Exam 2: HAI & Antibiotics Flashcards
What are hospital acquired infections? (nosocomial)
infections that happen in the hospital - they were not present and not incubating at the time of admission
S2
____ in ____ hospital patients develop a nosocomial infection
1 in 31 pts
S3
What are sources of hospital-acquired infections?
- CVL sepsis
- UTI 13%
- Surgical ste infection 22%
- Hospital acquired PNA 22%
- Vent associated PNA (long term vent)
- C-diff 12%
S4
Risk factors in developing a HAI?
- Patient’s immune status
- Infection control practices
- Prevalence of certain pathogens in community
- Older age
- Longer hospital stays
- Multiple chronic illnesses
- Mechanical ventilatory support
- Critical care unit stays
S5
How is the infection transmitted?
- direct contact with healthcare workers
- Contaminated environments
- Extraluminal migration
what the HEC
S6
What are examples of contaminated environments that increase susceptibility to HAI’s?
- Inguinal
- Perineal
- Axilla
Gloves dont prevent contamination
S6
What H&P symptoms suggest a pre-existing infection? (common sense)
- Subjective fever
- Chills
- Night sweats
- Altered mental status
- Productive cough
- Shortness of breath
- Rebound tenderness
- Suprapubic pain
- Dysuria
- CVA tenderness (costovertebral tenderness)
- Vital Signs (HoTN, tachypnea, low sats, tachycardia)
S7
Labs that you can get to look for the evidence of organ dysfunction (duh)
Lactic acid
Prothrombin time
BUN/Creatinine
Elevated WBC
Hypo/hyperglycemia
Cultures
S9
What bacteria are your skin flora?
Coagulase-negative staphylococci
Lecture
Surgical site infections typically occur within ___ days of surgery.
30
S11
What are the categories for surgical site infection?
- Superficial = skin & SC
- Deep = fascia & muscle
- Organ/Space
S12
Signs of a Surgical Site infection
Redness
Delayed healing
Fever
Pain
Warmth
Swelling
Drainage of pus (abscess)
S13
What are the three most common types of bacteria associated with surgical site infections?
- Staphylococcus
- Streptococcus
- Pseudomonas
S14
How would a Clean wound be described?
Clean: not inflamed or contaminated and does not involve internal organs
S15
How would a Clean-contaminated wound be described?
Clean-Contaminated: no outward signs of infection but does involve internal organs
S15
How would a contaminated wound be described?
Contaminated: involves internal organ infection along with spillage of contents into surrounding tissue
i.e. ruptured appendix
S15
How would a dirty wound be described?
Dirty: known infection at the time of surgery
S15
What are risks factors for SSI?
- > 2hr surgery
- Comorbidities (smoker, DM, cancer, obese, immunocompromised etc)
- Elderly
- Emergency surgery
- Abdominal surgery
ACEE’S
S15
Potentially ___% of SSI’s are preventable.
50%
S16
What is a category 1A recommendation?
1A = Strongly recommended; moderate to high quality of evidence
S18
What is a category 1B recommendation?
1B = Strongly recommended; low quality evidence
S18
What is a category 1C recommendation?
1C = Strong recommendation based on state/federal regulation
S18
What is a category II recommendation?
Weak recommendation
S18
What exclusions were there to the Guideline for Prevention of SSI’s?
- SSI not a reported outcome
- All patients w/ “dirty procedures”
- No dental or oral health procedures
- Procedure did not have primary closure
- Study included wound protectors post-incision
They eliminated studies where interventions were already in place that woulld skew the results
S19
What are the recommendations for parenteral antibiotics?
1B - Administer only when indicated
1B - Time so that agent is active on tissue incision
S20
What are the recommendations for non-parenteral antibiotics?
1B - no antibiotic ointment on incision
Dry incisions are better.
S21
What recommendations are there for antibiotic irrigation and prosthetic soaking in antibiotic solution?
No recommendations on prosthetic soaking in abx solution or abx irrigation
Dr M says you will still see abx irrigation but it wont hurt anythign
S21
What are the 1A recommendation levels for glycemic control?
- Perioperative control of glucose
- Target glucose < 200 mg/dL (both intraop and postop)
S22
What is the recommendation level for A1C targets?
No recommendation for A1C target
Just acute control of BG.
S22
Maintaining perioperative normothermia is a ___ recommendation.
1A
No rec for strategies to maintain normothermia - just use what you have to maintain temp)
S23
What is the 1A recommendation for oxygenation in GETA patients?
- No recommendation for increased FiO2 in normally functioning patients
- Only increase the FiO2 with…
- intraoperatively with GETA (i.e. not necessary in Preop with a normal pt)
- Neuraxial anesthesia
- Postoperatively by mask or nasal cannula
- No trials r/t percentage/duration/delivery method
Recommendation is losing credibility as a way to prevent SSI’s - contradictory (Dr. Schaffer’s research).
S24
What are the recommendations for antiseptic prophylaxis?
1A - Intraoperative skin prep w/ alcohol-based antiseptic.
1B - Shower or bathe w/ soap/antiseptic the night before surgery.
II - Consider intraoperative Iodine irrigation.
* No benefit intra-peritoneally,
* No benefit with iodine imbedded adhesive drapes
* No benefit soaking prosthetic devices
S25
What is the recommendation for blood transfusion?
1B - Do not withhold necessary blood transfusions as a means to prevent SSI.
S26
Should systemic corticosteroids be utilized in a patient with joint arthroplasty?
Uncertain. Infection is most common indication for TKA revision however.
S27
What does MIC stand for?
Minimum Inhibitory Concentration
What is the goal for preoperative prophylaxis?
- Adequate bactericidal concentration in serum and tissues when incision is made…
- MIC: Minimum inhibitory concentration within tissues
- Based on evidence
- Given by anesthesia
S29
**ancef is 15 min prior to incision - if given an hour before, must redose
**most antibiotics need to be completed within 15 minutes of surgery and intiated under an hour. This is 45 minutes of “working time”
What are the 6 general principles of preoperative antibiotic prophylaxis?
- Should be active against common SSI pathogens
- Proven efficacy by clinical trials
- MIC must be achieved
- Shortest possible effective course
- New ABX reserved for resistant infections
- If possible, use oldest/cheapest ABX
Active Ethyl Must Shortlist New Old-people
S30
ABX should be initiated within ____ hour of incision.
1 hour (30 min even better)
S31
____ and ____ can be initiated within 2 hours of incision.
Vancomycin and Fluoroquinolones (like Cipro)
S31
Status of abx prior to trouniquet use?
ABX must be completely infused prior to tourniquet use
* may hold abx for cultures
S31
Re-dosing of antibiotics is permissible after what conditions?
- 2 ABX half-lives
- Excessive blood loss
- Following Cardiac bypass
- Prolonged procedures (usually 2-4 hours in OR)
Phil Follows Blood Too (2 but yea…)
S32
What drugs are β-lactam based?
- Penicillins
- Cephalosporins
- Carbapenems
S33
What are the 5 major common surgical antibiotics?
- β-lactams
- Vancomycin
- Aminoglycosides (gentamycin)
- Fluoroquinolones (cipro)
- Metronidazole (flagyl)
S33
How do Penicillin β-lactam antibiotics work?
Inhibition of bacterial cell wall synthesis
S34
Resistance to Penicillin β-lactam antibiotics is based on what?
β-lactamase enzyme on outer surface of cytoplasmic membrane
S34
Penicillin β-lactams are the drug of choice for what pathogens?
Gram + Bacterium (Cocci)
- Streptococci
- Meningococci
- Pneumococci
+ about PMS
S34
β-lactams are good for which HAI’s?
Locations throughout body
skin, catheter, and upper respiratory infections
S34
What four examples of penicillin based antibiotics were given?
- Penicillin G
- Methicillin
- Nafcillin
- Amoxicillin
S34
What are the common adverse reactions to penicillin β-lactams?
- Hypersensitivity (includes anaphylaxis at 0.05%)
- GI upset with large doses
- Vaginal Candidiasis
S35
Cephalosporin - β-lactams are more stable against ____.
β-lactamases (broader spectrum)
S36
MOA for cephalosporin-beta lactams
Beta-lactam rings bind to Penicillin-binding protein and inhibit the normal activity of the protein (can’t synthesize a bacterial cell wall)
S36
Cephalosporin β-lactam antibiotics are the drug of choice for what?
- Surgical prophylaxis
- PCN allergy patients (except true anaphylaxis)
S36
can give a test dose of ancef because 99.9% of the time these reactions aren’t anaphylactic
Cefazolin is generation ____ with trade name(s) ____ and ____ and best at treating?
- 1st generation
- Ancef, Kefzol
- Does not penetrate BBB, Most gram + (staph and streptococci), Cellulitis, abscesses, URI, UTI
S37
Cefuroxime is generation ____ with trade name(s) ____ and ____ and best at treating?
- 2nd generation
- ceffin, Zinacef
- Better gram – coverage
H-influenzae pneumonia, UTI, otitis media
S37
Cefoxitin is generation ____ with trade name(s) ____ and ____.
- 2nd generation
- Metoxin
S37
Cefotetan is generation ____ with trade name(s) ____ and ____ .
- 2nd generation
- Cefotan
S37
Cefotaxime is generation ____ with trade name(s) ____ and ____ and best at treating?
- 3rd generation
- Claforan
- Some cross BBB, Better gram – than before; treats resistance
Meningitis
S37
Ceftriaxone is generation ____ with trade name ____ and best at treating?
- 3rd generation
- Rocephin
- Gonorrhea
S37
Ceftazidime is generation ____ with trade name(s) ____.
- 3rd generation
- Fortaz
S37
Cefepime is generation ____ with trade name ____ and best at treating?
- 4th generation
- Maxipime
- Most resistant to hydrolysis by beta lactamases, Usually reserved for multi-resistant organisms
Penetrates BBB well
S37
What cephalosporins do not penetrate the blood brain barrier?
Generation 1: Cefazolin
Generation 2: Cefuroxime, Cefoxitin, Cefotetan
Zol, Rox, Fox, Tetan
S37
What generation of cephalosporins penetrate the blood brain barrier well (the best)?
Generation 4: Cefepime (Maxipime)
Most resistant to β-lactamase.
Reserved for multi-resistant organisms.
S37
Adverse reactions to cephalosporins
Hypersensativity is uncommon
* rashes
* fever
* nephritis
* anaphylaxis
* potential production deficit of Vit K (be aware with clotting disorders)
S38
What drugs should be used if true anaphylaxis to penicillin exists?
Vancomycin or clindamycin
S38
What drugs are a common cause of colitis?
3rd generation cephalosporins
S38
Carbapenem β-lactams have good activity against ____ and ____.
Gram - rods (Pseudomonas Aeruginosa) and enterobacter
S39
What β-lactam drug class has the broadest spectrum of activity and can inhibit the β-lactamase enzyme? MOA?
Carbapenems
* inhibit the beta-lactamase enzyme and binds to penicillin-binding protein
S39
What type of infections are carbapenems saved for?
Intra-abdominal, resistant UTIs, and pneumonia
most penetrate BBB
S39
What examples of carbapenems were given?
- Ertapenem (Invanz)
- Meropenem (Merrem)
- Imipenem (Primaxin)
IM formulations of carbapenems contain ____.
Lidocaine
Consider LA allergies prior to IM administration.
S40
Carbapenems can decrease what medication by up to 90%?
What can this precipitate?
Valproic Acid (Depakote); and can precipitate seizures
S40
How does vancomycin work?
Inhibition of cell wall synthesis
S41
Vancomycin is active against ____ bacteria but is too large to penetrate ____ bacteria.
Active against gram +
too large for gram - bacteria
Vanco only works if the bacteria is actively dividing
S41
Vancomycin is most useful against what infections?
Blood stream MRSA
MRSA endocarditis
S41
What are the most common adverse reactions to vancomycin?
- Phlebitis at site
- Chills, fever
- Nephrotoxicity
- “Red man” syndrome from quick administration
S42
How do Aminoglycosides work?
Inhibition of ribosomal proteins and cause mRNA misreading
S43
Aminoglycosides have a ____ post-antibiotic effect.
prolonged (long 1/2 life)
S43
Aminoglycosides are ____ w/ β lactams or vancomycin.
Synergistic
Especially useful for enterococcal endocarditis.
S43
Gentamycin example
What are the adverse reactions associated with gentamycin?
- Ototoxicity
- Nephrotoxicity: (more than 5 days, elderly, renal insufficiency, high doses and with loop diuretics)
- Curare-like affect
S44
Explain the curare-like effect of gentamycin (aminoglycoside).
Gentamycin can interfere with ACh receptors and potentiate effects of NMB drugs. (seen more with depolarizing NMB)
S45
What is the treatment for curare-like effects from gentamycin?
Ca⁺⁺
Lecture
How do fluoroquinolones work?
Inhibit bacterial DNA synthesis
S45
Fluoroquinolones are best used for what type of bacteria? used on?
Gram - organisms:
- UTI
- Bacterial diarrhea
- Bone/joint infections
S45
What examples are there of fluoroquinolones?
- Ciprofloxacin
- Levofloxacin
S45
What are the adverse reactions for fluoroquinolones?
- N/V/D
- QT interval prolongation
- Cartilage damage / Tendon rupture
S46
Hint: fluroquinolones treat joint infections and diarrhea
What three factors will exacerbate cartilage damage and tendon rupture associated with fluoroquinolones?
- Renal insufficiency
- Concurrent steroids
- Advanced age
S46
What type of antibiotic is metronidazole?
Antiprotozoal / Anaerobic antibacterial
S47
How does Metronidazole work?
Forms toxic byproducts that destabilize bacterial DNA.
S47
What is metronidazole (flagyl) indicated for?
- Intra-abdominal infections
- Vaginitis
- C-diff
S47
What drug should Flagyl not be combined with?
EtOH
Disulfiram-like effect induces hangover-like s/s (flushing, dizziness, HA, CP, abd pain)
S48
What are the adverse reactions associated with metronidazole?
- Nausea
- Peripheral neuropathy (w/ prolonged use)
- Disulfiram-like effect
S48
What is (essentially) the first line antibiotic for essentially all surgical prophylaxis?
Cefazolin (Ancef)
S49
What is the most common alternative to cefazolin for surgical prophylaxis?
Clindamycin (or vancomycin)
S49
What drug(s) increases the likelihood of nephrotoxicity when paired with aminoglycosides?
Loop Diuretics
S44
With small intenstinal obstruction, what are the recommended antibiotics?
cefazolin + metronidazole, cefoxitin or cefotetan
S49
With Small intestine cocorectal surgery, what antibiotics are recommended?
Cefazolin +
metronidaxole, cefoxitin, cefotetan, ampicillin-sulbactam or ceftriaxone +
metronidazole or ertapenem
S49
Adult dosing for cefazolin
- 1g </= 80kg
- 2g 81-119kg
- 3g >/= 120kg
S50
