Microbiological Evaluation of PJIs Survey Results Lorenzo Drago IRCCS Galeazzi Institute –...
-
Upload
kathleen-lane -
Category
Documents
-
view
216 -
download
0
Transcript of Microbiological Evaluation of PJIs Survey Results Lorenzo Drago IRCCS Galeazzi Institute –...
Microbiological Evaluation of PJIsSurvey Results
Lorenzo DragoIRCCS Galeazzi Institute – University of Milan
Dear ISOC Members, based on an initiative from the ISOC group
during the last meeting in Hamburg, it was decided to send out a questionnaire to map the present microbiological routine used for the diagnosis of prosthetic joint infections.
We would like to have only one answer from each ISOC unit. The answers will be aggregated and presented in Mexico.
In addition the actual literature will be searched and a guideline document discussed in a workshop during the next ISOC meeting. Subsequently a document will be published on behalf of the ISOC group.
Galeazzi Institute Ortho Dept Lund HSS
ADDRESS
• Economic Impact of PJIs - wrong or delayed diagnosis
• Questionnaire answers examination
• Improving and debating matters
Guest editorial Prosthetic joint infections – a need for health
economy studies
• “An increase in the rate of revision due to infection….Needs
• “A rapid economic evaluation…..
• “A clear and common definition of deep infection…...
• “No model can depict the numerous possibilities……..
Acta Orthopaedica 2014
Costs Influences in PJIs
• Factors related to the patients• Revision Modalities• Surgical management Strategy• One-stage/two-stage
Economic burden of Hip PJI (UK)
0
5000
10000
15000
20000
25000
Mea
n co
st (£
)
Aseptic loosening Deep infection
Peri-prosthetic fracture Dislocation
+ 53%+ 84%
- 8.4%
Vanhegan IS et al. J Bone Joint Surg 2012
Complications for infections
Vanhegan IS et al. J Bone Joint Surg 2012
Indication Mean operating time
Mean blood loss
Complications rate
Hospital stay
Revision surgery
+41% +160% +32% Generally longer
Hip cost AnalysisIRCCS Galeazzi
The case of hip prosthesis” (full cost)
4,1%0,2 %
41,7%
4,3%
19,5%
3,5 %
Indirect costs
12,4%
14,4%
COSTS %
Instruments 0,2%
Lab 3,5%
Personnel 4,1%
drugs 4,3%
Consumables 12,4%Medical staff 14,4%
Indirect costs 19,5%
Prosthetic material 41,7%Total 100%
Variable costs increase of 30-50%
Other relevant factorsMicroorganisms-Dependent
• Culture negative PJI
• Factors related to the virulence
• MDR pathogens
PJIThe Economic Impact of Methicillin-Resistant
Infections
Parvizi J. et al. J Atrhoplasty, 2010
Irrigation and Debridment + 74
Resection artrhoplasty + 29
Revision (1-stage) + 41
Reimplantation + 30
Cost Per Procedure %
Days in hospital per visit + 50%
Days in hospital per patient + 78%
Microorganisms dependent factors
• Polymicrobial Infection + 41%
• Culture-Negative -29%
Journal of Hospital Infection, 2013
False negative!!!Biofilm notably hinders sampling and culturing;
Difficult to detach biofilm-embedded bacteria from prosthetic surfaces.
ISSUES FOR ORTHO-MICROBIOLOGISTS!
Up 30% of False Negative
Wrong or delayed diagnosis of PJIs
What is the financial impact of wrong or delayed diagnosis of PJI?
?
Wrong or delayed diagnosis of PJI
• Deterioration of bone• Complications risk (i.e. Longer stay)• Drugs (es. Antibiotics)• Diagnostic procedures (i.e. Imaging)• Loss of Medical Confidence• Patient’s psycological consequences
AIM ISOC Questionnaire
Mapping the microbiological routine used for the diagnosis of prosthetic
joint infections.
Criteria for Diagnosis of PJIIDSA
Presence of a sinus tract communicating with the prosthesis
Same
Same
Same
Presence of purulence without another known etiology surrounding the prosthesis
Growth of virulent microorganisms in a single specimen
MSIS
Major criteriaSame
Same
Minor criteria (3/5)CRP>10 mg/dL for acuteCRP> 1 mg/dL - ESR >30mm/hr chronic
Same
Elevated WBC, PMN% and ++ leukocyte esterase in synovial fluid
A single positive culture
AAOS
Positive cultures aspirate joint and elevated cell count/differential
Two or more intraoperative cultures +/- yielding the same organism.
ESR and CRP abnormal values
Histopathology of periprosthetic tissue suggestive for acute inflammation
Criteria for PJIs diagnosis
• MSIS criteria: 5 Centers• AAOS criteria: 7 Centers• IDSA criteria: 1 Center
• 1 Center: Presence of a fistula or sinus tract and elevated WBC count in joint fluids
• 1 Center: Elevated ESR and CRP values + positive cultures from prosthetic joint drainage or sinus
• 1 Center: Fistula, positive joint fluid culture and wbc count
What cut-off levels of ESR and CRP do you consider significant to suspect a prosthetic
infection?
MSISChronic: ESR: >30mm/hr
CRP>1mg/dLAcute: CRP>10mg/L
Do you consider the possibility of infection only in patients with abnormal ESR and/or CRP
values?MSIS
No: Clinical judgement should not be outweighed
by use of diagnostic algorithm or any individual test
CRP LABORATORY TESTING
Primary pathogens Low grade pathogens0
3
6
9
12
15
CR
P (
mg/
dL)
MEDIAN
Low levels of CRP may be found in infections with less virulent pathogens (Corynebacteria and Propionibacteria)
What cut-off value for WBC count and neutrophils percentage in joint aspirates do
you consider suggestive for PJIs?
MSISChronic: >3000 WBC
>80% PMNAcute: >10000 WBC
>90% PMN
Do you perform cultures from sinus tract in all patients?
MSISA sinus tract is pathognomonic
finding for PJI.
NO SWABS or CULTURE!!
Transport of samples to Laboratory
0
2
4
6
8
10
12
Inside Lab. Outside Lab0
2
4
6
8
10
Within 1hr
Within 2hrs
Within 6 hrs
After 6 hrs
Do you take tissue samples with the same surgical instrument?
0
2
4
6
8
10
YES NO
MSISEach sample should
be taken with an unused instrument
In your laboratory is sonication reserved to particular cases?
MSISSonication should be
limited to cases of suspected or proven PJI
Drago et al. Clin Orthop Relat Res. 2012 Jun 14.
Is DTT method reproducible and comparable to the
Sonication one?
Q8-9: Does your laboratory perform enrichment cultures and for how many days?
0
2
4
6
8
10
12
14
16
YES NO
MSISEnrichment cultures are
advisable
MSIS5-14 days or longer
Q10: What is your opinion about the use of molecular methods?
PROs•It may be useful in particular cases (n=7)
– Difficult to grow microorganisms (n=7)
– Suspected M. tuberculosis (n=3)
CONs•Oversensitive (n=4)
– Risk of false positive results (no differences between live and dead microorganisms)
•No data on susceptibility pattern (n=1)•Not useable in polymicrobic infections (n=1) •Not useful (n=1)
MSISNucleic acid based testing is not currently
a recommended routine diagnostic test for PJI
In cases of negative cultures or other diagnostic tests, molecular techniques
may help identify the unknown pathogens
Q11-12:Use of molecular methods
0
1
2
3
4
5
6
7
Multiplex P
CR
Real-time PCR
16S Sequencin
g
Not known
Q13: Usefulness of preliminary report
ALL:It is advisable to report isolation of each
microorganism as soon as possible. A preliminary report for negative samples after 5 days may be useful for clinicians, followed by a
conclusive report at the end of enrichment.
Conclusive Remarks• “Moderate” concordance
time to:
• Drafting a unique document
• Single Procedure
• Try to understand “discordances”
• Improve Methods and Procedures
• External Lab is a debating matter
Future “ISOC” Directions• Create Epidemiological Database
(Pathogens, Resistant %, Drugs used, Drugs rotation)
• Create “ISOC” Registry of Infections (per site, age, comorbidities)
• Create “ISOC” BIOBANK (study virulence, Biofilm, ATB susceptibility, new and old ATBs)
• Create New Fellowships (Microbiologists, Labs)
NOT WITHOUT A UNIQUE MICROBIOLOGICAL AND LAB
PROCEDURE!!!