CHAPTER 17 EQUIPMENT DECONTAMINATION AND INFECTION CONTROL
PRETEST QUESTIONS
1. Which of the following procedures is most often used to decontaminate a bacterial filter used on a mechanical ventilator?
2. Diseases that may be transmitted via airborne particles include which of the following?
3. Which of the following procedures are capable of sterilizing equipment?
4. Which of the following should be worn as a precautionary measure when changing a patient’s ventilator circuit?
5. A high-efficiency particulate air (HEPA) filter should be used in the room of a patient with which type of condition?
6. Biologic indicators are used in decontamination procedures for which of the following reasons?
REVIEW
A. Vegetative Organisms: organisms in active growth. These organisms pose the greatest hazard for infection via respiratory therapy equipment because the most common equipment contaminants are not spore-forming bacteria.
B. Spores: organisms in a resting, resistant stage. They are very difficult to kill but pose little threat for infection via respiratory therapy equipment.
C. Disinfection: killing of all vegetative forms of organisms but not spores. Agents that disinfect equipment are called disinfectants.
D. Sterilization: killing of all organisms, both vegetative and spores. An agent that sterilizes equipment is called a sterilant.
E. The suffix -cidal means to kill, as in bactericidal, which is said of something that kills bacteria.
F. The suffix -static means to prevent growth of, as in bacteriostatic, which is said of something that prevents the growth of bacteria.
G. Gram’s stain method for differential staining of bacteria. Gram-positive bacteria stain a purple-black color, and gram-negative bacteria stain a pink color.
H. Nosocomial Infection: a hospital-acquired infection. Often caused by Pseudomonas species, Staphylococcus species, Candida albicans, or Escherichia coli.
II. CONDITIONS THAT INFLUENCE ANTIMICROBIAL ACTION
B. Intensity of the Physical Agent: The more intense a physical agent (e.g., heat), the more rapidly the organisms are killed.
D. Temperature: Increasing the temperature of a chemical agent shortens the exposure time required to kill the organisms.
E. Type of Organism: Vegetative forms of bacteria are more easily killed than spore-forming bacteria. Spores are more resistant to both chemical and physical agents.
G. Nature of Material Bearing the Organism: The presence of blood, sputum, or other medium provides protection for the organisms. It is for this reason that equipment must be thoroughly washed in soapy water and rinsed off before the decontamination process.
Exam NoteIV. STERILIZATION AND DISINFECTION TECHNIQUES
a. Heat in the form of steam is one of the most dependable and practical methods for decontamination.
e. Bacteria filters are commonly sterilized by this method, but any material made of rubber cannot withstand the intense heat.
f. The tops of nebulizers and humidifiers should be attached loosely to allow exposure to all parts of the device.
g. Equipment to be autoclaved must be thoroughly washed in soapy water, dried, and wrapped in muslin, cloth, or a paper bag.
h. Written on the outside of the wrap should be information including the time and date of processing, what kind of equipment is inside the wrap, and who prepared the equipment for processing.
a. Equipment must be washed in soapy water and rinsed off before placement in the pasteurizing machine.
a. Equipment must be washed in soapy water, rinsed, dried completely, and placed in a sealed plastic bag before being placed in the sterilization chamber.
b. If equipment is not completely dry before the sterilization process, ethylene oxide combines with water to form ethylene glycol, an irritating substance found in antifreeze.
d. It is a highly flammable gas, but when it is mixed with approximately 90% carbon dioxide or freon, the explosive danger is minimized.
i. Because moisture enhances the action of ethylene oxide, it is recommended that the relative humidity within the sterilizing chamber be maintained at 50% or more.
j. Items placed in sealed plastic bags are suitable for use for up to 1 yr after gas sterilization, provided the bag is intact.
a. Ethyl alcohol (95% concentration) and isopropyl alcohol (70% concentration) are the most commonly used in the clinical setting.
b. Alcohols are bactericidal and fungicidal but not sporicidal; therefore, they disinfect (but do not sterilize) equipment.
c. These agents are bactericidal in 10 to 15 min and sporicidal in 3 to 10 h, depending on the temperature of the solution.
d. Glutaraldehydes are normally used to disinfect equipment but may be used to sterilize. Organisms are killed by coagulation of the cell protein.
f. On removal from the solution bath (with gloves to prevent skin irritation), the equipment should be rinsed off and thoroughly dried before packaging.
c. Acetic acid is used as a disinfectant for home care equipment and is often run through room humidifiers for cleaning purposes.
d. It is not recommended for use on respiratory therapy equipment in the clinical setting, unless it is used in combination with more effective methods.
V. IMPORTANT POINTS CONCERNING DECONTAMINATION OF EQUIPMENT
C. Always date the container that holds the solution after it is opened; solutions should be discarded after 24 h. This reduces the possibility of filling a reservoir with contaminated solution.
E. Provide a method of routine surveillance to determine the effectiveness of the decontamination process. This is referred to as quality control of equipment.
1. Processing indicators determine whether the disinfection or sterilization process was effective. There are two types of indicators.
a. Biologic indicators: Strips of paper impregnated with bacterial spores are placed in a glass ampule that contains a growth medium. The ampule is then placed inside the sterilizer. After the sterilization process is complete, the ampule is broken and the spore strip is exposed to the growth medium. After an incubation period, if the spore strip changes color, bacteria are present and the sterilization process was ineffective.
b. Chemical indicators are impregnated on packing tape and change color when exposed to certain conditions. Autoclave and ethylene oxide sterilization both use this type of indicator. These indicators show that the package went through the sterilization process but do not necessarily indicate that the equipment is sterile. Ensuring that the equipment is sterile is best accomplished with biologic indicators.
2. Culture sampling: Equipment disinfected by chemical solutions, such as glutaraldehyde, or by pasteurization should be evaluated to determine whether the disinfection process was effective.
3. Swab sampling: A sterile swab is used to wipe an area of the equipment and is placed in a tube of sterile liquid broth to determine the presence of microorganisms.
F. Use of disposable equipment decreases the potential for cross-contamination. Because warm, moist humidifiers and nebulizers are ideal breeding grounds for bacteria, disposables are for single-patient use only.
G. The most cost-effective method of preventing cross-contamination of equipment among patients is by proper HAND-WASHING techniques (see Universal Precautions later in the chapter).
1. All equipment and supplies taken from an isolation area must be double-bagged in nonporous plastic bags.
2. A person in isolation attire places the contaminated equipment into a bag while in the patient’s room and then drops it in a bag held outside the room by a second person. The person dropping the bag of contaminated material into the second bag must be careful not to touch the second bag.
3. The person outside the room then ties off the second bag and takes it to the proper decontamination area.
4. The bag should be labeled to indicate that it is from an isolation area. Labeling should also identify the bag contents as well as the patient’s name and room number. The labeling procedure may vary by institution.
VI. INFECTION CONTROL AND STANDARD (UNIVERSAL) PRECAUTIONS
CRT Exam Content Matrix: IIB4, IIB5
RRT Exam Content Matrix: IIB3, IIB4
A. Standard (Universal) Precautions: All health care providers should practice these precautions, regardless of the patient’s diagnosis or presumed diagnosis. They apply to blood, body fluids, secretions, excretions, mucous membranes, and nonintact skin.
1. Hand washing: should be done for 15 s before and after visiting every patient, even if the examiner is wearing gloves. Alcohol-based hand sanitizers that do not require the use of water are preferred over soap and water because of their superior antimicrobial action. Hand sanitizers are also more convenient and reduce the potential of drying out the skin.
3. Gown: should be worn when performing a task that may involve the splashing of fluids or spraying of blood.
4. Mask, eye goggles, face shield: should be worn when performing a task that may involve the splashing of fluids or spraying of blood.
5. Proper handling of needles and other sharp instruments: should be done as a precaution regardless of whether pathogens are thought to be present. Use extreme caution when handling needles and other sharp instruments.
B. Transmission-Based Precautions: These precautions are used when working with patients who have contagious diseases for which standard precautions are inadequate. These precautions are implemented in addition to standard precautions. There are three types of transmission-based precautions.
b. Examples of diseases requiring these precautions include hepatitis, AIDS, venereal diseases, and staphylococcal infections.
c. In addition to standard precautions, placing the patient in a private room and discarding gloves and gowns before exiting the room is required.
b. Diseases that may be transmitted by this route include tuberculosis, legionellosis, avian flu, and severe acute respiratory syndrome (SARS)
c. In addition to standard precautions, placing the patient in a private room with the door closed at all times is required; anyone entering the room should wear a HEPA mask.
d. To further aid in the reduction of airborne organisms, a special (negative pressure) ventilation system should be in place in the room so that air is safely discharged or recirculated in the room through a HEPA filter.
b. Examples of diseases transmitted by this route include Haemophilus influenzae infection, streptococcal pneumonia, epiglottitis, pertussis, meningitis, and adenovirus infections.
c. In addition to standard precautions, placing the patient in a private room and having anyone entering the room wear a mask is required.
If private rooms are not available for patients under these three types of special precautions, patients infected with the same organism may share a room. This is referred to as cohorting.
Exam NotePOSTCHAPTER STUDY QUESTIONS
1. List four diseases that are spread by airborne pathogens.
2. What device should be used in the ventilation system through which air is discharged safely from the room of a patient with a disease caused by an airborne pathogen?
3. List three methods that may be used to sterilize respiratory therapy equipment.
4. List three diseases transmitted by the spread of droplets.
5. What is a nosocomial infection?
6. List four gram-negative organisms that may result in necrotizing pneumonia.
7. What methods are used to determine the effectiveness of the decontamination process?
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