Short-Answer Disinfection and Sterilization

Summarize the three essential components of monitoring the sterilization process.

(1) Chemical: Chemical indicators aid in detecting potential sterilization failures that may result from machine malfunction, incorrect loading, or assembly of items. Types of chemical monitors include autoclave tape and internal indicators placed inside packs to be sterilized. Chemical monitoring only indicates that the parameters for sterilization have occurred. (2) Mechanical: Gauges, monitors, thermometers, charts, and printouts are used to record the processes performed by the autoclave as well as the time and temperature readings. (3) Biological: This is the only way to ensure that sterilization has occurred. A BI is a device containing microorganisms that will be killed when the sterilization process occurs.

List the three steps of instrument preparation for sterilization, and explain what happens during each phase.

(1) Inspection: Inspect instruments for proper elements and function. Examples: cutting edges of scissors (should be sharp with no nicks or burrs), ratchets (should lock efficiently), tips of forceps and jaws of clamps (should close evenly and be in proper alignment). (2) Reassembly: Some instruments with multiple pieces may need reassembly before reprocessing. However, many instruments must remain unassembled to allow sterilant to come into contact with all portions of the instrument. (3) Preparation: Instruments must be distributed into instrument trays evenly, instruments must be prepared so that sterilant comes into contact with all areas of the instrument, basins must be nested, and an absorbent towel should separate each basin.

Describe briefly the five general principles of packaging.

(1) Woven fabrics should be stored at 64-72°F and at a humidity of 35 to 70 percent for two hours to rehydrate the fabrics. (2) Linen packs should not weigh more than 12 pounds. (3) Linen packs should be packaged loosely to allow steam to contact all surfaces. (4) Double sequential wrapping is essential. (5) Commercial and facility-packaged items must be inspected for holds, perforations, and seal integrity. These five general principles are listed under the section titled "General Principles of Packaging." However, others are listed. Any principle from this section would be correct. Correct answers may vary.

Glutaraldehyde: (A) Compare the sterilization times for glutaraldehyde and peracetic acid. (B) What is the usual time for glutaraldehyde highlevel disinfection of an item? (C) Why is it necessary to rinse the glutaraldehyde completely from an item prior to use on the patient with sterile saline?

(A) Peracetic acid requires an exposure time of six minutes of a 23-minute cycle for sterilization to occur. Glutaraldehyde requires an immersion time of 10 hours. (B) The usual time for high-level disinfection is 20 minutes or according to the manufacturer's recommendations. (C) Thoroughly rinsing with saline prevents chemical burns from the glutaraldehyde. (Student may not identify that sterile normal saline is an isotonic solution, and the hypotonic water solution can cause cellular injury as cells burst from osmosis.)

Terminal Cleaning: (A) Does terminal cleaning take place at the end of the day or end of the case? (B) What principles are used in the terminal cleaning process? (C) What type of disinfectant is most likely to be used for terminal cleaning? (D) What is the preferred method of floor cleaning?

(A) Terminal cleaning takes place at the end of the day. (B) It is more thorough than case-to-case cleaning. It begins from top to bottom (highest surface) and from the cleanest areas to the dirtiest areas using the principles of confine and contain. It may include wiping down walls, floors and ceilings, cabinet doors and handles, and all furniture and equipment in each room down to the casters or wheels. (C) Phenols (D) Floods the floor with disinfectant and wet vacuum.

Differentiate between the chemical indicator and biological methods of monitoring the sterilization process.

A chemical indicator only means that the item has been exposed to the conditions of sterilization, such as temperature, humidity, and sterilant. Biologic monitoring is the only method that ensures the item is sterile and the conditions for sterilization have been met. Positive turning of the chemical indicator indicates that it was exposed to the conditions of sterilization and can be considered sterile provided all other operating mechanical parameters are met. A positive biologic monitor (yellow color) means that the bacteria grew, and the sterilization cycle failed.

Analyze and compare the differences between disinfection and sterilization; antiseptics and disinfectants.

Disinfection is when a chemical agent (disinfectant) is used on inanimate objects to re- duce the number of microbes. Various levels of dis- infection take place depending on the agent used, time exposed to the agent and level of bioburden. Sterilization is the process of destroying all microorganisms, including spores. Like disinfection, it is only performed on inanimate objects. Antiseptic chemical agents are used to reduce/remove microbes from animate (living objects). (pt. prep or scrub). Sterilization is the process of destroying all microorganisms, including spores. Like disinfection, it is only performed on inanimate objects.

Describe the difference between a prokaryote and eukaryote cell.

Prokaryote cells include bacteria cells only and divide by binary fission because they do not have a nucleus. Eukaryotes include all other cellular structures for humans,protozoa, fungi, all plant and animal cells, and green, brown,or red algae.

Describe why a towel should be placed between metal basin sets before wrapping the basins for steam sterilization.

Steam needs to be able to penetrate all surface areas of the basins as it wicks between the basins.

Analyze the process of sterilization, and describe the four methods of monitoring that are required for all loads containing an implantable.

Loads containing any implantable must always have a biological indicator run and read prior to use of the implantable. The usual methods to monitor the system include mechanical (recorders and gauges that allow the operator to monitor the progress of the machine during the sterilization cycle), chemical (chemical indicators or integrators are used externally and internally to verify that item(s) have been exposed to sterilizing conditions), biological indicator (BI) (device that contains a specific type of microorganism that is killed when exposed to the sterilizing conditions), and administrative (proper documentation).

Analyze and interpret the information in Tables 7- 16 and 7-17 regarding minimum steam sterilization exposure cycles. There are two basic types of steam sterilizers, the gravity sterilizer whereby steam enters at the back/top of the chamber and progresses downward and out the bottom front drain, and pre-vacuum, whereby a pump at the bottom front suctions the air out of the chamber, creating a vacuum, and then the valve is opened for the steam to enter in a rush to fill the void created. What is the minimum steam sterilization exposure cycle time for each of the following situations?

a. Wrapped instrument set at 250° in a gravity sterilizer 30 minutes. b. Unwrapped single no-lumen instrument in a gravity sterilizer 3 minutes c. Unwrapped lumened instrument set at 270° in a gravity sterilizer 10 minutes. d. Wrapped instrument tray set, unwrapped instrument set, or lumened instrument set at 270° in a pre-vacuum sterilizer 4 minutes.