Examples: Aldehyde, gases Uses: for endoscope and surgical instruments 2. INTERMEDIATE LEVEL DISINFECANTS Example: alcohol, iodophore Uses: laryngoscope 3. LOW LEVEL DISINFECTANTS Example: quaternary ammonium compounds Uses: electrocardiogram, stethoscope

31. CLEANING AGENT Most disinfectants act well when instrument or surface - is free from organic matter Therefore, cleaning is a very important step which need be performed before the disinfectants are applied An ideal cleaning agent should have the following properties: Easily emulsifiable Saponifiable Water softening Non-toxic Have surfactant like action.

32. Enzymatic (proteolytic) cleaners: Contain enzymes such as amylase, lipase, cellulase, protease which break down proteinaceous matter present on equipment. Cleaning chemicals (detergents): Act by reducing surface tension and dissolving fat and organic matter. Manual cleaning Automatic or mechanical cleaning (e.g. ultrasonic washers, washer disinfectors)– useful to clean hard-to reach parts of instruments

33. ENVIRONMENTAL CLEANING Environmental cleaning of floor and surface of hospitals play a vital role in controlling the spread of infections. General principles of environmental cleaning are as follows: Cleaning followed by disinfection Frequency of cleaning depends up on: Probability of contamination, Vulnerability of population to infection, Frequency of hand contact

34. Frequency of cleaning for common situations: Non-critical surfaces and floors - 2–3 times a day Mattress used for patients - cleaned weekly and after discharge Doors, windows, walls and ceiling - once a month and spot-cleaning when soiled High touch areas - every 3–4 hours

35. Disinfection of Operation Theatre Surface disinfection: Cleaning with a cleansing agent, followed by disinfection by using aldehyde-based disinfectant. First cleaning of the day (before cases begin) In between cases (cleaning 3 to 4 feet perimeter around the OT table) Terminal cleaning of OT after the last case Detailed wash-down of the OT complex once a week During renovation or construction of OT or nearby places

36. Fogging (aerial disinfection ): Spraying of a disinfectant ( e.g.Formaldehyde , glutaraldehyde,H 2 O 2 or QAC based product) with the help of a fogger machine.

37. Central Sterile Supply Department (CSSD) Definition: as that service, with in the hospital, catering for the sterile supplies to all departments , both to specialized units as well as general wards and OPDs. AIMS To provide sterilized material from a central department where sterilizing process is carried out under properly controlled conditions To alleviate the burden of work of the nursing personnel, there by enabling them to devote more of their time to patient care .

38. Performs sterilization of medical devices, equipment and consumables Processing area of CSSD - four unidirectional zones starting from an unsterile area to a sterile area separated by physical barrier. Decontamination area – washing by manual or automated washers Packaging area –items are enclosed safely to allow penetration of sterilant Sterilization area –steam sterilizer or ETO or plasma sterilizer Sterile storage area

39. ADVANTAGES ; 1. Bacteriological safe sterilization. 2. Less expensive. 3. Elimination of unsound practices & establishment of standard procedures. 4. Assurance of adequate supply of sterile products immediately and constantly available for sometime as well as emergency use. 5. Conservation of trained staff. 6. Better quality control 7. Better flow of material 8. Prolonged life by proper care of equipment

40. ITEMS COMMONLY HANDLED BY CSSD STORES 1. Syringes 2. Procedure Sets Lumbar puncture ; sternal puncture ; venesection ; paracentesis ; aspiration ; catheterization ; tracheotomy ; suturing ; dressing ; biopsy ; incision & drainage ; aortography ; cardiac resuscitation ; etc. 3. Needles 4. Gloves 5. I.V.Fluids .

41. 6. Treatment Trays. 7. O.T Instruments. 8. O.T. Linen 9. Infusion Fluids for Renal Dialysis. 10. All times LINEN. (other than O.T)