1. Antiseptics and Disinfectants
Chapter 44
Antiseptics and Disinfectants

2. Role of Antiseptics and Disinfectants
Used to reduce microbial growth and contamination from exogenous sources and reduce the risk of infection
Usually chemical solutions that are topically applied to surfaces such as skin, mucous membranes, or inanimate objects
Antiseptics and disinfectants destroy microorganisms on contact.
Antiseptics- associated with destroying organisms on living tissue surfaces
Disinfectants- associated with destroying organisms on nonliving surfaces
Learning Outcome
44.1 Explain the difference between antiseptics and disinfectants.
Microorganisms are everywhere and migrate freely on skin, hair, furniture, and in air currents. Given the right environment, any microbe can produce an infection. At home, simple wounds and skin abrasions provide potential pathogens an access route to the blood.

3. Sources of Infection Sources of infection
Microorganisms are everywhere.
Skin, hair, furniture, and in air currents
Pathogenic microorganisms can gain access to the general circulation.
Overuse of antibiotics has created “super bugs” as bacteria have developed resistance

4. Categories of Antisepsis and Disinfection
Microbicidal and microbiostatic
Chemicals that kill (-cidal)
Fungicidal, bactericidal, virucidal
Chemicals that reduce or inhibit growth (-static)
Bacteriostatic, fungistatic
The difference between cidal and static is related to the concentration of the chemical used and the amount of time it remains in contact with the surface
Learning Outcome
44.2 Explain the categories of antisepsis and disinfection, such as virocidal and bacteriostatic.
Chemicals that kill microorganisms (-cidal) are termed germicidal, bactericidal, fungicidal, or virucidal, depending on the type of microorganism they affect.
Chemicals that reduce or inhibit growth without eradicating the microorganisms are considered –static agents, such as bacteriostatic or fungistatic. Antiseptics and disinfectant solutions differ in their antimicrobial potency (bactericidal versus bacteriostatic), spectrum of activity (the range of microorganisms they affect), and duration of action.
Broad-spectrum chemicals are effective against bacteria, bacterial spores, fungi, viruses, and protozoa. They include formaldehyde, glutaraldehyde, and iodine-containing solutions. Selective agents such as hexachlorophene and benzalkonium chloride are primarily effective against gram-positive bacteria. Vegetative forms of gram-positive and gram-negative bacteria are killed using alcohol (40 to 70 percent ethyl alcohol solutions).

5. Categories of Antisepsis and Disinfection
Sterilization
Complete eradication of all spores and microorganisms
Achieved by using high-pressure steam in autoclaves
Chemicals are used to disinfect a room.
Disinfection and sterilization are two different terms
Disinfection removes many mircoorganisms but does not remove spores
Learning Outcome
44.2 Explain the categories of antisepsis and disinfection, such as virocidal and bacteriostatic.
Sometimes it is absolutely necessary to sterilize equipment or an operating room. Sterilization is the complete eradication of all microorganisms and spores. It can be achieved by using high-pressure steam for hours in specialized tanks called autoclaves. Rooms are disinfected using chemicals. Since microorganisms are affected to different degrees by the available disinfectants, protocol requires that a sequence of disinfectant solutions be applied after pre-cleaning the area. Disinfection refers to the elimination of many microorganisms but not spores on inanimate objects.

6. Categories of Antisepsis and Disinfection
Cleaning technique
Surfaces must be cleaned thoroughly before applying a disinfectant
Combination of alcohol, phenols, or iodophors may be washed over the area
Disinfectant-to-surface contact time is important in cleaning
Learning Outcome
44.2 Explain the categories of antisepsis and disinfection, such as virocidal and bacteriostatic.
Surfaces, whether walls, fingernails, or open wounds, must be thoroughly cleaned prior to using disinfectants or antiseptics. Organic matter, such as pus, mucus, or protein exudate, may reduce the effectiveness of the disinfectant or antiseptic by binding with it to form proteins. The density of organic matter on surfaces is also a barrier to disinfectant or antibiotic action.
Depending on the nature of the surface to be treated, a combination of alcohol, phenols, or iodophors may then be generously washed over the area. The recommended time for disinfectant-to-surface contact varies; The AORN (Association of Perioperative Registered Nurses) and CDC have recommendations for hand scrubs. According to research, 10 minutes of bacterial load reduction is equivalent to 2–3 minutes of hand washing.

7. Clinical Uses of Antiseptics and Disinfectants
Antibiotics, antiseptics, and disinfectants
Antibiotics
Kill pathogens in the bloodstream
Targeted at specific microorganisms
Easily available
Antiseptics
Cleanse and irrigate wounds, cuts, and abrasions
Prepare patients’ skin prior to procedures
Do not cause skin sensitivity
Learning Outcome
44.3 Describe the clinical uses of antiseptics and disinfectants.
Antibiotics are similar to antiseptics and disinfectants in the sense that they eliminate disease-causing microorganisms.
Antibiotics kill microorganisms in the blood stream, and they are used in treatment to target specific microorganisms even though they may be broad spectrum agents. Antiseptics and disinfectants are never intended for internal use; even mouth washes are not expected to be swallowed. When these chemicals are used, it is to eliminate multiple organisms at one time.

8. Clinical Uses of Antiseptics and Disinfectants
Clean and store surgical instruments
Disinfect operating room walls and floors
Sterilize objects through cold sterilization
Learning Outcome
44.3 Describe the clinical uses of antiseptics and disinfectants.
Disinfectants are used to clean and store surgical instruments, to disinfect operating room walls and floors, and to sterilize (cold sterilization) objects that cannot tolerate the high temperatures associated with routine steam sterilization procedures.

9. Common Chemicals that Inhibit Infectious Microorganisms
Chlorine
Common chlorine bleach
Effective against most common pathogens, tuberculosis, hepatitis B and C, and fungi
Learning Outcome
44.4 Identify common chemicals used to inhibit infectious microorganisms.
Of the chlorine compounds, the most cost-effective disinfectant is common chlorine bleach (a 5 percent or 10 percent solution of sodium hypochlorite).
This solution is effective against most common pathogens, including such difficult organisms as tuberculosis, hepatitis B and C, fungi, antibiotic-resistant strains of Staphylococcus and Enterococcus, and viruses.
A 1-to-20 solution in water is effective simply by being wiped on and left to dry. The user should wear rubber gloves. Chlorine bleach is caustic to the skin, lungs, and eyes. As soon as the container is opened, the solution begins to lose potency and must be used within 28 days.

10. Common Chemicals that Inhibit Infectious Microorganisms
Alcohol: Ethyl and isopropyl alcohol
Ethyl alcohol is antiseptic at concentrations of less than 70%.
Isopropyl alcohol is bactericidal at all concentrations.
Alcohol can be used alone or in combination with other compounds.
Prep wipes contain isopropyl alcohol.
Learning Outcome
44.4 Identify common chemicals used to inhibit infectious microorganisms.
Ethyl alcohol is an effective antiseptic in concentrations of less than 70 percent, whereas isopropyl alcohol (rubbing alcohol) is bactericidal at all concentrations (50 to 90 percent).
Alcohol can be used alone or in combination with other topical agents to degerm the skin prior to surgery, placement of intravenous lines, or hypodermic injection. Studies have demonstrated that formulations containing 60 to 95 percent alcohol alone or 50 to 95 percent when combined with limited amounts of a quaternary ammonium compound, hexachlorophene, or chlorhexidine gluconate lower bacterial counts on the skin immediately after scrubbing more effectively than do other agents.
Most “prep” wipes or swabs contain isopropyl alcohol, which quickly evaporates following topical application and sucks the life out of the bacteria as it evaporates.

11. Common Chemicals that Inhibit Infectious Microorganisms
Peroxides: Hydrogen peroxide, benzoyl peroxide, chlorhexidine
Hydrogen peroxide
Oxidizing agent
Used to medically clean wounds, to remove dead tissue, and as an oral debriding agent
Chlorhexidine
Used as an oral rinse to decrease plaque and to prevent canker sores and bleeding of gums
Learning Outcome
44.4 Identify common chemicals used to inhibit infectious microorganisms.
Hydrogen peroxide is an oxidizing agent that is generally regarded as safe and effective by the FDA. It is used medically for cleaning wounds, for removing dead tissue, and as an oral debriding agent. When used to clean abrasions with slow blood oozing, it rapidly stops capillary bleeding. It is also used as a mouthwash in the treatment of Vincent’s infection (trench mouth).
Chlorhexidine (Bio-scrub, hibiclens) is bacteriostatic in low concentrations (0.5 percent) and bactericidal at higher concentrations (2 to 4 percent). It is effective against gram-positive and gram-negative bacteria; yeasts, including Candida; and viruses such as influenza, Herpes, and HIV.
As an oral rinse it is used to treat redness, swelling, and bleeding of inflamed gums (gingivitis), prevent aphthous ulcers (canker sores), and decrease the amount of plaque deposited on teeth.

12. Adverse Effects and Special Cautions
Dryness
Irritation
Hypersensitivity
Special cautions
Avoid oral consumption
Learning Outcome
44.5 Describe adverse effects and special cautions associated with antiseptics
and disinfectants.
The common side effects associated with the topical use of disinfectants and antiseptics in general are skin dryness, irritation, rash, and hypersensitivity at the contacted surface.
Iodophors have been reported to penetrate the eschar of burn patients, leading to increased absorption of iodine. Absorbed iodine crosses the placenta and can cause hypothyroidism and goiter in the fetus and newborn. In cases of accidental iodine ingestion, sodium thiosulfate is the antidote of choice.
Antiseptics and disinfectants such as ethyl alcohol and isopropyl alcohol are not to be ingested because they contain denaturing agents, methylisobutylketone, and color additives that are poisonous. The ingestion of hexachlorophene can cause anorexia, vomiting, abdominal cramps, convulsions, and death.