Transcript Pre-operative MSU culture may help prevent, but stone

Pre-operative MSU culture may
help prevent, but stone culture
helps predict, post-operative
sepsis risk at PCNL
Cetti RJ, Boucher L, Ranasinghe W, McCahy P
Monash Medical Centre,
Melbourne, Australia
Introduction
 Percutaneous nephrolithotomy (PCNL) remains the
preferred modality of treatment for large renal calculi
>2cm [1].
[1] Turk C et al. EAU guidelines on Urolithiasis. Limited update 2014.
Introduction
 PCNL has an estimated complication rate of 20.5%,
including a risk of sepsis approaching 5% even in the
presence of a sterile pre-operative urine, and with the
routine use of peri-operative antibiotics [2].
[2] Labate G et al. J Endourol 2011.
Introduction
 Intra-operative kidney stone culture may help in the
post-operative septic patient to guide antibiotic
treatment.
Study
n=
SIRS rate
+ve SC
+ve MSU
Stone Culture/Sepsis
(%)
(%)
(%)
Sensitivity
Specificity
PPV
Korets et al 2011
204
9.8
16.2
10.3
45.0
87.0
27.3
Gonen et al 2008
61
1.6
50
40
50.0
82.3
89.4
Mariappan et al 2005
54
37.0
35.2
11.1
73.7
81.8
70.0
Margel et al 2006
75
22
48.0
25.3
76.5
60.3
36.1
Introduction
 Intra-operative kidney stone culture may help in the
post-operative septic patient to guide antibiotic
treatment.
Study
n=
SIRS rate
+ve SC
+ve MSU
Stone Culture/Sepsis
(%)
(%)
(%)
Sensitivity
Specificity
PPV
Korets et al 2011
204
9.8
16.2
10.3
45.0
87.0
27.3
Gonen et al 2008
61
1.6
50
40
50.0
82.3
89.4
Mariappan et al 2005
54
37.0
35.2
11.1
73.7
81.8
70.0
Margel et al 2006
75
22
48.0
25.3
76.5
60.3
36.1
Introduction
 Intra-operative kidney stone culture may help in the
post-operative septic patient to guide antibiotic
treatment.
Aim
 The aim of this study was to evaluate the clinical
benefit of pre-operative midstream urine culture
(MSUC), stone analysis and stone culture (SC) in
predicting sepsis risk at PCNL.
Methods
 A prospective analysis of pre-operative MSUC; SC,
stone analysis and sepsis for all patients undergoing
PCNL at Casey hospital, Monash Health, between May
2013 and May 2014.
2 or more of the following:
Temp >38°C (100.4°F) or < 36°C (96.8°F)
Heart Rate > 90bpm
WBC > 12,000/mm3, < 4,000/mm3
Respiratory Rate > 20 or PaCO2 < 32 mm Hg
AND:
SBP <90 or SBP Drop ≥ 40 mm Hg of normal
Methods
 All patients were prospectively investigated with a
MSUC. All patients with a positive result were
prescribed appropriate antibiotics, and proceeded
with PCNL when results were subsequently confirmed
negative.
 Ceftriaxone 1g or Gentamicin 2.5mg/kg, and Ampicillin
1g iv.
 Antiseptic preparation was 10% povidone-iodine for
the genitalia and 1% iodine/70%alcohol for the PCNL
site.
Methods
 PCNL was performed with a single track, undertaken
in the Casey modified supine position [3] under one
surgeon (PM).
McCahy P et al. J Endourol. 2013
Results
Mean Age (yrs)
54
Range
5-88
Sex:
M
31
F
22
Mean Stone size (mm)
20.9
Range
9-60
Stone Constituents (n):
Urate
0
Ca Oxalate
34 (65.4%)
Ca Oxalate Urate
6 (11.5%)
Cysteine
2 (3.8%)
Struvite
10 (19.2%)
Postop drainage (n):
Truly tubeless
11 (21.6%)
20Fr Nephrostomy and 6Fr stent 4 (7.8%)
6Fr Stent
4 (7.8%)
20Fr Nephrostomy
33 (64.7%)
Bowel Injury
0%
Results
 4 (7.5%) procedures were complicated with sepsis.
 3/4 required intensive care treatment.
 6 (11.2%) patients had a positive pre-operative MSUC. All were treated
with appropriate pre-operative antibiotics. 5 (83.3%) of these patients
still grew concordant pure growth micro-organisms from their stone
culture, but none suffered post-operative sepsis.
 13 (24.5%) patients had positive stone cultures, 8 of which had negative
preoperative MSUC’s, including the 4/13 (30.8%) who developed post-
operative sepsis.
ResultsPredicting stone colonisation from preoperative MSUC.
SC +ve
SC -ve
MSUC +ve
5
1
6
MSU -ve
8
39
47
13
40
53
Sensitivity of MSU to predict +ve stone culture: 38.5%
Specificity of MSU to predict +ve stone culture: 97.5%
PPV 83%
NPV 83%
ResultsPredicting sepsis risk from stone culture.
SC +ve
Sepsis +ve
Sepsis –ve
4
9
13
Sensitivity of SC to predict sepsis: 100%
Specificity of SC to predict sepsis: 81.6%
PPV: 30.8%
NPV: 100%
SC –ve
0
40
40
4
49
53
Sensitivity of SC to predict sepsis: 100%
Specificity of SC to predict sepsis: 81.6%
PPV: 30.8%
NPV: 100%
Results
Stone Constituent
n=
+ve preop
+ve SC
Sepsis
MSUC
Calcium Oxalate
34
3 (8.8%)
5 (14.7%)
1 (2.9%)
Ca Oxalate Urate
6
-
2 (33.3%)
2 (33.3%)
Cysteine
2
-
-
0
Struvite
10
3 (30%)
5 (50%)
1 (10%)
• Statistically significant increased risk of stone colonisation in struvite
compared to calcium oxalate stones (p=0.03)
• Increased risk of sepsis in mixed uric acid stones compared with pure
calcium oxalate stones (p=0.05)
Conclusions
 Pre-operative MSUC is mandatory.
 Pre-operative MSUC is, however, not sensitive for
predicting positive stone culture and subsequent
sepsis risk.
 Stone culture should be mandatory, to help direct
post-operative antibiosis. Particularly in those
patients with urate and struvite calculi.
Limitations
 Sample size.
 Tertiary referral.
 Data on DM, obesity, transfusion, dual access,
operative time.
Questions?