Asepsis

Asepsis A. Chain of infection I. etiologic agent a. the microorganism responsible for the infection i. types a. bacteria i. prokaryotic, single-celled microorganisms that differ from all other organisms in lacking a true nucleus and organelles such as mitrochondria, chloroplasts, and lysosomes

ii. classification of bacteria a. by shape i. spherical (cocci) ii. rod-shaped (bacilli) iii. corkscrew (spirochete) b. by reaction to gram stain i. gram stain + a. have a thick cell wall that resists discoloration (loss of color) b. stain violet ii. gram stain a. have a chemically more complex cell wall that can be decolorized by alcohol b. do not stain violet c. by need for oxygen i. aerobic a. requires oxygen to live ii. anaerobic a. does not require oxygen to live b. fungi i. eukaryotic, single-celled microorganisms marked by the absence of chlorophyll, the presence of a rigid cell wall in some stage of the life cycle, and reproduction by means of spores

c. yeast i. single-celled, nucleated, usually round fungi that reproduce by budding d. parasite i. microorganism that lies in or on another and obtains nourishment from it e. viruses i. microorganisms consisting of genetic material, which may be either DNA or RNA, and is surrounded by a protein coat and, in some viruses, by a membranous envelope

b. potential for microorganisms to produce disease i. depends on the following: a. number of microorganisms b. virulence of the microorganisms c. competence of the person's immune system d. length and intimacy of the contact between an individual and the microorganisms II. the reservoir a. sources of microorganisms, e.g.: i. other humans ii. patient's own microorganisms iii. plants iv. animals v. general environment, e.g.: a. soil, food, water III. the portal of exit from the reservoir a. the way microorganisms leave the reservoir, e.g.: i. respiratory tract, e.g.: a. nose/mouth: sneezing, coughing, breathing, or talking b. endotracheal tubes c. tracheostomies ii. gastrointestinal tract, e.g.: a. mouth: saliva, vomitus b. anus/ostomies: feces c. drainage tubes (e.g., nasogastric, T-tubes) iii. urinary tract, e.g.: a. urethral meatus b. urinary diversion ostomies iv. reproductive tract, e.g.: a. vagina: vaginal discharge b. urethral meatus c. semen d. urine v. blood, e.g.: a. open wound b. needle puncture site c. any disruption of intact skin or mucous membrane surfaces vi. tissue IV. the method of transmission

a. the way microorganisms reach another person or host i. through direct transmission, e.g.: a. touching b. biting c. kissing d. sneezing e. coughing f. spitting g. talking ii. through indirect transmission (three types) a. vehicle-borne i. by way of inanimate objects (fomites), e.g.: a. water b. food c. milk d. blood e. serum f. plasma b. vector-borne i. by way of animate objects, e.g.: a. flying or crawling insects b. ticks iii. through airborne transmission a. transmitted by air currents, e.g.: i. by way of droplet nuclei ii. by way of dust particles V. the portal of entry to the susceptible host a. the way microorganisms enter the body b. usually the same way they exit from the reservoir VI. the susceptible host a. a person at risk for infection from microorganisms B. Breaking the chain of infection I. cleaning a. the process of eliminating foreign materials (e.g., organic material, such as blood, pus, or inorganic material, such as soil) from objects b. steps in cleaning i. don gloves ii. rinse the article with cold water to remove organic material a. hot water coagulates protein of organic material and makes it adhere to the object iii. wash the article in hot soap and water iv. clean equipment that has grooves and corners with an abrasive, such as a stiff-bristled brush v. rinse the article well with warm-hot water vi. dry the article vii. clean the brush, gloves, and sink II. disinfecting a. the process of eliminating almost all microorganisms b. disinfectants i. chemical preparations used on inanimate objects c. antiseptics i. chemical preparations used on skin or tissue d. commonly used disinfectants and antiseptics i. isopropyl alcohol a. effective against: i. bacteria ii. tuberculosis iii. fungi iv. viruses b. used on: i. hands ii. thermometers iii. vial stoppers ii. chlorine (bleach) a. effective against: i. bacteria ii. tuberculosis iii. fungi iv. viruses v. spores b. used on: i. blood spills iii. hydrogen peroxide 3% a. effective against: i. bacteria ii. tuberculosis iii. fungi iv. viruses v. spores a. used on:

i. surfaces iv. iodophors a. effective against: i. bacteria ii. tuberculosis iii. fungi iv. viruses v. spores a. used on: i. equipment ii. intact skin and tissues if diluted v. phenol a. effective against: i. bacteria ii. tuberculosis iii. fungi iv. viruses a. used on: i. surfaces vi. chlorhexidine gluconate (Hibiclens) a. effective against: i. bacteria ii. viruses b. used on: i. hands vii. triclosan (Bacti-Stat) a. effective against: i. bacteria b. used on: i. hands ii. intact skin III. sterilizing a. the process of eliminating all microorganisms, including spores and viruses b. four common methods of sterilization i. moist heat (steam) a. steam under pressure (autoclaves) i. 15 to 17 pounds of pressure ii. 121° to 123° C (250° - 254° F) iii. sterilizes objects that cannot be destroyed at the higher temperature of the autoclave b. free steam i. 100° C (212° F) ii. 30 minutes times three days iii. sterilizes objects that can be destroyed at the higher temperature of the autoclave ii. gas a. ethylene oxide b. sterilizes heat-senstive items iii. radiation a. ionizing or non-ioninzing radiation b. sterilizes food, drugs, and other heat-sensitive items iv. boiling water a. 100° C (212° F) b. minimum of 15 minutes c. disinfection of articles in the home C. Factors influencing development of an infectious process I. age, e.g.: a. newborns and infants have immature immune systems i. protected for the first two to three months by immunoglobulins passed on by the mother ii. start synthesizing their own immunoglobulins between one to three months of age b. elderly have weakened immune systems i. weakened immune response II. inadequate primary defenses, e.g.: a. broken skin or mucous membranes b. traumatized tissue c. decrease in ciliary action d. stasis of body fluids e. change in pH of secretions f. altered peristalsis III. inadequate secondary defenses, e.g.: a. decreased hemoglobin b. leukopenia i. drug or disease-related c. suppressed inflammatory response i. drug or disease-related d. immunosuppression IV. inadequate active immunity, e.g.: a. lack of childhood immunization, lack of exposure to childhood infections, lack of hepatitis B vaccinations V. tissue destruction, e.g.:

a. scalds, gangrene, sunburn VI. increased environmental exposure, e.g.: a. crowded living conditions, poor air circulation in airplanes, hospital rooms VII. invasive procedures, e.g.: a. intravenous lines, indwelling urinary retention catheters, bronchoscopy VIII. chronic disease, e.g.: a. diabetes, asthma, sickle-cell disease IX. malnutrition, e.g.: a. kwashiorkor, marasmus, cachexia X. trauma, e.g.: a. gunshot wounds, stab wounds, fractures XI. pharmaceutic agents, e.g.: a. immunosuppressive therapy, antibiotics, antineoplastic agents XII. rupture of amniotic membranes, e.g.: a. premature rupture of anmiotic membranes in a pregnant patient at 36 weeks XIII. insufficient knowledge to avoid exposure to microorganisms, e.g.: a. blind patient unable to see spoiled food, toddler fails to wash his hands before eating, illiterate patient unable to read isolation placards in the hospital D. Stages of an infectious process I. incubation period a. time between the entry of microorganisms and the onset of symptoms i. e.g., common cold: 1 - 2 days; tetanus: 2 - 21 days II. prodromal period a. time between the onset of nonspecific symptoms and when specific symptoms of the infection appear i. the most infectious stage ii. nonspecific symptoms include the following.: a. fatigue, malaise, low-grade fever III. illness period a. time when specific symptoms develop and become evident i. can be localized ii. can be systemic IV. convalescent period a. time from when specific symptoms start to abate until the return to a normal state of health E. Nosocomial infections I. infections associated with the delivery of healthcare services in a healthcare facility that develop during the patient's hospital stay or shortly after discharge II. most common site in the healthcare facility where nosocomial infections occur: a. medical and surgical intensive care units III. most common site in the patient where nosocomial infections occur: a. surgical wounds IV. where microorganisms originate that cause nosocomial infections: a. endogenous i. from within the patient b. exogenous i. from the hospital environment and hospital personnel V. the most common microorganisms that cause nosocomial infections: a. Escherichia coli b. Staphylococcus aureus c. enterococci VI. methods to reduce the incidence of nosocomial infections a. constant surveillance by an infection-control committee and nurse epidemiologists b. written guidelines for health personnel to observe when caring for patients with infections c. use practices to help promote and keep patients in the best possible physical condition d. following techniques of medical and surgical asepsis with precision F. Asepsis I. freedom from infection or infectious material II. types of asepsis a. medical asepsis i. also known as clean technique ii. practices intended to confine a specific microorganism to a specific area a. objects are rendered either clean or dirty i. clean a. absence of almost all microorganisms ii. dirty a. likely presence of microorganisms iii. basic principles of medical asepsis a. wash hands frequently, but especially before handling foods, before eating, after using a handkerchief, after going to the toilet, before and after each patient contact, and after removing gloves keep soiled items and equipment from touching the clothing do not place soiled bed linen or any other items onto the floor avoid having patient's cough, sneeze, or breath directly on others move equipment away from you when brushing, dusting, or scrubbing articles avoid raising dust clean the least soiled areas first then more soiled ones dispose of soiled or used items directly into appropriate containers pour liquids that are to be discarded directly into the drain so as to avoid splatterings in the sink and onto you use practices of personal grooming that help prevent spreading microorganisms follow guidelines conscientiously for isolation or barrier techniques as prescribed by the healthcare agency surgical asepsis

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i. also known as sterile technique ii. surgical asepsis are practices intended to keep an area or objects free of all microorganisms and spores iii. basic principles of surgical asepsis a. only a sterile object can touch another sterile object b. open sterile packages so that the first edge of the wrapper is directed away from the worker to avoid the possibility of a sterile wrapper touching unsterile clothing avoiding spilling any solution on a cloth or paper used as a field for a sterile set-up hold sterile objects above the level of the waist avoid talking, coughing, sneezing, or reaching over a sterile field or object never walk away from or turn your back on a sterile field all items brought into contact with broken skin or used to penetrate the skin in order to inject substances into the body, or to enter normally sterile body cavities, should be sterile h. use dry, sterile forceps when necessary i. consider the edge (outer 1 inch) of a sterile field to be contaminated j. consider an object contaminated if you have any doubt as to its sterility Providing isolation and control of communicable disease I. a protective procedure that limits the spread of infectious disease among hospitalized patients, hospital personnel and visitors II. accomplished by development of a barrier to transmission of infectious microorganisms III. based on the manner in which the microorganisms leave the person (reservoir) and their ability to survive and be transmitted to another person IV. isolation precautions sometimes called protection specific technique or barrier techniques because of the unfavorable connotation of the word isolation Centers for Disease Control (CDC) Isolation Precautions I. standard precautions a. standard precautions are to be instituted on ALL patients receiving care in a hospital regardless of their diagnosis b. standard precautions are utilized for the following: i. blood ii. all body fluids with or without blood iii. secretions and excretions (except sweat) iv. non-intact skin v. contaminated items vi. mucous membranes c. steps in standard precautions: i. wash hands before and after patient care, regardless of whether gloves are worn ii. wash hands immediately after gloves are removed and between patient contacts iii. wear gloves when touching blood, body fluids, secretions, excretions, and contaminated items iv. put on clean gloves just before touching mucous membranes and non-intact skin v. wear mask and eye protection or a face shield to protect mucous membranes of the eyes, nose, and mouth during procedures and patient-care activities that are likely to generate splashes or sprays of blood and body fluids vi. wear a gown to protect skin and prevent soiling of clothing during procedures and patient -care activities that are likely to generate splashes or sprays of blood and body fluids vii. take care to prevent injuries when using needles, scalpels and other sharp instruments or devices; when handling sharp instruments after procedures; when cleaning used instruments; and when disposing of used needles viii. use mouthpieces, resuscitation bags or other ventilation devices as an alternative to mouth-to-mouth resuscitation II. transmission based precautions a. airborne precautions i. airborne precautions are to be instituted on patients who have infections spread by small particles that can travel a long distance ii. airborne precautions are utilized for the following diseases: a. measles b. chicken pox c. tuberculosis b. steps in airborne precautions: i. place patient in a private room that has monitored negative air pressure; 6 to 12 air changes per hour; and discharge of air outdoors or HEPA filtration before air is recirculated ii. wear a N95 respirator mask for known or suspected acid-fast bacilli (tuberculosis) iii. susceptible persons should not enter the room of patients with known or suspected measles (rubeola) or chicken pox (varicella) if immune caregivers are available iv. if susceptible persons must enter the room, wear appropriate face mask v. limit the movement/transport of patients from room to essential purposes only; during transport, place surgical mask on the patient, if possible c. droplet precautions i. droplet precautions are to be instituted on patients who have infections spread by large particles traveling a short distance ii. droplet precautions are utilized for the following diseases: a. influenza b. pertussis c. streptococcal pharyngitis d. rubella e. parvo virus B 19 f. neisseria meningitis iii. steps in droplet precautions: a. place patient in a private room b. when a private room is not available, cohort with patient(s) who has active infection with the same microorganism c. maintain spatial separation of at least 3 feet from other patients and visitors if cohorting or private room is not available d. wear a mask when working within 3 feet of patient (or when entering room) e. limit the movement/transport of patients from room to essential purposes only; during transport, place surgical mask on the patient, if possible d. contact precautions i. contact precautions are instituted on patients who have infections spread by drainage ii. contact precautions are instituted for the following: a. clostridium difficile

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rhino simplex virus (RSV) in children shigella scabies methicillin resistant staphylococcus aureus (MSRA) large draining wounds zoster - localized (shingles) zoster - disseminated (also requires airborne precautions) steps in contact precautions: a. place patient in a private room b. when a private room in not available, cohort with patient(s) who has active infection with the same microorganism but with no other infection c. wear gloves when entering patient's room d. change gloves after contact with infective material e. remove gloves before leaving patient's room f. wash hands with antimicrobial agent immediately after glove removal and before leaving the patient's room g. wear a gown if you anticipate that your clothes will have substantial contact with the patient, environmental surfaces, or items in the patient's room or if the patient has any of the following: incontinence, diarrhea, colostomy, ileostomy, wound drainage not covered by a dressing h. remove gown before leaving the patient's room i. limit the movement/transport of patients from room to essential purposes only; during transport, ensure that all precautions are maintained at all times j. when possible, dedicate the use of noncritical patient-care equipment to a single patient; if common equipment is used, clean and disinfect between patients end