Surg Techniques: Sterilization and Disinfection

Thermal sterilization agents

- dry heat - Steam under pressure

Chemical Sterilization agents

- ethylene oxide gas - gluteraldehyde - peracetic and acetic acid - ozone gas

Halogens and halogen compounds

1. Chlorine compounds: Sodium hypochlorite (bleach), Chlorinated lime (bleaching powder) 2. Iodine-based compounds (Iodophor)

Types of Steam sterilizers

1. Gravity displacement 2. Pre-vacuum or high vacuum 3. High speed steam sterilizer (Flash autoclave) 4. Washer-sterilizer

Package size requirements

1. no larger than 12x12x20 inches 2. no heavier than 12 lbs 3. no greater than 7.2 lbs per cubic ft in density

Examples of level 2 disinfectant

60-90% ethyl or isopropyl alcohol, hexachlorophene, iodophor solution, and sodium hypochlorite

Examples of level 3 disinfectant

70-90% ethyl or isopropyl alcohol, phenolic germicidal solution, bleach, quaternary ammonium compounds

antiseptic

a chemical agent that inhibits the growth of microorganisms without necessarily killing them

Ethylene oxide sterilization

a colorless gas that can be used at its full concentration or comes as a compound with inert chemicals; requires direct contact in its gaseous form to destroy amino acids and proteins; used for pressure- and temperature-sensitive equipment; highly flammable, highly toxic, and is a known carcinogen

spore

a highly resistant, protective covering or casing formed by a bacterium

sanitization

a means of reducing microbes

Flask

a small glass receptacle for holding liquids or powders

Chelation

action of organic matter attaching itself to the water hardness particles, principally those of calcium and magnesium, and inactivation them so they will not combine with other material

Activated glutaraldehyde

activated when an agent is added to make a 2% solution alkaline; kills microbes by attacking cell proteins; has a broad antimicrobial range; effective agains most bacteria in 10 minutes; minimum exposure time 20-30 minutes; total immersion requires 10 hours

Bioburden

actual or suspected relative number or microorganisms found in an area or on an item

sporicidal

agent capable of killing spore-forming organisms in the free spore state

germicide

agent that destroys germs

event-related sterility

any occurrence that compromises the sterility of the package

pathogen

causative agent that is spread by persons coming into contact with body fluids or droplets that leave by means of an infected person's portals of exit

disinfectant

chemical agent that destroys microorganisms

washer-sterilizer

cleans items to at leas an intermediate disinfected level, making the items safe for handling but not immediately ready for use; pH value near 7.0

Phenols and derivatives: Hexachlorphene and carbolic acid (phenol)

destroy microorganisms through denaturation and coagulation of proteins; minimum 10 minutes (20 minutes for tuberculocidal); remain active after prolonged drying

Physical irradiation

destroys all microbes and spores by disrupting DNA; primarily used for commercially sterilized, pre-packaged items ex) Microwave, X-ray

Alcohol-Isopropyl (rubbing) and ethyl (grain)

destroys microbes by coagulating cellular proteins; used as a bactericidal, tuberculocidal, fungicidal, and virucidal (does not kill spores); exposure time 10 seconds to 1 hour; effective against HIV; can damage protective sealant on lensed instruments

Ortho-Phthaldehyde 0.55% (Cidex OPA)

destroys microbes by denaturation of cellular proteins; minimum exposure time of 12 min for disinfection; must be rinsed thoroughly with sterile water 3x

Hydrogen peroxide gas/plasma sterilization

destroys microbes by interfering with the cell membrane, nucleic acids, and enzymes; destroys a broad spectrum of microorganisms; primarily used for heat- and moisture-sensitive items

Ozone gas sterilization

destroys microorganisms but is highly unstable; cycle is 4 hrs 15 minutes at 30-35 degrees C; use of biological and chemical indicator; works on wide range of materials from stainless steel to Teflon

Sodium hypochlorite

disrupts the cellular metabolism of microbes by oxidizing enzymes; high concentrations inactivate HIV, Hepatitis B, and mycobacterium tuberculosis

Washer-sterilizer

generally used in central processing to disinfect, wash and terminally sterilize surgical instruments; temp 270 degrees F; pressure 27 psi; complete cycle 3 minutes

Examples of level 1 disnfectant

glutaraldehyde, 6% hydrogen peroxide, peracetic acid, and chloride compounds

fungicidal

having the capacity to chemically destroy or inhibit the growth of fungi

pseudomonacidal

having the capacity to chemically kill pseudomonas bacteria which commonly causes infections in wounds, burns, and the urinary tract

virucidal

having the capacity to or tending to destroy or inactivate viruses

bactericidal

having the capacity to prevent or destroy the growth or action of bacteria

critical level

high-level asepsis for critical items; required for any items introduced to internal body areas or areas with high risk of infection. if contaminated with microorganisms, including bacterial spores

nosocomial

hospital-acquired infection

antisepsis

infection prevention through the inhibition of microbial growth on objects

washer-decontaminator

items are considered clean and have been exposed to an intermediate level of disinfection but are not considered sterile; water temp 180-190 degrees F

noncritical level

items that come in contact with intact skin but not mucosa membranes

Chemical sterilization

liquid, gas, or plasma agent; used primarily for heat-intolerant instruments

Gaseous chlorine dioxide sterilization

microbial destruction occurs by the interference with the cellular process; not mutagenic or carcinogenic in humans; as the concentration increases the time required to achieve sterilization becomes shorter; not cleared by the FDA

Thermal sterilization

most efficient and least expensive method for temperature-tolerant instruments

lumen

open inner space of a tube, which can be in an endoscope, catheter, or needle; a hollow cavity in an organ or a blood vessel

Iodine-based compounds (Iodophor)

penetrate cell wall of microorganism quickly and disruption of protein and nucleic acid structures and synthesis; rapidly kills Staphylococcus aureus and Mycobacterium chelonae within minutes at 1:100 concerntration

Gravity displacement

primarily used to sterilized wrapped/unwrapped instruments, linen packs, and solutions; temp- 250 to 254 degree F; pressure 15-17 lbs psi; cycle time 15-30 min

surgical asepsis

protection against wound infection pre-, inter-, and post-operatively through aseptic technique

ultrasonic cleaner

provides a cleaning process, not a thermal or chemical disinfection or sterilization process; detergent with pH no higher than 8

Liquid sterilization

provides immersible instruments with a wide antimicrobial treatment ex) Acetic and peracetic acid, activated glutaraldehyde

Gas sterilization

provides nontoxic, dry, low-temperature sterilization ex) Ethylene oxide gas, Hydrogen peroxide gas plasma, Ozone gas

Chlorinated lime

reacts through oxidation with the organic material and microbes in the water to kill them; pH range 5.5-7.5; 18-20 degrees C and above for 30 minutes

semicritical level

sterility is less critical for those items that come in contact with mucous membrane or broken skin; considered clean and require minimal disinfection using a chemical disinfectant

sterilant

substance that kills all forms of living matter including spore-bearing ones

substrate

surface or medium on which an organism grows or is attached

Solubilization

the action of a disinfecting agent to make substances dissolve

Enzymatic

the action of enzymes that break down or digest large organic molecules that then interact with and break down a particular molecule and move on and repeat

disinfection

the chemical or physical process of destroying all microorganisms, except spore-bearing ones

concurrent disinfection

the immediate disinfection process following discharge of infectious material from the body of an infected person or after contamination of articles by an infectious agent

Emulsification

the physical action in which fats are mechanically broken up into very small particles which are uniformly suspended in the disinfecting solution

sterilization

the process of destroying pathogenic and nonpathogenic microorganisms including viruses, fungi, and all forms of bacteria and their spores by using sterilant or sporicidal agents

terminal disinfection

the process of rendering all articles, materials, and their immediate physical environment incapable of conveying infectious agents to other persons after the patient has left the room

cross contamination

transmission of microorganisms from patient to patient and from inanimate objects to patients and vice versa

Level 1 high level disinfectant

used for laparoscopes, arthroscopes, and endoscope accessories; disinfects or sterilizes surgical instruments; exposure time 20 minutes or longer

High speed steam sterilizer (Flash autoclave)

used most frequently in the operating room for unplanned sterilization of urgently needed unwrapped items (dropped instruments); temp 270-275 degrees F; pressure 27 psi; 3 minutes for unwrapped, nonporous items and 10 minutes for porous items

Level 3 low level disinfectant

used on floors, walls, stainless steel furniture; achieved through surface cleaning or washing; exposure time less than 10 minutes

Dry heat sterilization

used only for materials that cannot be penetrated with other forms of sterilization or when moisture could cause damage; protective of delicate, sharp or cutting instruments; 320 degrees F for 2 hrs; 325 degrees F for 1.5 hrs

Level 2 intermediate level disinfectant

used or laryngoscopes, bronchoscopes, endotracheal tubes, and respiratory/anesthesia equipment; achieved through immersion of the time in the agent for 10 minutes or less

Dry heat sterilization

uses extreme heat

Steam sterilization

uses pressurized moist heat in the form of saturated steam; destroys microorganisms by breaking down proteins within bacterial cells; primary variables used are temperature, pressure, and length of exposure

Moist heat sterilization

uses pressurized steam ex: washer sterilizer, "flash", Gravity displacement sterilizer, pre-vacuum sterilizer

Peracetic acid systems

utilizes peracetic acid and an anticorrosive agent to react with various cellular systems, destroying microbes; most commonly for endoscopes; low temp of 122 to 131 degrees F; cycle time 20-30 minutes

droplet

very small mass of liquid carried in a spray from the nose or mouth which falls to surface upon expiration as liquid and which is not readily inhaled

2% glutaraldehye

widely used disinfection agent that destroys microbes by denaturation of cellular proteins; pH of 7.5-8.5 to kill spores; minimum exposure time 20 min to disinfect and 10 hours of immersion to sterilize

Irradiation

x-ray action causes ionization that increases thermal and chemical activity; microwave non-ionization disrupts microbe and spore DNA as a by-product of molecular exchanges that increase thermal activity; primarily used for commercially sterilized; prepackaged OR and hospital items; Cobalt 60 most commonly used source

Pre-vacuum or high vacuum

Commonly used in Central Processing; temp 270-276 degrees F; pressure 27-30 lbs psi; complete cycle 15-20 minutes with minimum 4 minutes exposure