Princess Alexandra Hospital, Brisbane

Transcription

1 Princess Alexandra Hospital Coagulase Negative Staphylococcal Peritonitis in Australian Peritoneal Dialysis Patients Predictors, Treatment and Outcomes in 936 cases Dr Magid Fahim Princess Alexandra Hospital, Brisbane On behalf of the Peritoneal Dialysis Working Group: On behalf of the Peritoneal Dialysis Working Group: Prof David Johnson, Dr Fiona Brown, A/Prof Stephen McDonald, Dr Johan Rosman, Dr Kathryn Wiggins, A/Prof Kym Bannister, and A/Prof Carmel Hawley

2 Coagulase Negative Staphylococci (CNS) Leading cause of PD-related peritonitis 11.4% % Decline following introduction of double-bag connection systems No comprehensive multi-centre examination of predictors, treatment and outcomes Only three previous reports Small study populations often from single centres No comparison group Limited depth of data collection

3 Aim To examine the frequency, potential predictors, treatment & clinical outcomes of coagulase negative staphylococcal peritonitis in all Australian PD patients, as recorded in ANZDATA Registry

4 Methods Nested case-control study based on the ANZDATA Registry All Australian PD patients 1 st Oct st Dec 2006 Exposure CNS (vs non-cns) peritonitis defined as: Clinical features of peritonitis (pain, cloudy bag) Dialysate WCC >100/ L with >50% PMNLs CNS on dialysate culture

5 Outcomes Relapse (same CNS within 4 weeks of Abs) Repeat (same CNS > 4 weeks after Abs) Peritonitis-associated hospitalisation Catheter removal Temporary haemodialysis (HD) transfer Permanent HD transfer Peritonitis-relatedrelated death

6 Group comparisons Statistical Analysis Chi-square test Unpaired t-test Mann-Whitney test Independent associations examined using multivariate multilevel mixed effects Poisson regression analysis Random effects for Australian State, treating unit and individual id patient t

7 Results 4675 pts followed for 6002 pt-yrs 3594 episodes of peritonitis iti in 1984 pts Overall peritonitis incidence rate = 0.6 episodes/pt-yr CNS peritonitis incidence rate = 0.16 episodes/pt-yr

8 Associations of CNS Peritonitis Characteristic OR (95% CI) Asian Race 0.52 ( ) Renovascular Nephrosclerosis 0.40( ) 086) Early Referral to Renal Unit 0.38 ( ) Automated Peritoneal Dialysis 0.79 ( ) Not Significant - Age, gender, BMI, smoking, lung disease, coronary artery disease, peripheral vascular disease, cerebrovascular disease, diabetes, egfr at dialysis start, transportert status t or centre size

9 Antibiotic & Adjunctive Treatment Majority - either e vancomycin or cephazolin in combination with gentamicin Initial regimen changed in 57% after a median of 3-days Most often to vancomycin monotherapy Uro- or strepto- kinase more common with: Any CNS peritonitis (1.4% vs 0.6% p = 0.03) Relapsed CNS peritonitis (5%vs0.6%p<0.01)

10 Outcome Outcomes CNS vs Non-CNS Peritonitis Cure by Antibiotics Alone 76% vs 64% * Hospitalization 61% vs 73% * Duration of Hospitalization (days) 5 [3-9] vs 6 [3-13] * Catheter Removal 10% vs 26% * Permanent Haemodialysis Transfer 9.0% vs 21% * Death 10%vs27% 1.0% 2.7% Relapsed Peritonitis 17% vs 13% *p<0.001 p=0.002 p=0.003

11 Relapse & Repeat CNS Peritonitis CNSperitonitis associated with higher risk of relapse (17% vs 13% p=0.003) Relapsed peritonitis more likely to require catheter removal (22% vs 7%, p<0.001) Highest risk of repeat CNS peritonitis iti in 2 nd month following completion of therapy Shorter than for non-cns peritonitis (65 [37-174] days vs89[37-204] days p=0.005)

12 Associations of CNS Outcomes Outcome Characteristic OR (95% CI) Hospitalization with Female 1.70( ) CNS peritonitis Asian race ATSI race 0.51 ( ) 0.47 ( ) egfr at dialysis start Coronary artery disease Use of agent other than vanco. or cephalosporin Polymicrobial peritonitis 1.07 ( ) 1.58 ( ) 231( ( ) 2.79 ( ) Catheter removal after CNS peritonitis Polymicrobial peritonitis Cephalosporin p vs vancomycin as first agent 4.62 ( ) 0.41 ( )

13 Peritoneal Dialysate CNS Methicillin Sensitivities Australian State Number of CNS PD Isolates Tested for Methicillin Resist. n (%) Methicillin Resistant (%) Queensland (92.2) 69 Victoria (73.6) 62 South Australia (100) 62 New South Wales (100) 66 Western Australia (100) 77 Totals (94.8) 68 Isolates from centres servicing bulk of Australian PD patients represents 67% of all CNS isolates over study period Finding of a protective effect of cephalosporins likely Finding of a protective effect of cephalosporins likely represents confounding by indication

14 Limitations Residual confounding Reasons underpinning antibiotic & treatment decisions not captured Possibility of misclassification bias Limited depth of data collection Concomitant exit site infections, severity of comorbidities, antibiotic doses, and laboratory findings not captured

15 Conclusions CNS accounts for 26% of Australian PD peritonitis Associations More common in late-referred patients Less common in Asian race, RVN and APD Generally favourable outcome and good response to antibiotics 14 day course usually sufficient High rate of relapse (17%) and repeat (31%) episodes Repeat episodes most often within 2-months Relapse catheter removal (22% vs 7%)

16 Acknowledgements Australia & New Zealand Nephrology Community thank you! Microbiologists Dr Joan Faogali (Princess Alexandra Hospital) Dr Matthew O'Sullivan (Westmead Hospital) Dr Morgyn Werner (SA Pathology, Queen Elizabeth Hospital) Professor Keryn Christiansen (Royal Perth Hospital) PD working group 9 publications on infectious peritonitis iti in 2009 All referenced in latest ISPD guidelines on PD peritonitis Excellent involvement of trainees in publications