Sterilization

STERILIZATION & DISINFECTION Antiseptics • Typically an antiseptic is a chemical agent that is applied to living tissue to kill microbes Disinfectants • A disinfectant is a chemical or physical agent that is applied to inanimate objects to kill microbes Microorganism • an organism that is microscopic (usually too small to be seen by the naked human eye) Pathogenic Microorganisms Sterility • indicates a micro-environment (the surgical field) made free of infectious microorganisms. Disinfection • reducing the number of viable microorganisms present in a sample Sterilization • killing of all microorganisms in a material or on the surface of an object Bactericidal • antimicrobial that kills a microorganism

Bacteriostatic • antimicrobial inhibits bacterial growth but does not kill the bacteria Methods of Sterilization A. Physical Sterilization 1. Moist Heat – kills all bacteria by coagulating or denaturing of the protein of the bacteria a. Boiling (non-pressure sterilizer) b. Saturated Steam under pressure (AUTOCLAVE) 2. Dry Heat – recommended for use only where direct contact of material with steam is impractical of not available a. Dry Heat Autoclave (hot air oven) – used for oil, ointment, and powders. B. Chemical Sterilization • Accomplished by use of ethylene oxide gas • Ethylene oxide is a chemical agent that kills microorganisms, including spores, by interfering with the normal metabolism of protein and reproductive processes, resulting in death of cells Shelf-Life – expiration date 1. Condition of Storage • Free of dust, dirt and vermin • Paper-wrapped/muslin-wrapped items good for 30 days, open shelving 21 days • Protect from extreme temperature 2. Material used for packaging • Muslin and paper wrapped items may be stored for 24-30 days, afterwhich resterilization is required, but if sealed in airtight plastic bag, following cooling or aerating, shelf life can be prolonged from 6-12 months 3. Seal of the package • Tape sealed packages wrapped in non-warm fabrics or plastic film can be stored for 3-4 months 4. Integrity of the package

Disinfection • It differs from Sterilization by its lack of sporocidal power • Used in the OR to kill microorganisms on inanimate surfaces and objects that cannot be sterilized Limitations of Chemical Disinfection • Doesn’t KILL SPORES • Real STRENGTH not known • LONG TIMING • DIFFICULT to submerge some articles • NOT SUITABLE for some materials • Can cause IRRITATION to tissue • ABILITY to disinfect is limited to max concentration Uses for chemical disinfection • WOVEN • CATHETER • ENDOSCOPIC Instruments • POLYETHYLENE • EYE Surgery Pointers when Using Chemical Disinfection • Free from blood, secretions • Rinse and dry under sterile conditions • Solutions may be rinsed off if practical DISINFECTANTS • Formaldehyde (Formalin) • Glutaraldehyde (Cidex) • Phenol 100% • Lysol • Zephiran Chloride 17% ANTISEPTICS • Hexacholorophene - neurotoxic • Betadine –watch out iodine sensitivity • Mercurochrome • Aqueous Zephiran • Chorhexidine Gluconate