Urolithiasis DOI 10.1007/s00240-014-0688-6

Original Paper

Intra‑operative stone culture as an independent predictor of systemic inflammatory response syndrome after percutaneous nephrolithotomy Ali Roushani · Siavash Falahatkar · Seyed Hossein Hosseini Sharifi · Lida Mahfoozi · Seyed Mohammad Seyed Saadat · Aliakbar Allahkhah · Nadia Rastjou Herfeh · Keivan Gholamjani Moghaddam 

Received: 25 February 2014 / Accepted: 15 July 2014 © Springer-Verlag Berlin Heidelberg 2014

Abstract  To evaluate the correlation between preoperative urine culture and stone culture findings during PCNL and choosing the appropriate antimicrobial treatment of patients with urinary tract infection or SIRS after PCNL. From April 2007 to March 2008, 51 patients aged 24–66 years underwent PCNL under general anesthesia. Statistical analysis was performed using SPSS software (v.18), the Kolmogorov–Smirnov test, Student’s t test, and the Chi square or Fisher’s exact tests. Before operation, 11 patients (21.6 %) had positive urine culture. Sixteen patients (31.4 %) had

A. Roushani · S. Falahatkar · L. Mahfoozi · A. Allahkhah (*) · N. Rastjou Herfeh · K. Gholamjani Moghaddam  Urology Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran e-mail: [email protected] A. Roushani e-mail: [email protected] S. Falahatkar e-mail: [email protected] L. Mahfoozi e-mail: [email protected] N. Rastjou Herfeh e-mail: [email protected] K. Gholamjani Moghaddam e-mail: [email protected] S. H. Hosseini Sharifi  Shahid Labbafinejad Medical Center, Urology and Nephrology Research Center (UNRC), Shahid Beheshti University, M.C. (SBMU), Urology, Tehran, IRAN e-mail: [email protected] S. M. Seyed Saadat  Urology Research Center, Student Research Committee, GUMS, Rasht, Iran e-mail: [email protected]

positive stone culture during operation. SIRS occurred in 13 patients (25.5 %). In female group (10 cases, 45.5 %), SIRS was significantly higher than male group (3 cases, 10.3 %) (P  = 0.008). Positive stone culture was significantly more prevalent in cases with positive pre-operative urine culture than cases with negative pre-operative urine culture (P = 0.023). But positive stone culture in group with SIRS, was significantly more common than group without SIRS (P = 0.001). Also positive stone culture in female group had significantly higher than male group (P = 0.003). We found a significant, tenfold increase in the risk of developing SIRS after PNCL, only in patients with positive stone culture (OR = 9.96; 95 % CI = 2.37–41.85, P = 0.002). Positive stone culture is a significant predictor of SIRS after PCNL, regardless of other related factors. Therefore, in order to avoid using blind empirical antibiotic regimen and to reduce the risk of subsequent microbial resistance due to use of prevalent broad-spectrum antibiotics, it would be wise to choose appropriate antibiotic therapy based on the results of intraoperative stone culture. Keywords  Intra-operative · Stone culture · Systemic inflammatory response syndrome · Percutaneous nephrolithotomy · PCNL

Introduction Percutaneous nephrolithotomy (PCNL) is one of the most common treatments for the upper urinary tract stones. Despite providing sterile conditions and preoperative antimicrobial prophylaxis, several infectious complications may further occur including transient urosepsis, mild sepsis or fever, post-operative bacteremia, post-operative systemic inflammatory response syndrome (SIRS), and in severe

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cases progress to multiple organ dysfunction syndrome (MODS) [1–3]. Although Buck reported that irrigation via the nephrostomy with Noxythiolin solution is safe and can reduce SIRS in patients undergoing percutaneous drainage procedures, but the incidence of SIRS after PCNL was reported to be about 23.4 % in Chen et al.’s study [4, 5]. Polytrauma, severe burns, and major operations are among the major causes of SIRS that is due to hypoxia, enhanced adrenergic activity, or changes in blood flow in the initiation of SIRS [6–8]. The aim of the present study was to evaluate the correlation between preoperative urine culture (U/C) and stone culture (S/C) findings during PCNL and to investigate whether routine S/C may help choosing the appropriate antimicrobial treatment of patients with urinary tract infection (UTI) or SIRS after PCNL.

Patients and method This prospective cross-sectional study was performed in all 51 patients referred to our clinic from April 2007 to March 2008. The preoperative parameters including any pervious history of UTI, renal stone surgery and other medical diseases were considered. In all patients, laboratory tests including complete blood count (CBC), renal function test, blood sugar (BS), prothrombin time (PT), partial thromboplastin time (PTT), International normalized ratio (INR), bleeding time (BT), and preoperative midstream urine culture as well as radiological studies including ultrasonography, IVP or CT scan without contrast were performed. Inclusion criteria were: the presence of single or multiple stone(s) in upper urinary tract, the presence of staghorn stone with indication for PCNL, and negative preoperative U/C. Exclusion criteria were: a previous placement of stent, nephrostomy tube or indwelling catheter, history of diabetes mellitus and/or renal failure, fever prior to surgery, previous interventional procedure, concomitant bladder stone or tumor, concomitant therapy with other antibiotics, and the presence of contra-lateral renal or ureteral stone. Patients with positive urine culture were treated preoperatively with appropriate antibiotics for a 2-week period before surgery; based on U/C and sensitivity results, surgery was performed when urine became sterile. All patients with a negative preoperative U/C received prophylactic antibiotics with 1 g intravenous Ceftriaxon and 80 mg intramuscular Gentamicin. All PCNLs, using the standard method were performed by the same urologist under general anesthesia. Stone fragments were collected to be processed for culture and sensitivity test, using the technique described by

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Nemoy and Stamey [9]. A nephrostomy tube was inserted at the end of the procedure and crushed stones were cultured on thiosulfate citrate bile salt sucrose and MacConkey’s agar. All patients underwent routine imaging post-operatively, including noncontrast helical computed tomography or kidney, ureter, and bladder (KUB) radiography for radioluscent and radioopaque stones respectively to detect residual stones. Nephrostography was performed in all patients 48 h post-operatively after removal of the nephrostomy tube. In the post-operative period, patients were monitored for signs of SIRS, defined as the development of 2 of 4 criteria, namely temperature less than 36 °C or greater than 38 °C, heart rate greater than 100 beats per minute, respiratory rate greater than 20 breaths per minute and white cell count greater than 12 × 109/L or less than 4 × 109/L. A systolic blood pressure below 90 mmHg or decrease of 40 mmHg below baseline in the presence of SIRS was defined as septic shock [10]. In this study, urosepsis was defined as SIRS or shock as a result of urinary tract infection. The collected data were divided into two main groups, which are midstream urine (Msu) culture, and sensitivity, and stone culture and sensitivity. Statistical analysis Statistical analysis was performed using SPSS software (version 18). The Kolmogorov–Smirnov test was used to assess the normality of data distribution. All variables were normally distributed. Data were reported using mean  ± standard deviation (SD) or percentage. Student’s t test was used to compare continuous variables, and the Chi square or Fisher’s exact tests were used to compare categorical data between groups with and without SIRS. To identify the independent predictors of SIRS after PCNL, variables with a P value below 0.2 in the initial univariate analysis was included in the multiple logistic regression model, using the backward stepwise selection. Adjusted odd ratios and 95 % confidence intervals were calculated. All P values were two-tailed, and P value below 0.05 was considered statistically significant.

Results Between April 2007 and March 2008, 51 patients underwent PCNL for upper urinary tract stones. Mean age was 44.84 ± 11.07 (24–66) years. 29 patients were male (56.9 %) and 22 patients were female (43.1 %). Five patients (9.8 %) had previous stone surgery. Mean stone burden was 31.17 ± 8.46 (18–60) mm. 33 patients (64.7 %) had single stone and 18 patients (35.5 %) had multiple stones. Fourteen patients (27.5 %) had staghorn stone. Before operation, 11 patients (21.6 %) had positive urine

Urolithiasis Table 1  Patients demographics data in two groups Parameters

All

Group with SIRS (N = 13) (%) Group without SIRS (N = 38) (%)

P value

Mean age (± SD), (years) Male n (%)

44.84 ± 11.07 29 (56.9)

42.69 ± 9.33 (2.58) 3 (10.3)

45.57 ± 11.63 (1.88) 26 (89.7)

0.423 0. 008

Female n (%)

22 (43.1)

10 (45.5)

12 (54.5)

Single stone, n (%)

5 (9.8) 46 (90.2) 31.17 ± 8.46 33 (64.7)

2 (15.4) 11 (84.6) 32.46 ± 7.12 (1.97) 6 (18.2)

3 (7.9) 35 (92.1) 30.73 ± 8.91 (1.44) 27 (81.8)

Multiple stones, n (%)

18 (35.3)

7 (38.9)

11 (61.1)

Staghorn stone, n (%)  Yes  No

14 (27.5) 37 (72.5)

4 (30.7) 9 (69.3)

10 (26.3) 28 (73.7)

0.734

Pre-operative urine culture, n (%)  Positive  Negative

11 (21.6) 40 (78.4)

4 (30.7) 9 (69.3)

7 (18.4) 31 (81.6)

0.439

Stone culture, n (%)  Positive

16 (31.4)

9 (69.3)

7 (18.4)

0.001

35 (68.6)

4 (30.7)

31 (81.6)

Previous stone surgery, n (%)  Yes  No Mean stone burden (± SD), (mm)

 Negative

Table 2  Comparison of the data between two groups regarding to positive pre-operative urine culture and positive stone culture Parameter

Male group

Female group

Staghorn stone, n (%) Positive pre-operative urine culture, n (%)

7 (24.1)

7 (31.8)

0.752

4 (13.8)

7 (31.8)

0.173

Positive stone culture, n (%)

4 (13.8)

12 (54.5)

0.003

P value

culture. Sixteen patients (31.4 %) had positive stone culture during operation. SIRS occurred in 13 patients (25.5 %). No significant difference was seen in mean age between groups with and without SIRS, respectively (42.69 ± 9.33 vs. 45.57 ± 11.63 years; P = 0.423). In female group (10 cases, 45.5 %), SIRS was significantly higher than male group (3 cases, 10.3 %) (P = 0.008). Groups with and without SIRS were similar in previous stone surgery (N  = 2, 15.4 % vs. N = 11, 84.6 %; P = 0.591) and stone burden (32.46  ± 7.12 vs. 30.73 ± 8.91 mm; P  = 0.531). SIRS occurred in six patients (18.2 %) with single stone and seven patients (38.9 %) with multiple stones. This difference was non-significant (P  = 0.177). No significant difference was seen in staghorn stone between groups with (N = 4, 30.7 %) and without (N = 10, 26.3 %) SIRS (P = 0.734). Positive stone culture was significantly more prevalent in cases with positive pre-operative urine culture (N  = 7, 63.6 %) than cases with negative pre-operative urine culture (N = 9, 22.5 %) (P = 0.023).

0. 591 0.531 0.177

Positive pre-operative urine culture was reported in 4 patients (30.7 %) of group with SIRS and 7 patients (18.4 %) of group without SIRS. This difference was nonsignificant (P = 0.35). But positive stone culture in group with SIRS (9 patients, 69.2 %), was significantly more common than group without SIRS (7 patients, 18.4 %) (P = 0.001). There were no significant difference between two groups regarding to the type of stone (staghorn stone) (M  = 7, 24.1 % vs. F  = 7, 31.8 %; P  = 0.752) and positive preoperative urine culture (M = 4, 13.8 % vs. F = 7, 31.8 %; P = 0.173). Comparison of patient’s demographics data in two groups is showed in Table 1. But positive stone culture in female group (N  = 12, 54.5 %) was significantly (P  = 0.003) higher than male group (N = 4, 13.8 %). Positive pre-operative urine culture (P  = 0.148) and positive stone culture (P  = 0.099) were 35.7 % (N = 5) and 50 % (N = 7) in staghorn stones and 16.2 % (N = 6) and 24.3 % (N = 7) in non-staghorn stones, respectively. Using backward stepwise logistic regression and after adjustment for potential covariates (i.e. sex and stone multiplicity), we found a significant, tenfold increase in the risk of developing SIRS after PCNL, only in patients with positive stone culture (OR = 9.96; 95 %CI = 2.37–41.85, P = 0.002). Comparison of the data between two groups regarding to positive pre-operative urine culture and positive stone culture is showed in Table 2.

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Discussion Despite that urine culture is routinely performed before urological surgery to ensure sterility, and appropriate antibiotics were used for patients with infection, urosepsis is still considered as a serious complication in patients undergoing PCNL [11, 12]. A recent study by Dogan et al. [13], which investigate the infectious complications in 338 patients undergoing PCNL, showed that 66 % of 82 patients with SIRS had negative preoperative U/C. In our study, about one-fourth of patients developed SIRS following PNCL. The incidence was higher in women than men, and in those who had positive intraoperative S/C. However, positive S/C remained the only predictor of developing SIRS, after adjustment for other related covariates. The current study showed that 25.5 % of the patients developed SIRS after PCNL. This finding seems to be consistent with previous studies in the literature [11, 13–15]. Mariappan et al. [11] reported that 37 % of patients, and Margel et al. [14] demonstrated that 22 % of patients develop SIRS following PCNL. The possible explanation for bacterial dissemination (urosepsis) related to PCNL includes: (1) bacterial colonization of stone and release of endotoxins during the fragmentation of infected stone and washing out (irrigation of) the fragments with irrigating fluid. (2) Systemic absorption of irrigation fluid containing bacteria and endotoxin via the venous system or lymphatic channels due to increased positive pressure through the nephroscope (nephrostomy tract) during surgical procedure [18]. Our result is also in agreement with Sharifi Aghdas et al. [15] findings which showed a higher incidence of fever after PCNL in women than men. The result of our study showed that of the 29 male patients, only 3 developed SIRS after PCNL. The findings confirm that the men who underwent PCNL may not benefit from intraoperative stone culture as much as women, so intraoperative stone culture may be considered more serious in women than men. The higher incidence of infected stone in women may be explained by the fact that they are more likely than men to develop UTI and therefore are at increased risk to form an infected stone and develop post-PCNL SIRS [15, 19]. In the present study, we demonstrated a significant association between preoperative U/C and intraoperative S/C. However, among 7 patients with simultaneous positive U/C and S/C, only 4 cases (57 %) had the same pathogenic microorganisms, with Escherichia coli the most common causative pathogen. This result is differed from previous studies [11, 16], which reported that positive U/C and S/C were simultaneously present in a small proportion of cases with positive U/C, and therefore concluded that U/C is a poor predictor of positive S/C. In a study conducted on 198

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patients undergoing PCNL, Korets et al. [17] showed that 17 out of 47 patients (36 %) with positive U/C had simultaneous positive U/C and S/C. In addition, in comparison to our study, they found a higher concordance (70.6 %) for causative microorganism isolated from both positive U/C and S/C. The findings of our study confirm the earlier investigation by Mariappan et al. [11] conducted on 54 patients undergoing PCNL, who univariately showed a fourfold greater risk of developing post-PCNL SIRS in patients with positive intraoperative S/C. Our results also support previous research by Margel et al. [14] who showed that positive intraoperative S/C is the only predictor of post-PCNL SIRS on univariate analysis. In contrast to earlier findings by Korets et al. [17] who did not found a significant association between S/C and post-PCNL SIRS on multivariate analysis, we found that S/C was associated with tenfold increase in the risk of postPCNL SIRS on logistic regression analysis [11, 14], after adjustment for other predictors of SIRS. This confirms that positive intraoperative S/C is a strong predictor of SIRS following PCNL, irrespective of other potential variables, especially preoperative U/C. Despite the limited sample size in our study and in the prior studies, this significant association shows the strength of the association. Our results are in agreement with previous studies [11, 14], which showed no association between positive preoperative U/C and developing SIRS following PCNL. In fact, prophylactic treatment with appropriate antibiotics based on the preoperative U/C and sensitivity results does not significantly decrease the number of patients at higher risk for the developing SIRS. Taken together, it can be concluded that preoperative U/C is not a reliable exam to detect the pathogenic microorganism of SIRS, while intraoperative S/C is the one that can help to choose the appropriate antimicrobial therapy by detecting the pathogenic microorganism.

Limitation The present study has several limitations. Because of small sample size, caution needs to be applied concerning the generalizability of the research findings. In addition, the effects of other potential covariates on developing SIRS after PCNL such as, prophylactic antibiotic administration, hydronephrosis, previous history of UTI, length of hospital stay, supra or infra-costal access, duration of nephrolithiasis, renal pelvic urine, duration of surgery and time elapsed from PCNL to the onset of SIRS were not taken into account in this study. Further comprehensive work with larger sample size is suggested to establish this.

Urolithiasis

Conclusion The results of this study indicate that positive S/C is a significant predictor of SIRS after PCNL, regardless of other related factors. Therefore, in order to avoid using blind empirical antibiotic regimen and to reduce the risk of subsequent microbial resistance due to use of prevalent broad spectrum antibiotics, it would be wise to choose appropriate antibiotic therapy based on the results of intraoperative S/C. Conflict of interest None.

References 1. Cadeddu JA, Chen R, Bishoff J, Micali S, Kumar A, Moore RG et al (1998) Clinical significance of fever after percutaneous nephrolithotomy. Urology 52(1):48–50 2. Deitch EA, Goodman ER (1999) Prevention of multiple organ failure. Surg Clin North Am 79(6):1471–1488 3. O’Keeffe N, Mortimer A, Sambrook P, Rao P (1993) Severe sepsis following percutaneous or endoscopic procedures for urinary tract stones. Br J Urol 72(3):277 4. Buck AC (1988) The use of noxythiolin (Noxyflex ‘S’) as an antiseptic irrigant in upper urinary tract drainage following percutaneous nephrolithotomy. Br J Urol 62:306–310. doi:10.1111/ j.1464-410X.1988.tb04353.x 5. Chen L, Xu QQ, Li JX et al (2008) Systemic inflammatory response syndrome after percutaneous nephrolithotomy: an assessment of risk factors. Int J Urol 15(12):1025–1028. doi:10.1111/j.1442-2042.2008.02170.x 6. Bone RC, Balk RA, Cerra FB, Dellinger RP, Fein AM, Knaus WA et al (1992) Definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis. The ACCP/SCCM Consensus Conference Committee. American College of Chest Physicians/Society of Critical Care Medicine. Chest J 101(6):1644–1655 7. Hierholzer C, Billiar TR (2001) Molecular mechanisms in the early phase of hemorrhagic shock. Langenbeck’s Archiv Surg 386(4):302–308

8. Mueller L, Broering DC, Meyer J, Vashist Y, Goettsche J, Wilms C et al (2002) The induction of the immediate-early-genes Egr-1, PAI-1 and PRL-1 during liver regeneration in surgical models is related to increased portal flow. J Hepatol 37(5):606–612 9. Nemoy NJ, Stamey TA (1971) Surgical, bacteriological, and biochemical management of infection stones. JAMA J Am Med Assoc 215(9):1470–1476 10. Dunne JR, Malone DL, Tracy JK, Napolitano LM (2004) Allogenic blood transfusion in the first 24 hours after trauma is associated with increased systemic inflammatory response syndrome (SIRS) and death. Surg Infect 5(4):395–404 11. Mariappan P, Smith G, Bariol SV, Moussa SA, Tolley DA (2005) Stone and pelvic urine culture and sensitivity are better than bladder urine as predictors of urosepsis following percutaneous nephrolithotomy: a prospective clinical study. J Urol 173(5):1610–1614 12. Wolf JS Jr, Bennett CJ, Dmochowski RR, Hollenbeck BK, Pearle MS, Schaeffer AJ (2008) Best practice policy statement on urologic surgery antimicrobial prophylaxis. J Urol 179(4):1379– 1390 Epub 2008/02/19 13. Dogan HS, Guliyev F, Cetinkaya YS, Sofikerim M, Ozden E, Sahin A (2007) Importance of microbiological evaluation in management of infectious complications following percutaneous nephrolithotomy. Int Urol Nephrol 39(3):737–742 Epub 2007/02/13 14. Margel D, Ehrlich Y, Brown N, Lask D, Livne PM, Lifshitz DA (2006) Clinical implication of routine stone culture in percutaneous nephrolithotomy–a prospective study. Urology 67(1):26–29 Epub 2006/01/18 15. Sharifi Aghdas F, Akhavizadegan H, Aryanpoor A, Inanloo H, Karbakhsh M (2006) Fever after percutaneous nephrolithotomy: contributing factors. Surg Infect 7(4):367–371 16. Fowler JE Jr (1984) Bacteriology of branched renal calculi and accompanying urinary tract infection. J Urol 131(2):213–215 17. Korets R, Graversen JA, Kates M, Mues AC, Gupta M (2011) Post-percutaneous nephrolithotomy systemic inflammatory response: a prospective analysis of preoperative urine, renal pelvic urine and stone cultures. J Urol 186(5):1899–1903 18. Lojanapiwat B, Kitirattrakarn P (2011) Role of preoperative and intraoperative factors in mediating infection complication following percutaneous nephrolithotomy. Urol Int 86:448–452. doi:10.1159/000324106 19. Tolley DA, Segura JW (2002) Fast facts—urinary stones. Health Press, Oxford

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Intra-operative stone culture as an independent predictor of systemic inflammatory response syndrome after percutaneous nephrolithotomy.

To evaluate the correlation between preoperative urine culture and stone culture findings during PCNL and choosing the appropriate antimicrobial treat...
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