Renal ultrasonography

Acute urinary retention in children: causes and the role of bladder catheterization and ultrasonogram

BACKGROUND

Acute urinary retention in children is uncommon and can be related to several causes. The role of abdominal ultrasound and catheterization is controversial. We aimed to identify the most common causes of acute urinary retention in children, focusing, particularly on the role of bladder catheterization and the diagnostic value of acute ultrasound.

METHODS

We retrospectively analyzed all consecutive children admitted to our emergency department with acute urinary retention from 2010 to 2020. Post-operative acute urinary retention, neonatal age, and known urological or neurological disorders were excluded. Diagnostic workup and management were adopted in each patient. Results were compared in patients with more and less than 5 years old.

RESULTS

193 patients were included. Median age was 3 (2-16) years; 53.4% were girls. Ultrasound evaluation was performed in (129/193; 66.8%) patients, more commonly <5-year-old (74% vs. 26%, P<0.01). A previously unknown urological condition was detected in (16/129; 12%). The majority of patients (124/193; 64%) were managed without bladder catheterization. These patients were significantly younger than the remainder (3- vs. 4-year-old, P<0.01) and the most common diagnosis was external genitalia inflammation (53%). Of the remaining patients, (34/69; 49%) restored spontaneous micturition after a single catheterization, whereas 35 required admission. The latter were more commonly males (32%, P=0.01), with higher incidence of abnormal ultrasound (33% vs. 7%, P<0.001).

CONCLUSIONS

Acute urinary retention in commonly due to external genitalia inflammation, particularly in patients <5-year-old, and can be generally managed, without bladder catheterization. Abdominal ultrasound is an important diagnostic tool, that should be performed only in selected cases.

Prediction of mechanical ventilation outcome by early abdominal-visceral-blood-flow-and-function score in critically ill patients after cardiopulmonary bypass in the ICU: A prospective observational study

Background

Abdominal organs are important organs that sense and respond to ischemia and hypoxia, but there are few evaluation methods.We use ultrasonography to evaluate abdominal organ function and blood flow in patients with mechanical ventilation (MV) after cardiopulmonary bypass and to obtain a semiquantitative score for abdominal organ function and blood flow.

Methods

Patients with cardiopulmonary bypass in the Critical Care Department of Peking Union Medical College Hospital in China from March to July 2021 were enrolled in this prospective observational study. The correlation of the abdominal-visceral-blood-flow-and-function score (AVBFS) with the duration of MV, number of days spent in the intensive care unit (ICU), acute physiology and chronic health evaluation II (APACHE-II), sequential organ failure assessment (SOFA), lactate, epinephrine, and norepinephrine use was analyzed, and the results were used to assess the predictive value of the receiver operating characteristic curve (ROC) regression analysis score for the duration of MV.

Results

Of the 92 patients who underwent cardiopulmonary bypass, 41 were finally included. The AVBFS were significantly correlated with the duration of MV, number of days spent in the ICU, APACHE-II score, SOFA score, and norepinephrine use time. The AVBFS in a group of patients using ventilators ≥36 h were significantly higher than those obtained for a group of patients using ventilators <36 h (P <0.05). The evaluation results for the AVBFS at 0-12 h after ICU admission were as follows: area under the ROC curve (AUC)=0.876 (95% confidence interval [CI]: 0.767 to 0.984), cut-off value=2.5, specificity=0.842, and sensitivity=0.773.

Conclusions

Abdominal visceral organ function and blood perfusion can be used to evaluate gastrointestinal function. It is related to early and late extubation after cardiac surgery.

Kidney segmentation in ultrasound, magnetic resonance and computed tomography images: A systematic review

BACKGROUND AND OBJECTIVE

Segmentation is an essential step in computer-aided diagnosis and treatment planning of kidney diseases. In recent years, several researchers proposed multiple techniques to segment the kidney in medical images from distinct imaging acquisition systems, namely ultrasound, magnetic resonance, and computed tomography. This article aims to present a systematic review of the different methodologies developed for kidney segmentation.

METHODS

With this work, it is intended to analyze and categorize the different kidney segmentation algorithms, establishing a comparison between them and discussing the most appropriate methods for each modality. For that, articles published between 2010 and 2016 were analyzed. The search was performed in Scopus and Web of Science using the expressions "kidney segmentation" and "renal segmentation".

RESULTS

A total of 1528 articles were retrieved from the databases, and 95 articles were selected for this review. After analysis of the selected articles, the reviewed segmentation techniques were categorized according to their theoretical approach.

CONCLUSIONS

Based on the performed analysis, it was possible to identify segmentation approaches based on distinct image processing classes that can be used to accurately segment the kidney in images of different imaging modalities. Nevertheless, further research on kidney segmentation must be conducted to overcome the current drawbacks of the state-of-the-art methods. Moreover, a standardization of the evaluation database and metrics is needed to allow a direct comparison between methods.

An overview of emergency ultrasound in the United States

BACKGROUND

As emergency ultrasound use explodes around the world, it is important to realize the path its development has taken and learn from trials and tribulations of early practitioners in the field.

METHODS

Approaches to education, scanning, documentation, and organization are also described.

RESULTS

Machines have reduced in price and once purchased further material costs are low. Staffing costs in terms of training, etc have yet to be assessed, but indications from elsewhere are that these are low. Length of stay in the emergency department dramatically decreases, thus increasing patient satisfaction while maintaining an even higher standard of care.

CONCLUSION

Emergency screening ultrasound is now a nationally accepted tool for the rapid assessment of the emergency patient.

Imaging modalities in obstetrics and gynecology

The practicing emergency physician often encounters diagnostic dilemmas involving the choice of the most appropriate radiologic study to evaluate patients in the emergency department. In addition, the uncertainty of potentially harmful fetal effects of radiation in the pregnant patient may add unnecessary delay and concern in the workup of obstetric emergencies. An emergency physician's in-depth understanding of the strengths, limitations, and potentially harmful effects of radiologic studies allows the safest and most appropriate studies to be ordered for the gynecologic and obstetric population. With the explosion of interest and growing level of expertise in focused emergency department ultrasonography during the last decade, the practicing emergency physician should add this skill to his or her armamentarium in the future. Many emergency physicians are already comfortable in using radiologic technologies in their daily practice and have discovered how quickly vital and specific information can be obtained.

Bedside ultrasound: a useful tool for the on-call urologist?

OBJECTIVE

To assess the accuracy and benefit of urgent bedside ultrasound scanning in urological emergencies by urology trainees.

METHODS

In this prospective study, 111 patients (86 acute flank pain, 15 renal failure, 10 haematuria) referred as urological emergencies, were scanned for urinary tract abnormalities at the bedside, by a trainee urologist, over 18 months. The ultrasound findings were compared with the results of imaging performed by a consultant radiologist and its influence on clinical management analysed.

RESULTS

Bedside ultrasound proved life saving in 5 patients (2 pyonephrosis, 2 leaking aneurysms, one bilateral ureteric injury). It significantly influenced management in 11 patients, excluded obstruction in the presence of infection.in 13 patients, helped in early diagnosis in 32 patients and ruled out gross urological pathology in 28 patients. It was misleading in 22 patients, mainly with ureteric colic (where the timing of the test can affect the findings), though the outcome was not adversely affected in any. Bedside ultrasound was reasonably accurate (sensitivity 81% and specificity 92%).

CONCLUSIONS

Bedside ultrasound is a useful tool to help the decision-making in urological emergencies and reasonably accurate in hands of a trainee urologist. It is especially helpful for excluding obstruction in presence of infection or renal failure. However it has inherent limitations in assessing acute ureteric colic.

Genitourinary trauma

Injuries to the GU system commonly occur in patients with high-energy lower abdominal or pelvic trauma. The emergency physician should be well versed in the diagnosis and management of GU trauma, although these injuries are not usually life threatening because of the potential for loss of urinary or sexual function. In the setting of hemodynamic instability, diagnosis and treatment of GU injuries is often accomplished in the operative setting. In the stable patient, diagnostic testing is directed by the type of suspected injury and must proceed in a reverse manner, i.e., external injury then urethral injury then bladder, and finally urethral and renal damage. Treatment focuses on a team approach between the emergency physician, general, orthopedic, and urologic surgeon. The decision for operative repair is often dictated more by other associated injuries than urologic injuries, and the urologic surgeon often provides temporizing measures with definitive repair at a later time. Prompt diagnosis and treatment of injuries to the external genitals results in excellent long-term outcome, minimizing the devastating consequences of impotence, urinary incontinence, and sexual disfiguration.

Diagnostic procedures for the urogenital system

In making clinical decisions concerning the urogenital system, the emergency department physician has many different diagnostic tools at his or her disposal. Choosing the appropriate diagnostic study can often be difficult. For well over a thousand years, the initial step in assessing almost any urologic condition has been to examine the urine. Thankfully, this has progressed from a gustatory approach to the modern urinalysis. There is certainly a great deal of information that may be gleaned from the urinalysis, but the physician must also be mindful of its limitations. Overuse of the urinalysis can result in unwanted and unhelpful information. Although IVP is still the study of choice in assessing the functional status of the kidney, the introduction of CT and ultrasound technology to clinical medicine has revolutionized the emergency department assessment of the urogenital tract. CT and ultrasound can help differentiate between the urologic emergencies and the various surgical conditions that can mimic them.

Ultrasonography of flank pain in the emergency department: renal cell carcinoma as a diagnostic concern

Acute flank pain is a common emergency department presenting symptom, and bedside ultrasound is being used increasingly in its evaluation. Emergency renal ultrasonography concentrates on the focused presence or absence of hydronephrosis as is often seen in patients with acute flank pain secondary to renal colic. We present three cases in which other abnormal sonographic signs not commonly taught prompted further investigation, revealing renal cell carcinoma. Baseline knowledge of sonographic characteristics of tumors will benefit the occasional emergency patient who has unsuspected renal carcinoma.

Ultrasonography by emergency physicians in patients with suspected ureteral colic

We performed a prospective study of patients with suspected ureteral colic to evaluate the test characteristics of bedside renal ultrasonography (US) performed by emergency physicians (EPs) for detecting hydronephrosis, and to evaluate how US can be used to predict the likelihood of nephrolithiasis. Thirteen EPs performed US, recorded the presence of hydronephrosis, and made an assessment of the likelihood of nephrolithiasis. All patients underwent i.v. pyelography (IVP) or unenhanced helical computed tomography (CT). There were 126 patients in the study: 84 underwent IVP; 42 underwent helical CT. Test characteristics of bedside US for detecting hydronephrosis were: sensitivity 72%, specificity 73%, positive predictive value (PPV) 85%, negative predictive value (NPV) 54%, accuracy 72%. The PPV and NPV for the ability of the EP to predict nephrolithiasis after performing US were 86% and 75%, respectively. We conclude that bedside US performed by EPs may be used to detect hydronephrosis and help predict the presence of nephrolithiasis.