Diagnostic Accuracy of Point-of-Care Gram Stains in Obstructive Pyelonephritis due to Ureteral Stones

Background

The diagnostic utility of point-of-care (POC) Gram stains for obstructive pyelonephritis with hydronephrosis is not well established. The current study aimed to assess the diagnostic accuracy of urine Gram stains in patients with obstructive pyelonephritis due to ureteral stones.

Methods

A retrospective observational study was conducted on patients with obstructive pyelonephritis admitted to our hospital between January 2011 and December 2021. The diagnostic accuracy of Gram stains was evaluated based on the severity of hydronephrosis, including Gram stains performed by both trained physicians and microbiological technicians.

Results

After analyzing 210 patients, POC Gram stains of bladder urine presented a sensitivity, specificity, positive predictive value, and negative predictive value of 86.8%, 81.8%, 93.7%, and 66.7%, respectively, for gram-negative rods and 65.7%, 83.4%, 48.9%, and 91.0%, respectively, for gram-positive cocci. The agreement between POC Gram stains and urine culture was good for gram-negative rods, with a kappa (κ) coefficient of 0.637 and agreement rate of 85.6%, and moderate for gram-positive cocci, with a κ coefficient of 0.435 and agreement rate of 80%. The agreement between POC Gram stains and bladder urine culture results for gram-negative rods was higher in the mild hydronephrosis group (κ coefficient = 0.677) than in the severe hydronephrosis group (κ coefficient = 0.466). Discrepancies in Gram stain results between physicians and technicians were observed in 21 of 180 cases (11.7%).

Conclusions

POC Gram stains for gram-negative rods may be a useful diagnostic tool for obstructive pyelonephritis, particularly in cases of mild hydronephrosis.

Impact of early ureteral drainage on mortality in obstructive pyelonephritis with urolithiasis: an analysis of the Japanese National Database

BACKGROUND

The impact of early drainage on mortality in patients with obstructive pyelonephritis with urolithiasis was evaluated.

METHODS

We identified 34,924 patients in the Japanese Diagnosis Procedure Combination database with obstructive pyelonephritis with urolithiasis receiving ureteral drainage. The effects of early drainage (1-2 days) compared to those of delayed drainage (on 3-4 and ≥ 5 hospital days) on mortality were evaluated among 31,696 patients hospitalized for ≥ 5 days. Multivariate analysis was performed to identify independent factors for mortality.

RESULTS

The mortality rates for overall cases and those hospitalized for ≥ 5 days were 2.0% and 1.6%, respectively. Those receiving drainage on 1-2, 3-4, and ≥ 5 days had mortality rates of 1.5%, 2.0%, and 2.5%, respectively (p < 0.001). Multivariate analysis revealed that delayed drainage was an independent factor for higher mortality (odds ratio [OR] on days 3-4 and ≥ 5; 1.44, p = 0.018; and 1.69, p < 0.001). Increasing age (OR for 60 s, 70 s, and ≥ 80 years; 2.02, 3.85, and 7.77), Charlson comorbidity index score (OR, 1.41 by 1-point increase), disseminated intravascular coagulation (OR, 2.40), ambulance use (OR, 1.22), impaired consciousness at admission (disoriented, arousable with stimulation, and unarousable; OR 1.58, 2.84, and 5.50), and nephrostomy (OR, 1.65) were associated with higher mortality. In contrast, female sex (OR, 0.76) and high hospital volume (OR on 9-16, and ≥ 17 cases/year; 0.80, and 0.75) were associated with lower mortality.

CONCLUSION

Ureteral drainage within 2 hospital days was an independent factor for low mortality in obstructive pyelonephritis with urolithiasis. Delayed drainage could increase mortality in a time-dependent manner.

Ureteral stone with hydronephrosis and urolithiasis alone are risk factors for acute kidney injury in patients with urinary tract infection

To identify whether urolithiasis with or without hydronephrosis has an impact on acute kidney injury (AKI) in patients with urinary tract infection (UTI). This study aimed to identify whether urolithiasis with or without hydronephrosis has an impact on AKI in patients with UTI. This retrospective study enrolled hospitalized UTI patients who underwent imaging in an acute care setting from January 2006 to April 2019. Of the 1113 participants enrolled, 191 (17.2%) had urolithiasis and 76 (6.8%) had ureteral stone complicated with hydronephrosis. Multivariate logistic regression analysis showed that in UTI patients with urolithiasis, the presence of ureteral stone with concomitant hydronephrosis was an independent risk factor for AKI (odds ratio [OR] 2.299, 95% confidence interval [CI] 1.112–4.755, P = 0.025). In addition, urolithiasis was associated with an increased risk for AKI (OR 2.451, 95% CI 1.369–4.389, P = 0.003) in UTI patients without hydronephrosis. The presence of ureteral stone with hydronephrosis increases the risk for AKI of UTI patients with urolithiasis, and urolithiasis remains a risk factor of AKI in UTI patients without hydronephrosis.

Risk of Urolithiasis in Patients With Inflammatory Bowel Disease: A Nationwide Danish Cohort Study 1977-2018

BACKGROUND AND AIMS

Patients with inflammatory bowel disease (IBD) are suggested to be at increased risk of urolithiasis, but the magnitude of risk and the impact of medical and surgical treatment on this risk remain unknown. We therefore aimed to determine overall and treatment-related risk of urolithiasis in patients with IBD in a nationwide population-based cohort study.

METHODS

Using national registers, we identified all patients with IBD and all cases of urolithiasis in Denmark during 1977-2018. We obtained information on all IBD medications and surgical procedures during 1995-2018. IBD cases were matched 1:10 on age and sex to non-IBD individuals.

RESULTS

In total, 2,549 (3%) of 75,236 IBD patients and 11,258 (2%) of 767,403 non-IBD individuals developed urolithiasis, resulting in a 2-fold increased risk of urolithiasis (HR, 2.27; 95% CI, 2.17-2.38) in patients with IBD. The patients were also at increased risk of repetitive urolithiasis events (RR, 1.09; 95% CI: 1.04-1.15) and had increased risk of urolithiasis prior to IBD diagnosis (OR, 1.42; 95% CI: 1.34-1.50). After IBD diagnosis, risk of urolithiasis was associated with anti-TNF therapy and surgery.

CONCLUSION

Patients with IBD had a 2-fold increased risk of urolithiasis after IBD diagnosis and a 42% increased risk prior to IBD diagnosis. Risk was increased in anti-TNF exposed patients, and after surgery, suggesting that IBD severity per se and surgery, with altered intestinal absorption, increase risk of urolithiasis. Since stone formation is associated with adverse outcomes including sepsis, subpopulations of IBD patients, especially those undergoing strong immunosuppression might benefit from additional urolithiasis screening.

Determinants of pyelonephritis onset in patients with obstructive urolithiasis

BACKGROUND

Acute obstructive pyelonephritis due to urolithiasis represents a medico-surgical emergency that can lead to life-threatening complications. There are still no established factors that reliably predict progression toward acute pyelonephritis in patients presenting with a simple renal colic.

OBJECTIVE

To investigate clinical and paraclinical factors that are associated with the onset of acute obstructive pyelonephritis.

METHODS

Patients presenting to the emergency department for renal colic with obstructive urolithiasis on imaging were enrolled in the study. Demographic data, vital signs, medical comorbidities, blood test results, urinalysis, and radiological findings were recorded. Obstructive pyelonephritis was defined by the presence of two or more of the following criteria: fever, flank pain or costovertebral angle tenderness, and a positive urine culture.

RESULTS

Seventeen patients out of 120 presenting with renal colic, were diagnosed with acute obstructive pyelonephritis (14%). Parameters that were associated with the onset of obstructive pyelonephritis were: diabetes (p = 0.03), elevated CRP (p = 0.01), stone size (>5 mm) (p = 0.03), dilatation of renal pelvis (p = 0.01), peri-renal fat stranding (p = 0.02), and positive nitrites on urinalysis (p < 0.01). Hyperleukocytosis, acute kidney injury, multiple stones, pyuria (>10/mm³), hypertension, and were not associated with the onset of obstructive pyelonephritis.

CONCLUSION

This study showed that known diabetic status, elevated CRP, positive urine nitrites, stone size (>5 mm), pyelic dilatation, and peri-renal fat stranding were associated with the onset of pyelonephritis in patients presenting to the emergency department with obstructive urolithiasis.

Patients' poor performance status is an independent risk factor for urosepsis induced by kidney and ureteral stones

This study was aimed to identify the risk factors for urosepsis caused by kidney and ureteral stones. One hundred and nine patients who had kidney or ureteral stones and who were treated with trans-ureteral lithotripsy (TUL) at our institution from 2016 to 2020 were included. We investigated the risk factors for urosepsis caused by kidney or ureteral stones that occurred prior to TUL. Thirty patients (28%) had urosepsis prior to TUL. Patients were divided into a urosepsis group (n = 30, 28%) and a non-urosepsis group (n = 79, 72%). Patients' characteristics (gender, age, performance status [PS] score, presence of diabetes mellitus, and skeletal muscle mass), as well as their stone and urine characteristics (stone size, presence of obstructive ureteral stones, stone composition, and urine and stone cultures), were compared between the two groups. When compared to the non-urosepsis group, patients with urosepsis were more likely to be older (p < 0.001), female (p < 0.001), with lower skeletal muscle mass (p < 0.001) and with poor PSs (p < 0.001). For stone and urine characteristics, infection stones (p = 0.01), positive urine (p < 0.001) and stone culture (p = 0.007) were more often detected in patients with urosepsis. A multivariate analysis showed patients' poor PS to be an independent risk factor for urosepsis due to kidney and ureteral stones (OR = 15.7; 95% CI = 2.2-115, p = 0.007). Our study revealed that the most significant risk factor for urosepsis caused by kidney and ureteral stones was the patients' poor PS.

Gender differences in acute stone admissions - should we have a lower threshold for treatment in female patients?

OBJECTIVES

To examine the gender-related differences in the presentation, management and outcomes of patients admitted with acute renal colic at our institution.

PATIENTS AND METHODS

A retrospective analysis of 231 consecutive patients requiring inpatient admission for acute renal colic between October 2015 and March 2018. For each admission, data on demographics, admission blood results, stone characteristics, management and outcomes were collected. Differences between genders were compared using the chi-squared and Student's t-test.

RESULTS

Gender distribution was 35% female: 65% male. There was no significant difference in age, American Society of Anesthesiologists Physical Status Classification grade or history of diabetes. Women had a higher admission C-reactive protein level (89.3 vs 32.9 mg/L, P < 0.001) and neutrophil count (10.0 vs 8.8 × 10⁹ /L, P = 0.04) than men. They also had more positive cultures (34.1% vs 6.0%, P < 0.001) and were more likely to require percutaneous nephrostomy insertion (9.8% vs 0.7%, P = 0.005). Women had more intensive therapy unit (ITU) admissions (12.2% vs 0.6%, P < 0.001) and longer lengths of stay (4.4 vs 1.8 days, P < 0.001) than men. There was no mortality in our series.

CONCLUSION

In the present study, women admitted with acute renal colic were more likely to have an associated infection than men and require rapid decompression. Although there was no difference in mortality, women experienced greater morbidity as evidenced by the higher rate of ITU admissions and longer length of stay. These differences are important to consider when assessing the suitability of conservative management for female patients.

Urolithiasis Is a Risk Factor for Uroseptic Shock and Acute Kidney Injury in Patients With Urinary Tract Infection

Urinary tract infection (UTI) is a common complication in patients with urolithiasis. This study aimed to compare clinical manifestations and treatment outcomes among UTI patients with or without urolithiasis. It also focused on identifying relationships among urolithiasis, uroseptic shock, and acute kidney injury (AKI). This retrospective study enrolled hospitalized UTI patients who underwent imaging in an acute care setting from January 2006 to March 2015. Of 662 participants enrolled, 113 (17.1%) had urolithiasis, 107 (16.2%) developed uroseptic shock, and 184 (27.8%) developed AKI. A multivariate logistic regression analysis showed that in UTI patients, urolithiasis is associated with an increased risk of uroseptic shock (OR 1.80, 95% CI: 1.08-3.02, P = 0.025), AKI (OR 1.95, 95% CI: 1.22-3.12, P = 0.005), and bacteremia (OR 1.68, 95% CI: 1.08-2.64, P = 0.022). Urolithiasis is common in UTI patients and is associated with an increased risk of uroseptic shock and AKI.

Create a predictive model for neurogenic bladder patients: upper urinary tract damage predictive nomogram

Objective: To create a nomogram to evaluate the risk of upper urinary tract damage (UUTD) in patients with neurogenic bladder (NGB) Methods: A retrospective analysis was conducted on 301 patients with NGB who were admitted to certain hospitals. Data collected included clinical symptoms, patients' characteristics, laboratory parameters, imaging findings, and urodynamic parameters. The least absolute shrinkage and selection operator（LASSO）regression model was used to optimise the selection of predictors. Multivariate logistic regression analysis was performed to develop a UUTD risk predictive model. Validation was performed by bootstrap. Results: The predictors included in the nomogram included sex, duration of disease, history of UTI, bladder compliance, and fecal incontinence. The model presented good discrimination with a C-index value of 0.796 (95% confidence interval: 0.74896-0.84304) and good calibration. The C-index value of the interval validation was 0.7872112. The results of decision curve analysis (DCA) demonstrated that the UUTD-risk predictive nomogram was clinically useful. Conclusion: The nomogram incorporating the sex, duration of disease, history of UTI, bladder compliance, and fecal incontinence could be an important tool of UUTD risk prediction in NGB patients.