Intro to Antimicrobials (Exam 1a.) Flashcards
Antimicrobials
Medications that slow or inhibit the growth of bacteria, or kill bacteria
Naturally occuring in nature (Antibiotics)
Synthetic
Semi-synthetic
Bacteriostatic
Medications that slow or inhibit bacterial growth
Bactericidal
Medications that kill bacteria
Broad spectrum
-Effective against numerous organisms
-Shotgun approach
-Don’t know specific organisms
Narrow spectrum
-Effective against a fe wspecies or organisms
-Using a BB gun
-Know the organism and what drug it is sensitive to
Resistance
-Ability of an organism to survive against an antimicrobial or to render the antimicrobial ineffective
-Innate (always been like that) or acquired (pathogen has mutated)
Super infections
An infection that occurs because of during treatment for a primary infection
Prophylactic antibiotic use
-Antibiotics that are used to prevent infections
-Some procedures have a higher risk of infections
Surgical procedures - Dental procedures in patients at risk for endocarditis - Immunocompromised patients
Antimicrobials are separated based on
MOA’s
How to choose an antibiotic: Community vs Hospital acquired
-Different susceptibility patterns
-Different organisms
How to choose an antibiotic: Site of infection
-Antimicrobials that can penetrate areas of infections (can it get to bone?)
-Antimicrobials that work in specific areas (lung liver kidneys?
How to choose an antibiotic: Suspected organism
-Choose an antimicrobial that is effective against the suspected organism
Choosing an antimicrobial: Goal
-Try and get cultures before starting antimicrobials
-If patient is critically ill and cultures might be delayed, there may be a need to begin antimicrobials prior to cultures
-Meningitis
-Sepsis
-Giving antimicrobials might prevent organism from growing in culture
Different places to get cultures
Sputum
Urine
Blood
Sputum Cultures
Gram stain
C&S
Urine cultures
-Urinalysis
-C&S
Blood Cultures
-Aerobic and anaerobic bottles
-2 sets
-One should always be peripheral
-Skin organisms can contaminate
Minimum Inhibitory Concentrations (MIC)
-Grow organisms in tubes that have different concentrations of an antimicrobial
-Minimum inhibitory concentration (Lowest amount of drug that inhibits bacterial growth) (Does not kill organism)
-Lowest concentrations that decreases size of bacterial colonies by 99.9%
Patient Characteristics: Allergies
-Antimicrobial will not work
-What is the allergy? N/V is not an allergy; it is an adverse effect
-Rash, welts, and anaphylaxis is signs of an allergy
Penicillin allergy
-May also be allergic to cephalosporins
-Cross sensitivity
When do allergy typically develop?
Age extremes: Young or old age. But can develop at any stage
Dose and Length of treatment depends on
-Patient host defense?
-Site of infections?
-Organism causing infection?
-How sick is the patient?
-Time versus concentration
Nosocomial Infections
-Infections that occur within a healthcare facility.
-More drug resistant
Infections can be resistance to a specific drug
MRSA
-Methicillin resistant Staph areus
Infections can be resistant to an anitmicrobial class
-CRE
-Carbapenem resistant eneterobacteriacease
Infections can be resistance to multiple drugs/classes
-MDRO
Post-Operative Infections: Respirartory
Increase risk of atelectasis
Increased risk of pneumonia
Post operative infections: Surgical wound infections
-What would you expect a fresh incision to look like?
-Wound dehiscence (opening of the wound - portal for bacterial contamination)
Post-operative infections: UTI
-Cath increase risk
Antimicrobial resistance
Organisms are able to live and grow in an environment where antimicrobials are present
Innate resistance (born that way)
Sharing of genetic material between organisms (a learned response)
Antimicrobial Resistance: Mutations
-exposure to an antimicrobial agent. Not given. taken, long enough to kill all the organsims. (survival of the fittestI
Antibiotic Prescribing
-Patents demand them (want pill)
Upper Respiratory Infection (mostly viruses) (1 in 4000 chanc eAbx will help acute URI) (1 in 1000 chance Abx will send you to the ED) (rahs, allergic reactions, Diarrhea)
Environment
C.Diff spores can survive 5 or more months (Even reports of years)
Clothing
-37% of HCW gowns contaminated after care of patient with VRA
65% HCW gows contaminated after morning care in patients with MRSA in wound or urine
40% contamination after care of patient colonized with MRSA or VRE
Treatment Failures
-wrong drug used
-started too late
-Too low dose
-Not taken long enough
