Control Of Microorganisms And Hospital Hygiene PDF

CONTROL OF MICROORGANISMS Sterilization and disinfection Physical and chemical methods HOSPITAL HYGIENE  CONTROL OF MICROORGANISMS The control in the transmision of infeccious diseases is critical in hospitals : Microorganisms + hosts in the same place. Control of the transm...

CONTROL OF MICROORGANISMS Sterilization and disinfection Physical and chemical methods HOSPITAL HYGIENE  CONTROL OF MICROORGANISMS The control in the transmision of infeccious diseases is critical in hospitals : Microorganisms + hosts in the same place. Control of the transmision * Sterilization Techniques * Disinfection Techniques * Antiseptic Techniques * Cleaning Techniques  Classification of hospital materials High risk material.- The material in contact with the internal parts of the body or with the blood. Medium risk Material.- The material in contact with the skin or the mucosa (normal microbiota) as the endoscopes, breathing assistance masks,… Low risk material.- Materials and surfaces not in direct contact with the patient (walls, furnitures,…).  TYPES OF CONTROL PHYSICAL A- Heat B- Cold C- Radiation D- Filtration E- Dessication F- Osmotic pressure CHEMICAL: Products  HEAT Denaturation of proteins a) Dry heat - Flaming: Incineration - Hot air sterilization b) Moist heat - Pasteurization - Boiling - Steam at atmospheric pressure - Steam under pressure: Autoclave a) Dry heat Kills by oxidation effects – Flaming – Incineration – Hot air sterilization Placed in oven 170 ° C for 2 hours B) Moist heat Action: Denaturing proteins Hydrogen bonds are broken Types: Boiling.- Temperature at 100oC Koch/Arnold’s steamer.- Steam at atmospheric pressure Pasteurization.- Temp below 100oC + cooling Autoclave.- Steam under pressure: - Is the preferred method - Steam under pressure increases temperature, making steam more effective - 121° C for 15 minutes will kill all organisms Aplications.- Culture media, cloths, …. Limitations.- Material must be able withstand heat and moisture  COLD Action.- Microbiostatic Types: * Cold storage * Freezing  RADIATIONS Ionizing radiation – High energy – Penetrate deeply but require longer times – Radioactive elements X Ray Gamma rays Cathod rays…. Very dangerous Used for thick materials Non- ionizing radiation (UV light) – Low energy – Rays do not penetrate U – Damages in DNA inhibiting correct replication of DNA Desinfection of water, sterilization of some materials  FILTRATION Action.- Microorganism retention. Types: - Liquids filtration.- Small pores prevent passage of bacteria and fungi (no for virus) Aplication.- Liquids heat sensitive materials - Air filtration.- HEPA High efficiency particulate air filters Operating rooms Masks Aplications.- Operating rooms, burn rooms, biological security booths, assembly room of "chips", etc...  DESICCATION Action.- Elimination of water. Types: * Evaporation * Sublimation  OSMOTIC PRESSURE Using high concentrations of salts. CHEMICAL CONTROL The microbiocides acts according to their chemical structure, nature and concentration. Biostatic (inhibits the growth or multiplication of an microorganism) Biocide (kill the microorganism) Effective disinfection depends on: – Class of organisms – Substance disinfecting – Proper dilution – Presence organic material – Contact time Types: Phenol Aldehydes Bisguanides Halogens Oxidizing agents Heavy metals Detergents…. Actions of Microbial Agents  Alter membrane permeability Damage phospholipids or proteins in plasma membrane Cellular contents leak out Interferes with growth  Damage to proteins and nucleic acids  Denatures proteins  Enzyme  Proteins necessary for bacteria metabolism  Shape necessary for function  Nucleic Acids  DNA and RNA  Can no longer replicate or synthesize proteins Antiseptic Disinfectant (animated) (inanimated)  Sterilizing products (kill microorganisms and the resistance forms)  Alkylating agents Transfer of an alkyl group from one molecule to another, inactivating proteins. Types: Liquids: Formaldehyde Preservative and in vaccinations Use to conservation of organic material Glutaraldehyde (Use in medical instruments) Gaseous: Ethylene oxide Beta- propiolactone Used on medical instruments Suspected carcinogens Very toxic Aplications.- Sterilization of disposable sanitary equipment, medical instruments, material that cannot be sterilized by heat.  DISINFECTION AND ANTISEPSIS Destruction of vegetative forms of harmful microorganisms (such as bacteria and fungi) especially on inanimate objects but that may be less effective in destroying spores, using chemical products (disinfectants). When is used on the skin are called antiseptics  Phenols Phenols – Rarely used now – Irritate skin Phenolics.- Derivatives of phenol  Increased antibacterial activity  Injure plasma membrane  Aldehydes: Actuation.- Inactivation of proteins reacting with some of their functional groups. Aplicaction.- Disinfection of metals , lens, plastics… Types:. Glutaraldehyde-phenolate. Glutaraldehyde 2%. Precautions:Aireation of the materials. Care in preparation.  Halogens Chlorine and derivatives - Used as disinfect in drinking water, swimming pools, sewage - Can kill endospores (anthrax) - Chlorine dioxide (ClO2) - Gas (Cl2) or in combination - Hypochlorous acid (HOCl) forms in water (bleach) Iodine (I2) and derivatives Oldest (used as antiseptic). Very effective against bacteria, endospores, various fungi, some viruses Povidone iodine Betadine Damages the cell wall by oxidation Problems: It's inactive with light. Do not use in conjunction with mercurials Do not use in people who are intolerant or with thyroid alterations.  Alcohols Denature proteins and dissolve lipids. Kill bacteria and fungi Ineffective on endospores and non-enveloped viruses Often added to other disinfectants to increase effectiveness (Tinctures) Types: Ethanol Isopropranol Uses.- 70º as antiseptic 96º for disinfection  Heavy Metals Denature proteins at – SH bonds Silver – Silver nitrate sticks Inorganic mercury – Mercuric chloride – Mercurochrome – Bacteriostatic – Toxicity Copper – Copper sulfate Destroy algae  Quaternary Ammonium Compounds (Quats) Alteration of plasma membrane. Actuation: Strong bactericidals (alter plasma membrane) Fungicidal Amoebicidal Viricidal (enveloped) Do not kill – Endospores – Mycobacteria Uses: Disinfectants of feeding utensils and small instruments (Non-toxic).  Oxidizing agents Oxidize cellular components  Ozone (water and environment)  Hydrogen peroxides Depending of the concentration Little antiseptic activity because it is broken down by tissue catalase. Unstable  Biguanides Chlorhexidine (2%) and Alexidine – Acts in membrane – Used on skin and mucus membranes Scrubs Washes – Low toxicity – Damaging to eyes and ears – Broad spectrum: Bactericidal properties Effective on some viruses  Surfactant agents Are compounds that lower the surface tension (or interfacial tension) between two liquids or between a liquid and a solid. Types - Soap. - Detergents. According to polar head group: - If the charge is negative, the surfactant is more specifically called anionic - If the charge is positive, it is called cationic. HOSPITAL HYGIENE  Guidelines according with the zone 1.- Surgery, operating room, blood banks, hemodyalisis, intensive care unit (ICU)… 2.- Hospitalization area, rehabilitation, sonography, emergency room…. 3.- Bath rooms.  1.- Surgery, operating room, blood banks, hemodyalisis, intensive care unit (ICU)… Sweep and disinfection with detergents and after with phenolic compounds at 4 %. In hemodyalisis and blood banks use bleach at 0,5 %. Frecuency.- In surgery room and delivery room before and after each use.  2.- Hospitalization area, rehabilitation, sonography, emergency room…. Cleaning with detergent and after disinfection with bleach at 0,5 %. If feces or urine must phenolic compounds must be used. If contamination for blood previously must be used bleach at 0,5 %. Frecuency.- Twice per day and each time when contamination. 3.- Bath rooms Cleaning with detergent and after disinfection with bleach at 0,5 %. Sink, toilet, WC,.. must be disinfected with chlorinated abrasive products. The materials used in each part must be rejected. Always use gloves.. Frecuency.- Twice per day. How to manage the materials according to the zone a) Critical material. Sterilization (autoclave or ethylene oxide) b) Semi-critical material. High level disinfection de alto nivel (Glutaraldehyde 2%, Bleach 1%, H2O2 6%) c) No critical material. Normal disinfection (Ethanol, Benzalconium chloride,…)  Hand Hygiene In general: Short nails, without nail polish Avoid the use of watch, bracelet, rings… Careful hand washing Cleansing after patient contact during 30 seg. To dry with paper towel. Hygienic hand washing Cleansing after contamination using antispptic soap or isopropanol 70%, during 60 seg. To dry with paper towel. Surgical hand disinfection Preoperative disinfection of hands and forearm with clorhexidine …. 2 min. To dry with sterilized towel. Essentials of the standard precautions to be used in the care of all patients Hand washing Wash hands after touching blood, secretions, excretions and contaminated items, whether or not gloves are worn. Wash hands immediately after gloves are removed, between patient contacts. Use a plain soap for routine hand washing. Use an antimicrobial agent for specific circumstances. Essentials of the standard precautions to be used in the care of all patients Gloves Wear gloves when touching blood, body fluids, secretions, excretions, and contaminated items. Put on clean gloves just before touching mucous membranes and non-intact skin. Mask, eye protection, face shield Wear a mask and eye protection or a face shield during procedures and patient-care activities that are likely to generate splashes or sprays of blood, body fluids, secretions, and excretions. Gown Wear a gown during procedures and patient-care activities that are likely to generate splashes or sprays of blood, body fluids, secretions, or excretions. Patient-care equipment Ensure that reusable equipment is not used for the care of another patient until it has been cleaned and reprocessed appropriately. Linen Handle used linen, soiled with blood, body fluids, secretions, and excretions in a manner that prevents skin and mucous membrane exposures, and that avoids transfer of microorganisms to other patients and environments. Occupational health and bloodborne pathogens Take care to prevent injuries when using needles, scalpels, and other sharp instruments or devices. Use ventilation devices as an alternative to mouth-to-mouth resuscitation methods. Place of care of the patient Place a patient who contaminates the environment or who does not assist in maintaining appropriate hygiene in an isolated (or separate) room.