Sterile Processing Technical Manual - Chapter 14: High-Temperature Sterilization

What specific action does the control system of a sterilizer undertake once the desired temperature is achieved during the exposure phase?

After the desired temperature is reached, the sterilizer's control system begins timing the cycle's exposure phase.

What happens once the sterilizer's door is closed and the sterilization cycle begins?

After the sterilizer's door is closed and the sterilization cycle begins, steam is injected into the chamber.

In steam flush pressure pulse (SFPP) sterilizers, how does the air removal process take place?

Air removal occurs above atmospheric pressure; no vacuum is required.

How can air removal, steam penetration, and condensate drainage be improved during sterilization?

Air removal, steam penetration and condensate drainage are enhanced by proper positioning - and by the use of perforated or mesh-bottom trays or baskets.

What can be a significant factor contributing to sterilization failure?

Any coating of soil, such as protein or oils, can protect the microorganisms from direct steam contact.

During the conditioning phase, what happens to the pressure and temperature of the steam as it continues to enter the sterilizer's chamber?

As steam continues to enter the sterilizer's chamber, pressure begins to rise, as does the steam temperature.

During the conditioning phase of a saturated steam sterilization cycle, where does the steam enter the sterilizer?

At the beginning of the sterilization cycle, steam enters at the upper back portion of the sterilizer.

What occurs during the exhaust phase?

At the end of the exposure phase, the chamber's drain is opened, and the steam is removed through the discharge line.

Why is it important to ensure that these containers are correctly positioned?

Basins and other items that can hold water must be positioned so air can be removed and water (condensed steam) can escape.

Why is steam the most frequently used sterilant for devices in healthcare?

Because of its successful record of efficacy, reliability, and low cost, steam is the most frequently used sterilant for devices not adversely affected by moisture or heat.

What type of utility malfunctions can arise during the sterilization process, and who is responsible for making the necessary repairs in such situations?

Boiler or steam delivery system problems can occur, and a qualified service representative is needed to make repairs, as specified in the sterilizer manufacturer's service manual.

What specific action is required to be taken with charts or printouts from a sterilization process?

Charts or printouts are signed by the sterilizer operator, indicating that parameters have been reviewed.

What is the distinction between the processes of cleaning and decontamination?

Cleaning involves the removal of all visible soil, and decontamination kills most but not all microorganisms.

What is a fundamental guideline for loading a sterilizer with surgical instrument trays that have perforated bottoms and rigid container systems?

Ensuring that surgical instrument trays with perforated bottoms and most rigid container systems sit flat on the shelf to maintain even instrument distribution and facilitate proper drainage.

What is the recommended procedure for items in sterilizers that do not have carts, specifically regarding the appropriate cooling period?

For sterilizers without carts, items should remain in the sterilizer chamber until properly cooled.

Define: Noncondensable gas

Gases that cannot be liquified by compression under the conditions of temperature and pressure used during the sterilization process.

What types of physical monitoring controls are typically used in gravity air displacement sterilizers?

Gravity air displacement sterilizers have physical monitoring controls such as temperature-indicating charts and printouts for recordkeeping.

How is high-temperature sterilization achieved?

High-temperature sterilization is achieved by subjecting items being processed to thermal energy from moist heat (steam).

What is the sterilization process of choice in many healthcare facilities?

High-temperature sterilization is the process of choice in many healthcare facilities.

What actions need to be taken if any of the steam sterilization parameters are not met?

If any steam sterilization parameter was not met, the supervisor should be notified immediately, and the sterilization load should not be released.

Why is it important to refrain from touching packages during the cooling period after sterilization?

If packages are touched at this point, the vapor present might carry microorganisms from one's hand through the packaging material, leading to contamination of the item.

What is a common issue associated with packaging in the context of steam sterilization, specifically when packs are wrapped too tightly?

If packs are wrapped too tightly, air become trapped ad cannot escape.

How does the gravity displacement cycle in sterilizers work to remove air from the chamber?

In a gravity displacement cycle, steam enters the chamber and because air is heavier than steam, the steam forces the cooler air to the bottom of the chamber and out the drain.

How is steam typically supplied to sterilizers in most hospitals?

In most hospitals, steam is supplied to the sterilizers from a main steam line; these units themselves do not generate steam.

How would you describe the ideal composition of steam in terms of weight, specifically the balance between saturated water and dry, saturated steam?

In other words, steam ideally should consist of (by weight) two to three parts of saturated water and 97 to 98 parts of dry, saturated steam.

What is the potential consequence of insufficient exposure times during the sterilization process?

Inadequate sterilization exposure times can lead to failure of the sterilization process.

What is the general rule regarding the usage of items that have undergone immediate use steam sterilization (IUSS), and under what circumstances can these items be stored for later use?

Items sterilized using IUSS should be used immediately and cannot be stored for use at a later time, unless such a process has been approved by the U.S. Food and Drug Administration (FDA).

What is the level of cleaning and preparation required for items that are intended for immediate use steam sterilization (IUSS) compared to items that undergo terminal sterilization?

Items using IUSS must undergo the same cleaning and preparation as items that are terminally sterilized.

What risk does moisture pose in terms of microbial contamination during the sterilization process?

Moisture can create a pathway for microorganisms to travel from the outside to the inside of a package.

What is the purpose of the small drain strainer typically found at the bottom of the chamber in most sterilizers?

Most sterilizers have a small drain strainer at the bottom of the chamber to keep lint, tape, and other small objects from entering the exhaust line.

How are packages classified as "wet" in the context of sterilization?

Packages are considered wet when moisture in the form of dampness, droplets, or puddles of water are found on or within a package after a completed sterilization process.

What is an important consideration when arranging packs on a cart for steam sterilization? Additionally, what potential issues can arise when loads are too crowded?

Packs must be arranged with adequate spacing on the cart. If they are packed too tightly, air my be entrapped, and steam may not be able to penetrate all areas.

What is the typical range of cooling times for different types of sterilized items, such as small sets or peel pouches versus larger sets?

The cooling time may be only 30 minutes for small sets or peel pouches but can take two hours or longer for larger sets.

What is the primary function of the door gasket in a steam sterilizer?

The door gasket is designed to maintain a tight seal that prevents steam from escaping from the chamber, and air from entering the chamber.

How does the safety locking mechanism of the door in a steam sterilizer function, and under what conditions does it automatically activate and unlock?

The door has a safety locking mechanism that automatically activates when chamber pressure is applied, and it can only be unlocked when pressure is exhausted.

In a steam sterilizer, which specific component is considered the weakest part?

The door is the weakest part of a steam sterilizer.

In a sterilizer, which specific areas are considered the coolest?

The drain and the area surrounding it are the coolest areas in the sterilizer.

What is the recommended frequency for cleaning drain screens in sterilizers?

The drain screen must be cleaned at least daily and more often, as needed.

What is the recommended source of information for determining the appropriate time and temperature requirements for sterilizing each specific instrument or instrument set?

The instrument's manufacturer's IFU should be consulted for the specific time and temperature for each instrument/set sterilized to ensure the cycle is appropriate.

What is the recommended relative humidity (RH) range for the moisture content of saturated steam?

The moisture content of saturated steam should possess a relative humidity (RH) of 97% to 100%.

What is the primary cause of sterilization failure in most cases?

The most common reason for sterilization failure is the lack of contact between steam and the entire surface of the device being sterilized.

Define: Bioburden

The number of microorganisms on an object; also called "bioload" or "microbial load".

What specific actions should be taken by the operator in regard to the physical monitors to indicate an acceptable cycle during the sterilization process?

The physical monitors (recording chart, printer or tape) should be reviewed, signed and dated by the operator to indicate an acceptable cycle.

What is the significance of time in the steam sterilization process?

The steam sterilization process can only be effective if all items within the load are exposed to the elevated temperatures and steam contact (moisture) for an adequate amount of time.

What are the typical temperature ranges associated with two commonly encountered methods of steam sterilization, namely gravity sterilization and dynamic air removal?

The two most commonly encountered temperatures for steam sterilization are gravity sterilization 250°F (121°C) and dynamic air removal 270°F to 275°F (132.2°C to 134°C).

What is the primary purpose of immediate use steam sterilization (IUSS)?

Their intended use is for the emergency sterilization of instruments when there is not enough time for terminal sterilization.

What are the various types of monitors used in sterilizers?

There are different types of monitors such as digital printouts, electronic recording/data capture, and gauges.

What are some of the different methods employed by dynamic air removal sterilizers to achieve effective air removal during the preconditioning phase?

These include variations of prevacuum air removal and above-atmospheric-pressure processes, such as the steam flush pressure pulse (SFPP) process.

What is the primary purpose of achieving specific temperatures during steam sterilization?

These temperatures are needed to kill heat-resistant bacteria.

In immediate use steam sterilization (IUSS), what is the expected condition of the instruments or equipment at the sterilization process's conclusion regarding temperature and moisture content?

These types of sterilization processed have little or no dry time; therefore, at the end of the sterilization process, instrumentation is expected to be hot and wet.

What happens following the removal of steam during the exhaust phase?

This creates a void in the chamber; filtered air is gradually reintroduced into the chamber and the chamber gradually returns to room pressure.

What are the potential causes of sterilization failure?

This failure may be related to human error or mechanical malfunction.

What is a critical requirement for steam sterilization to be effective?

To be effective, steam sterilization must occur at specific temperatures.

What are the two fundamental sterilization cycles that SP technicians should be familiar with?

To begin, SP technicians should be familiar with two basic sterilization cycles: immediate use steam sterilization (IUSS) and terminal sterilization.

What is the recommended method for ensuring air removal in prevacuum steam sterilizers, and how often should it be performed to check the integrity of the sterilizer?

To ensure air removal in these sterilizers, the integrity of the sterilizers should be checked daily by processing a Bowie-Dick (or daily air removal) test.

What is the typical operating temperature range for prevacuum steam sterilizers?

Typical operating temperatures are 270°F to 275°F (132°C to 135°C).

In the context of sterilization, what is the recommended approach with regards to wet items?

Wet items should be considered contaminated, even if they have not been touched.

What is a recommended practice when loading a sterilizer to prevent condensation from dripping onto lower packs, particularly when combining loads?

When combining loads, placing hard goods, such as rigid containers, on the bottom to prevent condensation from dripping onto lower packs.

After removing the cart from a sterilizer, what precautions should be taken regarding its placement?

When the cart is removed, it should be placed in a low-traffic area where there are no air conditioning or other cold air vents in close proximity.

What is a primary contributing factor to sterilization failures and how can these failures be mitigated?

While mechanical malfucntions can occur, many sterilization failures are caused by human error and can be prevented by good work practices.

What are the different phases that comprise a saturated steam sterilization cycle?

‣ Conditioning ‣ Exposure ‣ Exhaust ‣ Drying (in most instances)

What specific information is typically included in a printout from a steam sterilization cycle?

‣ Date and time the cycle began ‣ Selected cycle parameters such as type of cycle, sterilization temperature, and dry times ‣ A written record of actual cycle activities (e.g., temperatures, exposure times, and pressure)

To unload sterile items from a sterilizer, what are the general procedures or guidelines that should be followed?

‣ Do not unload packages before they cool. Placing hot or warm packages on cold surfaces will cause condensation to develop beneath and/or between them. ‣ Handle the sterile packages as little as possible. Items should not be moved or touched until they have cooled to room temperature.

What are some common factors that contribute to the failure of steam contact during the sterilization process?

‣ Failure to adequately clean the object being sterilized ‣ Density ‣ Packages wrapped too tightly ‣ Loads that are too crowded ‣ Containers that are positioned incorrectly ‣ Clogged drain strainer ‣ Mechanical malfunctions ‣ Utility malfunctions

What problems can arise during sterilization if the steam used is not saturated (less than 97% to 100% relative humidity)?

‣ Items in the sterilizer will remain dry, and microorganisms cannot be killed as readily as under wet conditions. ‣ Textiles and paper become scorched and rubber deteriorates rapidly.

What are some of the reasons that make steam the sterilant of choice?

‣ Low cost ‣ Rapid sterilization cycles ‣ Relatively simple technology ‣ Leaves no chemical residues or byproducts

What is the specific process employed by steam flush pressure pulse (SFPP) sterilizers?

Steam flush pressure pulse sterilizers (SFPP) sterilizers use a repeated sequence of a steam flush and pressure pulse to remove air from the sterilizing chamber and processed materials.

What are the different sizes and cycle choices available for steam sterilizers, and how do they cater to various needs?

Steam sterilizers come in many sizes and cycle choices, from small tabletop sterilizers used primarily in clinic and dental settings, to mid-sized and large units designed to sterilize large quantities of items.

Define: Saturated steam

Steam that contains the maximum amount of water vapor.

In Sterile Processing departments (SPDs), what type of sterilizers are typically utilized?

Sterile Processing departments (SPDs) typically use jacketed sterilizers.

Why is sterilization necessary in the final step of the process?

Sterilization is required to kill any remaining microorganisms, including spores.

Where are the sterilizers typically situated for the purpose of immediate use steam sterilization (IUSS)?

Sterilizers used for IUSS are typically located outside of the SPD.

In what types of healthcare settings are tabletop sterilizers commonly utilized?

Tabletop sterilizers are frequently used in clinics and dental offices.

Where is terminal sterilization typically carried out?

Terminal sterilization is most often performed in the SPD.

What is the definition of terminal sterilization?

Terminal sterilization refers to the sterilization of an item that is expected to be dry upon completion of the sterilization process.

How did the autoclave, resembling a pressure cooker?

The autoclave resembled a pressure cooker and was able to use pressurized steam to reach temperatures of 248°F (120°C) and higher.

What is the significance of ensuring thorough cleaning before attempting sterilization for a medical device?

The cleaning process is absolutely essential as a first step in sterilization. A device can be cleaned without sterilizing, but sterilization cannot be achieved if a device hasn't been thoroughly cleaned.

How does debris in the chamber drain screen impact the performance of a sterilization cycle?

Debris in the chamber drain screen can impede cycle performance by blocking the removal of air and steam.

What are some examples of mechanical malfunctions that can potentially arise during the sterilization process, and who should be contacted to address these issues?

Defective steam traps, clogged exhaust lines, and similar mechanical malfunctions can occur and cannot be repaired by an SP technician. A qualified service representative should be called to perform the necessary maintenance.

What specific characteristics does the steam need to possess for it to be considered effective in the process of sterilization?

Dry, saturated steam is required for effective sterilization.

When does the drying phase of a sterilization cycle commence?

Drying begins after the exhaust phase.

What factors determine the duration of the drying phase in a sterilization cycle?

Drying times are based on the device, packaging, and sterilizer IFU.

How do dynamic air removal sterilizers differ from gravity air displacement sterilizers in terms of their construction and the method used to remove air from the chamber?

Dynamic air removal sterilizers are similar in construction to gravity air displacement sterilizers, except there is a vacuum pump or water ejector that removes air from the chamber more effectively during the preconditioning phase, before reaching the exposure temperature.

What is the typical temperature range at which dynamic air removal sterilizers operate, and how does it compare to the operating temperature range of gravity sterilizers?

Dynamic air removal sterilizers usually operate at high temperatures [270°F to 275°F] (132°C to 135°C)] than gravity sterilizers.

What is another critical factor for achieving effective sterilization regarding contact?

Effective sterilization requires that the sterilizing agent contact all surfaces of the devices for the prescribed time.

What specific information do physical monitors on a sterilizer record?

Physical monitors on a sterilizer record the time, temperature, and pressure.

How do physical monitors contribute to the sterilization process?

Physical monitors verify that parameters of the sterilization cycle have been met.

What are the potential issues that can arise from placing paper/plastic peel pouches plastic side down or plastic side up during the loading of a sterilizer?

Placing paper/plastic peel pouches plastic side down may cause moisture to remain inside, and placing them plastic side up may cause water to stand on top of plastic.

When loading a sterilizer, what is the recommended positioning for textile packs to ensure optimal sterilization?

Positioning textile packs so the layers within them are perpendicular to the shelf.

Before the widespread use of steam sterilization, what was the commonly employed method to achieve the killing of bacteria?

Prior to steam sterilization, boiling water was commonly used to kill bacteria.

What are the four essential conditions that must be satisfied, irrespective of the method employed for steam sterilization?

Regardless of the type of steam sterilization method used, the same four conditions - contact, temperature, time, and moisture - must be met.

What responsibilities do SP technicians have when it comes to monitoring physical parameters during the sterilization cycle?

SP technicians must check them throughout the sterilization cycle to ensure that necessary parameters are met.

What is the difference between saturated steam and dry steam in terms of their ability to carry thermal energy?

Saturated steam is a much better "carrier" of thermal energy than dry steam.

Why did scientists recognize the necessity of increasing temperatures beyond the boiling point when it came to sterilization?

Scientists recognized the need to increase temperatures beyond the boiling point to kill greater numbers of heat-resistant bacteria.

What are the potential issues related to the density of instrument sets or the improper positioning of instruments?

Sets that are too dense, or instruments positioned in a way that does not allow steam contact.

What are the two types of cycles commonly found in small-to-medium-sized sterilizers?

Some small-to-medium-sized sterilizers have gravity displacement and dynamic air removal cycles.

What is the purpose of the automatic cycle, known as the vacuum leak test, in certain sterilizers?

Some sterilizers have an automatic cycle (vacuum leak test) to test the vacuum tightness of the chamber.

What is a recommended procedure for loading sterilizers when it comes to standing basin sets, and how should they be positioned?

Standing basin sets on edge. They should be tilted for drainage so if water is present, it will run out.

What is the recommended method for loading paper/plastic peel pouches in a sterilizer?

Standing paper/plastic peel pouches on edge using a basket or rack. Place them so that the sterilization pouches are placed paper-to-plastic for air and steam circulation.

What are some of the factors and conditions that impact the effectiveness of sterilization methods, particularly those utilizing high temperature?

‣ The type of microorganisms present - Some microorganisms are more resistant to the sterilization process than others. ‣ The design of the medical device - Complex devices present a challenge to the sterilization process. ‣ The number of microorganisms (bioburden) present - When there are more microorganisms on a medical device, the sterilization process becomes more difficult. ‣ The amount and type of soil present - Soil acts as a shield to protect microorganisms.