TABLE 10-1
ROUTE DESCRIPTION EXAMPLE
Contact transmission Direct contact Indirect contact Droplet transmission Airborne transmission
Vehicle transmission
Vector transmission
Actual physical transfer from one infected person to another (body surface to body surface contact) Contact between a susceptible person and a
contaminated object
Transfer of moist particles from an infected person who is within a radius of 3 feet
Movement of microorganisms attached to evapo- rated water droplets or dust particles that have been suspended and carried over distances greater than 3 feet
Transfer of microorganisms present on or in contaminated items such as food, water, medications, devices, and equipment Transfer of microorganisms from an infected
animal carrier
Sexual intercourse with an infected person Use of a contaminated surgical instrument Inhalation of droplets released during sneezing,
coughing, or talking Inhalation of spores
Consumption of water contaminated with microorganisms
Diseases spread by mosquitoes, fleas, ticks, or rats
BOX 10-2 ● Factors Affecting Susceptibility to Infections
❙ Inadequate nutrition
❙ Poor hygiene practices
❙ Suppressed immune system
❙ Chronic illness
❙ Insufficient white blood cells
❙ Prematurity
❙ Advanced age
❙ Compromised skin integrity
❙ Weakened cough reflex
❙ Diminished blood circulation
Stop • Think + Respond BOX 10-1 Use the chain of infection to trace the transmission of a common cold from one person to another.
C H A P T E R 1 0 ● Asepsis 139
• Blood, body fluids, cells, and tissues are considered major reservoirs of microorganisms.
• Personal protective equipment such as gloves, gowns, masks, goggles, and hair and shoe covers serves as a barrier to microbial transmission.
• A clean environment reduces microorganisms.
• Certain areas—the floor, toilets, and insides of sinks—
are more contaminated than others. Cleaning should be done from cleaner to dirtier areas.
Examples of medical aseptic practices include using antimicrobial agents, performing hand hygiene, wear- ing hospital garments, confining and containing soiled materials appropriately, and keeping the environment as clean as possible. Measures used to control the trans- mission of infectious microorganisms are discussed in more detail in Chapter 22.
Using Antimicrobial Agents
Antimicrobial agentsare chemicals that destroy or suppress the growth of infectious microorganisms (Table 10-2).
Some antimicrobial agents are used to clean equipment, surfaces, and inanimate objects. Others are applied directly to the skin or administered internally. Examples are anti- septics, disinfectants, and anti-infective drugs.
ANTISEPTICS. Antiseptics, also known as bacteriostatic agents,inhibit the growth of, but do not kill, microorgan- isms. An example is alcohol. Antiseptics generally are applied to the skin or mucous membranes. Some also are used as cleansing agents.
DISINFECTANTS. Disinfectants, also called germicidesand bactericides,destroy active microorganisms but not spores.
Phenol, household bleach, and formaldehyde are exam-
ples. Disinfectants rarely are applied to the skin because they are so strong. Rather, they are used to kill and remove microorganisms from equipment, walls, and floors.
ANTI-INFECTIVE DRUGS. The two groups of drugs used most often to combat infections are antibacterials and antivirals.
The chemical actions of antibacterials, which consist of antibiotics and sulfonamides, alter the metabolic pro- cesses of bacteria but not viruses. They damage or destroy bacterial cell walls or the mechanisms that bacteria need to grow. They also, however, destroy normal bacterial flora. Before the advent of antibacterial therapy, wound infections, dysentery, and many contagious diseases cut short life expectancy. Some believe humans will return to the days of epidemics, plagues, and pestilence if anti- bacterial agents can no longer control microorganisms.
Antiviral agents were developed more recently, most likely in response to the rising incidence of blood-borne viral diseases such as AIDS. Antivirals do not destroy the infecting viruses; rather, they control viral replication (copying) or release from the infected cells. The virus remains alive and still can cause reactivation of the ill- ness. The goal of antiviral therapy is to limit the viral load
(numbers of viral copies).
Handwashing
Handwashingis an aseptic practice that involves scrubbing the hands with soap, water, and friction. This process mechanically removes dirt and organic substances. Plain soap or detergents do not have bactericidal activity. Hand- washing removesresident microorganisms(generally non- pathogens constantly present on the skin) and transient microorganisms(pathogens picked up during brief contact with contaminated reservoirs).
ANTIMICROBIAL AGENTS
TABLE 10-2 TYPE
Soap Detergent Alcohol Iodine
Chlorine Chlorhexidine Mercury Glutaraldehyde
MECHANISM
Lowers the surface tension of oil on the skin, which holds microorganisms; facilitates removal during rinsing Acts as soap, except detergents do not form
a precipitate when mixed with water
Injures the protein and lipid structures in the cellular mem- brane of some microorganisms (70% concentration) Damages the cell membrane of microorganisms and
disrupts their enzyme functions; not effective against Pseudomonas,a common wound pathogen
Interferes with microbial enzyme systems
Damages the cell membrane of microorganisms, but is ineffective against spores and most viruses
Alters microbial cellular proteins
Inactivates cellular proteins of bacteria, viruses, and microbes that form spores
EXAMPLE
Dial, Safeguard Dreft, Tide
Isopropanol, ethanol Betadine
Bleach, Clorox Hibiclens
Merthiolate, Mercurochrome Cidex
USE
Hygiene Sanitizing eating
utensils, laundry Cleansing skin,
instruments Cleansing skin
Disinfecting water, utensils, blood spills Cleansing skin and
equipment Disinfecting skin Sterilizing equipment
140 U N I T 4 ● Performing Basic Client Care
Although transient microorganisms are more patho- genic, handwashing more easily removes them. They tend to cling to grooves and gems in rings, the margins of chipped nail polish and broken or separated artificial nails, and long fingernails. Thus, these items are contra- indicated when caring for clients. Without conscientious handwashing, transient microorganisms become resi- dents, thereby increasing the potential for transmission of infection. One possible explanation for the increase of antimicrobial-resistant pathogens is that nosocomial pathogens are replacing the normal flora of clients when health care workers fail to wash their hands at appropri- ate times for a minimum of 15 seconds (Goldmann et al., 1996; Paul-Cheadle, 2003). Considering how often health care personnel use their hands with clients, it is no sur- prise that handwashing is the single most effective way to prevent infections. Skill 10-1 describes the steps of handwashing.
Certain situations require handwashing; in others, nurses may substitute hand antisepsis (Box 10-3).
Performing Hand Antisepsis
Because research has shown that approximately 40% to 50% of health care workers comply with the minimum requirements for handwashing (Kovach, 2003), the Cen- ters for Disease Control and Prevention (Boyce & Pittet,
2002) approved new guidelines for hand antisepsis with alcohol-based hand rubs. Hand antisepsis means the removal and destruction of transient microorganisms without soap and water. It involves products such as alcohol-based liquids, thick gels, and foams. Alcohol-based hand sanitizers are not substitutes for handwashing in all situations (see Box 10-3). Alcohol does not remove soil or dirt with organic material; however, it does produce anti- sepsis when the hands are visibly clean. Alcohol rubs, when used for a minimum of 5 seconds, remove 99% of microorganisms on the hands, including gram-positive and gram-negative bacteria, fungi, multidrug-resistant pathogens, and viruses (Kovach, 2003; Paul-Cheadle, 2003). Because alcohol formulations have a brief rather than sustained antiseptic effect, however, nurses must reuse them over the course of a day (Kovach, 2003).
Advantages of alcohol hand rubs are that they (1) take less time, (2) are more accessible because they do not require sinks or water, (3) increase compliance because they are easier to perform, (4) provide the fastest and great- est reduction in microbial counts on the skin, (5) reduce costs by eliminating paper towels and waste management, and (6) are less irritating and drying than soap because they contain emollients (Hand Hygiene Resource Center, 2004; Paul-Cheadle, 2003).
When decontaminating with an alcohol-based hand rub, the nurse
• Applies about a nickel- to quarter-sized volume of the product to the palm of one hand or the amount recom- mended by the manufacturer
• Distributes the product to cover all surfaces of the hands and fingers
• Rubs the product between the hands until the hands are dry (Boyce & Pittet, 2002)
The CDC believes that with higher compliance, the poten- tial for reducing the rate of nosocomial infections is greater.
BOX 10-3 ● Handwashing and Hand Antisepsis Guidelines
Handwashing with either a non-antimicrobial or an antimicrobial soap and water is performed:
❙ When hands are visibly dirty
❙ When hands are contaminated with proteinaceous material
❙ When hands are visibly soiled with blood or other body fluids
❙ Before eating and after using a restroom
❙ If exposure to Bacillus anthracisis suspected or proven
Hand antisepsis with an alcohol-based hand rub can be substituted for hand- washing:
❙ Before having direct contact with clients
❙ After contact with a client’s intact skin (e.g., when taking a pulse or blood pressure, lifting a client)
❙ Before donning sterile gloves to insert invasive devices such as urinary catheters, peripheral vascular catheters, central intravascular catheters, or other devices that do not require a surgical procedure
❙ After contact with body fluids or excretions, mucous membranes, nonintact skin, and wound dressings if hands are not visibly soiled
❙ If moving from a contaminated body site to a clean body site during client care
❙ After contact with inanimate objects (including medical equipment) in the immediate vicinity of the client
❙ After taking off gloves because gloves are not an impervious barrier
Boyce, J. M., & Pittet, D. (2002). Guideline for hand hygiene in health- care settings. Recommendations of the Healthcare Control Practice Advisory Committee and the HICPAC/SHEA/APIC/IDSA Hand Hygiene Task Force. Morbidity & Mortality Weekly Report html51(RR16):1–44.
http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5116a1.htm Accessed June 2003.
Stop • Think + Respond BOX 10-2 Discuss actions for ensuring appropriate handwashing before and after caring for a client in his or her home. Use a scenario in which the client has bar soap that rests on the bathroom sink and terrycloth hand towels shared among an entire family.
Performing a Surgical Scrub
Asurgical scrub, a type of skin and nail antisepsis, is per- formed before donning sterile gloves and garments when the nurse is actively involved in an operative or obstetric procedure. The purpose is to more extensively remove transient microorganisms from the nails, hands, and fore- arms. In fact, the cleanser should reduce microbial growth
C H A P T E R 1 0 ● Asepsis 141 for increasingly longer periods with successive numbers
of scrubs. Table 10-3 lists several differences between a surgical scrub and handwashing.
To reduce the numbers of microorganisms maximally, the fingernails must be short—no more than 1⁄4inch long, which does not extend beyond the tip of the fingers (Morantz & Torrey, 2003). Artificial nails are prohib- ited. Nail polish is discouraged, especially if it is chipped, worn, or on for more than 4 days, because it is conducive to increased microorganisms. All rings, watches, and jewelry are removed and safeguarded before the surgical scrub (Skill 10-2).
Wearing Personal Protective Equipment
Health care personnel wear various garments to reduce the transfer of microorganisms between themselves and clients: uniforms, scrub suits or gowns, masks, gloves, hair and shoe covers, and protective eyewear. They wear some of these items when caring for any client regardless of diagnosis or presumed infectious status (see Chap. 22).
UNIFORMS. Health care professionals wear their uni- forms only while working with clients. Some nurses wear a clean laboratory coat over their uniform to reduce the spread of microorganisms onto or from the surface of clothing worn from home. When caring for clients, they wear a plastic apron or cover gown over the uniform if there is a potential for soiling it with blood or body flu- ids. When not wearing a cover, nurses take care to avoid touching the uniform with any soiled items such as bed linen. After work, they change the uniform as soon as possible to avoid exposing the public to the microorgan- isms present on work clothing.
SCRUB SUITS AND GOWNS. Scrub suits and gowns are hos- pital garments worn instead of a white uniform. Their use is mandatory in some areas of a hospital—the nursery, operating room, and delivery room. These garments pre- vent personnel from bringing microorganisms on their clothes into the hospital environment. Employees in other departments sometimes wear their own scrub suits or gowns because they are comfortable and practical. Person- nel who work in mandatory-wear areas don scrub suits and gowns when they arrive for work. They wear cover gowns over the scrubs when taking coffee or lunch breaks.
MASKS. Masks cover the nose and mouth (Fig. 10-3) and help to prevent droplet and airborne transmission of microorganisms. To prevent the transmission of TB, the CDC (Garner, 1996) recommends the use of a disposable or replaceable particulate air filter respirator (Fig. 10-4).
The minimum specification for a particulate air filter respirator is N-95; N refers to “not resistant to oil”
(i.e., it is effective in blocking particulate aerosols that are free of oil) (CDC, 1999). An N-95 air filter respira- tor can filter particles 0.3 micron with a minimum effi- ciency of 95%. The respirator must have a label indicating approval by the National Institute of Occupational Safety and Health (NIOSH).
Particulate respirators are custom sized and fitted for each health care worker to obtain a face-seal leakage of less than 10% (Bartley & Pugliese, 2001). The same health care worker can reuse a disposable N-95 respira- tor as long as it remains intact and clean. All particulate air filter respirators are checked for leakage initially, before each use, and if the user gains or loses 10 lbs.
In certain high-risk situations, such as when a bron- choscopy or autopsy is performed on a client with TB,
DIFFERENCES BETWEEN HANDWASHING AND A SURGICAL SCRUB
TABLE 10-3 HANDWASHING
Plain wedding band may be worn.
Faucets with hand controls are used; elbow, knee, or foot controls are preferred.
Liquid, bar, leaflet, or powdered soap or detergent is used.
Washing lasts a minimum of 10 to 15 seconds.
Hands are held lower than the elbows during washing, rinsing, and drying.
Areas beneath fingernails are washed.
Friction is produced by rubbing the hands together.
Hands are dried with paper towels; the paper is used to turn off hand-regulated faucet controls.
Clean gloves are donned if the nurse has open skin or if there is a potential for contact with blood or body fluids.
SURGICAL SCRUB
All hand jewelry, including watch, is removed.
Faucets are regulated with elbow, knee, or foot controls.
Liquid antibacterial soap is used; scrubbing devices may be incorporated with antibacterial soap.
Scrubbing lasts 2 to 5 minutes, depending on the antibacterial agent and time interval between subsequent scrubs.
Hands are held higher than the elbows during washing, rinsing, and drying.
Areas beneath fingernails are cleaned with an orange stick or similar nail cleaner.
Friction is produced by scrubbing with a sponge.
Hands are dried with sterile towels.
Sterile gloves are donned immediately after the hands are dried.
142 U N I T 4 ● Performing Basic Client Care
Latex and vinyl gloves are equally protective with non- vigorous use, but latex gloves have some advantages.
They stretch and mold to fit the wearer almost like a sec- ond layer of skin, permitting greater flexibility with move- ment. Perhaps most importantly, they can reseal tiny punctures.
Unfortunately some nurses and clients are allergic to latex. Reactions vary and range from annoying symp- toms such as skin rash, flushing, itching and watery eyes, and nasal stuffiness to life-threatening swelling of the airway and low blood pressure. Nurses who are sensitive to latex can wear alternative types of gloves, or they can wear a double pair of vinyl gloves when the risk for con- tact with blood or body fluids is high.
Nurses change gloves if they become perforated, after a period of use, and between the care of clients. Vinyl gloves are not as protective after 5 minutes of wear. By using aseptic techniques, nurses remove gloves without directly touching their more contaminated outer surface.
See Nursing Guidelines 10-2.
FIGURE 10-3
•
Face mask and hair cover. (Copyright B. Proud.)FIGURE 10-4
•
Replaceable filter and disposable respirators.Replaceable Disposable
a respirator that exceeds the minimum standard is used.
In those cases, a powered air-purifying respirator (PAPR) or positive-pressure airline respirator equipped with a half- or full-face mask is required (CDC, 1999). See Nurs- ing Guidelines 10-1.
GLOVES. Nurses wear clean gloves, sometimes called examination gloves, in the following circumstances:
• As a barrier to prevent direct hand contact with blood, body fluids, secretions, excretions, mucous membranes, and nonintact skin
• As a barrier to protect clients from microorganisms transmitted from nursing personnel when performing procedures or care involving contact with the client’s mucous membranes or nonintact skin
• When there is a potential transfer of microorganisms from one client or object to another client during sub- sequent nursing care
Examination gloves are generally made of latex or vinyl, although other types are available (see Chap. 19).
NURSING GUIDELINES 10-1
Using a Mask or Particulate Filter Respirator
❙ Wear a mask if there is a risk for coughing or sneezing within a radius of 3 feet. The mask blocks the route of exit.
❙ Wear a mask or particulate filter respirator if there is a potential for acquiring diseases caused by droplet or airborne transmission. The mask blocks the port of entry.
❙ Position the mask or respirator so that it covers the nose and mouth.
The mask provides a barrier to nasal and oral ports of entry.
❙ Tie the upper strings of a mask snugly at the back of the head and the lower strings at the back of the neck. Proper placement reduces the exit and entry routes for microorganisms.
❙ Avoid touching the mask or respirator once it is in place. Touching the mask transfers microorganisms to the hands.
❙ Change the mask or respirator every 20 to 30 minutes or when it becomes damp; particulate filter respirators can be worn multiple times, but they must be rechecked for leakage and fit. Changing the mask preserves its effectiveness.
❙ Touch only the strings of the mask or the respirator strap during removal.Touching the mask transfers microorganisms to the hands.
❙ Discard used masks or respirators into a lined or waterproof waste container.Proper disposal reduces the transmission of
microorganisms to others.
❙ Perform handwashing or hand antisepsis after removing a mask or respirator.Handwashing and hand antisepsis remove
microorganisms from the hands.
Stop • Think + Respond BOX 10-3 What is the best action to take if while donning sterile gloves, a nurse touches the thumb of an already gloved finger to his or her ungloved wrist?
C H A P T E R 1 0 ● Asepsis 143 Confining Soiled Articles
Health care agencies use several medically aseptic prac- tices to contain reservoirs of microorganisms, especially those on soiled equipment and supplies. They include using designated clean and dirty utility rooms and vari- ous waste receptacles.
UTILITY ROOMS. Health care agencies have at least two utility rooms: one designated clean and the other consid- ered dirty. Personnel must not place soiled articles in the clean utility room.
The dirty or soiled utility room contains covered waste receptacles, at least one large laundry hamper, and a flush- able hopper. This room also houses equipment for test- ing stool or urine. A sink is located in the soiled utility room for handwashing and for rinsing grossly contami- nated equipment.
WASTE RECEPTACLES. Agencies rely on various methods to contain soiled articles until they can be discarded.
Most clients have a paper bag at the bedside for tissues or other small, burnable items. Wastebaskets generally are lined with plastic. Suction and drainage containers are kept covered and emptied at least once each shift. Most client rooms have a wall-mounted puncture-resistant container for needles or other sharp objects (Fig. 10-7).
Keeping the Environment Clean
Health agencies employ laundry staff and housekeeping personnel to assist with cleaning. In general, if soiled linen is bagged appropriately or handled with gloves, the detergents and heat from the water and the dryer pro- duce laundry that is sufficiently clean and free of patho- genic organisms.
Housekeeping personnel are responsible for collecting and disposing of accumulated refuse and for perform- ing concurrent and terminal disinfection. Housekeepers who follow the principles of medical asepsis carry out
NURSING GUIDELINES 10-2
Removing Gloves
❙ Grasp one of the gloves at the upper, outer edge at the wrist (Fig. 10-5).
This position maintains a barrier between contaminated surfaces.
❙ Stretch and pull the upper edge of the glove downward while inverting the glove as it is removed. This action encloses the soiled surface, blocking a potential exit route for microorganisms.
❙ Insert the fingers of the ungloved hand within the inside edge of the other glove. The inside edge is the cleaner surface of the glove.
❙ Pull the second glove inside out while enclosing the first glove within the palm. This action contains the reservoir of microorganisms.
❙ Place the gloves within a lined waste container. Proper disposal confines the reservoir of microorganisms.
❙ Wash hands or perform hand antisepsis with an alcohol rub immediately after removing gloves. Handwashing and hand antisepsis removes transient and resident microorganisms that have proliferated within the warm, dark, moist environment inside the gloves.
A B C
FIGURE 10-5
•
(A) Pulling at cuff. (B) Inverting the glove. (C) Enclosing contaminated surfaces. (Copyright B. Proud.)HAIR AND SHOE COVERS. Hair and shoe covers reduce the transmission of pathogens present on the hair or shoes. Health care personnel generally wear these gar- ments during surgical or obstetric procedures. Shoe cov- ers are fastened so that they cover the open ends of pant legs. Hair covers should envelop the entire head. Men with beards or long sideburns wear specially designed head covers that resemble a cloth or paper helmet. Even though hair covers are not required during general nurs- ing care, health care workers should keep their hair short or contained with a clip, band, or some other means.
PROTECTIVE EYEWEAR. Protective eyewear is essential when there is a possibility that body fluids will splash into the eyes. Goggles are worn along with a mask, or a multipurpose face shield is used (Fig. 10-6).