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  • 1. Prevention of Hospital Infection Exogenous infection

2. Hospital Infection

  • Surgical wards
  • Operation Theaters
  • Surgical Instruments

3. Surgical wards

  • Should be well ventilated and cleaned
  • The floor should be scrub washed once a week
  • Preop. Ptsshould not be mixed with postop. Pts.
  • Severely infected cases should be isolated
  • Immuno suppressed pts also isolated

4. Operation Theaters

  • Adjacentto ICU
  • Height 3M. Floor area 10 sqM.
  • Anaesthetic room -10 Sqm.
  • Minimise bacterial contamination
  • The concept Site away from the wards of zones : a) outer zone reception area. b) clean zone between the reception and OR. C) asceptic zone OR . D) dirty zone disposal area and space for cleaning of instruments
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5. Air flow of OR

  • Filtered air directed vertically or horizontally
  • Ideal laminar flow
  • Restrictentry of nonessential personnel & their movements
  • Temperature 20 - 22 C

6. Other Measures

  • Wearing of disposable nonwoven fabric
  • Masks
  • Head & beard cover
  • Preparation of the surgical team
  • Preparation of the patient
  • Preoperative hospitalisation minimised
  • Skin infection treated
  • Hair removal
  • Skin preparation, Drapes

7. Disinfection

  • The process that reduces the no. of viable microorganisms, but does not affect the spores

8. Disinfection

  • Three levels of disinfection
  • 1. Low: reduces the overall no. of vegetative microorganisms. Does not destroy TB bacilli or bacterial spores .Application environmental surfaces
  • 2. Intermediate :kills TB bacilli, most viruses,and some fungi but only some spores. Application horizontal surfaces,floors
  • 3. High: kills most forms of microbial life including TB bacilli but not some spores. Application flexible endoscopes

9. Disinfection

  • Heat disinfection
  • 1) Pasteurization
  • 2) Boiling
  • 3)Low temperature steam disinfection

10. Chemical disinfection

  • Chemical disinfectants are used to reduce the pathogenic microbes of inanimate objects, which are heavily contaminated.
  • Alcohols, aldehydes, halogens, phenolics and quaternary ammonium compounds

11. Chemical disinfectants

  • Alcohol isopropyl alcohol & ethyl alcohol kills most vegetative bacteria in less than 30 seconds , relatively inactive against spores and fungi. 70% alcohol is usually used.
  • Aldehydes glutaraldehyde & formaldehyde good activity against spores, bacteria, virus and fungi . 2% glutaraldehyde rapidly inactivates HIV and hepatitis B after exposure for 10 minutes.

12. Chemical disinfection

  • Diguanides e.g. chlorhexidine good activity against gm + ve organisms , moderate activity against gm- ve organisms, poor activity > TB bacilli, spores , fungi & viruses . Used as an antiseptic for skin & mucous memb.
  • Halogens e.g. hypochlorites and chlorine active against bacteria including spores ,fungi, hepatitis B & HIV virus

13. Chemical disinfection

  • Iodophores -1% availableIodine mixed with alcohol excellent skin preparation
  • Phenolics e.g phenol &chlorxylenol surface cleaning Hexachlorophene preparation of surgeon's hands
  • Quaternary ammonium compounds good detergent properties savlon when mixed with chlorhexidine

14. Sterilization

  • Complete removal of all microbes including spores
  • Methods :Heat method dry or moist
  • Ionization radiation
  • Ethylene oxide gas

15. Heat Methods

  • Dry heat Hot air ovens which have controlled cycles, such as 160 C for 1 hour suitable for killing bacteria on materials which are not penetrable by steam e.g. glassware, powder such as talc, oils & petroleum jelly.
  • Moist heat Steam under pressure simplest is domestic pressure
  • High pressure vacuum autoclaves
  • Low temp. steam(73C) & formaldehyde suitable for heat sensitive materials and equipment with plastic component

16. Ionising Radiation

  • Gamma rays lethal, noncharged, ultrashort, wavelength rays with great penetrating power from a radioactive isotope such asCobalt-60 e.g.Disposable syringes, sutures and rubber gloves
  • The radiation dose 2.5 mrad kills bacteria by ionising their DNA.

17. EthyleneOxide

  • It should be used with suitable humidity at the correct temp. for sufficient time
  • CO2 is mixed with ethylene oxide to reduce Highly toxic inflammable gas kills all types of microbes including spores.
  • the risk of explosion
  • It diffuses well through items such as plastic materials, swabs and paper.