The evaluation and management of urolithiasis in the ED: A review of the literature

Simultaneous determination of plasma protein binding of five C-glycosylflavones from TFDS by rapid equilibrium dialysis

The total flavonoids of Desmodium styracifolium (TFDS) are flavonoid-rich extracts obtained from Desmodii Styracifolii Herba, which is approved for the treatment of urolithiasis in China. C-glycosylflavones including schaftoside, vicenin-1, vicenin-2, vicenin-3, and isovitexin are the main active constituents. In this study, the plasma protein binding of these compounds was determined for the first time in rat and human plasma by rapid equilibrium dialysis combined with HPLC-MS/MS method. The developed method was validated in terms of specificity, linearity, accuracy, precision, extraction effect, matrix effect, and stability. Schaftoside, vicenin-1, vicenin-2, and vicenin-3 exhibited moderate plasma protein binding, ranging from 56.6% to 61.5% in rat plasma and 55.0%-62.9% in human plasma. In comparison, isovitexin demonstrated a higher plasma protein binding in the range of 92.3-93.1% and 95.1-96.2% in rat and human plasma, respectively. Furthermore, the potential interactions mediated via plasma protein binding between isovitexin and nonsteroidal anti-inflammatory drugs (NSAIDs) were investigated by rapid equilibrium dialysis. No significant changes were observed, indicating a lower likelihood of interaction between TFDS and NSAIDs due to plasma protein binding in the treatment of urinary system disorders.

Predictive Factors for Major Complications and Urological Cancer Diagnosis in Older Adults (≥80 Years) Admitted to the Emergency Department for Hematuria

Background: Gross Hematuria is a relevant cause of admission to the emergency department in the general population and particularly in older adults (≥80 years). This specific urological symptom is often underestimated and usually associated with benign conditions such as urinary infections or poor hydration. Nevertheless, hematuria could lead to severe acute complications or be the first symptom of urological cancers. Methods: We retrospectively analyzed clinical data from 1169 patients aged ≥80 years consecutively admitted to the emergency department for hematuria. The primary endpoint of the study was to identify risk factors for major complications, and the secondary endpoint was to analyze risk factors for urological cancer diagnosis. The median age was 85 years (IQR 82-88 years), and 908 (77%) were males. Among them, 449 (38.4%) had a past medical history of urological neoplasm (kidney, ureter, bladder, prostate, or urethral cancer). Results: Overall, 87 patients (7.4%) had major complications (patient death, septic shock, and admission to the intensive care unit). Worse vital signs at admission, fever, and confusion (p < 0.001, OR 18.0 IC 95% [5.5-58.7]; p = 0.015, OR 2.0 IC 95% [1.1-3.5]; p = <0.001, OR 4.2 IC 95% [1.9-3.5], respectively), as well as lower hemoglobin values and higher Charlson comorbidity index (p < 0.001, OR 0.8 IC 95% [0.7-0.9]), p = 0.002, OR = 1.2 [1.1-1.3]) were independent predictive factors for major complications. The multivariate analysis identified as risk factors for diagnosis of urological cancer older age, male sex and higher comorbidity (OR 1.05 IC95% [1-1.09]; OR 2.19 IC95% [1.42-3.39] and OR 1.11 IC95% [1.2-1.2], respectively); interestingly the presence of indwelling vesical catheter (IVC) (OR 0.44 IC95% [0.24-0.82]) resulted as an independent factor for absence of urological cancers. Conclusions: Hematuria is a frequent symptom in older adults admitted to the emergency department. While this is often associated with benign conditions, there are some risk factors for major complications and for urological cancer that must be taken into account to identify the patients who need further evaluation or prompt hospital admission.

A case of post-renal acute kidney injury caused by bilateral ureterolithiasis

Key Clinical Message

Bilateral ureterolithiasis is rare but can cause acute kidney injury (AKI). Clinicians should first examine for post-renal causes of AKI, even if the patient lacks subjective symptoms.

Abstract

This letter describes a case of bilateral ureterolithiasis which presented with post-renal acute kidney injury (AKI) and was successfully treated by bilateral retrograde ureteric stenting. Clinicians should be aware of post-renal AKI caused by bilateral ureterolithiasis when acute worsening of renal function with oliguria is observed.

The association between non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) and kidney stones: a cross-sectional study

BACKGROUND

The relationship between the NHHR and kidney stone risk remains unknown. The purpose of this study was to evaluate the association between adult NHHR and kidney stone occurrence in USA.

METHODS

This study used a variety of statistical techniques such as threshold effects, subgroup analysis, smooth curve fitting, multivariate logistic regression, and data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2014. We aimed to clarify the relationship between the NHHR and kidney stone risk.

RESULTS

The average age of the 21,058 individuals in this research was 49.70 ± 17.64 years. The mean NHHR was 3.00 ± 1.47, and the overall prevalence of kidney stone occurrence was 9.05%. The prevalence within the quartile ranges (Q1-Q4) was 7.01%, 8.71%, 9.98%, and 10.49%, respectively. The overall average recurrence rate of kidney stones was 3.05%, demonstrating a significant increase with increasing NHHR (Q1: 1.92%, Q2: 2.92%, Q3: 3.35%, Q4: 4.00%, P < 0.01). The occurrence of kidney stones increased by 4% (95% CI: 1.00-1.08, P = 0.0373) and the chance of recurrence increased by 9% (95% CI: 1.03-1.14, P < 0.01) with each unit increase in NHHR. The interaction analysis results demonstrated that the relationship between the NHHR and the risk of kidney stones was not significantly impacted by the following factors: sex, body mass index, poverty income ratio, diabetes, or hypertension. Curve fitting and threshold effect analysis also demonstrated a non-linear association, with a breakpoint found at 3.17, between the NHHR and the risk of kidney stones.

CONCLUSIONS

In adults in the USA, there is a substantial correlation between elevated NHHR levels and a higher probability of kidney stones developing and recurring. Timely intervention and management of NHHR may effectively mitigate the occurrence and recurrence of kidney stones.

Risk relationship between inflammatory bowel disease and urolithiasis: A two-sample Mendelian randomization study

BACKGROUND

The causal genetic relationship between common parenteral manifestations of inflammatory bowel disease (IBD) and urolithiasis remains unclear because their timing is difficult to determine. This study investigated the causal genetic association between IBD and urolithiasis using Mendelian randomization (MR) based on data from large population-based genome-wide association studies (GWASs).

METHODS

A two-sample MR analysis was performed to assess the potential relationship between IBD and urolithiasis. Specific single nucleotide polymorphism data were obtained from GWASs, including IBD (n = 59957) and its main subtypes, Crohn's disease (CD) (n = 40266) and ulcerative colitis (UC) (n = 45975). Summarized data on urolithiasis (n = 218792) were obtained from different GWAS studies. A random-effects model was analyzed using inverse-variance weighting, MR-Egger, and weighted medians.

RESULTS

Genetic predisposition to IBD and the risk of urolithiasis were significantly associated [odds ratio (OR), 1.04 (95% confidence interval [CI], 1.00-.08), P = 0.01]. Consistently, the weighted median method yielded similar results [OR, 1.06 (95% CI, 1.00-1.12), P = 0.02]. The MR-Egger method also demonstrated comparable findings [OR, 1.02 (95% CI, 0.96-1.08), P = 0.45]. Both funnel plots and MR-Egger intercepts indicated no directional pleiotropic effects between IBD and urolithiasis. CD was strongly associated with it in its subtype analysis [OR, 1.04 (95% CI, 1.01-1.07), P = 0.01], and UC was also causally associated with urolithiasis, although the association was not significant [OR, 0.99 (95% CI, 0.95-1.03), P = 0.71].

CONCLUSION

A unidirectional positive causal correlation was identified between IBD and urolithiasis, with varying degrees of association observed among the different subtypes of IBD. Recognizing the increased incidence of urolithiasis in patients with IBD is crucial in clinical practice. Early detection and surveillance of IBD, improved patient awareness, adoption of preventive strategies, and promotion of collaborative efforts among healthcare providers regarding treatment methodologies are vital for improving patient outcomes.

Utility of Dual-Energy Computed Tomography in Clinical Conundra

Advancing medical technology revolutionizes our ability to diagnose various disease processes. Conventional Single-Energy Computed Tomography (SECT) has multiple inherent limitations for providing definite diagnoses in certain clinical contexts. Dual-Energy Computed Tomography (DECT) has been in use since 2006 and has constantly evolved providing various applications to assist radiologists in reaching certain diagnoses SECT is rather unable to identify. DECT may also complement the role of SECT by supporting radiologists to confidently make diagnoses in certain clinically challenging scenarios. In this review article, we briefly describe the principles of X-ray attenuation. We detail principles for DECT and describe multiple systems associated with this technology. We describe various DECT techniques and algorithms including virtual monoenergetic imaging (VMI), virtual non-contrast (VNC) imaging, Iodine quantification techniques including Iodine overlay map (IOM), and two- and three-material decomposition algorithms that can be utilized to demonstrate a multitude of pathologies. Lastly, we provide our readers commentary on examples pertaining to the practical implementation of DECT's diverse techniques in the Gastrointestinal, Genitourinary, Biliary, Musculoskeletal, and Neuroradiology systems.

Prevalence and associated factors for asymptomatic microscopic hematuria in adults in the PERSIAN Guilan cohort study (PGCS)

Although hematuria is not life-threatening, some could be the result of a more severe condition. Our objectives are to report on the prevalence and risk factors of asymptomatic microscopic hematuria (AMH) in the prospective epidemiological research studies of the Iranian adults (PERSIAN) Guilan cohort study (PGCS) population. This cross-sectional study was conducted from 2014 to 2017 and consisted of 10,520 individuals aged 35-70. Data collection was conducted using a questionnaire during a face-to-face interview. The urine analyses (UA) were done up to 2 h after sample collection. Based on a urine microscopy evaluation, AMH is defined as 3 or more red blood cells per high power field (HPF). Simple and multiple logistic regression analysis was conducted to explore factors associated with AMH. The prevalence of AMH in this study was 34.1% and was more prevalent in participants of older ages and female gender as well as those with low educational level, underweight-body mass index (BMI), high physical activity, smoking, alcohol consumption, and kidney stone disease. On the other hand, obesity, opium, and diabetes decreased the likelihood of AMH. The results of the present study shed light on the prevalence and risk factors of AMH and suggested that a significant portion of the study population is affected by AMH. Considering the lack of consensus on a definite clinical guideline for AMH in our country, the results of the present study could be used to design a unit algorithm for screening and therapy of AMH.

A Multicentric Audit to Reevaluate the Guidelines Adherence in Computed Tomography of Kidneys, Ureters, and Bladder (CT-KUB) X-ray Imaging in Jordan

Background With the increasing use of imaging techniques involving ionizing radiation, the area of the body scanned should be restricted to what is required to answer the clinical question. Therefore, this is a retrospective audit that intends to evaluate the presence of overscanning in renal computed tomography (CT) scan images during the process of evaluation for urinary symptoms. Objective This study aims to reduce the unnecessary scan length and exposure to radiation in patients who undergo CT scans for urinary symptoms. Materials and Methods In two months duration, patients from different clinics underwent CT imaging, and the resulting radiographic images were collected and analyzed. Overscanning was defined to be more than 10% of the total scan. Subsequently, the total length of the CT scan was measured which is used to measure the unnecessary overscan above the highest kidney margin as a percentage of the total length. Results Out of the 88 patients who were evaluated, 100% did not meet the guidelines for renal CT imaging and were exposed to a high radiation dose. However, the minimum percentage of overscanned patients was 20-40%. Conclusion A significant number of scans demonstrated surplus overscanning above the highest kidney. Therefore, recognizing the suitable anatomical landmarks for scanning and establishing a follow-up audit are suggested measures to minimize the noxious effects of radiation exposure.

Nonpapillary Prone Endoscopic Combined Intrarenal Surgery (ECIRS): Five-Year Experience and Outcomes from a High-Volume Center

Endoscopic combined intrarenal surgery (ECIRS) provides simultaneous retrograde and percutaneous access to the upper urinary tract. The purpose of this study is to present revised data, tips and tricks, and technique modifications arising from our five-year experience with ECIRS. The data of 62 patients who underwent nonpapillary prone ECIRS from January 2019 to November 2023 were prospectively collected. All cases were performed in the prone position. Inclusion criteria were complex stone cases with stones in multiple calyces requiring either multiple accesses or multiple sessions to achieve stone-free status. Patients' mean age was 54.4 ± 12.39 years, while the mean stone size was 39.03 ± 13.93 mm. The mean operative time was 51.23 ± 17.75 min. Primary and final stone-free rates were 83.8% and 90.3%, respectively. In total, nine patients presented with postoperative complications, which were all Grade II ones. The holmium-YAG laser type during retrograde lithotripsy was associated with significantly shorter operative times compared to the thulium fiber laser. Nonpapillary prone ECIRS is a feasible, safe, and efficient approach for patients with specific stone and anatomy characteristics. The implementation of more, higher-evidence studies is of utmost importance so that safer conclusions can be drawn.

Comprehensive prediction of urolithiasis based on clinical factors, blood chemistry and urinalysis: UROLITHIASIS score

Comprehensive prediction of urolithiasis using available factors obtained in the emergency department may aid in patient-centered diagnostic imaging decisions. This retrospective study analyzed the clinical factors, blood chemistry and urine parameters of patients who underwent nonenhanced urinary computed tomography for suspected urolithiasis. A scoring system was developed from a logistic regression model and was tested using the area under the curve (AUC). The prevalence of urolithiasis and important possible causes in the three risk subgroups were determined. Finally, the scoring model was validated. In the derivation cohort (n = 673), 566 patients were diagnosed with urolithiasis. Age > 35 years, history of urolithiasis, pain duration < 8 h, nausea/vomiting, costovertebral angle tenderness, serum creatinine ≥ 0.92 mg/dL, erythrocytes ≥ 10/high power field, no leukocytes ≤  + , and any crystalluria were retained in the final multivariable model and became part of the score. This scoring model demonstrated good discrimination (AUC 0.808 [95% CI, 0.776-0.837]). In the validation cohort (n = 336), the performance was similar (AUC 0.803 [95% CI, 0.756-0.844]), surpassing that of the STONE score (AUC 0.654 [95% CI, 0.601-0.705], P < 0.001). This scoring model successfully stratified patients according to the probability of urolithiasis. Further validation in various settings is needed.

Value of detected hydronephrosis and hydroureter on ultrasound for detecting a ureteral stone: a retrospective study

To investigate the predictive value of hydronephrosis and hydroureter in the detection of ureteral stones using ultrasound, a total of 366 patients suffering from ureteral stones confirmed by ultrasound, computed tomography (CT) and their follow-up treatments were consecutively collected. All the included patients underwent systematic ultrasound scanning of the kidney and ureter. The hydronephrosis and hydroureter in each patient were measured using a digital caliper. Then, receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff values for hydronephrosis and hydroureter to predict a ureteral stone's location and size. The hydronephrosis, hydroureter, and stone size measurements showed good interobserver agreement (P < 0.001). Using the lower border of the sacroiliac joint as a demarcation point, we found larger widths of hydronephrosis and hydroureter in the proximal ureteral stone group than in the distal ureteral stone group (P < 0.001). Additionally, 10.9 mm and 5.9 mm were identified as optimal cutoff values for predicting a distal position (P < 0.001), with no significant difference in their predictive value (P > 0.05). Similar comparisons between groups based on size stratification revealed no significant difference in hydronephrosis between the > 5 mm group and the ≤ 5 mm group. However, the hydroureter was larger in the > 5 mm group than in the ≤ 5 mm group after identifying 6 mm as the best cutoff (P =0.004). In summary, the ultrasound measurement of hydronephrosis and hydroureter may predict the position and size of a possible ureteral stone in patients with colic symptoms.

Comparison of paravertebral block vs. general anesthesia for percutaneous nephrolithotomy: A retrospective study

Background

General anesthesia is used in the majority of patients undergoing percutaneous nephrolithotomy. To reduce the general anesthesia-related risks and complications, this study evaluated the efficacy and safety of the paravertebral block as a novel and alternative anesthetic method for percutaneous nephrolithotomy.

Methods

This was a retrospective study. A total of 198 patients under percutaneous nephrolithotomy were included. Among them, 76 patients received paravertebral block and 122 received general anesthesia. Patients' characteristics, surgical outcomes, anesthetic outcomes, and perioperative complications and the visual analog scale (VAS) were recorded to evaluate the efficacy and safety of paravertebral block compared with general anesthesia. Intergroup differences of the parameters were analyzed using an independent t-test and χ²-tests appropriate.

Results

Seventy-six patients who underwent paravertebral block completed the surgery successfully, three patients were supplemented with propofol for discomfort during ureteroscopy, and two patients were supplemented with remifentanil for incomplete nerve blockade. Patients who underwent paravertebral block had a higher American Society of Anesthesiologists grade and heart function grade, including patients with contraindications to general anesthesia. Intraoperative and postoperative adverse events and the anesthesia costs were less in patients who underwent paravertebral block. VAS pain scores during the postoperative period in patients who underwent paravertebral block were lower than those in patients who underwent general anesthesia without the use of patient-controlled intravenous analgesia.

Conclusion

In this retrospective study, paravertebral block was found to be effective and safe in providing intraoperative anesthesia for percutaneous nephrolithotomy, and had less adverse events and anesthesia costs. Paravertebral block is an attractive alternative anesthesia for patients at increased risk of comorbidities following general or neuraxial anesthesia.

Urinary stone disease in Syrian children

BACKGROUND

Pediatric urinary stone disease (USD) is a costly medical problem. This study aims to assess the clinical characteristics and outcomes of common and rare causes of pediatric USD.

METHODS

A retrospective descriptive cohort study included all children < 13 years of age with confirmed USD admitted to the Children's University Hospital in Damascus, Syria, from January 2013 to December 2019. The study sample was divided into two groups based on etiologies: common and rare causes groups.

RESULTS

We evaluated 235 patients; 147 of them were males, and the male-to-female ratio was 1.7:1. The common causes group consisted of 203 patients (mean age 3.52 ± 3.66 years) and mainly included metabolic disorders (45.5%) and anatomical abnormalities (22.3%), while the rare causes group included 32 cases (mean age 4.93 ± 4.08 years), 12 patients with uric acid stones (37.5%), 7 patients with cystinuria (21.9%), and primary hyperoxaluria in 5 patients (15.6%). In addition, 39.6% of study patients were born to consanguineous marriages. Sixty-two patients developed AKI, and eleven patients had chronic kidney disease (CKD). Patients with rare causes were more likely to have AKI, CKD, bilateral stones, and recurrent stones (P-value < 0.05). Stone analysis was performed on 83 patients, and the main stone types were calcium oxalate (34.9%), uric acid (14.4%), and struvite stones (12%). Surgery was the most performed treatment in 101 patients (56.7%).

CONCLUSION

Patients with rare causes of pediatric USD are at a higher risk for severe complications and require early diagnosis and management. The high rate of uric acid stones in our society requires further evaluation for possible underlying causes. A higher resolution version of the Graphical abstract is available as Supplementary information.

Physiologically based pharmacokinetic modelling and simulation to predict the plasma concentration profile of schaftoside after oral administration of total flavonoids of Desmodium styracifolium

Introduction: The total flavonoids of Desmodium styracifolium (TFDS) are the flavonoid extracts purified from Desmodii Styracifolii Herba. The capsule of TFDS was approved for the treatment of urolithiasis by NMPA in 2022. Schaftoside is the representative compound of TFDS that possesses antilithic and antioxidant effects. The aim of this study was to develop a physiologically based pharmacokinetic (PBPK) model of schaftoside to simulate its plasma concentration profile in rat and human after oral administration of the total flavonoids of Desmodium styracifolium. Methods: The physiologically based pharmacokinetic model of schaftoside was firstly developed and verified by the pharmacokinetic data in rats following intravenous injection and oral administration of the total flavonoids of Desmodium styracifolium. Then the PBPK model was extrapolated to human with PK-Sim^® software. In order to assess the accuracy of the extrapolation, a preliminary multiple-dose clinical study was performed in four healthy volunteers aged 18-45 years old. The predictive performance of PBPK model was mainly evaluated by visual predictive checks and fold error of C_max and AUC_0-t of schaftoside (the ratio of predicted to observed). Finally, the adult PBPK model was scaled to several subpopulations including elderly and renally impaired patients. Results: Schaftoside underwent poor metabolism in rat and human liver microsomes in vitro, and in vivo it was extensively excreted into urine and bile as an unchanged form. By utilizing literature and experimental data, the PBPK model of schaftoside was well established in rat and human. The predicted plasma concentration profiles of schaftoside were consistent with the corresponding observed data, and the fold error values were within the 2-fold acceptance criterion. No significant pharmacokinetic differences were observed after extrapolation from adult (18-40 years old) to elderly populations (71-80 years) in PK-Sim^®. However, the plasma concentration of schaftoside was predicted to be much higher in renally impaired patients. The maximum steady-state plasma concentrations in patients with chronic kidney disease stage 3, 4 and 5 were 3.41, 12.32 and 23.77 times higher, respectively, than those in healthy people. Conclusion: The established PBPK model of schaftoside provided useful insight for dose selection of the total flavonoids of Desmodium styracifolium in different populations. This study provided a feasible way for the assessment of efficacy and safety of herbal medicines.

Clinical Characteristics and In Silico Analysis of Cystinuria Caused by a Novel SLC3A1 Mutation

Cystinuria is a genetically inherited disorder of renal and intestinal transport, featured as a high concentration of cystine in the urine. Cumulative cystine in urine would cause the formation of kidney stones, which further leads to renal colic and dysfunction. Gene screens have found that mutations in SLC3A1 or SLC7A9 gene are responsible for most cases of cystinuria, for encoding defective cystine transporters. Here, we presented the genotypic and phenotypic characteristics of one unique case of a three-generation Chinese family. The proband developed severe urolithiasis combined with renal damage. The radiography and computed tomography (CT) scan showed calculus in the left pelvic kidney. Postoperative stone analysis revealed that the stones were mainly composed of cystine. Therefore, to explore its pathogenesis, next-generation Whole Exome Sequencing (WES) and Sanger sequencing identify the proband mutated gene of the proband’s family. In this article, we reported novel compound heterozygous mutations (c.818G>A and c.1011G>A) of the SLC3A1 gene in a 5-year-old child suffering from a cystine stone from a three-generation family. Bioinformatic analysis was used to predict the pathogenicity and conservation of the target mutation. Conservative sequence and evolutionary conservation analysis indicated that cystine273 and proline337 were highly conserved among species, and both mutations listed here (Cys273Tyr and Pro337Pro) were pathogenic. To conclude, our study expands the phenotypic and genotypic spectrum of SLC3A1 and indicates that genetic screening should be considered in the clinic to provide more effective and precise treatment for cystinuria.

Opioid Analgesic Use After an Acute Pain Visit: Evidence from a Urolithiasis Patient Cohort

Introduction: Urolithiasis causes severe acute pain and is commonly treated with opioid analgesics in the emergency department (ED). We examined opioid analgesic use after episodes of acute pain. Methods: Using data from a longitudinal trial of ED patients with urolithiasis, we constructed multivariable models to estimate the adjusted probability of opioid analgesic use 3, 7, 30, and 90 days after ED discharge. We used multiple imputation to account for missing data and weighting to account for the propensity to be prescribed an opioid analgesic at ED discharge. We used weighted multivariable regression to compare longitudinal opioid analgesic use for those prescribed vs not prescribed an opioid analgesic at discharge, stratified by reported pain at ED discharge. Results: Among 892 adult ED patients with urolithiasis, 79% were prescribed an opioid analgesic at ED discharge. Regardless of reporting pain at ED discharge, those who were prescribed an opioid analgesic were significantly more likely to report using it one, three, and seven days after the visit in weighted multivariable analysis. Among those who were not prescribed an opioid analgesic, an estimated 21% (not reporting pain at ED discharge) and 30% (reporting pain at discharge) reported opioid analgesic use at day three. Among those prescribed an opioid analgesic, 49% (no pain at discharge) and 52% (with pain at discharge) reported using an opioid analgesic at day three. Conclusion: Urolithiasis patients who received an opioid analgesic at ED discharge were more likely to continue using an opioid analgesic than those who did not receive a prescription at the initial visit, despite the time-limited nature of urolithiasis.

Potential Markers to Reduce Non-Contrast Computed Tomography Use for Symptomatic Patients with Suspected Ureterolithiasis

Most patients with ureterolithiasis are managed successfully with conservative treatment. In this context, delineation of clinical risk factors that identify patients with low risk for surgical intervention may reduce use of Non-Contrast Computed Tomography (NCCT). Here, emergency department patient files from a 14-month period were reviewed retrospectively, to identify patients who underwent NCCT and showed a ureteral stone. Demographic, clinical and laboratory information was collected. Patients were grouped to either requiring surgical intervention (Group 1) or having successful conservative management (Group 2). The cohort included 368 patients; 36.1% ultimately required surgical intervention (Group 1) and 63.9% were successfully treated conservatively (Group 2). On univariate analysis, patients who required surgical intervention were older, had longer duration of symptoms, had history of urolithiasis and surgical intervention for urolithiasis and had higher serum creatinine levels. Multivariate analysis identified the following risk factors associated with surgical intervention: creatinine >1.5 mg/dL, duration of symptoms ≥ 1.5 days and age > 45 years. Patients with 0, 1, 2 or 3 of the identified risk factors had 19%, 32%, 53% and 73% likelihood, respectively, of surgical intervention. Incorporating these data may reduce the use of NCCT scans in patients who are likely to pass a stone via conservative management.

Increased Sulfation in Gracilaria fisheri Sulfated Galactans Enhances Antioxidant and Antiurolithiatic Activities and Protects HK-2 Cell Death Induced by Sodium Oxalate

Urolithiasis is a common urological disease characterized by the presence of a stone anywhere along the urinary tract. The major component of such stones is calcium oxalate, and reactive oxygen species act as an essential mediator of calcium oxalate crystallization. Previous studies have demonstrated the antioxidant and antiurolithiatic activities of sulfated polysaccharides. In this study, native sulfated galactans (N-SGs) with a molecular weight of 217.4 kDa from Gracilaria fisheri were modified to obtain lower molecular weight SG (L-SG) and also subjected to sulfation SG (S-SG). The in vitro antioxidant and antiurolithiatic activities of the modified substances and their ability to protect against sodium oxalate-induced renal tubular (HK-2) cell death were investigated. The results revealed that S-SG showed more pronounced antioxidant activities (DPPH and O₂^- scavenging activities) than those of other compounds. S-SG exhibited the highest antiurolithiatic activity in terms of nucleation and aggregation, as well as crystal morphology and size. Moreover, S-SG showed improved cell survival and increased anti-apoptotic BCL-2 protein in HK-2 cells treated with sodium oxalate. Our findings highlight the potential application of S-SG in the functional food and pharmaceutical industries.

Development and validation of a clinical diagnostic model for pregnant women with renal colic in the emergency department in China: a protocol for a retrospective cohort study

INTRODUCTION

Urolithiasis affects many people throughout their lives. Among the maternal population, although the morbidity of acute urolithiasis in pregnant women is unremarkable, it is the leading cause of hospitalisation during pregnancy. There is no effective clinical diagnostic tool to help doctors diagnose diseases. Our primary aim was to develop and validate a clinical prediction model based on statistical methods to predict the probability of having disease in pregnant women who visited the emergency department because of urolithiasis-induced colic.

METHODS AND ANALYSIS

We will use multivariate logistic regression analysis to build a multivariate regression linear model. A receiver operating characteristic curve plot and calibration plot will be used to measure the discrimination value and calibration value of the model, respectively. We will also use least absolute shrinkage and selection operator regression analysis combined with logistic regression analysis to select predictors and construct the multivariate regression model. The model will be simplified to an application that has been reported before, and users will only need to enter their clinical parameters so that risk probability is automatically derived.

ETHICS AND DISSEMINATION

The review and approval documents of the clinical research ethics committee have been received from the ethics committee of our hospital (The Third Affiliated Hospital of Wenzhou Medical University). We will disseminate research findings through presentations at scientific conferences and publication in peer-reviewed journals.

Is This Your Stone? Distinguishing Phleboliths and Nephroliths on Imaging in the Emergency Department Setting

BACKGROUND

Ureteral stones are a common diagnosis in the emergency department (ED) setting, often found with computed tomography (CT). The high frequency of phleboliths can confound ureteral stone diagnosis on CT imaging.

OBJECTIVE

This article provides a narrative review of the etiological, epidemiological, and radiological distinctions between ureteral stones and phleboliths for appropriate ED diagnosis and management.

DISCUSSION

Multiple studies demonstrate phleboliths, benign calcified thrombi largely in pelvic vasculature, are found at frequencies equal to or greater than those of ureteral stones on CT imaging. The calcified foundation of phleboliths and most ureteral stones, as well as the close proximity of the distal ureters to pelvic vasculature, can cause consternation in the proper diagnosis of ureteral stones in the patient with abdominal pain. Radiological findings of circumferential ureteral soft tissue edema ("rim sign") and an irregular tapering soft tissue mass ("comet tail sign") can suggest a ureteral and phlebolith etiology, respectively. These signs demonstrate high specificity but low sensitivity, and clinicians must use history, examination, and secondary signs on imaging to differentiate ureteral stones from phleboliths.

CONCLUSIONS

Phleboliths are a common finding on CT imaging. Radiological findings of rim sign and comet tail sign may help to differentiate phleboliths and ureteral stones; however, their low sensitivity and inconsistent presentation should prompt greater reliance on other signs of ureteral obstruction to aid in diagnosis of undifferentiated pelvic calcifications.

Predictors of renal infarction in patients presenting to the emergency department with flank pain: A retrospective observational study

Objectives

Flank pain is a common symptom in the emergency department and can be caused by a variety of diseases. Renal infarction (RI) is a very rare disease, and many RI patients complain of flank pain. However, there is no definitive predictor of RI when patients complain of flank pain. This study aimed to identify the clinical factors for predicting RI in patients with flank pain.

Methods

This retrospective single-center study was conducted on patients complaining of flank pain from January 2016 to March 2020 at a South Korean tertiary care hospital. Exclusion criteria included patients who did not undergo contrast-enhanced computed tomography, age < 18 years, and trauma. Demographic and laboratory data were obtained from medical records. Logistic regression analysis was conducted to identify predictors of RI occurrence.

Results

In all, 2,131 patients were enrolled, and 39 (1.8%) had RI. From a multivariable logistic regression analysis, an age ≥ 65 years (odds ratio [OR], 3.249; 95% confidence interval [CI], 1.366–7.725; p = 0.008), male sex (OR, 2.846; 95% CI, 1.190–6.808; p = 0.019), atrial fibrillation (OR, 10.386; 95% CI, 3.724–28.961; p < 0.001), current smoker (OR, 10.022; 95% CI, 4.565–22.001; p < 0.001), and no hematuria (OR, 0.267; 95% CI, 0.114–0.628; p = 0.002) were significantly associated with the occurrence of RI.

Conclusions

Five clinical factors, i.e., age ≥ 65 years, male sex, atrial fibrillation, current smoker, and no hematuria, were significantly associated with the occurrence of RI in patients with flank pain.

Clinical differentiation between acute renal infarction and acute ureteral stone in the emergency department: A single-center retrospective case-control study

BACKGROUND

Few studies have compared renal infarction (RI) and ureteral stone (US), so there is insufficient evidence for emergency clinicians (ECs) to quickly suspect RI during the first assessment. Therefore, we compared the initial clinical presentation and laboratory findings of these diseases in the emergency department (ED) to determine a factor that may indicate RI.

METHODS

This single-center retrospective case-control study included 42 patients with acute RI and 210 with US who visited the ED from 2014 to 2020. Medical record data from first ED arrival were investigated, and clinical presentations, blood and urine test results obtained in the ED were compared and analyzed using logistic regression analysis.

RESULTS

ECs never suspected the initial diagnosis of RI as RI. The most common initial diagnosis was US (40.5%). Among patients with US, 150 patients (71.4%) were suspected of having US (p < 0.001). Abdominal pain (61.9%) was the most common chief complaint in the RI group, and flank pain (73.8%) was the most common in the US group (p < 0.001). 27 factors showed significant differences between the groups. Among those, age ≥ 70 years (odds ratio [OR]: 311.2, 95% confidence interval [CI]: 2.0-47,833.1), history of A-fib (OR: 149872.8, 95% CI: 289.4-7.8E+07), fever ≥37.5 °C (OR: 297.3, 95% CI: 3.3-27,117.8), Cl^- ≤ 103 mEq/L (OR: 9.0, 95% CI: 1.0-80.1), albumin ≤4.3 g/dL (OR: 26.6, 95% CI: 2.1-330.3), LDH ≥500 IU/L (OR: 17.9, 95% CI: 1.8-182.5), and CRP ≥0.23 mg/dL (OR: 7.5, 95% CI: 1.1-52.3) showed significantly high ORs, whereas urine RBCs (OR: 0, 95% CI: 0-0.02) showed a low OR (p < 0.05). The regression model showed good calibration (chi-square: 6.531, p = 0.588) and good discrimination (area under the curve = 0.9913).

CONCLUSIONS

When differentiating acute RI from US in the ED, age ≥ 70 years, history of A-fib, fever ≥37.5 °C, LDH ≥500 IU/L, Cl^- ≤ 103 mEq/L, albumin ≤4.3 g/dL, CRP ≥0.23 mg/dL and negative urine RBC result suggest the possibility of RI.

Factores asociados a complicaciones infecciosas posoperatorias en pacientes con urolitiasis

Introducción Se encuentran múltiples tratamientos para la urolitiasis, los cuales dependen en gran medida del tamaño y la ubicación de la litiasis. Dentro de las opciones terapéuticas se encuentran la expulsión activa, utilización de ondas de choque, las ureterolitotomias, y procedimientos endoscópicos, todas con diferentes tasas de efectividad y riesgo de complicación infecciosa. El objetivo del estudio fue evaluar los factores asociados a la complicación infecciosa posterior al procedimiento urológico en pacientes con urolitiasis.

Métodos Estudio de casos y controles anidado a una cohorte de pacientes programados para procedimientos urológicos como tratamiento para la urolitiasis durante el periodo 2015 - 2019. Se consideraron casos, aquellos con complicación infecciosa posoperatoria dentro de los 30 días posteriores al procedimiento urológico. Los controles se seleccionaron de la cohorte inicial y fueron los pacientes que no presentaron complicación infecciosa.

Resultados En el periodo de estudio, fueron atendidos 350 pacientes con litiasis renal, con un total de 1258 cálculos. El número promedio de cálculos por paciente fue de 3,59; la prevalencia de litiasis bilateral fue del 57%, siendo similar la cantidad de cálculos en el lado izquierdo (promedio = 1,4) y en el derecho (promedio = 1,44).

La tasa de complicación infecciosa posquirúrgica fue del 4% (n= 14) y se asoció con la presencia de al menos un cálculo mayor de 20 mm (OR 4,49 IC95% 1,39–14,52).

Conclusión La tasa de complicación infecciosa posoperatoria en pacientes con urolitiasis y programados para procedimientos urológicos es baja. Una longitud del cálculo mayor de 20 mm es un factor asociado a la infección posoperatoria.

Emergent urinary decompression in acute stone-related urinary obstruction: A systematic review and meta-analysis

Introduction:

Emergent urinary decompression through percutaneous nephrostomy (PCN) or ureteric stent (URS) remains a mainstay in the management of urethral calculi-related obstruction with associated signs of infection or renal injury. Available evidence has shown similar performance, and current guidelines endorse both treatment strategies.

Methods:

A systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analysis criteria up until August 2020. Studies included data on stone size and location, operative time, complications, length of stay, analgesic consumption, quality of life (QoL), and clinical outcomes between URS and PCN.

Results:

Ten studies with a total population of 772, of which 420 were treated with URS and 352 with PCN, were included. No statistical difference in operative time between both techniques was found. Nevertheless, length of stay in PCN was longer than in USR, with a mean difference of −1.87 days ((95% CI −2.69 to −1.06), Z=4.50, p=0.00001). No differences were found in the time to normalization of temperature or white blood cell counts. There were no significant differences in success rates, with an overall odds ratio (OR) of 0.60 ((95% CI 0.26 to −1.40), Z=1.17, p=0.24), or spontaneous passage after emergent drainage between groups. Complication rates ranged from 5% to 25% in URS and from 0% to 38% in PCN. In the studied population, out of the 157 patients from four studies describing complications, only 5% of URS procedures presented complications compared to 2% in PCN, showing a relatively low complication rate for either group (OR=2.07 (95% CI 0.89–4.84), Z=1.68, p=0.09). Differences in QoL were not significant.

Conclusion:

Both methods are equally effective, with no clear advantage for PCN over URS.

Level of evidence:

IV

Transversus abdominis plane block: A new method in renal colic pain management

In recent decades, regional plane blocks via ultrasonography have become very popular in regional anesthesia and are more commonly used in pain management. The transversus abdominis plane (TAP) block is a procedure where local anesthetics are applied to block the anterior divisions of the tenth thoracic intercostal through the first lumbar nerves (T10-L1) into the anatomic space formed amidst the internal oblique and transversus abdominis muscles located in the antero-lateral part of the abdomen wall. The most important advantage of this block method is that ultrasonographic identification is easier and its complications are fewer compared with central neuroaxial or paravertebral blocks. Here, we describe three cases where pain management in renal colic was treated with the TAP block.

Variation in opioid analgesia administration and discharge prescribing for emergency department patients with suspected urolithiasis

OBJECTIVE

Previous research has suggested caution about opioid analgesic usage in the emergency department (ED) setting and raised concerns about variations in prescription opioid analgesic usage, both across institutions and for whom they are prescribed. We examined opioid analgesic usage in ED patients with suspected urolithiasis across fifteen participating hospitals.

METHODS

This is a secondary analysis of a clinical trial including adult ED patients with suspected urolithiasis. In multilevel models accounting for clustering by hospital, we assessed demographic, clinical, state-level, and hospital-level factors associated with opioid analgesic administration during the ED visit and prescription at discharge.

RESULTS

Of 2352 participants, 67% received an opioid analgesic during the ED visit and 61% were prescribed one at discharge. Opioid analgesic usage varied greatly across hospitals, ranging from 46% to 88% (during visit) and 34% to 85% (at discharge). Hispanic patients were less likely than non-Hispanic white patients to receive opioid analgesics during the ED visit (OR 0.72, 95% CI 0.55-0.94). Patients with higher education (OR 1.29, 95% CI 1.05-1.59), health insurance coverage (OR 1.27, 95% CI 1.02-1.60), or receiving care in states with a prescription drug monitoring program (OR 1.64, 95% CI 1.06-2.53) were more likely to receive an opioid analgesic prescription at ED discharge.

CONCLUSION

We found marked hospital-level differences in opioid analgesic administration and prescribing, as well as associations with education, healthcare insurance, and race/ethnicity groups. These data might compel clinicians and hospitals to examine their opioid use practices to ensure it is congruent with accepted medical practice.

Polycyanoacrylate (super glue) as bladder concretion in a patient after bilateral inguinal hernioplasty

A rare case of cyanoacrylate urine bladder urolithiasis in a 60-year-old male is presented. The application of surgical glue (Glubran) as treatment of seroma one month after laparoscopic inguinal hernioplasty led to the instillation of the n-butyl cyanoacrylate into the bladder resulting in the formation of a concretion. Infrared spectroscopy of the urine stone removed by cystoscopic laser lithotripsy four months after the surgery allowed the identification of the nature of the stone and revealed cyanoacrylate as the major component and co-monomer methacryloxy sulfolane as the minor component. Polypropylene from the mesh was not detected.

Evaluation of a child with suspected nephrolithiasis

PURPOSE OF REVIEW

As the incidence of nephrolithiasis in children doubles every 10 years it is becoming a common disease associated with significant morbidity along with considerable economic burden worldwide. The aim of this review is to summarize current data on the epidemiology and causes of renal stones in children and to provide a frame for the first clinical evaluation of a child with suspected nephrolithiasis.

RECENT FINDINGS

Dietary and environmental factors are the driving force of changing epidemiology. Diagnosis should be based on medical history, presenting signs, examination, first laboratory and radiological workup. Ultrasound should be the initial diagnostic imaging performed in pediatric patients while low-dose computed tomography is rarely necessary for management. Metabolic factors including hypercalciuria, hypocitraturia, low fluid intake as well as specific genetic diseases should be explored after the resolution of initial signs and symptoms.

SUMMARY

Appropriate initial evaluation, imaging technique, identification of risk factors and other abnormalities are essential for early diagnosis and prevention of stone-related morbidity in children with suspected nephrolithiasis.

Usefulness of Protocolized Point-of-Care Ultrasonography for Patients with Acute Renal Colic Who Visited Emergency Department: A Randomized Controlled Study

Background and Objectives: Ultrasonography is useful in evaluating patients with renal colic and it has high sensitivity and specificity for diagnosing ureter stones by revealing hydronephrosis. We evaluated the efficacy of point-of-care ultrasonography protocol in managing patients with acute renal colic who visited the emergency department (ED). Materials and Methods: Between March 2019 and July 2019, patients who visited the ED because of renal colic were randomly assigned by date of visit either to the conventional group (CG), who underwent routine diagnostic work-up without ultrasonography, or to the ultrasonography group (UG), who underwent bedside ultrasonography as an initial diagnostic testing. When hydronephrosis was detected in the UG group, a confirmatory non-contrast abdomen computed tomography scan was promptly performed. The ED length of stay, complications, and missed or delayed high-risk diagnosis were evaluated. Results: In total, 128 of 147 analyzed patients were confirmed to have ureter stones. The ED length of stay was significantly lower in the UG group than in the CG group (mean 172 min; 95% confidence interval (CI): 151–194 min vs. mean 234 min; 95% CI: 216–252 min). The medical cost was also remarkably lower in the UG group than in the CG group (259 USD vs. 319 USD; p < 0.001). The incidence of complications within 30 days after visiting ED and missed or delayed high-risk diagnosis were not significantly different between the two groups. Conclusions: We found that protocolized point-of-care ultrasonography in patients with acute renal colic who visited the ED can more effectively reduce the length of stay and medical cost without 30-day complication than usual clinical practice.

Imaging Modalities in Genitourinary Emergencies

Emergency physicians rely on a multitude of different imaging modalities in the diagnosis of genitourinary emergencies. There are many considerations to be taken into account when deciding which imaging modality should be used first, as oftentimes several diagnostic tools can be used for the same pathologic condition. These factors include radiation exposure, sensitivity, specificity, age of patient, availability of resources, cost, and timeliness of completion. In this review, the strengths and weaknesses of different imaging tools in the evaluation of genitourinary emergencies are discussed.

External validation of the CHOKAI score for the prediction of ureteral stones: A multicenter prospective observational study

OBJECTIVE

The CHOKAI and STONE scores are clinical prediction rules to predict ureteral stones in patients presenting with renal colic. Both systems contribute to reducing diagnostic radiation exposure; however, few studies have compared the two scoring systems. Therefore, we aimed to compare these systems and assess their diagnostic accuracy for ureteral stones.

METHODS

This was a multicenter prospective observational study performed between 2017 and 2018, including patients aged >15 years with renal colic and suspected with ureteral stones. We calculated the CHOKAI and STONE scores of each patient based on their medical interviews and physical and laboratory findings. Primary outcome was differences in the area under the receiver operating characteristic curve in each model, and secondary outcome was diagnostic accuracy at the optimal cut-off point.

RESULTS

Of the 124 patients included, 84 were diagnosed with ureteral stones. The area under the curve of the CHOKAI score was 0.95, showing a sensitivity of 0.93, specificity of 0.90, positive likelihood ratio of 9.3, and negative likelihood ratio of 0.079, at an optimal cut-off point of 6. The area under the curve of the STONE score was 0.88, showing a sensitivity of 0.68, specificity of 0.90, positive likelihood ratio of 6.8, and negative likelihood ratio of 0.36, at an optimal cut-off point of 9. Thus, the area under the curve was significantly higher for the CHOKAI score than for the STONE score (p = 0.0028).

CONCLUSIONS

The CHOKAI score has a diagnostic performance superior to that of the STONE score in this population.

The Urological Association of Asia clinical guideline for urinary stone disease

The Urological Association of Asia, consisting of 25 member associations and one affiliated member since its foundation in 1990, has planned to develop Asian guidelines for all urological fields. The field of stone diseases is the third of its guideline projects. Because of the different climates, and social, economic and ethnic environments, the clinical practice for urinary stone diseases widely varies among the Asian countries. The committee members of the Urological Association of Asia on the clinical guidelines for urinary stone disease carried out a surveillance study to better understand the diversity of the treatment strategy among different regions and subsequent systematic literature review through PubMed and MEDLINE database between 1966 and 2017. Levels of evidence and grades of recommendation for each management were decided according to the relevant strategy. Each clinical question and answer were thoroughly reviewed and discussed by all committee members and their colleagues, with suggestions from expert representatives of the American Urological Association and European Association of Urology. However, we focused on the pragmatic care of patients and our own evidence throughout Asia, which included recent surgical trends, such as miniaturized percutaneous nephrolithotomy and endoscopic combined intrarenal surgery. This guideline covers all fields of stone diseases, from etiology to recurrence prevention. Here, we present a short summary of the first version of the guideline - consisting 43 clinical questions - and overview its key practical issues.

α-Blockers for uncomplicated ureteric stones: a clinical practice guideline

OBJECTIVE

To develop an evidence-based recommendation concerning the use of α-blockers for uncomplicated ureteric stones based on an up-to-date Cochrane review, as the role of medical expulsive therapy for uncomplicated ureteric stones remains controversial in the light of new contradictory trial evidence.

METHODS

We applied the Rapid Recommendations approach to guideline development, which represents an innovative approach by an international collaborative network of clinicians, researchers, methodologists and patient representatives seeking to rapidly respond to new, potentially practice-changing evidence with recommendations developed according to standards for trustworthy guidelines.

RESULTS

The panel suggests the use of α-blockers in addition to standard care over standard care alone in patients with uncomplicated ureteric stones (weak recommendation based on low-quality evidence). The panel judged that the net benefit of α-blockers was small and that there was considerable uncertainty about patients' values and preferences. This means that the panel expects that most patients would choose treatment with α-blockers but that a substantial proportion would not. This recommendation applies to both patients in whom the presence of ureteric stones is confirmed by imaging, as well as patients in whom the diagnosis is made based on clinical grounds only.

CONCLUSION

The Rapid Recommendations panel suggests the use of α-blockers for patients with ureteric stones. Shared decision-making is emphasised in making the final choice between the treatment options.