Preoperative antibiotic therapy exceeding 7 days can minimize infectious complications after percutaneous nephrolithotomy in patients with positive urine culture.

PURPOSE: To explore an appropriate duration of antibiotic therapy before percutaneous nephrolithotomy (PCNL) in patients with positive urine culture. METHODS: From March 2016 to May 2018, consecutive patients with positive urine culture undergoing PCNL were prospectively registered. Initial preoperative antibiotics were given empirically. If needed, antibiotics were upgraded or adjusted to susceptible antibiotic after obtaining antibiotic-sensitivity test. Postoperative systemic inflammatory response syndrome (SIRS) was the primary outcome. RESULTS: Among the 220 participants, the incidence of positive stone culture and SIRS were 85.5% and 36.8%. Escherichia coli (53.6%, 44.5%) and Proteus mirabilis (8.2%, 10.0%) were the top two bacteria in urine and stones. In univariable analysis, patients with postoperative SIRS had a higher rate of stone culture positivity (97.5% VS 78.4%, P < 0.001) and a shorter duration of preoperative antibiotics therapy (3.4 ± 2.7 days versus 4.2 ± 2.8 days, P = 0.037). The landscape of SIRS showed a declining trend as the elongation of preoperative antibiotics (P = 0.039). In a day-by-day comparison, SIRS was less prevalent in patients treated by pre-PCNL antibiotics ≥ 7 days than in those with antibiotics ≤ 6 days (21.7% VS 40.8%, P = 0.017). Multivariable logistic regression confirmed positive stone culture (P = 0.001, OR 11.115) as an independent risk factor and pre-PCNL antibiotics ≥ 7 days (P = 0.048, OR 0.449) as an independent protective factor for SIRS. Preoperative antibiotic ≥ 7 days decreased SIRS from 45.4 to 27.8% and from 9.1 to 0% in patients with a positive and negative stone culture, respectively. CONCLUSION: Exceeding seven days should be appropriate duration of antibiotic therapy before PCNL in patients with positive urine cultures.

The antibiotic strategies during percutaneous nephrolithotomy in China revealed the gap between the reality and the urological guidelines.

BACKGROUND: Correct perioperative antibiotic strategies are crucial to prevent postoperative infections during percutaneous nephrolithotomy (PCNL). We aimed to compare the realistic antibiotic strategies applied in China with current urological guidelines. METHODS: Between April and May 2020, urologists from China were invited to finish an online cross-sectional survey. The questionnaire was designed according to the current urological guidelines and literatures. RESULTS: 3393 completed responses were received. 61.1% (2073/3393) respondents had urological experience of more than 10 years. 72.4% urologists chose multiple-dose antibiotics for patients with both negative urine culture (UC-) and negative urine microscopy (UM-) preoperatively. Respondents in central China (OR = 1.518; 95% CI 1.102-2.092; P = 0.011), east China (OR = 1.528; 95% CI 1.179-1.979; P = 0.001) and northeast China (OR = 1.904; 95% CI 1.298-2.792; P = 0.001) were more likely to prescribe multiple-dose antibiotic for UC-UM- patients. Notably, the respondents who finished PCNL exceeded 100 cases per year were in favor of single-dose administration (OR = 0.674; 95% CI 0.519-0.875; P = 0.003). There are only 8.3% urologists chose single-dose antibiotic for UC-UM+ patients, whereas 65.5% administered antibiotics for 1-3 days. Meanwhile, for UC+ patients, 59.0% of the urologists applied antibiotics shorter than 1 week, and only 26.3% of the urologists carried out routine re-examination of UC. Moreover, postoperative antibiotics were frequently prescribed for 3-6 days (1815; 53.5%). Finally, although 88.2% urologists considered stone culture important for management of postoperative antibiotics as the guideline recommended, only 18.5% performed it routinely. CONCLUSIONS: The antibiotic strategies are different between current practice in China and the urological guidelines. The dissimilarities suggested that further studies should be conducted to investigate the reasons of the differences and standardize the application of antibiotics.

Composition of Urine Collected from Non-Stone-Forming Chinese Persons during Different Short-Term Periods of the Day.

The purpose of this study in a small group of non-stone-forming Chinese persons was to measure the levels of supersaturation with calcium oxalate and calcium phosphate and pH with the aim of confirming if any of the different short-term urine samples were better for risk evaluation than a 24-h sample. Nine normal men and 1 woman collected urine during 4 periods of the day. Period 1 between 08 and 12 h, Period 2 between 12 and 18 h, Period 3 between 18 and 22 h, and Period 4 between 22 and 08 h. Each sample was analysed for calcium, oxalate, citrate, magnesium and phosphate, and estimates of supersaturation with calcium oxalate (CaOx) and calcium phosphate (CaP) were expressed in terms of AP(CaOx) and AP(CaP) index. An estimate of the solute load of CaOx was also calculated. Urine composition for 24-h urine (Period 24) was obtained mathematically from the analysed variables. Urine composition corresponding to 14-h urine portions 22-12 h (Period 14N) and 08-22 h (Period 14 D) were calculated. The lowest pH levels were recorded in Period 1 urine. The highest level of AP(CaOx) index was recorded during Period 1, and the product AP(CaOx) index × 107 × hydrogen ion concentration was significantly higher in Period 1 urine than in 24-h urine (p = 0.02). Also, the product SL(CaOx) × 107 × hydrogen ion concentration was significantly higher in Period 1 urine (p = 0.02). Low AP (CaP) index levels were recorded in Period 4, but also in all periods following dietary loads of calcium and phosphate. With the important reservation that the analytical results were obtained from non-stone-forming persons, the conclusion is that analysis of urine samples collected between 08 and 12 h might be an alternative to 24-h urine. The risk evaluation might advantageously be expressed either in terms of the product AP(CaOx) index × 107 × hydrogen ion concentration or the product SL(CaOx) × 107 × hydrogen ion concentration.

Trends in urinary stone composition in 23,182 stone analyses from 2011 to 2019: a high-volume center study in China.

PURPOSE: To evaluate the distribution and dynamic trends in constituents of urinary stones in China. MATERIALS AND METHODS: The composition of 23,182 stones were analyzed and then recorded between January 2011 and December 2019. The characteristics in terms of stone patient's gender, age and calendar year were analyzed. RESULTS: Most stones (22,172, 95.64%) had several crystal components, among which 40.25% (8925/22,172) were mixtures with infection components. Calcium oxalate (CaOx) and uric acid (UA) stones were more commonly encountered in men, but calcium phosphate (CaP), magnesium ammonium phosphate (MAP) and carbonate apatite (CA) stones were more prevalent in women (p < 0.05). In males, the proportion of CaOx stones increased up to the age of 40, but subsequently decreased (p < 0.001). Interestingly, females showed an inverse trend regarding CaOx stones (p < 0.001). The proportion of UA stones increased with age (p < 0.001), and CA stones most frequently were recorded at age 20-49. Over the past 9 years, UA, CA, and MAP stones increased over time, whereas there was a tendency for CaOx stones to decrease (p < 0.05). CONCLUSIONS: The scarcity of pure stones and a certain proportion of mixtures with infection stone components (e.g., mixtures of CaOx and CA) suggest that treatment directed against a single stone component is insufficient for effective recurrence prevention. Age and gender were significant determinants of stone composition, and according to the observed chronological trends, it seems that in the future, more UA, CA and MAP stones and fewer CaOx stones may be encountered in the studied population.

Is multiple tract percutaneous nephrolithotomy a safe approach for staghorn calculi?

PURPOSE: To explore the safety of multiple tract percutaneous nephrolithotomy (PNL) in terms of complication and draw a nomogram to predict the possibility of significant renal function decline (SRFD). MATERIALS AND METHODS: Patients with complex renal calculi appropriate for PNL at our institution between August 2016 and February 2018 were included in the study. The outcome of single and multiple tract PNL was analyzed retrospectively. A nomogram was created to predict the probability of SRFD. RESULTS: 793 (88.4%) patients were treated with single tract PNL (Group 1) and 104 patients (11.6%) treated with multiple tract PNL (Group 2). Group 2 had a significantly greater hemoglobin reduction (16.0 ± 12.5 vs. 11.4 ± 11.8 g/L, p < 0.001), higher rate of postoperative fever (19.2% vs. 11.9%, p = 0.034) and longer duration of the operation (110.6 ± 39.6 vs. 97.8 ± 34.5 min, p < 0.001). A nomogram for predicting the probability of SRFD was constructed based on identified risk factors: patients' age, positive urine culture (UC +), hemoglobin reduction and embolization. The area of receiver operating characteristic (ROC) curve was 70%. Bootstrapping technique utilized to make the calibration plot showed a high reliability of the nomogram. CONCLUSIONS: Multiple tract PNL had a higher risk of hemoglobin reduction and postoperative fever than single tract PNL. Multiple tracts had no effect on SRFD, but old age, UC + , hemoglobin reduction and embolization were risk factors for SRFD. A nomogram with the aim of predicting the probability of SRFD based on these parameters demonstrated good uniformity in internal validation.

The analysis of microbial spectrum and antibiotic resistance of uropathogens isolated from patients with urinary stones.

PURPOSE: The characteristics and resistance patterns of urine bacteriology in patients with urinary tract stones have not been extensively studied. This study aims to investigate the microbial spectrum and antibiotic resistance of uropathogens isolated from urinary tract infections in patients with urinary stones and provide a basis for appropriate antimicrobial treatments. METHODS: The results of positive bladder midstream urine cultures and their antimicrobial susceptibility were retrospectively analysed from hospitalised patients with diagnosis of urinary calculi and urinary tract infections between January 2010 and December 2015. RESULTS: A total of 3892 samples were analysed during the study period: 2201 were female patients (56.6%) and 1691 were male patients (43.4%). The 4 most common uropathogens were Escherichia coli (48.7%), Klebsiella pneumoniae (10.4%), Enterococcus faecalis (8.7%) and Proteus mirabilis (5.2%). Both E. coli (60.8%) and Proteus mirabilis (7.5%) were higher in female patients than in male patients (32.8%; 2.3%; P < .05). ESBL-positive E. coli accounted for 59.5% of total number of E. coli, while ESBL-positive K. pneumoniae comprised 42.0% of total K. pneumoniae. The majority of uropathogens in patients with stones had high resistance to fluoroquinolones, ceftriaxone, ceftazidime, cefepime, penicillins, sulfonamides and monobactams (resistance >20%). CONCLUSIONS: The microbial spectrum in patients with urinary stones had a complex pattern. The uropathogens showed marked multidrug resistance and a large proportion of the uropathogens were able to produce ß-lactamase.

Engineering Better Lithotripters.

Although shock wave lithotripsy (SWL) remains an excellent non-invasive method for active removal of stones from the ureter and kidney, its popularity has decreased during recent years and the arguments for choosing endoscopic procedures rather than the only non-invasive surgical procedure are usually based on the opinion that SWL results are inferior to those obtained with endoscopic methods. It is considered that slow technical progress has not sufficiently met the requirements of disintegration, reduced need of repeated treatments, shorter treatment duration and less negative effects on tissues. This article summarises some recently published articles that address these problems and have the aim of improving the function of lithotripters. Modification of the shock wave geometry, elimination or control of cavitation bubbles, and different techniques of disintegration studied in in vitro and in animal experiments suggest several possible future directions that might provide a basis for development of a new "gold standard" lithotripter.

Characteristics of Bacteria in Urine and Stones from Patients Treated with Percutaneous Nephrolithotomy and Association with Postoperative Infection.

Background: The purpose of this study was to identify bacterial differences between urine cultures (UC) and stone cultures (SC) in patients with complex kidney stones and to determine any correlation with post-percutaneous nephrolithotomy Systemic Inflammatory Response Syndrome (SIRS). Methods: Perioperative data of 1055 patients with complex kidney stones treated with first-stage Percutaneous Nephrolithotomy (PCNL) from September 2016 until September 2021 were included. Preoperative mid-stream urine samples and surgically obtained stone material were subjected to bacterial culture and antibiotic sensitivity tests. Preoperatively, antibiotic usage was determined by the UC or local bacterial resistance patterns. After PCNL treatment, antibiotic selection was guided by stone bacterial culture result and clinical symptoms. The effect of different preoperative antibiotic regimens based on urine cultures and postoperative antibiotic treatment based on stone cultures were assessed. Results: Positive stone cultures (SC+) were significantly more common than positive urine cultures (UC+) (31.9% vs 20.9%, p < 0.05). Escherichia coli (E. coli) was the most common uropathogen in both urine (54.3%) and stones (43.9%). The difference was statistically significant (p < 0.05). Moreover, UC+SC-, UC-SC+, UC+SC+, and preoperative serum creatinine were independent risk factors of postoperative SIRS. The incidence of SIRS in the UC+SC+ patients with different bacteria in stones and urine (51.6%) was higher than that in other culture groups. The antibiotic resistance of E. coli inside the stone was increased when prolonged preoperative antibiotics were administered to UC+ patients. Conclusion: The bacterial spectrum and positive outcome of culture in urine and stones were significantly different. The incidence of postoperative SIRS was highest in patients with UC+SC+ but with different bacteria strains. Prolonged pre-surgical antibiotic treatment apparently induced higher drug resistance for bacteria inside the stone.

International Alliance of Urolithiasis Guideline on Shockwave Lithotripsy.

Different international associations have proposed their own guidelines on urolithiasis. However, the focus is primarily on an overview of the principles of urolithiasis management rather than step-by-step technical details for the procedure. The International Alliance of Urolithiasis (IAU) is releasing a series of guidelines on the management of urolithiasis. The current guideline on shockwave lithotripsy (SWL) is the third in the IAU guidelines series and provides a clinical framework for urologists and technicians performing SWL. A total of 49 recommendations are summarized and graded, covering the following aspects: indications and contraindications; preoperative patient evaluation; preoperative medication; prestenting; intraoperative analgesia or anesthesia; intraoperative position; stone localization and monitoring; machine and energy settings; intraoperative lithotripsy strategies; auxiliary therapy following SWL; evaluation of stone clearance; complications; and quality of life. The recommendations, tips, and tricks regarding SWL procedures summarized here provide important and necessary guidance for urologists along with technicians performing SWL. PATIENT SUMMARY: For kidney and urinary stones of less than 20 mm in size, shockwave lithotripsy (SWL) is an approach in which the stone is treated with shockwaves applied to the skin, without the need for surgery. Our recommendations on technical aspects of the procedure provide guidance for urologists and technicians performing SWL.

Aspects on how extracorporeal shockwave lithotripsy should be carried out in order to be maximally effective.

The present review summarizes the most important considerations and steps for an optimal result of extracorporeal shockwave lithotripsy. The relationship between shockwave path, geometry and anatomical conditions is of utmost importance. Selection of appropriate treatment variables in terms of shockwave number, power and frequency, is an important prerequisite for proper disintegration and prevention of complications. Several supportive measures such as inversion therapy, citrate therapy, high diuresis, α-receptor antagonists, chemolysis and recurrence preventive measures are important parts of the management of this group of patients in order to avoid problems with residual fragments and new stone formation. Proper understanding of these factors as well as of the physics of shockwaves is necessary for a successful application of this non-invasive technology treatment concept.

Simplified estimates of ion-activity products of calcium oxalate and calcium phosphate in mouse urine.

This study aimed at formulating simplified estimates of ion-activity products of calcium oxalate (AP(CaOx)) and calcium phosphate (AP(CaP)) in mouse urineto find the most important determinants in order to limit the analytical work-up. Literature data on mouse urine composition was used to determine the relative effect of each urine variable on the two ion-activity products. AP(CaOx) and AP(CaP) were calculated by iterative approximation with the EQUIL2 computerized program. The most important determinants for AP(CaOx) were calcium, oxalate and citrate and for AP(CaP) calcium, phosphate, citrate, magnesium and pH. Urine concentrations of the variables were used. A simplified estimate of AP(CaOx) (AP(CaOx)-index(MOUSE)) that numerically approximately corresponded to 10(8) × AP(CaOx) was given the following expression:[Formula: see text]For a series of urine samples with various composition the coefficient of correlation between AP(CaOx)-index(MOUSE) and 10(8) × AP(CaOx) was 0.99 (p = 0.00000). A similar estimate of AP(CaP) (AP(CaP)-index(MOUSE)) was formulated so that it approximately would correspond numerically to 10(14) × AP(CaP) taking the following form:[Formula: see text]For a series of variations in urine composition the coefficient of correlation was 0.95 (p = 0.00000). The two approximate estimates shown in this article are simplified expressions of AP(CaOx) and AP(CaP). The intention of these theoretical calculations was not to get methods for accurate information on the saturation levels in urine, but to have mathematical tools useful for rough conclusions on the outcome of different experimental situations in mice. It needs to be emphasized that the accuracy will be negatively influenced if urine variables not included in the formulas differ very much from basic concentrations.

International Alliance of Urolithiasis (IAU) guidelines on the metabolic evaluation and medical management of urolithiasis.

The aim of this study was to construct the fourth in a series of guidelines on the treatment of urolithiasis by the International Alliance of Urolithiasis (IAU) that by providing a clinical framework for the metabolic evaluation, prevention, and follow-up of patients with urolithiasis based on the best available published literature. All recommendations were summarized following a systematic review and assessment of the literature in the PubMed database from January 1976 to June 2022. Each generated recommendation was graded using a modified GRADE methodology. Guideline recommendations were developed that addressed the following topics: initial evaluation, metabolic testing, dietary measures, medical management, and follow-up of recurrent stone formers. It was emphasized by the Panel that prevention of new stone formation is as important as the surgical removal of the stones. Although general preventive measures may be effective in reducing stone recurrence rates in some patients, specific medical and dietary management should be well considered and eventually applied in an individualized manner based on the outcomes of metabolic work-up, stone analysis and some certain patient related factors. A detailed follow-up of each case is essential depending on the metabolic activity of each individual patient.

A hypothesis of calcium stone formation: an interpretation of stone research during the past decades.

An interpretation of previous and recent observation on calcium salt crystallization and calcium stone formation provide the basis for formulation of a hypothetical series of events leading to calcium oxalate (CaOx) stone formation in the urinary tract. The various steps comprise a primary precipitation of calcium phosphate (CaP) at high nephron levels, establishment of large intratubular and/or interstitial (sub-epithelial) aggregates of CaP. These crystal masses subsequently might be dissolved during periods with low urine pH. On the denuded surface of subepithelial or intratubularly trapped CaP, release of calcium ions can result in very high ion-activity products of CaOx, particularly during simultaneous periods with peaks of CaOx supersaturation. Crystals of CaOx may result from nucleation in the macromolecular environment surrounding the apatite crystal phase. In the presence of low pH, low citrate and high ion-strength of urine, formation of large CaOx crystal masses can be accomplished by self-aggregation of Tamm-Horsfall mucoprotein. Following dislodgment of the initially fixed CaOx stone embryo, the further development into to clinically relevant stone is accomplished by CaOx crystal growth and CaOx crystal aggregation of the retained stone material. The latter process is modified by a number of inhibitors and promoters present in urine. The retention of the stone is a consequence of anatomical as well as hydrodynamic factors.

Simulating calcium salt precipitation in the nephron using chemical speciation.

Theoretical modeling of urinary crystallization processes affords opportunities to create and investigate scenarios which would be extremely difficult or impossible to achieve in in vivo experiments. Researchers have previously hypothesized that calcium renal stone formation commences in the nephron. In the present study, concentrations of urinary components and pH ranges in different regions of the nephron were estimated from concentrations in blood combined with a knowledge of the renal handling of individual ions. These were used in the chemical speciation program JESS to determine the nature of the solution complexes in the different regions of the nephron and the saturation index (SI) of the stone-forming salts calcium oxalate (CaOx), brushite (Bru), hydroxyapatite (HAP) and octacalcium phosphate (OCP). The effect of independent precipitation of each of the latter on the SI values of other salts was also investigated. HAP was the only salt which was supersaturated throughout the nephron. All of the other salts were supersaturated only in the middle and distal regions of the collecting duct. Supersaturations were pH sensitive. When precipitation of CaOx, Bru and OCP was simulated in the distal part of the collecting duct, little or no effect on the SI values of the other stone forming salts was observed. However, simulation of HAP precipitation caused all other salts to become unsaturated. This suggests that if HAP precipitates, a pure stone comprising this component will ensue while if any of the other salts precipitates, a mixed CaOx/CaP stone will be formed. Application of Ostwald's Rule of Stages predicts that the mixed stone is likely to be CaOx and Bru. Our modelling demonstrates that precipitation of stone-forming salts in the nephron is highly dependent on the delicate nature of the chemical equilibria which prevail and which are themselves highly dependent on pH and component concentrations.

The characteristic and relationship of Escherichia coli isolated from urine and stones in patients with calcium oxalate stones.

Previous clinical studies have shown that Escherichia coli (E. coli) predominated in urine and stone culture from calcium oxalate (CaOx) stone disease. The characteristic and relationship between E. coli isolated from urine cultures (EUC) and stone cultures (ESC) are compared. 83 E. coli (33 EUC and 50 ESC, respectively) from 66 CaOx stone patients were recruited in the study. E. coli in urine and stones from those patients were assessed by antimicrobial susceptibility test, genotyping and phylogenetic grouping. Furthermore, whole genome sequencing and comparative genomic analysis in paired ESC and EUC isolated strains from eight patients were carried out. The E. coli strains from ESC and EUC were not only multidrug resistant (MDR), but also had the similar pattern of resistant genes. The dominant phylogenetic group was B2, which was found in 54.0% of the ESC samples and 69.7% of the EUC samples, respectively. The virulence genes of E. coli, which isolated from stones and urine in the same patients, were highly homologous and largely consistent. Meanwhile, these E. coli strains were located in the same clade originated from a common ancestor. ESC and EUC isolated from patients with CaOx stones had a high prevalence of phylogenetic groups B2. Bacterial strains isolated from urine and stones in the same patient had consistent antimicrobial susceptibility profiles, genotyping, phylogenetic groups, virulence and resistance genes, also with high sequence co-linearity and close relationships.

Characteristics of Double-J Stent Encrustations and Factors Associated with their Development.

PURPOSE: To evaluate the chemical composition of double-J stent encrustation and to assess risk factors associated with their development. MATERIALS AND METHODS: Patients who had double-J stents removed between July 2016 and June 2017 were recruited for this study prospectively. The clinical features of the patients were recorded and the composition of encrustation material was analyzed by infrared spectroscopy. RESULTS: Encrustments from a total of 372 double-J stents were collected. The mean age of patients was 50.4±13.1 years and deposits possible to analyze were obtained from 228 males (61.3%) and 144 females (38.7%). Calcium oxalate monohydrate was the most common constituent of stone and encrustments. The encrustation rate of vesical coils was significantly higher than that of renal coils (P<0.001). There was no significant difference in chemical composition between stone and encrustation regarding renal (P=0.086) and vesical coils (P=0.072). The only predictive risk factor for the development of encrustation on double-J stents was indwelling time. This phenomenon was observed in both renal (P<0.001) and vesical coils (P=0.021). Interestingly, patient with chronic kidney disease (CKD) was associated with less risk of encrustation on both renal (P<0.001) and vesical coils (P=0.001). CONCLUSION: The chemical composition of double-J stent encrustation was the same as the urinary stone. The prevention strategy for stone composition is also suitable for the prevention of encrustation of double-J stent. The only predictive factor for double-J stent encrustation was the indwelling time. CKD patient was shown to be less at risk for the development of encrustation.

Enhanced Antibiotic Treatment Based on Positive Urine Dipstick Infection Test Before Percutaneous Nephrolithotomy Did Not Prevent Postoperative Infection in Patients with Negative Urine Culture.

Introduction: Urinary tract infection (UTI) should be treated before percutaneous nephrolithotomy (PCNL). However, the most appropriate treatment strategy in patients with negative urine culture but positive urine dipstick infection test (positive urinary leukocyte or nitrite reaction) remains unclear. Materials and Methods: From August 2016 to February 2018, 806 consecutive patients who had undergone the first-stage PCNL with negative urine culture were included. Preoperative urinalysis, antibiotic treatment, intraoperative stone culture, and postoperative systemic inflammatory response syndrome (SIRS) were prospectively recorded. The primary outcome was SIRS. The impact of preoperative antibiotics on preoperative UTI, stone culture, and postoperative SIRS was studied. Results: Among the 806 participants, the rate of positive urine dipstick infection test and SIRS were 26.8% and 7.2%, respectively. In univariable analysis, positive urinary nitrite (p < 0.001), positive urinary leukocytes (p < 0.001), positive urine dipstick infection test (p < 0.001), longer duration of pre-PCNL antibiotics (p = 0.001), higher level of pre-PCNL antibiotics (p = 0.010), infection stones (p = 0.001), and positive stone culture (p < 0.001) were risk factors for SIRS. However, multivariable analysis showed that positive stone culture (p = 0.004) and prolonged preoperative treatment with antibiotics (p = 0.021) were independent risk factors for SIRS. Although preoperative antibiotics reduced the incidence of positive urine leukocyte (p < 0.001) or nitrite reactions (p < 0.001), prolonged or upgraded preoperative antibiotics did not affect the incidence of positive stone culture. Whether stone culture was positive (p = 0.023) or negative (p = 0.025), prolonged preoperative treatment with antibiotics was associated with a higher incidence of SIRS. Conclusions: Enhanced preoperative antibiotic treatment based on positive urine dipstick infection tests was insufficient to reduce the incidence of positive stone culture but increased the risk of SIRS after PCNL in patients with negative urine cultures.

Urine and stone analysis for the investigation of the renal stone former: a consensus conference.

The Consensus Group deliberated on a number of questions concerning urine and stone analysis over a period of months, and then met to develop consensus. The Group concluded that analyses of urine and stones should be routine in the diagnosis and treatment of urinary stone diseases. At present, the 24-h urine is the most useful type of urine collection, and accepted methods for analysis are described. Patient education is also important for obtaining a proper urine sample. Graphical methods for reporting urine analysis results can be helpful both for the physician and for educating the patient as to proper dietary changes that could be beneficial. Proper analysis of stones is also essential for diagnosis and management of patients. The Consensus Group also agreed that research has shown that evaluation of urinary crystals could be very valuable, but the Group also recognizes that existing methods for assessment of crystalluria do not allow this to be part of stone treatment in many places.

New horizons in the management of patients with cystinuria.

PURPOSE OF REVIEW: Although the formation of cystine stones is seen in only a small fraction of all patients with urolithiasis, this disease is associated with a pronounced morbidity. The difficult clinical management of these patients, with the aim of arresting or decreasing the rate of recurrent stone formation, is well recognized. This review summarizes some recent knowledge. RECENT FINDINGS: An early and correct diagnosis of cystinuria is fundamental for a successful course of the disease in these patients. Formation starts early in life, and attention to this diagnosis is necessary for the paediatric stone formers. New radiological and biochemical improvements seem useful in this respect. A combination of medical tools is usually necessary to influence the very often, troublesome stone-forming activity. Urine dilution, alkalization and chelating therapy have remained the cornerstones of the therapeutic approach. The importance of a high urine pH has been further emphasized, and the possibility to use acetazolamide is a promising improvement of the medical treatment. In order to increase the compliance and reduce the need of active stone removal, special stone clinics seem to be of particular value. The understanding of the genetic background might open future treatment alternatives. SUMMARY: Patients afflicted by cystine stone disease need an aggressive medical treatment, gentle stone-removing surgery and careful follow-up.

Is high diuresis an important prerequisite for successful SWL-disintegration of ureteral stones?

A randomised comparison was made between high and normal diuresis during the primary session of extracorporeal shock wave lithotripsy (SWL) for removal of ureteral stones. High diuresis was accomplished by pressure infusion of approximately 1 L of Ringer acetate solution together with 20 mg of furosemide during the 30-40 min treatment session (Group D). These patients also had a bladder catheter. Patients in Group 0 had a normal diuresis and no bladder catheter. The mean (SD) number of treatment sessions for the 65 patients in Group D were 1.26 (0.51) and for the 60 patients from Group 0 1.35 (0.84) [p > 0.10]. 51 (78%) and 46 (77%) patients in Group D and Group 0, respectively, required only one SWL session. Stones were located in the proximal, mid and distal ureter in 22, 9, and 29 of the patients in Group D and in 22, 5, and 38 in Group 0. No difference in treatment outcome was observed with regard to stone localisation. The stone treatment index (STI(GR)) calculated for Group D and Group 0 were 4.77 and 4.70, respectively. In conclusion there was no obvious advantage of using a forced diuresis during the primary SWL-session for treating patients with ureteral stones. Although a high diuresis and bladder catheter might be beneficial in certain complicated cases, in most situations it seems appropriate to omit this step.