University:
American Career College
Course:
NURS115 | Intermediate Medical
Academic year:

2020
Views:

200

Pages:

18
Author:

Jazmyn Acevedo

Chemical Agents Chemical Agents 1) High-level disinfectants A germicide that kills all microbial pathogens except large numbers of bacterial spores Glutaraldehyde, hydrogen peroxide, peracetic acid, and chlorine compounds. 2) Intermediate-level disinfectants A germicide that kills all microbial pathogens except bacterial endospores Alcohols, iodophor compounds, phenolic compounds 3) Low-level disinfectants A germicide that kills most vegetative bacteria and lipid-enveloped viruses Quaternary ammonium compounds Classes of Germicidal Chemicals Halogens Phenolics Chlorhexidine Alcohols Hydrogen peroxide Detergents & soaps Heavy metals Aldehydes Gases and aerosols Aldehydes  Glutaraldehyde, formaldehyde, and orthophthalaldehyde (OPA)  Alkylating proteins and nucleic acids  A 2% solution of alkaline glutaraldehyde (Cidex) Chemical sterilants for treating heat-sensitive medical items  Formaldehyde HCHO is used as a gas or an aqueous 37% solution called formalin Ethylene Oxide (C2H4O) Gas For sterilization at low temperatures (20–60 oC) Cannot kill dried microorganisms  Ethylene oxide goes into solution in plastics, rubber  Longer period Ethylene oxide is mutagenic  Propylene oxide, betapropiolactone & chlorine dioxide  Strong alkylating agents, sporicidal Halogens Act by oxidizing proteins and other essential cell components Chlorine Cl2, hypochlorites (chlorine bleach) Iodine I2, iodophors (betadine) Antiseptic Agents Iodophors Excellent skin antiseptic 1 to 2 mg of free iodine/L, 1% to 2% available iodine Are slightly more toxic to the skin than is alcohol, Have limited residual activity Inactivated by organic matter Alcohols  Act as surfactants Coagulating enzymes and proteins and by damaging lipid membranes  Aqueous solutions of 60% to 80% ethyl or isopropyl alcohol rapidly kill vegetative bacteria and fungi  Do not reliably destroy bacterial endospores and some naked viruses Biguanides Chlorhexidine  Mechanism of action is membrane disruption  Extensively used in antiseptic products  It adheres to and persists on skin and mucous membranes  Antiseptic skin creams, disinfectants, and mouthwashes  0.5% to 4%  Mycobacteria, endospores, and protozoan cysts are not affected 29 Phenolics Disrupt cell membranes & precipitating proteins Bactericidal, fungicidal, virucidal, not sporicidal Lysol, Triclosan Antibacterial additive to soaps Common antiseptic agent in deodorant soaps and some toothpastes 0.3% to 2% Detergents & Soaps Amonia compounds act as surfactants alter membrane permeability of some bacteria & fungi Not sporicidal Soaps mechanically remove soil and grease containing microbes Low concentrations: Only have microbistatic effects Quaternary Ammonium Compounds Germicidal The activity is determined by the nature of the organic groups Greatest activity with compounds with 8 to 18 carbon Quaternary Ammonium Compounds Benzalkonium chloride and Cetylpyridinium chloride  Denaturing cell membranes  Bacteriostatic at low concentrations Bactericidal at high concentrations  Pseudomonas and Mycobacterium are resistant Heavy Metals Ions of mercury, silver, arsenic, zinc, and copper Effective but usually toxic Combine with and inactivate proteins; may also precipitate proteins kill vegetative cells in low concentrations Not sporicidal Methods of Sterilization Methods of Disinfection Antiseptic Agents Germicidal Properties of Disinfectants and Antiseptic Agents