Sterilization Methods CTVT pages 1158-1168 Objectives: Understand aseptic technique and it’s importance in surgery. Learn how to properly sterilize instruments and equipment.

Asepsis- condition of sterility where no living organisms are present Aseptic technique- all steps taken to prevent contamination of surgical site by infectious agents Goal: to maintain asepsis and watch for “breaks” in aseptic technique

Ways to Maintain Aseptic Technique Disinfection - destruction of pathogens on inanimate objects (Kennel Care, Accel) Doesn’t effect bacteria spores Sanitization - acceptable level of contaminants present Antiseptic – inhibits growth of infectious agents on living tissue (Chlorhexidine) Sterilization - complete destruction or elimination of all living organisms Including viruses and bacterial spores Always inorganic material

When does aseptic technique begin? It’s always happening! Cleaning of instruments (see Instrument Guide) Surgery suite sanitation/disinfection Patient prep Surgical team scrub Surgical suite etiquette Contamination cannot always be avoided Skin abscess, wounds, organ rupture, dental disease

Methods of Sterilization Physical Sterilization Filtration Radiation Heat 2. Chemical Sterilization Liquid Gas

1. Filtration Sterilization P 1. Filtration Sterilization Microorganisms separated from liquid Utilized by pharmaceutical companies Filter can be placed on IV line or syringe

2. Radiation Sterilization P 2. Radiation Sterilization Destruction of microorganism without significant increase in temperature Ex. Gloves and suture material *Filtration and radiation are typically performed by the manufacturer before shipments - anything that comes pre-sterilized - a lot of “one time use” products - items which cannot be heat sterilized

P 3. Heat Sterilization Most common sterilization technique Destroys bacteria by denaturing their proteins Two options: a. Dry Heat Sterilization High temperatures for a long period of time b. Wet Heat Sterilization Creating steam under pressure at high temperatures

a. Dry Heat Sterilization P a. Dry Heat Sterilization Used for instruments sensitive to moisture Advantage: no rust or corrosion Disadvantages: Takes longer than wet heat Requires _______________ temperatures Not for items that can burn Ex. setting= 300°f for 2 ½ hours

b. Wet Heat Sterilization P b. Wet Heat Sterilization Pack must be able to withstand heat AND moisture! Pre-vacuum sterilizer A pump evacuates the air before the steam enters More even penetration of steam Shorter duration Gravity Displacement Sterilizer Steam enters the top and forces air to bottom Most commonly used type

Autoclave Sterilization (Gravity Displacement) Used most commonly for “packs” Heat = _______ °F minimum Pressure = ______ PSI Time = _____ minutes at temp (exposure time) Total cycle =Heat-up + exposure + dry time Usually 45-60 minute cycle total Always use _____________ water! *Every machine is different, refer to the operator's manual

Proper placement of packs in the autoclave: Steam should be allowed to flow around every surface of each pack Use multiple racks if sterilizing a lot of packs

Pack Preparation 1. Instruments must be clean and dry 2. All locking instruments should be _________________ 3. Should be labeled appropriately 4. Sharp edges should be protected 5. Should contain a ______________ _______________ muslin

Pack Materials Wrap materials must be steam permeable 1. Woven = double thickness _____________ Reusable 2. Non-woven = crepe paper One time use …mostly 3. Laminate packs/peel pouches clear pouches made of plastic and paper **According to AAHA practices, all packs should be double wrapped

Pouch Preparation Instrument is placed into pouch with the handles toward the ____________ end Pre-cut sizes or on rolls Self-sealing or heat sealed Plastic side should face down in autoclave

Labeling of Packs Three requirements: 1. _______________________ 2. _______________________ 3. _______________________ *VTI- which patient it is for

Sterility Indicators Autoclave Tape –specific part of the pack was exposed to steam Commonly used on the outside of packs Use sharpie to write information directly on tape Tape should NOT be used to keep the pack closed

Sterility Indicators 2. Chemical Indicator Strips- change color when exposed to steam for adequate time Examples: Peel packs – indicator on the outside of the paper OK Strip - can be placed in the center of the pack Chemical sticker- can be placed anywhere (mostly for gas)

Sterility Indicators 3. Pellet glass – glass ampule containing a temperature sensitive pellet that melts around 250 °F 4. Biological/Culture tests – contain a spore population of bacteria (usually Bacillus sp.) Confirms that microorganisms were in fact killed if the sample does not grow anything after incubation Disadvantage: Most effective method for testing machine functionality- not individual packs

Autoclave Quality Control Performed by the technicians to ensure proper sterilization technique is being used 1. Sterility Indicators Must be used in combination, as not just one will cover all requirements 2. Autoclave maintenance Ex. Speed-Clean – liquid is mixed into water Ex. Chamber Brite – powder is sprinkled on the bottom of cold chamber; cycle is ran without drying *Both require a “rinse” cycle to be ran after use

After the Autoclave Cycle Let the dry cycle finish completely! Packs must cool slowly to prevent condensation which could: 1. 2. 3. Door should be cracked to vent first Open door with caution!

Maintaining Sterile Packs The outside is not sterile Storage: dust free, dry, well-ventilated, away from contaminated areas Ex. A closed cabinet is safer than an open area Broken sterility = dropped on floor, wet, broken outer wrap (ex. instrument penetrates paper) Never assume sterility - autoclave again if pack is in question Monitor dates for expired sterility (follow clinic protocol)

Length of Sterility Table on page 1163 in CTVT 1. Date related practice: Which one lasts longer? Double vs. single wrapped Non-woven vs. Woven Closed vs. open cabinet Heat sealed vs. Self-sealed 2. Event related practice: item is sterile until an event in which the sterility is broken

Flash Sterilization Instruments are placed __________________________ in a perforated metal tray ________ for _____ minute exposure time Removed with detachable metal handles and carried straight to surgery (or use oven mitt or huck towel) Instruments must cool before use Some machines have a preset button