Antibiotics

Question 1

Normal Flora: Nasopharynx

Answer 1

Staph, Strep, Moraxella catarrhalis, Hemophilus

Question 2

Normal Flora: Oropharynx

Answer 2

Strep, Moraxella catarrhalis, Hemophilus

Question 3

Normal Flora: Skin

Answer 3

Staph epidermidis, Staph aureus

Question 4

Normal Flora: Intestine

Answer 4

Bacteroides fragilis, Strep, Enterococci

Question 5

Normal Flora: Genital Tract (female)

Answer 5

Strep, Staph

Question 6

Bactericidal Antimicrobials

Answer 6

cephalosporins, aminoglycosides, fluoroquinollines, vancomycin, daptomycin, and metronidazole

Question 7

Bacteriostatic Antimicrobials

Answer 7

macrolides, tetracyclines, trimethoprim, and sulfonamides

Question 8

Wound Classification

Answer 8

Clean: Closed, elective procedures
Clean-contaminated: GI,GU, biliary, re-operation within 7 days
Contaminated: Acute inflammation, penetrating trauma (4hr)

Question 9

Cephalosporin Mechanism of Action

Answer 9

Beta lactam ring inhibits cell wall synthesis
Binds Penicillin-binding proteins (PBPs) found on the outer membrane of Gram-Pos bacteria and innermembrane of Gram-Neg
Efficacy is dependent on the percent time above minimum inhibitory concentrations

Question 10

Choice of Antibiotic: Clean Procedures

Answer 10

Cefazolin 1-2 grams IV

Question 11

Choice of Antibiotic: Thoracic and Orthopedic

Answer 11

Cefuroxime 1.5 grams IV

Question 12

Choice of Antibiotic: Bowel

Answer 12

Cefoxitin 1-2 grams IV
Cefazolin 1-2 gram + metronidazole 500 mg
Ampicillin/sulbactam (Unasyn) 3 grams

Question 13

Choice of Antibiotic: PCN Allergies

Answer 13

Most patients treated with cefazolin
Vancomycin 1 gram (10-15 mg/kg)
Clindamycin (600-900 mg)

Question 14

Choice of Antibiotic: Gram negative coverage may be +

Answer 14

Gentamicin, ciprofloxacin, levofloxacin, aztreonam

Question 15

Local resistance patterns should be taken into account

Answer 15

MRSA

Question 16

Redman syndrome

Answer 16

Vancomycin
Pruritus, flushing, erythema of head and torso
Arterial hypotension

Question 17

Ototoxicity

Answer 17

Gentamicin

Question 18

Vancomycin

Answer 18

Used when MRSA is prevalent; No benefit; Risk of VRE

Bactericidal against Gram +

Question 19

Neurosurgical

Answer 19

Cefazolin (1-2 g)
Nafcillin (1-2 g)
Vancomycin (1g)

Question 20

Head and Neck

Answer 20

Cefazolin (1-3g)

Clindamycin (600-900mg) + gentamicin(1.5/mg/kg)

Question 21

Cardiac Surgery

Answer 21

Cefuroxime is agent of choice

Vancomycin and clindamycin are alternatives

Question 22

Noncardiac Thoracic Surgery

Answer 22

Cefazolin (1-2 grams)
Cefuroxime (1.5 grams)
Vancomycin* (1 gram [10-15 mg/kg])
Clindamycin** (600-900 mg)

Question 23

GI-Appendectomy

Answer 23

Cefoxitin (1-2 g)
Ampicillin-sulbactam (3 g)
Cefazolin (1-2 g) + metronidazole (0.5 g)
PCN allergic: Clindamycin + gentamicin (cipro, levo)

Question 24

Esophageal & Gastroduodenal

Answer 24

Cefazolin (1-2 g)

Question 25

GI-Biliary Tract

Answer 25

Cefazolin (1-2 g)

Question 26

Orthopedic

Answer 26

Clean: No antibiotic
Otherwise: Cefazolin (1-2 g)
Vancomycin (1 g)

Question 27

Cesarean Delivery

Answer 27

Single dose of cefazolin before incision
Historically post clamping
Clindamycin+gentamicin

Question 28

Timing for antibiotics

Answer 28

Best results preoperative (0-2 hours before surgery)

Question 29

SBE Prophylaxis

Answer 29

Heart Issues
Recommendation: Ampicillin (2 g)
For GI and GU: Gentamicin (1.5 mg/kg; 120 mg max)
PCN allergy:
Clindamycin (600 mg)
Cefazolin (1 g)
Vancomycin (1 g) (± Gentamicin for GI and GU)

Question 30

C-diff

Answer 30

Clostridium difficile