Surgical Prophylaxis

Question 1

Risk factors for VRE (vancomycin-resistant enterococci)

Answer 1

Concomitant diseases
Immunosuppression
ICU admission
Previous intraabdominal or cardiothoracic surgery
Indwelling catheters
Prolonged course of abx

Question 2

IDSA guidelines of preadministration of abx

Answer 2

Within 60 mins of incision; FQs and vanc should begin within 120 mins of incision

Question 3

Duration of prophylaxis

Answer 3

New recommendations short course of post-operative course of abx
Majority of post-op abx course must complete within 24 hrs of anesthesia close time
Cardiothoracic x 48 hrs

Question 4

Cefazolin in obesity

Answer 4

Dosing shown in obese pts to lead to more SSIs for surgical prophylaxis
2 gms for pts >80 kg
3 gms for pts >120 kg
PK/PD data conflicting

Question 5

Bacterial colonization with MRSA

Answer 5

Presence of bacteria on a body surface without causing an infection- colonization
Long-lasting
Pt with MRSA colonization has increased risk for MRSA infections
MRSA carriers also serve as reservoirs for future transmission

Question 6

IDSA guidelines for MRSA colonization

Answer 6

Vanc + abx of choice for procedure should be used for institutions that have a high prevalence of MRSA SSIs and for pts who are known to be colonized with MRSA and/or have a hx of a MRSA infection

Question 7

Urologic preop

Answer 7

E. coli
First line: FQ (levofloxacin 500 mg IV/po) x 1 dose
Allergy: Aminoglycoside (gentamicin 5 mg/kg) with or without clindamycin (900 mg) IV x 1 dose

Question 8

Colorectal (enteric gm-neg bacilli and anaerobes) preop

Answer 8

First line: ceftriaxone 2 gm IV x 1 dose + metronidazole 500 mg IV x 1 dose or ertapenem 1 gm IV x 1 dose
Ceftriaxone preferred over ertapenem
Beta-lactam allergy: Clindamycin 900 mg IV + aminoglycoside (gentamicin 5 mg/kg) IV OR
Metronidazole 500 mg IV + aminoglycoside

Question 9

Colorectal postop

Answer 9

Ceftriaxone and Ertapenem (no postop)
Metronidazole 500 mg IV q8h x 24 hrs
Duration: Preop single dose or <24 hrs
Ceftriaxone is preferred over Ertapenem
Flagyl causes a reaction with EtOH (disulfuram)- not even mouthwash or cough syrup

Question 10

Neuro preop

Answer 10

S. aureus
First line: Cefazolin 2 gms (>80 kg) IV x 1 dose
Beta-lactam allergy: Vanc (15 mg/kg) OR
Clindamycin 900 mg IV x 1 dose

Question 11

Gyn postop

Answer 11

Cefazolin 2 gms IV q8h x 24 hrs

Duration: <24 hrs

Question 12

Beta-lactams MOA

Answer 12

Inhibits bacterial cell wall synthesis

Question 13

SEs of beta-lactams

Answer 13

Anaphylaxis, hives, pseudomembranous colitis, seizures (rare)

Question 14

Examples of beta-lactams

Answer 14

Pen G
Nafcillin/Oxacillin
Ampicillin/sulbactam (beta-lactamase inhibitor)

Question 15

Indication for beta-lactams

Answer 15

Streptococci
Enterococcus
S. aureus

Question 16

Cephalosporins MOA

Answer 16

Inhibits bacterial cell wall synthesis

Question 17

SEs of cephalosporins

Answer 17

Skin rash
Diarrhea
Leukopenia

Question 18

Aminoglycosides MOA

Answer 18

Interferes with bacterial protein synthesis by binding to 30s and 50s ribosomal subunits

Question 19

SEs of aminoglycosides

Answer 19

Renal function, hearing impairment, ataxia, confusion, and C. difficile-associated diarrhea

Question 20

Examples of aminoglycosides

Answer 20

Gentamicin
Tobramycin
Amikacin

Question 21

Vancomycin MOA

Answer 21

Inhibits bacterial cell wall synthesis

Question 22

SEs of vancomycin

Answer 22

Associated with nephrotoxicity, Red Man Syndrome (histamine release)

Question 23

Pharmacokinetic monitoring of vancomycin

Answer 23

Peaks and troughs

Question 24

Indication of Vancomycin

Answer 24

Gram + (including methicillin resistant)

Question 25

FQs MOA

Answer 25

Inhibits DNA gyrase, promoting the breakage of DNA strands

Question 26

SEs of FQs

Answer 26

Associated with N/V, potential to prolong the QT interval, potential to produce hypoglycemia (elderly) tendon inflammation/rupture

Question 27

Examples of FQs

Answer 27

Levofloxacin Ciprofloxacin Moxifloxacin

Question 28

Indication for FQs

Answer 28

Broad-spectrum gram pos and gram neg +/- anaerobes, +/- pseudomonas

Question 29

Dosing of abx

Answer 29

Lipophilic drugs- use ABW | Hydrophilic drugs- use IBW

Question 30

Cardiac/thoracic preop

Answer 30

S. aureus First line: Cefazolin 2 gms (>80 kg) IV x 1 dose Beta-lactam allergy: Vanc 15 mg/kg or Clinda 900 mg x 1 dose

Question 31

Cardiac/thoracic postop

Answer 31

First line: Cefazolin 1 gm or 2 gms IV q8h < 24 hrs | Cardiac Thoracic surgery: 48 hrs

Question 32

Cardiac/thoracic hx of MRSA, colonization, and/or suspected MRSA

Answer 32

Add Vancomycin 15 mg/kg IV q12h x 24 hrs plus the abx of choice Intranasal mupirocin -Cardiac surgery high rate of S. aureus infection and increased MRSA infection -Preoperative eradication

Question 33

Ortho preop

Answer 33

S. aureus First line: Cefazolin 2 gms (>80 kg) IV x 1 dose Beta-lactam allergy: Vanc 15 mg/kg or Clinda 900 mg IV x 1 dose

Question 34

Ortho postop

Answer 34

First line: Cefazolin 1 gm or 2 gms IV q8h < 24 hrs

Question 35

Ortho hx of MRSA, colonization, and/ or suspected MRSA

Answer 35

Add Vanc 15 mg/kg IV q12h x 24 hrs + the abx of choice

Question 36

Ortho antimicrobial-laden bone cement for hips/knees

Answer 36

FDA approved premixed aminoglycoside bone cement for use in hip, knee, and other joint in second-stage revision Not approved in prophylaxis in primary joint replacement in US

Question 37

Urologic postop

Answer 37

No FQ | Gentamicin 5 mg/kg IV x 1 additional dose with or without clindamycin 900 mg IV q8hrs < 24 hrs

Question 38

FQ resistance with urologic

Answer 38

Increased resistance to E. coli Increased risk of tendonitis and tendon rupture (not first-line in peds) Peripheral neuropathy which may be permanent

Question 39

Mechanical bowel prep (MBP)

Answer 39

Neomycin (1 gm) + erythromycin (1 gm) OR | Neomycin (1 gm) + Metronidazole (1 gm) x 3 doses 10 hrs the afternoon or evening before surgery

Question 40

Neuro postop

Answer 40

Cefazolin 1 gm or 2 gms IV q8h <24 hrs

Question 41

Gyn preop

Answer 41

Enteric Gm neg bacilli, anaerobes, group B strep, enterococci First line: Cefazolin 2 gms (>80 kg) IV x 1 dose Second line: Cefotetan IV OR Cefoxitin IV OR ampicillin-sulbactam IV Beta-lactam allergy: Clinda 900 mg IV x 1 dose OR Vanc 15 mg/kg IV x 1 dose + aminoglycoside OR aztreonam OR FQ