Resistenze batteriche e terapia delle infezioni postoperatorie

1
Resistenze batteriche e terapia delle infezioni
postoperatorie

• Fausto de Lalla,Vicenza

2
Postoperative infection 2006

• Despite the great advances in surgical technique
  and antibiotic prophylaxis, and ongoing research
  in this field, wound infection remains a
  considerable cause of morbidity and mortality
  among surgical patients

3
Antibiotic Resistance
The knowledge of sensitivity patterns of
the most likely etiological agents of
postoperative infections is pivotal for the
success of both - perioperative
prophylaxis, and - empiric treatment of
SSIs
4
TRADITIONAL CLASSIFICATION

• Clean surgery
• Clean-contaminated surgery
• Contaminated surgery
• Dirty surgery

5
Pathogens Causing Surgical Site
Infections
Are different, in respect to the surgical
procedure and the site of infection.
Infections following - CLEAN
SURGICAL PROCEDURES (with or without
implantation of vascular grafts or prosthetic
devices) - SUPERFICIAL,INCISIONAL SSIs (i.e.
simple infection of the surgical incision,
involving only skin and subcutaneous tissue)
are most often caused by
Staph. aureus or coag. negative staphylococci
(patients skin flora, surgical team,
exogenous environment)
6
Pathogens Causing Surgical Site Infections

• Deep and organ space infections following
• CLEAN- CONTAMINATED SURGERY
• - are more often polymicrobial infections
• - are caused by the normal endogenous
  microflora of the structure which has been
  transected

7
Most Likely SSI Pathogens according to
Operation Type

• Operation Likely
  pathogens
• Appendectomy - gram-negativi bacilli
  anaerobes
• colorectal (B.fragilis)
• Gastroduodenal - gram-negativi bacilli ?
  oropharingeal
• 
  anarobes streptococci
• Biliary tract - gram-negativi
  bacilliEnterococcus spp
• OB/GYN. - gram-negativi bacilli
  anaerobes (B.
• 
  fragilis) enterococcus spp streptococc
• Urologic - gram-negative bacilli
• Head and neck - oropharingeal anarobes
  gram-negative bacilli
  streptococci

8

• Eziologia delle infezioni postoperatorie
• Resistenze
• -gram positivi
• - gram negativi
• microrganismi in situazioni
• particolari

9
Emerging Gram-positive Micro-organisms in
Postoperative Infections

• MR staphylococci
• VR enterococci

10
Surgical Infection with Antibiotic-resistant
Microorganisms
Surgical patients with infections
by MR staphylococci or VRE have
? a significantly higher mortality rate
? ?longer hospitalization ? longer
treatment before the discharge than patients
with infections by MS staphylococci or
glycopeptide sensitive enterococci Nichols
RL, Am J Med 1998 Gleason et al, Arch Surg
1999 Mekontso DA, et al. CID 2001 Edmond
MB, et al. CID 1996
11
Significance of Enterococci in Surgical Infections

• Enterococcal bacteremia carries a serious
  prognosis
• Patients with intra-abdominal infection and an
  initial isolation of enterococci have a
  significant higher treatment failure rate
• VRE infections, and particularly VRE bacteremia,
  are associated with high morbidity and
  mortality
• Burnett RJ, Dellinger EP, et al. Surgery 1995
• Edmond MB, et al. CID 1996

12
Microbiologia delle peritoniti secondaria(comunita
ria) e postoperatoria (ospedaliera)

• microrganismo comunitaria ()
  ospedaliera() p
• Enterococchi 5 21
  ? 0,001
• E. coli 36
  19 ? 0,005
• Enterobacter spp. 3 12 ?
  0,05
• Bacteroides spp 10 7 NS
• Klebsiella spp 7 7
  NS
• S.aureus 1 6
  ? 0,05
• S.coagulasi neg. 1 5
  ? 0,05
• Streptococcus spp 14 4 ?
  0,005
• Pseudomonas spp 2 6
  NS
• Roehrborn A. CID 2001331513-9

13
VRE isolamenti per materiale
ANNO MATERIALE N ISOLAMENTI
2001 Feci 24
Urine 7
Ferita chir. 3
Sangue 2
Liquor 1
Drenaggio bil. 1

2002 Feci 85
Urine 3
Piaga decubito Bile 1 1

14
MR Staphylococci in Surgical Site Infections
(S.Bortolo Hospital)

• Dept. S.aureus
  Coag. Neg. staph.
• MR/ tot S.aureus ()
  MR/ tot. CNS ()
• - Neurosurg. 35/39 (89.7) 18/26
  (69.2)
• - Cardiosurg. 11/18 (61.1) 11/15
  (73.3)
• - Orthoped. 32/58 (55.2)
  12/18 (66.7)
• TOTAL 78/115 (67.8)
  41/59 (69.5)
• de Lalla F. J Hosp Infect 2002

15
MR Staphylococci in Surgical Site Infections in
Italy

• ? Ancona and Pesaro Hospitals (676 patients)
• - MR S. aureus/total S.aureus
  104/191 (54)
• - MR CNS/total CNS
  71/138 (51)
• S.Bortolo Hospital,Vicenza
• - MR S. aureus/total S.aureus 78/115
  (67.8)
• - MR CNS/total CNS 41/59 (69.5)
• ? 86 orthopedic centers (2,013 isolates from
• SSIs following TH or TK arthroplasties)
• - MR S. aureus/total S.aureus
  212/463 (46)
• - MR CNS/total CNS
  156/304 (51)
• Giacometti A et al. J Clin Microbiol 2000 de
  Lalla et al,J Hosp Infect 2002 Mini E et al,
  J Chemother 2001

16
Implications of Resistance for Selection of
Antibiotics in Surgery (1)
TREATMENT OF ESTABLISHED
INFECTIONS 1) SSIs following clean surgery
- the high frequency of MR staphylococci as
causative agents should be kept in mind,
AND -
glycopetides should be administered in the
empiric treatment of the most serious of these
infections (e.g. prosthetic infections)

17
PERIOPERATIVE PROPHYLAXIS - The administration
of glycopeptides as prophylactic agents in clean
prosthetic major surgery is suggested by some
Authors (at least for those cardiovascular and
orthopedic Depts. in which the prevalence of MR
staphylococci is considerably high) -
prophylactic glycopeptides are extensively used
in clinical practice
18
If the proportion of postoperative S. aureus
infection caused by MRSA (in major vascular and
orthopedic surgical prostheses) were to rise to
20, we would probably advise using vancomycin
or teicoplanin as prophylactic agents in both of
these areas. Adam P Fraise, J Antimicrob
Chemother 1998 42287-289
19
Antibiotic of choice in clean surgery prophylaxis
Vancomycin may be the agent of choice in certain
clinical circumstances,such as a cluster of MRSA
mediastinitis or incision infection due to MR
coag.neg staphylococci. A threshold has not been
scientifically defined that can support the
decision to use vancomycin. The decision should
involve local considerations. CDC Guidelines
20
Clinical consequences and cost of limiting use of
vancomycin for perioperative prophylaxisexample
of coronary artery bypass surgery (CABS)

• -to compare clinical results and
  cost-effectiveness of no prophylaxis, cefazolin
  and vancomycin in CABS
• -Decision-analytic models
• -Vancomycin resulted in 7 fewer surgical
  infections and 1 lower all-cause mortality and
  saved 117 per procedure,compared with
  cefazolin.
• -Cefazolin resulted in substantially fewer
  infections and deaths and lower costs than no
  prophylaxis
• -Data on vancomycins impact on resistance are
  needed to quantify..the future long
  term-consequences to society
• Zanetti,Goldie, Platt, Emerg Infect Dis
  2001820-7

21
Glycopeptides Are No More Effective than ß-Lactam
Agents for Prevention of Surgical Site Infection
after Cardiac Surgery a Meta-analysis (Bolon et
al,CID 2004)

• 7 trials published between 1988-2002 on 5,761
  subjects
• Glycopeptide vancomycin (4 studies) or
  teicoplanin (3 trials)
• Comparators cefazolin (3),cefuroxime
  (1),ceftriaxone (1),fluctobra (1)
• Prevalence of MRSA low (6 trials), high (1
  study)
• Blinded No (5 trials), yes (2studies)
• RESULTS neither agent proved to be superior
  for prevention of occurrence of SSI (primary
  outcome at 30 days !!)
• In subanalyses
• - ß-lactams were superior to
  glycopeptides for prevention of chest SSIs, and
• - glycopetides were superior for
  prevention of SSIs caused by MR gram bacteria.

22
Implications of Resistance for Selection of
Antibiotics in Surgery (2)

• during treatment with 3rd gen cephalosporins
• enterococcal superinfection can occurs
• the use of 3rd gen ceph.s is an important risk
  factor for VRE colonization and infection in
  surgical patients
• in the hospitals with high rates of VRE,
  limitation of 3rd gen ceph.s use, with an
  increase of penicillins -?LI combinations, is
  followed by a significant decrease in the VRE
  infection
• Dahms RA et al, Arch Surg 1998 May AK,
  Shock 2000 ?

23
Implications of Resistance for Selection of
Antibiotics in Surgery (3)

• - The particular role of Enterococcus spp. as an
  etiological agent of tertiary peritonitis
  (hospital acquired peritonitis) should be kept in
  mind (use of extended spectrum penicillins and
  penicillin- ?LIs combinations in the treatment
  of abdominal and pelvic surgical infections)
• - Postoperative infections in patients who
  have been hospitalized for a prolonged period
  prior to surgery, and/or have received prior
  antibiotic treatment are more likely to involve
  antibiotic resistant Gram negative bacilli(ESBL
  producing Klebsiella pneumoniae, E.coli,
  C.freundi, E.cloacae, S. marcescens ..). the
  possible administration of carbapenems should be
  kept in mind