Antibiotics Flashcards
What are methods in surgical technique that lead to less SSI?
gentle traction Effective hemostasis removal of devitalized tissues obliteration of deadspace irrigation with saline fine non-absorbed suture closed suction drains wound closure without tension
What patient conditions may lead to increased SSI?
Extremes of age malnourished obesity Diabetes Recent operation corticosteroid therapy immunocompromised
What are perioperative factors that may increase SSI?
Body temperature FiO2 fluid management blood glucose blood transfusion antimicrobial prophylaxis
What are the benefits of normothermia during surgery?
wound healing
less vasoconstriction
how does hypothermia lead to SSI?
decreased tissue perfusion
decreased super oxide radicals
induced anti-inflammatory profile
decreased collagen production
More oxygen leads to _______ wound healing
improved
At what FiO2 is decreased incidence of SSI seen?
0.8
Which fluid is better for preventing SSI, colloid or crystalloid?
no difference
Why is keeping the patient euvolemic important for preventing SSI?
prevents subq tissue from being hypervolemic
HOw does hyperglycemia affect infection?
increased morbidity and mortality
Deactivation of immunoglobulins
functional deficits in neurtophil function
SSI is decreased with _____ PRBC transfusion
auto
HOw should rbc’s be prepared to reduce risk of infection?
leukocyte reducted
What are the goals of surgical prophylaxis?
prevent postoperative SSI Prevent post-op M&M reduce duration of healthcare Reduce cost of healthcare Produce no adverse effects Have no adverse consequences
What are the normal flora of the skin?
Staph epidermidis
staph aureas
What is the ideal antibiotic therapy
active against most likely pathogen given in appropriate dosage given at appropriate time safe administered for shortest period
when and how often are antimicrobials dosed?
1 hour before incision
must exceed minimum inhibitory concentration
Every 1-2 half lives, terminating within 24 hours
This type of proceure is elective, not emergency, nontraumatic, primarily closed, no breack in techinique. Respiratory , GI, biliary and GU tracts not entered
clean procedure
What is a contaminated procedure?
Nonpurilent inflammation, gross spillage from GI tract, entry ito GU or biliary tract i presence of infected bile or urine. penetrating trauma <4 hours old
Purulent inflammation (e.g., abscess); preoperative perforation of respiratory, gastrointestinal, biliary or genitourinary tract; penetrating trauma > 4 hours old l
dirty procedure
Urgent or emergency case that is otherwise clean; elective opening of respiratory, gastrointestinal, biliary or genitourinary tract with minimal spillage (e.g., appendectomy) not encountering infected urine or bile; minor technique break
clean contaminated
Nonpurulent inflammation; gross spillage from gastrointestinal tract; entry into biliary or genitourinary tract in the presence of infected bile or urine; major break in technique; penetrating trauma
contaminated procedure
Which antibiotic should be used for clean procedures?
cefazolin 1-2 grams IV
What antibiotic should be given for thoracic/orthopedic procedures?
cefuroxime 1.5 grams IV
What antibiotics should be given for bowel procedures?
cefoxitin 1-2 grams IV
cefazolin 1-2 gram + methonidazole 500mg
Ampicillin/subactam (unasyn) 3 grams
What class of antimicrobial is ampicillin and amoxicillin?
penicillinase with gram (-) activity
What class of antimicrobial is methicillin, oxacillin and nafcillin?
Pinicillinase-resistant
What class of antimicrobial is ampicilln-sulbactam
penicillin with beta lactamase inhibitor
What class of antimicrobial is imipenem?
carbapenem
What class of antimicrobial is gentamicin, tobramycin?
aminoglycosides
What class of antimicrobial is erythromycin, clrithomycin?
macrolide
What class of antimicrobial is clindamycin
lincomycins
What class of antimicrobial is vancomycin?
glycopeptide derivative
What class of antimicrobial is ciprofloxacin, levofloxacin?
fluroquinolones
Cephazolin belongs to which cephalosporin class?
1st generation
Cefuroxime (and cefaclor) belongs to which cephalosporin class?
2nd generation
ceftizoxime belongs to which cephalosporin class?
3rd generation
Cefclidine and cefepime belongs to which cephalosporin class?
4th generation
As the generation of cephalosporin increases, there is increased coverage for gram _____, while some coverage for gram ____ is lost
negative
positive
Which abx may be used if pt is allergic to penecillin?
Vancomycin 1gram (15 mg/kg) clindamycin (600-900 mg)
What abx may be used to add gram negative coverage?
gentamicin
ciprofloxacin
levofloxacin
aztreonam
What are the possible benefits of adding vancomycin to the mix?
prevention of MRSA
prosthetic heart valve and vascular graft
recent broad spectrum therapy
–studies show no benefit to using vanc.
-muse be cautious due to increased incidence of VRE
Repeat dosing shows no benefit in procedures +/- ___ hours but significant benefit in those > ____ hours
4, 7
How long are antibiotics given post closure?
24 hours (most) 48 hours (cardiac)
REpeat dosing for Cefazolin
2-5 hour
Repeat dosing for cefoxitin
2-3 hour
Repeat dosing for cefuroxime
3-4 hours
Repeat dosing for Ampicillin/sulbactam
2-4 hours
Repeat dosing for Nafcillin
2 hours (used for neurosugery
Repeat dosing for Vancomycin
6-12 hours
Repeat dosing for clindamycin
3-6 hours
Repeat dosing for metronidazole
6-8
What organisms do you need to treat for in neurosurgery? How do you treat it?
staph aureus, s. epidermatis
Cefazolin (1-2g)
Nafcillin(1-2g)
Vancomycin (1-2g)
Head and neck procedures are clean or clean-contaminated t or f?
true
What organisms are in head and neck?
Mouth: streptococci, S. epidermidis
Nose: Staph and strep
What are recommendations for head and neck surgery?
Clean: Not clear
Clean-contaminated:
Cefazolin (1-3g)
Clindamycin (600-900mg) + gentamicin(1.5/mg/kg)
Cardiac Sx is clean contaminated. T/F
F. Clean
Low risk but catastrophic complications
Organisms associated with cardiac Sx.
S. aureus and coagulase-neg staph
Gram (-) bacilli with saphenous vein harvest
Recommendations for cardiac Sx
Cefuroxime is agent of choice
Vancomycin and clindamycin are alternatives
Organisms associated with noncardiac thoracic Sx
same as cardiac
S. aureus and coagulase-neg staph
recommendations for noncardiac thoracic Sx
Cefazolin (1-2 grams)
Cefuroxime (1.5 grams)
Vancomycin* (1 gram [10-15 mg/kg])
Clindamycin** (600-900 mg)
organisms associated with Colorectal Sx
Gram-neg bacilli, anaerobes, enterococci
recommendations for Colorectal Sx
Oral regimen -Neomycin + erythromycin -Neomycin + metronidazole Intravenous regimen -Cefazolin (1-2 g) + metronidazole (0.5 g) -Cefoxitin or cefotetan (1-2 g) -Ampicillin-sulbactam (3 g)
what are recommendations for colorectal Sx for PCN and Cephalosporin allergic pts
Clindamycin (600-900 mg) plus -Gentamicin (1.5 mg/kg) or -Ciprofloxacin (400 mg) or -Levofloxacin (750 mg) or -Moxifloxacin (400 mg) Metronidazole + aztreonam (1-2 g) + gentamicin
Organisms associated With GI-Appendectomy
Aerobic / anaerobic gram-neg enteric
Recommendatinos for GI-appendectomy
Cefoxitin (1-2 g)
Ampicillin-sulbactam (3 g)
Cefazolin (1-2 g) + metronidazole (0.5 g)
Recommendations for GI-appendectomy-PCN allergic
Clinamycin + gentamicin (cipro, Levo)
Organisms associated with esophageal and gastroduodenal Sx
E. coli, staph, strep, enterococci
Recommendations for esophageal/gastroduodenal Sx
cefazolin (1-2 g)
Recommendations for esophageal/gastroduodenal Sx-PCN or cephalosporin allergy
Clindamycin +
-Ciprofloxacin, Levofloxacin, gentamicin
Organisms-GI-Biliary tract
E.coli, Klebsiella, enterococci
recommendations for GI-Biliary tract
Cefazolin (1-2g)
(may ask for cefoxitin just in case they puncture the gut
recommendations for GI-Biliary tract-PCN or cephalosporin allergy
Clindamycin +
-Ciprofloxacin, Levofloxacin, gentamicin
Recommendation-clean orthopedic procedures
None
organisms-orthopedic
S. epidermidis, S. aureus, gram- neg bacilli
which orthopedic procedures should antibiotic be used for
Hip repair, joint replacement, fixation
What are recommendations if you ar going to give prophylaxis for orthopedic procedures?
Cefazolin (1-2 g) Vancomycin (1 g) Other options -Antimicrobials in bone cement -Ultraclean O.R.
how often does endometritis happen in cesarean?
85%
-prolonged labor and ruptured membranes
Organisms-cesarean delivery
Vaginal tract: strep, staph, enterococci
Wound: S. Aureus, staphylococci
recommendation-cesarean delivery
Single dose of cefazolin before incision
-Historically post clamping
Clindamycin+gentamicin
Organisms-hysterectormy
Post op differs from Pre-op
polymicrobial
recommendation-hysterectomy
Cefazolin, Cefoxitin, Ampicillin-Sulbactam
Clindamycin or Vancomycin + aminoglycoside, aztreonam or fluoroquinolone
Metronidazole + aminoglycoside or fluroquinolone
Organism-GU
E. coli
Procedures indicating prophylaxis for GU Sx
any transurethral Sx or catheter placement
Recommendations for GU
Clean procedures—cefazolin
Clean contaminated—see bowel prophylaxis
Aminoglycoside + metronidazole or clindamycin
Infections associated with vascular Sx are associated with extensive morbidity and mortality. T or F
T
Organisms associated with vascular Sx
S. aureus, S. epidermidis, gram-neg bacilli
Recommendations-vascular Sx
Cefazolin (1-2 g)
Vancomycin (1g ) ± gentamicin (2 mg/kg)
Which procedures are at a high risk for SBE?
Prosthetic heart valves
-Biprosthetic and homograft valves
Prior history of IE
Complex cyanotic congenital heart dz
-Transposition of great vessels, single ventricle, Tetralogy of Fallot
Surgically constructed systemic and pulmonary conduits
Which procedures are at a moderate risk for SBE?
Other congenital cardiac malformation -Bicuspid aortic valve Acquired valvular dysfunction -AS, MS or valve repair Hypertrophic Obstructive Cardiomyopathy Mitral valve prolapse -With regurgitation on auscultation -Thickened leaflets on echo
Which procedures are at a low risk for SBE?
Physiologic or innocent murmurs Isolated secundum ASD Repair of ASD,VSD or PDA MVP without regurgitation Aortic valve sclerosis Physiologic MR on echo Mild TR CAD, rheumatic fever, pacemaker, stent
What are AHA guidelines for SBE prophylaxis?
Situations in which the risk of IE is considered by most authorities to be high
Antimicrobial prophylaxis is generally accepted as advisable
Conditions in which risk of IE is considered moderate
ABX for SBE prophylaxis
Ampicillin (2 g) Gentamicin (1.5 mg/kg; 120 mg max)-For GI and GU PCN allergy -Clindamycin (600 mg) -Cefazolin (1 g) -Vancomycin (1 g) ± Gentamicin for GI and GU
What can occur if vancomycin is given too fast? What are the symptoms? How should vanco be given?
Redman syndrome
Pruritus, flushing, erythema of head and torso
Arterial hypotension
Give over 1 hour
What happens if gentamycin is given too quickly? How fast should it be given?
Ototoxicity
give aminoglycosides over 20-30 minutes
