Smartphone-based pathogen diagnosis in urinary sepsis patients

Background

There is an urgent need for rapid, sensitive, and affordable diagnostics for microbial infections at the point-of-care. Although a number of innovative systems have been reported that transform mobile phones into potential diagnostic tools, the translational challenge to clinical diagnostics remains a significant hurdle to overcome.

Methods

A smartphone-based real-time loop-mediated isothermal amplification (smaRT-LAMP) system was developed for pathogen ID in urinary sepsis patients. The free, custom-built mobile phone app allows the phone to serve as a stand-alone device for quantitative diagnostics, allowing the determination of genome copy-number of bacterial pathogens in real time.

Findings

A head-to-head comparative bacterial analysis of urine from sepsis patients revealed that the performance of smaRT-LAMP matched that of clinical diagnostics at the admitting hospital in a fraction of the time (~1 h vs. 18–28 h). Among patients with bacteremic complications of their urinary sepsis, pathogen ID from the urine matched that from the blood – potentially allowing pathogen diagnosis shortly after hospital admission. Additionally, smaRT-LAMP did not exhibit false positives in sepsis patients with clinically negative urine cultures.

Interpretation

The smaRT-LAMP system is effective against diverse Gram-negative and -positive pathogens and biological specimens, costs less than $100 US to fabricate (in addition to the smartphone), and is configurable for the simultaneous detection of multiple pathogens. SmaRT-LAMP thus offers the potential to deliver rapid diagnosis and treatment of urinary tract infections and urinary sepsis with a simple test that can be performed at low cost at the point-of-care.

Fund

National Institutes of Health, Chan-Zuckerberg Biohub, Bill and Melinda Gates Foundation.

Cross-sectional imaging of complicated urinary infections affecting the lower tract and male genital organs

Complicated urinary tract infections (C-UTIs) are those associated with structural or functional genitourinary abnormalities or with conditions that impair the host defence mechanisms, leading to an increased risk of acquiring infection or failing therapy. C-UTIs occur in patients with risk factors such as neurogenic dysfunction, bladder outlet obstruction, obstructive uropathy, bladder catheterisation, urologic instrumentation or indwelling stent, urinary tract post-surgical modifications, chemotherapy- or radiation-induced damage, renal impairment, diabetes and immunodeficiency.

Multidetector CT and MRI allow comprehensive investigation of C-UTIs and systemic infection from an unknown source. Based upon personal experience at a tertiary care hospital focused on the treatment of infectious illnesses, this pictorial essay reviews with examples the clinical features and cross-sectional imaging findings of C-UTIs affecting the lower urinary tract and male genital organs. The disorders presented include acute infectious cystitis, bladder mural abscesses, infections of the prostate and seminal vesicles, acute urethritis and related perineal abscesses, funiculitis, epididymo-orchitis and scrotal abscesses. Emphasis is placed on the possible differential diagnoses of lower C-UTIs.

The aim is to provide radiologists greater familiarity with these potentially severe disorders which frequently require intensive in-hospital antibiotic therapy, percutaneous drainage or surgery.

Teaching Points

• Complicated urinary tract infections occur in patients with structural or functional risk factors.

• CT and MRI comprehensively investigate complicated urinary infections and sepsis from unknown sources.

• Infections of the urinary bladder, prostate, seminal vesicles, urethra and scrotum are presented.

• Emphasis is placed on differential diagnoses of complicated lower urogenital infections.

• Unsuspected urinary infections may be detected on CT performed for other clinical reasons.

[Mortality predictive factors in patients with urinary sepsis associated to upper urinary tract calculi]

PURPOSE

The aims of this study were to determine the clinical characteristics of patients with urinary sepsis associated to ureteral calculi admitted to the Intensive Care Unit (ICU), and to identify predictors of mortality in the first 24 hours of admission.

DESIGN

A retrospective observational study covering a 16-year period (2006-2011) was carried out.

SETTING

The combined clinical/surgical ICU of a secondary-level University hospital.

PATIENTS

All patients admitted to the ICU due to obstructive urinary sepsis.

INTERVENTIONS

None.

MAIN VARIABLES

We analyzed general clinical and laboratory test and urological data. The diagnostic technique, affected side, decompression technique, isolated microorganism and antibiotic therapy used were also considered. The assessment of risk factors was performed by multiple logistic regression analysis.

RESULTS

A total of 107 patients admitted to the ICU were included in the study, with a mortality rate of 19.6%. The diagnosis was mainly established by ultrasound, and the most commonly used decompression technique was retrograde JJ stenting. Microorganisms were isolated in 48.6% of the patients. In total, 20.6% of the patients had bacteremia. Multivariate analysis found age, acute renal failure and the use of vasoactive drugs administered continuously for the first 24 hours of admission to be independently associated to mortality.

CONCLUSIONS

Advanced age, acute renal failure and the need for vasoactive drugs were associated to an increased risk of mortality in patients with urinary sepsis associated to upper urinary tract calculi.

Risk factors of concurrent urinary sepsis in patients with diabetes mellitus comorbid with upper urinary tract calculi

BACKGROUND

Urinary sepsis is frequently seen in patients with diabetes mellitus (DM) complicated with upper urinary tract calculi (UUTCs). Currently, the known risk factors of urinary sepsis are not uniform.

AIM

To analyze the risk factors of concurrent urinary sepsis in patients with DM complicated with UUTCs by logistic regression.

METHODS

We retrospectively analyzed 384 patients with DM complicated with UUTCs treated in People's Hospital of Jincheng between February 2018 and May 2022. The patients were screened according to the inclusion and exclusion criteria, and 204 patients were enrolled. The patients were assigned to an occurrence group (n = 78) and a nonoccurrence group (n = 126). Logistic regression was adopted to analyze the risk factors for urinary sepsis, and a risk prediction model was established.

RESULTS

Gender, age, history of lumbago and abdominal pain, operation time, urine leukocytes (U-LEU) and urine glucose (U-GLU) were independent risk factors for patients with concurrent urinary sepsis (P < 0.05). Risk score = 0.794 × gender + 0.941 × age + 0.901 × history of lumbago and abdominal pain - 1.071 × operation time + 1.972 × U-LEU + 1.541 × U-GLU. The occurrence group had notably higher risk scores than the nonoccurrence group (P < 0.0001). The area under the curve of risk score for forecasting concurrent urinary sepsis in patients was 0.801, with specificity of 73.07%, sensitivity of 79.36% and Youden index of 52.44%.

CONCLUSION

Sex, age, history of lumbar and abdominal pain, operation time, ULEU and UGLU are independent risk factors for urogenic sepsis in diabetic patients with UUTC.

Construction and validation of the nomogram predictive model for post-percutaneous nephrolithotomy urinary sepsis

OBJECTIVE

This study aimed to construct and validate a simple and accurate clinical nomogram for predicting the occurrence of post-percutaneous nephrolithotomy sepsis, aiming to assist urologists in the early identification, warning, and early intervention of urosepsis, and to provide certain evidence-based medicine basis.

METHODS

This study included patients who underwent PCNL surgery due to kidney or upper ureteral stones at the Department of Urology, Affiliated Hospital of Zunyi Medical University, from January 2019 to September 2022. This study utilized univariate and multivariate logistic regression analysis to screen and evaluate the risk factors for sepsis and construct a predictive model. An evaluation was performed using the receiver operating characteristic curve, calibration curve, and decision curve analysis curve. All statistical analyses were conducted using R version 4.2.

RESULTS

A total of 946 patients who underwent post-PCNL were included in this study, among whom 69 patients (7.29%) developed post-PCNL urinary sepsis. Multiple-factor logistic regression analysis identified four independent risk factors associated with post-PCNL urinary sepsis, including positive urinary nitrite (OR = 5.9, P < 0.001), positive urine culture (OR = 7.54, P < 0.001), operative time ≥ 120 min (OR = 20.93, P = 0.0052), and stone size ≥ 30 mm (OR = 13.81, P = 0.0015). The nomogram model demonstrated good accuracy with an AUC value of 0.909, and in the validation cohort, the AUC value was 0.922. The calibration curve indicated a better consistency between the predictive line chart and the actual occurrence of post-PCNL urinary sepsis. The decision curve analysis curve showed favorable clinical utility.

CONCLUSION

Preoperative positive urine culture, positive urinary nitrite, operative time ≥ 120 min, and stone size ≥ 30 mm are independent risk factors for developing post-PCNL urinary sepsis. The constructed line chart based on these factors effectively assesses the risk of urinary sepsis in patients after PCNL.

[Emergency nephrectomies: retrospective monocentric study, about eight cases]

OBJECTIVE

Emergency nephrectomies are rare because of the improvement of the management of urinary tract infections and the development of radio-embolization. Few series of patients have been reported. The objective of our study is to assess the indication, the morbi-mortality and the outcome of the emergency nephrectomy performed in our hospital.

PATIENTS

Between January 2011 and November 2012, eight patients underwent an emergency nephrectomy at the University Hospital Center of Caen. The present review reports the characteristics of this emergency nephrectomy and their morbi-mortality.

RESULTS

Six women and two men were analyzed retrospectively between January 2011 and November 2012. All patients except one needed intensive care for a multiple-organ failure. All these eight emergency nephrectomies concerned a native kidney with a surgical approach as a lombotomy or subcostal laparotomy. Both patients survived. One patient need a renal dialysis support.

CONCLUSION

Emergency nephrectomy are rare. Uncontrolled urinary sepsis represents the main indication. Identifying the population at risk of evolution to the toxic shock is indispensable for a better and faster care and to reduce the mortality bound to the sepsis.