Sensitivity of emergency bedside ultrasound to detect hydronephrosis in patients with computed tomography-proven stones

ACR Appropriateness Criteria® Hydronephrosis on Prior Imaging-Unknown Cause

Initial imaging evaluation of hydronephrosis of unknown etiology is a complex subject and is dependent on clinical context. In asymptomatic patients, it is often best conducted via CT urography (CTU) without and with contrast, MR urography (MRU) without and with contrast, or scintigraphic evaluation with mercaptoacetyltriglycine (MAG3) imaging. For symptomatic patients, CTU without and with contrast, MRU without and with contrast, MAG3 scintigraphy, or ultrasound of the kidneys and bladder with Doppler imaging are all viable initial imaging studies. In asymptomatic pregnant patients, nonionizing imaging with US of the kidneys and bladder with Doppler imaging is preferred. Similarly, in symptomatic pregnant patients, US of the kidneys and bladder with Doppler imaging or MRU without contrast is the imaging study of choice, as both ionizing radiation and gadolinium contrast are avoided in pregnancy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Diagnostic Accuracy of a Handheld Ultrasound vs a Cart-based Model: A Randomized Clinical Trial

Introduction

Numerous studies have demonstrated the accuracy of point-of-care ultrasound (POCUS). Portable, handheld devices have expanded the clinical scope of POCUS at a fraction of the cost of traditional, cart-based models. There is a paucity of data assessing the diagnostic accuracy of portable devices. Our objective in this study was to compare the diagnostic accuracy of a portable device with a cart-based model.

Methods

This was an institutional review board-approved, observational, prospective, randomized clinical trial (NCT05196776) of a convenience sample of adult patients who presented to a university-based health system. Patients who required a cardiac, lung, renal, aorta, or biliary POCUS were randomized to a portable device or to a cart-based model. We hypothesized that the cart-based model would have a 90% diagnostic accuracy vs 70% for the handheld device. To detect a 20% difference, the sample size was calculated to be 98, with 49 patients randomized to each arm. We used standard 2x2 tables to calculate test characteristics with 95% confidence intervals (CI).

Results

A total of 110 patients were enrolled, with 56 patients randomized to the cart-based model and 54 to the handheld device. The sensitivity, specificity, and diagnostic accuracy of the cart-based vs handheld were 77.8% (40-97.2) vs 92.9% (66.1-99.8), 91.5% (79.6-97.6) vs 92.3% (79.1-98.4%), and 89.3% (78.1-96) vs 92.5% (81.8-97.9), respectively.

Conclusion

The diagnostic accuracy of a portable, handheld device is similar to that of a cart-based model.

Test characteristics of point-of-care ultrasonography in patients with acute kidney injury

BACKGROUND

Acute kidney injury is a common disorder that is associated with significant morbidity and mortality. Point-of-care ultrasonography (PoCUS) is an imaging modality performed at the bedside and is used to assess for obstructive causes of acute kidney injury. Little is known about the test characteristics of PoCUS in patients with acute kidney injury.

OBJECTIVE

Our primary objective was to describe the test characteristics of PoCUS for the detection of hydronephrosis in patients presenting with acute kidney injury at our centre. Our secondary objective was to describe the current rate of use of PoCUS for this indication.

RESULTS

In total, 7873 patients were identified between June 1, 2019 and April 30, 2021, with 4611 meeting inclusion criteria. Of these, 94 patients (2%) underwent PoCUS, and 65 patients underwent both PoCUS and reference standard, for a total of 124 kidneys included in our diagnostic accuracy analysis. The prevalence of hydronephrosis in our cohort was 33% (95% CI 25-41%). PoCUS had a sensitivity of 85% (95% CI 71-94%) and specificity of 78% (95% CI 68-87%) for the detection of hydronephrosis.

CONCLUSION

We describe the test characteristics of PoCUS for the detection of hydronephrosis in a cohort of patients with acute kidney injury. The low uptake of this test presents an opportunity for quality improvement work to increase its use for this indication.

Utilization of Point-of-Care Ultrasound as an Imaging Modality in the Emergency Department: A Systematic Review and Meta-Analysis

Point-of-care ultrasound (POCUS) is an imaging modality that has become a fundamental part of clinical care provided in the emergency department (ED). The applications of this tool in the ED have ranged from resuscitation, diagnosis, and therapeutic to procedure guidance. This review aims to summarize the evidence on the use of POCUS for diagnosis and procedure guidance. To achieve this, CrossRef, PubMed, Cochrane Library, Web of Science, and Google Scholar databases were extensively searched for studies published between January 2000 and November 2023. Additionally, the risk of bias assessment was performed using the Quality Assessment of Diagnostic Accuracy Studies 2 (for studies on the diagnostic role of POCUS) and Cochrane Risk of Bias tool (for studies on the use of POCUS for procedure guidance). Furthermore, diagnostic accuracy outcomes were pooled using STATA 16 software (StatCorp., College Station, TX, USA), while outcomes related to procedure guidance were pooled using the Review Manager software. The study included 81 articles (74 evaluating the diagnostic application of POCUS and seven evaluating the use of POCUS in guiding clinical procedures). In our findings sensitivities and specificities for various conditions were as follows: appendicitis, 65% and 89%; hydronephrosis, 82% and 74%; small bowel obstruction, 93% and 82%; cholecystitis, 75% and 96%; retinal detachment, 94% and 91%; abscess, 95% and 85%; foreign bodies, 67% and 97%; clavicle fractures, 93% and 94%; distal forearm fractures, 97% and 94%; metacarpal fractures, 94% and 92%; skull fractures, 91% and 97%; and pleural effusion, 91% and 97%. A subgroup analysis of data from 11 studies also showed that the two-point POCUS has a sensitivity and specificity of 89% and 96%, while the three-point POCUS is 87% sensitive and 92% specific in the diagnosis of deep vein thrombosis. In addition, the analyses showed that ultrasound guidance significantly increases the overall success rate of peripheral venous access (p = 0.02) and significantly reduces the number of skin punctures (p = 0.01) compared to conventional methods. In conclusion, POCUS can be used in the ED to diagnose a wide range of clinical conditions accurately. Furthermore, it can be used to guide peripheral venous access and central venous catheter insertion.

Incidental detection of malignancy on point-of-care renal ultrasound: A case series

Renal point-of-care ultrasound (POCUS) is an increasingly common initial imaging modality in the diagnostic workup of renal colic. The primary use of renal POCUS is to assess for hydronephrosis; however, other significant findings suggestive of malignancy can also be identified. We present three cases of unexpected findings identified initially on POCUS in the emergency department, which subsequently led to new diagnoses of malignancy. As renal POCUS becomes more frequently used in clinical practice, physicians must be able to recognise abnormal images that indicate possible malignancy and the need for further workup.

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.

Evaluation, management, and analysis of demographic and radiological characteristics of patients with renal colic at a tertiary hospital in Somalia

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Renal Colic is a common emergenbcy care complaint worldwide–but its epidemiology and strategies for evaluation and treatment have been little reported in Africa.

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To date, there have been no studies regarding epidemiologic and radiological findings of renal colic in the emergency centre reported from Somalia.

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Ultrasound can be the initial investigation of choice because it is safe, cheap, and may help guide for diagnosis and need for further imaging.

Background

Renal colic is a common emergency centre (EC) complaint worldwide, but its epidemiology and strategies for evaluation and treatment have been little reported in Africa. To the best of our knowledge, this is the first study aimed at evaluating the radiological investigations, management, and analysis of demographic characteristics of patients with urinary system stones who visited the EC.

Method

A 3-year retrospective study of a total of 435 patients with acute renal colic who underwent radiologic investigations was included in this study. The overall positive stone rate, stone location, size, and hydronephrosis grade were assessed. The sensitivity and specificity of ultrasound were evaluated using patients with both an ultrasound and a non-contrast CT (NCCT).

Results

The mean age of the patients was 34.7years; males accounted for 71.3% (n = 310), while females were 28.7% (n = 125). Urolithiasis was found in 63.4% of the cases, 71.3% of males and 28.7% of the females had a stone diagnosis (P < 0001). There was no statistically significant association between age and stone diagnosis (P > 0.05). The sensitivity and specificity of USG were 86.1% and 94%, respectively. Seventy-two percent of the cases had ureteral stones (29% in proximal, 25% in UVJ, 9% in mid, and 9% in distal ureter), followed by 28% having renal stones (19% calyces and 9% in renal pelvis). The mean size of the stone was 5.9±1.8, half of the cases harbour stone size <5mm, followed by 30% in 5mm-1cm.

Conclusion

Due to the scarcity of well-equipped tertiary care hospitals and the low socioeconomic status of the patients living in Sub-Saharan Africa, Ultrasound can be the initial investigation of choice because it is safe, cheap, and may help guide diagnosis and the need for further imaging. However, NCCT remains the gold standard diagnosis of choice for acute flank pain.

Bedside Assessment of the Kidneys and Bladder Using Point of Care Ultrasound

Given the contrasting echogenic characteristics of the urinary system and their easily identifiable distortion in response to numerous pathologic processes, the sonographic examination of the kidney and bladder can provide a wealth of clinical information [1, 2]. Although performed for decades as a referral and comprehensive radiologic study, improvement in the cost and performance of portable ultrasound devices has now made point of care ultrasound (POCUS) accessible to a growing number and variety of healthcare providers. The purpose of this review is to describe the technique and benefits of using POCUS to evaluate the kidneys, ureters, and bladder in common clinical scenarios.

Etiology of Hydronephrosis in adults and children: Ultrasonographic Assessment in 233 patients

Objectives:

Hydronephrosis (HN) is dilatation of the collecting system of the kidney due to obstruction of urine outflow. This study intended firstly, to investigate the efficacy of ultrasound (US) imaging to determine the cause of HN, and secondly, to list the causes of HN.

Methods:

In this retrospective study, 233 patients with HN were scanned to determine the cause of the HN in the period from 1^st January 2016 to 31^st October 2017. Categorical results were written as frequencies and percentages.

Results:

Out of 233, 91.41% were adults and 8.58% were children (P<0.001), 66.10% were male and 33.90% were female (P<0.001). In 55.36%, HN was in the right kidney and 44.64% was in the left (P=0.116). Exactly 58% of patients were suffering from grade-2, 21.5% grade-3, 11.6% grade-1, and 8.2% grade-4 HN. US imaging can determine the cause of HN in 70.4% of patients. Kidney or ureteric calculi were the cause of HN in 54.1% of cases, reflux was in 7.3%, and pelviureteric junction (PUJ) stenosis was in 3.9%.

In cases of calculi induced HN, 25.3% of the calculi were in the vesicoureteric (VUJ) junction, 21.5% were in the renal pelvis, 6.4% were in the PUJ or upper ureter, and only 0.9% were in the middle ureter.

Conclusion:

Ultrasound imaging can determine the cause of HN in more than two thirds of patients. Calculi are the most common cause of HN even in children and are most common in the VUJ junction.

Spontaneous Ureteric Rupture and Its Implications in the Emergency Department: A Case Report

INTRODUCTION

Spontaneous ureteric rupture is uncommon and has a wide range of presentations. Accurate diagnosis and timely treatment is necessary to avoid potential serious complications.

CASE REPORT

We present the case of a 55-year-old female who presented with severe right lower abdominal pain with rebound tenderness, vomiting, and a single episode of hematuria. A computed tomography with intravenous contrast of the abdomen and pelvis showed a 0.3-centimeter right upper ureteric calculus, with hydronephrosis and ureteric rupture. In view of the scan findings, a diagnosis of spontaneous ureteric rupture secondary to urolithiasis was made. The patient underwent a percutaneous nephrostomy and ureteric stenting.

CONCLUSION

Spontaneous rupture of the ureter is an uncommon diagnosis for which clinical and laboratory signs may not always be reliably present. A high index of suspicion is required for diagnosis, which is usually confirmed on advanced imaging. It may occur in serious complications of urinoma and abscess formation. As such, accurate diagnosis and timely treatment is crucial.

POCUS for Nephrologists: Basic Principles and a General Approach

Point-of-care ultrasonography (POCUS) has evolved as a valuable adjunct to physical examination in the recent past and various medical specialties have embraced it. However, POCUS training and scope of practice remain relatively undefined in nephrology. The utility of diagnostic POCUS beyond kidney and vascular access is under-recognized. Assessment of fluid status is a frequent dilemma faced by nephrologists in day-to-day practice where multiorgan POCUS can enhance the sensitivity of conventional physical examination. POCUS also reduces fragmentation of care, facilitates timely diagnosis, and expedites management. Although the need for further imaging studies is obviated in selected patients, POCUS is not meant to serve as an alternative to consultative imaging. In addition, the utility of POCUS depends on the skills and experience of the operator, which in turn depend on the quality of training. In this review, we discuss the rationale behind nephrologists performing POCUS, discuss patient examples to illustrate the basic principles of focused ultrasonography, and share our experience-based opinion about developing a POCUS training program at the institutional level.

Hydronephrosis severity clarifies prognosis and guides management for emergency department patients with acute ureteral colic

OBJECTIVE

In emergency department patients with ureteral colic, the prognostic value of hydronephrosis is unclear. Our goal was to determine whether hydronephrosis can differentiate low-risk patients appropriate for trial of spontaneous passage from those with clinically important stones likely to experience passage failure.

METHODS

We used administrative data and structured chart review to evaluate a consecutive cohort of patients with ureteral stones who had a CT at nine Canadian hospitals in two cities. We used CT, the gold standard for stone imaging, to assess hydronephrosis and stone size. We described classification accuracy of hydronephrosis severity for detecting large (≥ 5 mm) stones. In patients attempting spontaneous passage we used hierarchical Bayesian regression to determine the association of hydronephrosis with passage failure, defined by the need for rescue intervention within 60 days. To illustrate prognostic utility, we reported pre-test probability of passage failure among all eligible patients (without hydronephrosis guidance) to post-test probability of passage failure in each hydronephrosis group.

RESULTS

Of 3251 patients, 70% male and mean age 51, 38% had a large stone, including 23%, 29%, 53% and 72% with absent, mild, moderate and severe hydronephrosis. Passage failure rates were 15%, 20%, 28% and 43% in the respective hydronephrosis categories, and 23% overall. "Absent or mild" hydronephrosis identified a large subset of patients (64%) with low passage failure rates. Moderate hydronephrosis predicted slightly higher, and severe hydronephrosis substantially higher passage failure risk.

CONCLUSIONS

Absent and mild hydronephrosis identify low-risk patients unlikely to experience passage failure, who may be appropriate for trial of spontaneous passage without CT imaging. Moderate hydronephrosis is weakly associated with larger stones but not with significantly greater passage failure. Severe hydronephrosis is an important finding that warrants definitive imaging and referral. Differentiating "moderate-severe" from "absent-mild" hydronephrosis provides risk stratification value. More granular hydronephrosis grading is not prognostically helpful.

Does pain severity predict stone characteristics or outcomes in emergency department patients with acute renal colic?

OBJECTIVES

After initial emergency department (ED) management of acute renal colic, recurrent or ongoing severe pain is the usual pathway to ED revisits, hospitalizations and rescue interventions. If index visit pain severity is associated with stone size or with subsequent failure of conservative management, then it might be useful in identifying patients who would benefit from early definitive imaging or intervention. Our objectives were to determine whether pain severity correlates with stone size, and to evaluate its utility in predicting important outcomes.

METHODS

We used administrative data and structured chart review to study all ED patients with CT proven renal colic at six hospitals in two cities over one-year. Triage nurses recorded arrival numeric rating scale (NRS) pain scores. We excluded patients with missing pain assessments and stratified eligible patients into severe (NRS 8-10) and less-severe pain groups. Stone parameters were abstracted from imaging reports, while hospitalizations and interventions were identified in hospital databases. We determined the classification accuracy of pain severity for stones >5mm and used multivariable regression to determine the association of pain severity with 60-day treatment failure, defined by hospitalization or rescue intervention.

RESULTS

We studied 2206 patients, 68% male, with a mean age of 49 years. Severe pain was 52.0% sensitive and 45.3% specific for larger stones >5mm. After multivariable adjustment, we found a weak negative association (adjusted OR =0.96) between pain severity and stone width. For each unit of increasing pain, the odds of a larger stone fell by 4%. Index visit pain severity was not associated with the need for hospitalization or rescue intervention within 60-days.

CONCLUSIONS

Pain severity is not helpful in predicting stone size or renal colic outcomes. More severe pain does not indicate a larger stone or a worse prognosis.

Point-of-care ultrasound in nephrology

PURPOSE OF REVIEW

The use of POCUS has grown tremendously with the introduction of innovative, easy-to-carry and maneuver hand-held devices. This review focuses on nephrology-centric applications of POCUS that can be incorporated on a daily basis to make impactful and prompt clinical decisions.

RECENT FINDINGS

We review articles covering use of POCUS in the dialysis unit, the Emergency Department, office, and ICU for assessment of volume status, access issues, stones, obstruction, and to help manage patients with AKI, shock, and heart failure.

SUMMARY

POCUS is a welcome addition to our bedside diagnostic armamentarium and has great utility in nephrology. Trials are ongoing in evaluating outcomes with POCUS and physicians' clinical experience using it has been extremely positive.

Is Combined Ultrasound with Radiography Sufficient for the Diagnosis of Obstructive Ureteric Stone in Patients with Acute Flank Pain?

Context

Ultrasound (US) is excellent for detection of hydronephrosis but has poor sensitivity for stone detection. In contrast, radiography of the kidney-ureter-bladder has better sensitivity for detection of stone but limited sensitivity for hydronephrosis detection. A combination of these two modalities may improve both sensitivity and specificity for the diagnosis of obstructive ureteric stone.

Aims

This study aims to investigate the diagnostic accuracy of combined US with radiography for the diagnosis of obstructive ureteric stone in adult patients.

Settings and Design

Retrospective study with retrospective data collection performed in a 1500-bed university hospital.

Materials and Methods

A total of 90 patients were included. The electronic medical record, radiological reports, laboratory results, and patient management were extracted and analyzed.

Statistical Analysis Used

The diagnostic performance of US, radiography, and combined US with radiography were calculated and compared. The computed tomography was used as diagnostic reference.

Results

US alone had a sensitivity of 73.5%, specificity of 92.7%, and negative predictive value (NPV) of 74.5% for hydronephrosis. When US showed both ureteric stone and hydronephrosis, sensitivity dropped to 14.3% but specificity increased to 100%. Radiography alone had a sensitivity of 34.7%, specificity of 100%, and NPV of 56.2% for the detection of ureteric stone. Combining radiography with US raised the sensitivity for diagnosis of obstructive ureteric stone to 88% with a specificity of 93% and accuracy of 90%.

Conclusions

Combined US with radiography was accurate for the diagnosis of obstructive ureteric stone in patients presenting with acute flank pain.

Point-of-care ultrasound for the detection of hydronephrosis in emergency department patients with suspected renal colic

Background

Point-of-care ultrasound (PoCUS) by emergency physicians for renal colic has been proposed as an alternative to computed tomography (CT) to avoid ionizing radiation exposure and shorten emergency department length of stay. Previous studies have employed experienced or credentialed ultrasonographers or required advanced ultrasound skills. We sought to measure the diagnostic accuracy of PoCUS by physicians with varied experience using a simplified binary outcome of presence or absence of hydronephrosis. Secondary outcomes include assessment as to whether the presence of hydronephrosis on PoCUS is predictive of complications, and to evaluate possible causes for the reduced diagnostic accuracy such as body mass index (BMI) and time between PoCUS and formal imaging, and scanner experience.

Results

413 patients were enrolled in the study. PoCUS showed a specificity of 71.8% [95% CI 65.0, 77.9] and sensitivity of 77.1% [95% CI 70.9, 82.6]. Hydronephrosis on PoCUS was predictive of complications (relative risk 3.13; [95% CI 1.30, 7.53]). The time interval between PoCUS and formal imaging, BMI, and scanner experience did not influence the accuracy of PoCUS.

Conclusions

PoCUS for hydronephrosis in suspected renal colic has moderate accuracy when performed by providers with varied experience for the binary outcome of presence or absence of hydronephrosis. Hydronephrosis on PoCUS is associated with increased rates of complications. PoCUS for hydronephrosis is limited in its utility as a stand-alone test, however this inexpensive, readily available test may be useful in conjunction with clinical course to determine which patients would benefit from formal imaging or urologic consultation.

ClinicalTrials.gov Identifier NCT01323842

Portable Ultrasound Device Usage and Learning Outcomes Among Internal Medicine Trainees: A Parallel-Group Randomized Trial

BACKGROUND

Little is known about how to effectively train residents with point-of-care ultrasonography (POCUS) despite increasing usage.

OBJECTIVE

This study aimed to assess whether handheld ultrasound devices (HUDs), alongside a year-long lecture series, improved trainee image interpretation skills with POCUS.

METHODS

Internal medicine intern physicians (N = 149) at a single academic institution from 2016 to 2018 participated in the study. The 2017 interns (n = 47) were randomized 1:1 to receive personal HUDs (n = 24) for patient care vs no-HUDs (n = 23). All 2017 interns received a repeated lecture series regarding cardiac, thoracic, and abdominal POCUS. Interns were assessed on their ability to interpret POCUS images of normal/abnormal findings. The primary outcome was the difference in end-of-the-year assessment scores between interns randomized to receive HUDs vs not. Secondary outcomes included trainee scores after repeating lectures and confidence with POCUS. Intern scores were also compared with historical (2016, N = 50) and contemporaneous (2018, N = 52) controls who received no lectures.

RESULTS

Interns randomized to HUDs did not have significantly higher image interpretation scores (median HUD score: 0.84 vs no-HUD score: 0.84; P = .86). However, HUD interns felt more confident in their abilities. The 2017 cohort had higher scores (median 0.84), compared with the 2016 historical control (median 0.71; P = .001) and 2018 contemporaneous control (median 0.48; P < .001). Assessment scores improved after first-time exposure to the lecture series, while repeated lectures did not improve scores.

CONCLUSIONS

Despite feeling more confident, personalized HUDs did not improve interns' POCUS-related knowledge or interpretive ability. Repeated lecture exposure without further opportunities for deliberate practice may not be beneficial for mastering POCUS.

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.

Diagnostic imaging for acute abdominal pain in an Emergency Department in Italy

Imaging plays a key role in the diagnostic work-up of patients with non-traumatic acute abdominal pain (AAP) in emergency department (ED). We aimed to evaluate the use and diagnostic performance of imaging techniques in adult patients with AAP in an ED in Italy. Patients with non-traumatic AAP admitted at the ED of S. Orsola-Malpighi University Hospital of Bologna (Italy) from the 1st to the 30th November 2016 were included. Demographic and clinical data, data on radiological procedures and discharge diagnosis were collected. Sensitivity and specificity for detecting acute diseases were assessed using the discharge diagnosis from the ED as reference standard. Of the 578 patients (female 52.8%, mean age 51.3 years) admitted to the ED for AAP, 433 (74.9%) underwent abdominal imaging. The most frequent techniques used were abdominal plain radiography and ultrasonography (US), performed in 38.4% and 37.9% of patients, respectively, followed by computed tomography (CT) in 28% of patients. Plain radiography yielded a sensitivity of 28% and specificity of 91.1%; the sensitivity increased to 79.4% in patients with small bowel obstruction. Ultrasonography's sensitivity and specificity were 61.8% and 98.4%, respectively; the sensitivity of US reached 85.2% and 90% in patients with acute cholecystitis/biliary colic and urolithiasis, respectively. The sensitivity and specificity of CT were 87.8% and 92.9%, respectively. Plain radiography is still overused in the diagnostic work-up of AAP in ED in Italy, despite its unsatisfactory sensitivity. Ultrasonography and CT has a higher sensitivity and should be used as first-level imaging in most patients.

Imaging in Suspected Renal Colic: Systematic Review of the Literature and Multispecialty Consensus

BACKGROUND

Renal colic is common, and CT is frequently utilized when the diagnosis of kidney stones is suspected. CT is accurate but exposes patients to ionizing radiation and has not been shown to alter either interventional approaches or hospital admission rates. This multi-organizational transdisciplinary collaboration sought evidence-based, multispecialty consensus on optimal imaging across different clinical scenarios in patients with suspected renal colic in the acute setting.

METHODS

In conjunction with the American College of Emergency Physicians (ACEP) eQual network, we formed a nine-member panel with three physician representatives each from ACEP, the ACR, and the American Urology Association. A systematic literature review was used as the basis for a three-step modified Delphi process to seek consensus on optimal imaging in 29 specific clinical scenarios.

RESULTS

From an initial search yielding 6,337 records, there were 232 relevant articles of acceptable evidence quality to guide the literature summary. At the completion of the Delphi process consensus, agreement was rated as perfect in 15 (52%), excellent in 8 (28%), good in 3 (10%), and moderate in 3 (10%) of the 29 scenarios. There were no scenarios where at least moderate consensus was not reached. CT was recommended in 7 scenarios (24%), with ultrasound in 9 (31%) and no further imaging needed in 12 (45%).

SUMMARY

Evidence and multispecialty consensus support ultrasound or no further imaging in specific clinical scenarios, with reduced-radiation dose CT to be employed when CT is needed in patients with suspected renal colic.

Emergency Physician Interpretation of Point-of-care Ultrasound for Identifying and Grading of Hydronephrosis in Renal Colic Compared With Consensus Interpretation by Emergency Radiologists

OBJECTIVE

The ability of emergency physicians (EPs) to identify hydronephrosis using point-of-care ultrasound (POCUS) has been assessed in the past using computed tomography (CT) scans as the reference standard. We aimed to determine the ability of EPs to identify and grade hydronephrosis on POCUS using the consensus interpretation of POCUS by emergency radiologists as the reference standard.

METHODS

The study was conducted at an urban academic emergency department (ED) as a secondary analysis of previously collected ultrasound data from the EP-performed POCUS databank. Patients were eligible for inclusion if they had both POCUS and CT scanning performed during the index ED visit. Two board-certified emergency radiologists and six EPs interpreted each POCUS study independently. The interpretations were compared with the consensus interpretation by emergency radiologists. Additionally, the POCUS interpretations were also compared with the corresponding CT findings. Institutional approval was obtained for conducting this study. All the analyses were performed using Stata MP 14.0 (StataCorp).

RESULTS

A total of 651 patient image-data sets were eligible for inclusion in this study. Hydronephrosis was reported in 69.6% of POCUS examinations by radiologists and 72.7% of CT scans (p = 0.22). Using the consensus radiology interpretation of POCUS as the reference standard, EPs had an overall sensitivity of 85.7% (95% confidence interval [CI] = 84.3%-87.0%), specificity of 65.9% (95% CI = 63.1%-68.7%), positive likelihood ratio of 2.5 (95% CI = 2.3-2.7), and negative likelihood ratio of 0.22 (95% CI = 0.19-0.24) for hydronephrosis. When using CT scan as the reference standard, the EPs had an overall sensitivity of 81.1% (95% CI = 79.6% to 82.5%), specificity of 59.4% (95% CI = 56.4%-62.5%), positive likelihood ratio of 2.0 (95% CI = 1.8-2.2), and negative likelihood ratio of 0.32 (95% CI = 0.29-0.35) for hydronephrosis. The specificity of EPs was improved to 94.6% (95% CI = 93.7%-95.4%) for categorizing the degree of hydronephrosis as "moderate or severe" versus "none or mild," with positive likelihood ratio of 6.33 (95% CI = 5.3-7.5) and negative likelihood ratio of 0.69 (95% CI = 0.66-0.73).

CONCLUSIONS

Emergency physicians were found to have moderate to high sensitivity for identifying hydronephrosis on POCUS when compared with the consensus interpretation of the same studies by emergency radiologists. These POCUS findings by EPs produced more definitive results when at least moderate degree of hydronephrosis was present.

Association between grades of Hydronephrosis and detection of urinary stones by ultrasound imaging

Objective:

To correlate between hydronephrosis grades and detection of urinary stones by B-mode ultrasound imaging.

Methods:

This study included 210 ultrasound reports of patients who underwent abdominal ultrasound imaging in the period from 1st January 2016 to 31st October 2017, and diagnosed as hydronephrosis. Data collected from the ultrasound reports. The detection rates of stones using B-mode ultrasound imaging compared in different grades of hydronephrosis. Chi-square test and Odds Ratio (OR) were performed to assess the relationship between variables.

Results:

Of 210 patients, hydronephrosis was unilateral in 91.8% of patients and bilateral in 8.1%. It was distributed in grade 2, grade 3, grade 1 and grade 4 in 58.57%, 20%, 12.38% and 9.1% of the patients respectively. B-mode ultrasound imaging determined the cause of hydronephrosis in 65.2% of cases. Urinary stones were the cause in 60% of the patients. The detection rate of urinary stones was 50%, 61% and 71.4% for grades 1, 2 and 3 hydronephroses respectively. On simple logistic regression analysis, urinary stones detected in Grade-3 were four times more compared to that in grade 4 (P=0.016) (OR 4.125, 95% CI 1.29-13.136%).

Conclusion:

Detection of urinary stones as the cause of hydronephrosis increases with increasing the grade of hydronephrosis from Grade-I to Grade-III and decrease in Grade-IV. Urinary stones were the cause of hydronephrosis in 60% of the patients in this study.

The Role of Technology in the Bedside Encounter

Technology has the potential to both distract and reconnect providers with their patients. The widespread adoption of electronic medical records in recent years pulls physicians away from time at the bedside. However, when used in conjunction with patients, technology has the potential to bring patients and physicians together. The increasing use of point-of-care ultrasound by physicians is changing the bedside encounter by allowing for real-time diagnosis with the treating physician. It is a powerful example of the way technology can be a force for refocusing on the bedside encounter.

Ultrasound for the Diagnosis and Management of Suspected Urolithiasis in the Emergency Department

BACKGROUND

This review provides practicing emergency physicians updated information regarding point-of-care ultrasound (POCUS) imaging of patients with suspected urolithiasis.

METHODS

A PubMed literature search was conducted for articles published between January 1, 1996 and May 31, 2017 and limited to human clinical trials written in English with relevant keywords. High-quality studies identified then underwent a structured review. Recommendations herein are made based on the literature review.

RESULTS

Two hundred seventy-two abstracts fulfilling the search criteria were screened and 10 appropriate articles were rigorously reviewed in detail. There were 8 prospective studies and 2 retrospective studies. Only 1 of them was a multi-institutional randomized trial. POCUS performed in the emergency department (ED) is moderately sensitive and specific in making the diagnosis of urolithiasis in symptomatic patients. Suspected urolithiasis patients evaluated initially with ED POCUS have complication rates compatible with those evaluated initially with computed tomography.

CONCLUSIONS

POCUS has moderate accuracy in making the diagnosis of urolithiasis. Nevertheless, it may be safely used as a first line of imaging in ED patients with suspected symptomatic urolithiaisis.

Introduction of a new imaging guideline for suspected renal colic in the ED reduces CT urography utilisation

BACKGROUND

Patients presenting to the ED with suspected renal colic are frequently imaged with CT urography (CTU), which rarely alters diagnosis or management. To reduce use of CTU in this population, we instigated a new imaging and management guideline in our ED.

METHODS

This was a quasi-experimental prospective study, whereby a new guideline was commenced at the intervention site (Monash Medical Centre) and the existing guideline continued at the control site (Dandenong Hospital). The new guideline promotes focused ultrasound for diagnosing renal colic and restricts CT to those with poor response to analgesia or 'red flags'. A consecutive series of patients with suspected renal colic were prospectively enrolled and outcomes compared between the sites. The primary outcome was CTU utilisation and secondary outcomes were radiation exposure, stone rate on CTU, admission, ED length of stay and rates of urological intervention and returns to ED at 4-week follow-up.

RESULTS

Preintervention CTU rates were 76.7% at Monash and 72.1% at Dandenong. 324 patients were enrolled; 148 at Monash and 176 at Dandenong. Median age 47 years vs 49 years, males 76.4% vs 66.5% and medianSex, Timing, Origin, Nausea, Erythrocytes (STONE) score 10 vs 10 for Monash and Dandenong, respectively. CTU was performed in 54.1% vs 75.0% (p<0.001), median radiation exposure 2.8 vs 4.0 mSv (p<0.001) and urological intervention occurred in 16.4% vs 15.7% for Monash and Dandenong, respectively.

CONCLUSIONS

We found that use of CTU for renal colic was significantly reduced by introduction of a guideline promoting ultrasound and encouraging selective CTU. Although intervention rates were similar between the two sites, further prospective study is needed to ensure other patient-centred outcomes do not differ.

Clinical predictors of an abnormal ultrasound in patients presenting with suspected nephrolithiasis

Objective:

To determine any clinical features associated with an abnormal ultrasound in patients with suspected nephrolithiasis in an out-patient setting.

Methods:

The study design was cross-sectional in nature. The study was conducted at an out-patient nephrology department of a tertiary care facility over a 3 month period. Patients included in the study were 18-80 years old, who presented with unilateral flank or costovertebral angle pain with or without other clinical features suggestive of renal or ureteric calculus based on clinician’s judgement. Every patient’s history was reviewed to obtain information on age, gender, location and radiation of pain, onset, severity and nature of pain, associated urinary and systemic symptoms and past history of nephrolithiasis. An ultrasound was considered to be abnormal if there was documented presence of renal or ureteric stone and/or unilateral hydronephrosis.

Results:

A total of 209 patients were included in the study. Of these patients, 126 (60.3%) were males and 83 (39.7%) were females, 60 (28.7%) had prior history of nephrolithiasis. Ultrasound was abnormal in 110 patients (52.9%). On a multivariate logistic regression analysis, only past history of nephrolithiasis (OR 3.3, 95% CI 1.65-6.7) was associated with an abnormal ultrasound.

Conclusion:

In the absence of any significant clinical predictors use of ultrasound is justified in patients with suspected nephrolithiasis especially in those with prior history of stones.

A Comparison of Urolithiasis in the Presence and Absence of Microscopic Hematuria in the Emergency Department

Introduction

Urolithiasis is a common medical condition that accounts for a large number of emergency department (ED) visits each year and contributes significantly to annual healthcare costs. Urinalysis is an important screening test for patients presenting with symptoms suspicious for urolithiasis. At present there is a paucity of medical literature examining the characteristics of ureteral stones in patients who have microscopic hematuria on urinalysis versus those who do not. The purpose of this study was to examine mean ureteral stone size and its relationship to the incidence of clinically significant hydronephrosis in patients with and without microscopic hematuria.

Methods

This is a retrospective chart review of patient visits to a single, tertiary academic medical center ED between July 1, 2008, and August 1, 2013, of patients who underwent non-contrast computed tomography of the abdomen and pelvis and urinalysis. For patient visits meeting inclusion criteria, we compared mean stone size and the rate of moderate-to-severe hydronephrosis found on imaging in patients with and without microscopic hematuria on urinalysis.

Results

Out of a total of 2,370 patient visits 393 (16.6%) met inclusion criteria. Of those, 321 (82%) had microscopic hematuria present on urinalysis. Patient visits without microscopic hematuria had a higher rate of moderate-to-severe hydronephrosis (42%), when compared to patients with microscopic hematuria present (25%, p=.005). Mean ureteral stone size among patient visits without microscopic hematuria was 5.7 mm; it was 4.7 mm for those patients with microscopic hematuria (p=.09). For ureteral stones 5 mm or larger, the incidence of moderate-to-severe hydronephrosis was 49%, whereas for ureteral calculi less than 5 mm in size, the incidence of moderate-to-severe hydronephrosis was 14% (p < 0.0001).

Conclusion

Patients visiting the ED with single-stone ureterolithiasis without microscopic hematuria on urinalysis could be at increased risk of having moderate-to-severe hydronephrosis compared to similar patients presenting with microscopic hematuria on urinalysis. Although the presence of hematuria on urinalysis is a moderately sensitive screening test for urolithiasis, these results suggest patients without hematuria tend to have more clinically significant ureteral calculi, making their detection more important. Clinicians should maintain a high index of suspicion for urolithiasis, even in the absence of hematuria, since ureteral stones in these patients were found to be associated with a higher incidence of obstructive uropathy.

Ultrasound vs. Computed Tomography for Severity of Hydronephrosis and Its Importance in Renal Colic

Introduction

Supporting an “ultrasound-first” approach to evaluating renal colic in the emergency department (ED) remains important for improving patient care and decreasing healthcare costs. Our primary objective was to compare emergency physician (EP) ultrasound to computed tomography (CT) detection of hydronephrosis severity in patients with suspected renal colic. We calculated test characteristics of hydronephrosis on EP-performed ultrasound for detecting ureteral stones or ureteral stone size >5mm. We then analyzed the association of hydronephrosis on EP-performed ultrasound, stone size >5mm, and proximal stone location with 30-day events.

Methods

This was a prospective observational study of ED patients with suspected renal colic undergoing CT. Subjects had an EP-performed ultrasound evaluating for the severity of hydronephrosis. A chart review and follow-up phone call was performed.

Results

We enrolled 302 subjects who had an EP-performed ultrasound. CT and EP ultrasound results were comparable in detecting severity of hydronephrosis (x²=51.7, p<0.001). Hydronephrosis on EP-performed ultrasound was predictive of a ureteral stone on CT (PPV 88%; LR+ 2.91), but lack of hydronephrosis did not rule it out (NPV 65%). Lack of hydronephrosis on EP-performed ultrasound makes larger stone size >5mm less likely (NPV 89%; LR− 0.39). Larger stone size > 5mm was associated with 30-day events (OR 2.30, p=0.03).

Conclusion

Using an ultrasound-first approach to detect hydronephrosis may help physicians identify patients with renal colic. The lack of hydronephrosis on ultrasound makes the presence of a larger ureteral stone less likely. Stone size >5mm may be a useful predictor of 30-day events.

Is Hydronephrosis on Ultrasound Predictive of Ureterolithiasis in Patients with Renal Colic?

PURPOSE

Renal ultrasound accurately identifies hydronephrosis but it is less sensitive than computerized tomography for the detection of ureterolithiasis. We investigated whether the presence of hydronephrosis on ultrasound was associated with a ureteral stone in patients who underwent both ultrasound and computerized tomography during the evaluation of acute renal colic.

MATERIALS AND METHODS

We retrospectively reviewed the records of patients from 3 institutions who were evaluated for acute renal colic by both ultrasound and computerized tomography between 2012 and 2015. Patients were included in analysis if ultrasound and computerized tomography were performed on the same day. The presence of ureterolithiasis, stone location and hydronephrosis was reviewed and compared between imaging modalities.

RESULTS

Ureteral stones were present in 85 of 144 patients. Ultrasound identified hydronephrosis in 89.8% of patients and a ureteral stone in 25.9%. Computerized tomography identified hydronephrosis in 91.8% of patients and a ureteral stone in 98.8%. In 75.0% of cases the presence or absence of hydronephrosis on ultrasound correctly predicted the presence or absence of a ureteral stone on computerized tomography. Hydronephrosis on ultrasound had a positive predictive value of 0.77 for the presence of a ureteral stone and a negative predictive value of 0.71 for the absence of a ureteral stone.

CONCLUSIONS

Hydronephrosis on ultrasound did not accurately predict the presence or absence of a ureteral stone on computerized tomography in 25.0% of the patients in this study. Ultrasound is an important tool for evaluating hydronephrosis associated with renal colic but patients may benefit from other studies to confirm the presence or absence of ureteral stones.

Crossed Fused Renal Ectopia Diagnosed After Discovering an Absent Left Kidney by Point-of-Care Ultrasound

We report an incidental diagnosis of crossed fused renal ectopia diagnosed in a patient initially evaluated with an educational point-of-care ultrasound (US). We review the US technique, sonographic findings, and the relevant literature regarding renal US.

Ultrasonography for the prediction of urological surgical intervention in patients with renal colic

CONTEXT

There are no clear indicators of which ultrasound findings in an emergency department (ED) renal colic population are predictive of urological surgical intervention.

OBJECTIVE

To determine the sonographic findings of renal colic that predict surgical intervention.

METHODS

We conducted a retrospective cohort study of 500 consecutive ED patients with a diagnosis of renal colic that had ultrasonography (performed by radiology) during their ED visit. Our main outcome was urological surgical intervention. This was defined as extracorporeal shock wave lithotripsy, percutaneous nephrostomy or ureteroscopy performed within 16 weeks of the initial ED presentation.

RESULTS

Of the 500 identified patients, 483 met our eligibility criteria. Of this group, 67 (13.9%) received a surgical intervention. Ultrasound (US) findings were 97% (95% CI 88.7% to 99.5%) sensitive and 28.1% (23.9% to 32.8%) specific in 'diagnosing' the requirement for surgery when the ultrasound (US) showed either at least a stone present or showed moderate to severe hydronephrosis. The presence of stone and moderate to severe hydronephrosis had a + likelihood ratio (LR) 3.86 (2.46 to 6.07) and a -LR 0.72 (0.60 to 0.86). Having a stone ≥6 mm had a sensitivity of 77.6% (65.5% to 86.5%), a specificity of 73.6% (69.0% to 77.7%), a +LR of 2.94 (2.39 to 3.6) and a -LR 0.30 (0.19 to 0.48).

CONCLUSIONS

Radiology performed ultrasonography is a valuable tool for identifying renal colic that will go on to receive a surgical intervention in the 16 weeks following an ED visit. Further studies are needed to confirm the utility of ultrasound findings of stone visualisation, stone size and moderate to severe hydronephrosis in determining which patients need outpatient urology follow-up.

Clinician-performed abdominal sonography

INTRODUCTION

Point-of-care ultrasonography is increasingly utilized across a wide variety of physician specialties. This imaging modality can be used to evaluate patients rapidly and accurately for a wide variety of pathologic conditions.

METHODS

A literature search was performed for articles focused on clinician-performed ultrasonography for the diagnosis of appendicitis, gallbladder disease, small bowel obstruction, intussusception, and several types of renal pathology. The findings of this search were summarized including the imaging techniques utilized in these studies.

CONCLUSION

Clinician performed point-of-care sonography is particularly well suited to abdominal applications. Future investigations may further confirm and extend its utility at the bedside.