Validation of emergency physician ultrasound in diagnosing hydronephrosis in ureteric colic

Point-of-care abdominal ultrasound in pediatric and neonatal intensive care units

A spectrum of critical abdominal pathological conditions that might occur in neonates and children warrants real-time point-of-care abdominal ultrasound (abdominal POCUS) assessment. Abdominal radiographs have limited value with low sensitivity and specificity in many cases and have no value in assessing abdominal organ perfusion and microcirculation (Rehan et al. in Clin Pediatr (Phila) 38(11):637-643, 1999). The advantages of abdominal POCUS include that it is non-invasive, easily available, can provide information in real-time, and can guide therapeutic intervention (such as paracentesis and urinary bladder catheterization), making it a crucial tool for use in pediatric and neonatal abdominal emergencies (Martínez Biarge et al. in J Perinat Med 32(2):190-194, 2004) and (Alexander et al. in Arch Dis Child Fetal Neonatal Ed 106(1):F96-103, 2021).  Conclusion: Abdominal POCUS is a dynamic assessment with many ultrasound markers of gut injury by two dimensions (2-D) and color Doppler (CD) compared to the abdominal X-ray; the current evidence supports the superiority of abdominal POCUS over an abdominal X-ray in emergency situations. However, it should still be considered an adjunct rather than replacing abdominal X-rays due to its limitations and operator constraints (Alexander et al. in Arch Dis Child Fetal Neonatal Ed 106(1):F96-103, 2021). What is Known: • Ultrasound is an important modality for the assessment of abdominal pathologies. What is New: • The evidence supports the superiority of abdominal POCUS over an abdominal X-ray in emergency abdominal situations in the neonatal and pediatric intensive care units.

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.

Severe Hydronephrosis Secondary to Ovarian Serous Carcinoma

This case study examines a patient with severe hydronephrosis caused by ureteral obstruction, secondary to ovarian serous carcinoma. Gynecologic malignancies, especially advanced ovarian carcinoma, are common extrinsic causes of obstructive hydronephrosis. Sonography is a valuable modality to visualize the kidneys, diagnose hydronephrosis, and determine the grade of hydronephrosis. The treatment of hydronephrosis aims to remove the build-up of urine, prevent permanent kidney damage, and treat the underlying cause. Prolonged or severe cases of hydronephrosis can lead to acute kidney injury.

Ultrasound at the patient's bedside for the diagnosis and prognostication of a renal colic

Background

Diagnosing a ureteral colic is sometimes difficult; however, clinicians should not fail to detect a surgical emergency. This is why diagnostic strategies depend on the imaging examinations, especially ultrasound. Prior studies have investigated the accuracy of Point of Care Ultrasound (PoCUS), but there are relatively few. This study aimed to evaluate the performance of the PoCUS in the diagnosis of renal colic. The secondary objective was to evaluate the relationship between the imaging results and the treatment performed.

Methods

After the clinical evaluation of patients aged > 18 years with suspected ureteral colic, the Emergency Physician (EP) trained in ultrasound performed PoCUS to conclude whether a diagnosis of “renal colic” should be made. A computed tomography (CT) examination was subsequently performed, to determine whether ureteral or bladder lithiasis was present to diagnose a ureteral colic. The patient’s management was decided according to the to degree of urinary tract dilatation, presence of perinephric fluid, size, and localization of stones.

Results

Of the 12 Eps in our units, seven met the training criteria for the inclusion of patients. A total of 103 patients were analyzed, and the renal colic diagnosis was retained in 85 cases after the CT examination. The accuracy of PoCUS was 91% (86; 95%) for detecting urinary tract dilatation, 83% (76; 90%) for detecting perinephric fluid, and 54% (44; 64%) for detecting lithiasis. Only high urinary tract stones with ≥ 6 mm diameter were surgically managed (p < 0.01). Conversely, distal ureteral stones with a diameter of < 6 mm were managed with medical ambulatory treatment (p < 0.05).

Conclusion

PoCUS is a good diagnostic tool, for renal colic, and could help reduce the requirement for the CT examinations and, hence, reduce induced radiation exposure.

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.

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

Rare Causes of Hydronephrosis in Adults and Diagnosis Algorithm: Analysis of 100 Cases During 15 Years

Introduction Hydronephrosis (HN) is a common pathology that is with/without obstruction. HN should be promptly addressed; otherwise, it progresses to cause impaired kidney function. This study was conducted to define the diagnosis algorithm and poor prognostic parameters used to evaluate unknown HN. Materials and Methods This study enrolled 100 patients who were over 20 years of age and were admitted to the center between 2001 and 2015 for the diagnosis and treatment of HN. Although initial diagnostic tests were applied, the HN etiology of the patients could not be found in ambulatory conditions; therefore, they were hospitalized to seek the causes for their HN. Patients who had a malignancy or tuberculosis or any previous ureteral injury were excluded. Results Of these cases, 29 were on both sides, whereas 42 were on the left side. Despite further investigations, the etiology was not determined in five patients. The frequency of malignancy in patients with hematuria (5/15) was two times higher than in patients without hematuria (33% vs. 17.6%; p = 0.01). Additionally, the malignancy rate was significantly higher in patients with weight loss (100%) than those without weight loss (OR: 6.25; p < 0.001). Conclusions Further investigation is recommended to define the precise etiology of HN. Hematuria and weight loss should be considered poor predictive factors during diagnosis.

Appropriate use of CT for patients presenting with suspected renal colic: a quality improvement study

Introduction

CT use for renal colic has increased costs, radiation exposure and frequently does not alter management. Consequently, choosing wisely (CW) recommends avoiding CT imaging of otherwise healthy patients younger than 50 years presenting with symptoms of recurrent, uncomplicated renal colic. We evaluated the utilisation of CT imaging for this subgroup of patients and subsequently implemented a quality improvement initiative with an aim to reduce unnecessary radiation exposure.

Methods

A retrospective chart review was performed for all patients younger than 50 years who visited Sunnybrook Health Sciences Centre emergency department (ED) between December 2015 and May 2016 with a discharge diagnosis of renal colic. After the audit period, emergency physicians were engaged to perform a root cause analysis and a driver diagram was developed. In December 2016, a clinical decision tool was introduced to standardise the imaging for patients with presumed renal colic. In May 2017, a separate electronic order was created for low-dose CT for renal colic, including a prompt to remind clinicians of the CW recommendation. The impact of these changes was measured over 15 months.

Results

Over the initial audit period, 17/63 (27%) of our target population received a CT to rule out renal colic. Many patients received multiple CT scans for renal colic during past ED visits, while one received a total of 13 CTs. At the time of our interventions, the baseline rate of CT scans in our target population was 37%, which reduced to 29% after our project began.

Conclusion

CT is often used as an initial diagnostic modality for suspected recurrent renal colic despite current guidelines. While this initiative caused only a modest change in management, it led to the introduction of a new low-dose CT scan order specifically to reduce radiation exposure in patients at risk for repeat scans.

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.

Point-of-Care Ultrasound for the Pediatric Hospitalist's Practice

Point-of-care ultrasound (POCUS) has the potential to provide real-time valuable information that could alter diagnosis, treatment, and management practices in pediatric hospital medicine. We review the existing pediatric POCUS literature to identify potential clinical applications within the scope of pediatric hospital medicine. Diagnostic point-of-care applications most relevant to the pediatric hospitalist include lung ultrasound for pneumothorax, pleural effusion, pneumonia, and bronchiolitis; cardiac ultrasound for global cardiac function and hydration status; renal or bladder ultrasound for nephrolithiasis, hydronephrosis, and bladder volumes; soft tissue ultrasound for differentiating cellulitis from abscess; and procedural-guidance applications, including line placement, lumbar puncture, and abscess incision and drainage. We discuss POCUS applications with reviews of major pathologic findings, research gaps, the integration of POCUS into practice, and barriers to implementation.

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.

The Accuracy and Prognostic Value of Point-of-care Ultrasound for Nephrolithiasis in the Emergency Department: A Systematic Review and Meta-analysis

INTRODUCTION

Point-of-care ultrasound (POCUS) has been suggested as an initial investigation in the management of renal colic. Our objectives were: 1) to determine the accuracy of POCUS for the diagnosis of nephrolithiasis and 2) to assess its prognostic value in the management of renal colic.

METHODS

The review protocol was registered to the PROSPERO database (CRD42016035331). An electronic database search of MEDLINE, Embase, and PubMed was conducted utilizing subject headings, keywords, and synonyms that address our research question. Bibliographies of included studies and narrative reviews were manually examined. Studies of adult emergency department patients with renal colic symptoms were included. Any degree of hydronephrosis was considered a positive POCUS finding. Accepted criterion standards were computed tomography evidence of renal stone or hydronephrosis, direct stone visualization, or surgical findings. Screening of abstracts, quality assessment with the QUADAS-2 instrument, and data extraction were performed by two reviewers, with discrepancies resolved by consensus with a third reviewer. Test performance was assessed by pooled sensitivity and specificity, calculated likelihood ratios, and a summary receiver operator curve (SROC). The secondary objective of prognostic value was reported as a narrative summary.

RESULTS

The electronic search yielded 627 unique titles. After relevance screening, 26 papers underwent full-text review, and nine articles met all inclusion criteria. Of these, five high-quality studies (N = 1,773) were included in the meta-analysis for diagnostic accuracy and the remaining yielded data on prognostic value. The pooled results for sensitivity and specificity were 70.2% (95% confidence interval [CI] = 67.1%-73.2%) and 75.4% (95% CI = 72.5%-78.2%), respectively. The calculated positive and negative likelihood ratios were 2.85 and 0.39. The SROC generated did not show evidence of a threshold effect. Two of the studies in the meta-analysis found that the finding of moderate or greater hydronephrosis yielded a specificity of 94.4% (95% CI = 92.7%-95.8%). Four studies examining prognostic value noted a higher likelihood of a large stone when positive POCUS findings were present. The largest randomized trial showed lower cumulative radiation exposure and no increase in adverse events in those who received POCUS investigation as the initial renal colic investigation.

CONCLUSION

Point-of-care ultrasound has modest diagnostic accuracy for diagnosing nephrolithiasis. The finding of moderate or severe hydronephrosis is highly specific for the presence of any stone, and the presence of any hydronephrosis is suggestive of a larger (>5 mm) stone in those presenting with renal colic.

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.

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.

Pediatric emergency medicine point-of-care ultrasound: summary of the evidence

The utility of point-of-care ultrasound is well supported by the medical literature. Consequently, pediatric emergency medicine providers have embraced this technology in everyday practice. Recently, the American Academy of Pediatrics published a policy statement endorsing the use of point-of-care ultrasound by pediatric emergency medicine providers.  To date, there is no standard guideline for the practice of point-of-care ultrasound for this specialty. This document serves as an initial step in the detailed "how to" and description of individual point-of-care ultrasound examinations.  Pediatric emergency medicine providers should refer to this paper as reference for published research, objectives for learners, and standardized reporting guidelines.

Overview of point-of-care abdominal ultrasound in emergency and critical care

Point-of-care abdominal ultrasound (US), which is performed by clinicians at bedside, is increasingly being used to evaluate clinical manifestations, to facilitate accurate diagnoses, and to assist procedures in emergency and critical care. Methods for the assessment of acute abdominal pain with point-of-care US must be developed according to accumulated evidence in each abdominal region. To detect hemoperitoneum, the methodology of a focused assessment with sonography for a trauma examination may also be an option in non-trauma patients. For the assessment of systemic hypoperfusion and renal dysfunction, point-of-care renal Doppler US may be an option. Utilization of point-of-care US is also considered in order to detect abdominal and pelvic lesions. It is particularly useful for the detection of gallstones and the diagnosis of acute cholecystitis. Point-of-case US is justified as the initial imaging modality for the diagnosis of ureterolithiasis and the assessment of pyelonephritis. It can be used with great accuracy to detect the presence of abdominal aortic aneurysm in symptomatic patients. It may also be useful for the diagnoses of digestive tract diseases such as appendicitis, small bowel obstruction, and gastrointestinal perforation. Additionally, point-of-care US can be a modality for assisting procedures. Paracentesis under US guidance has been shown to improve patient care. US appears to be a potential modality to verify the placement of the gastric tube. The estimation of the amount of urine with bladder US can lead to an increased success rate in small children. US-guided catheterization with transrectal pressure appears to be useful in some male patients in whom standard urethral catheterization is difficult. Although a greater accumulation of evidences is needed in some fields, point-of-care abdominal US is a promising modality to improve patient care in emergency and critical care settings.

Point-of-care ultrasonography by pediatric emergency physicians. Policy statement

Point-of-care ultrasonography is increasingly being used to facilitate accurate and timely diagnoses and to guide procedures. It is important for pediatric emergency physicians caring for patients in the emergency department to receive adequate and continued point-of-care ultrasonography training for those indications used in their practice setting. Emergency departments should have credentialing and quality assurance programs. Pediatric emergency medicine fellowships should provide appropriate training to physician trainees. Hospitals should provide privileges to physicians who demonstrate competency in point-of-care ultrasonography. Ongoing research will provide the necessary measures to define the optimal training and competency assessment standards. Requirements for credentialing and hospital privileges will vary and will be specific to individual departments and hospitals. As more physicians are trained and more research is completed, there should be one national standard for credentialing and privileging in point-of-care ultrasonography for pediatric emergency physicians.

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.

Bilateral hydronephrosis and cystitis resulting from chronic ketamine abuse

Ketamine associated urinary dysfunction has become increasingly more common worldwide. Point-of-care ultrasound (POCUS) is an established modality for diagnosing hydronephrosis in the emergency department. We describe a case of a young male ketamine abuser with severe urinary urgency and frequency in which POCUS performed by the emergency physician demonstrated bilateral hydronephrosis and a focally thickened irregular shaped bladder. Emergency physicians should consider using POCUS evaluate for hydronephrosis and bladder changes in ketamine abusers with lower urinary tract symptoms. The mainstay of treatment is discontinuing ketamine abuse.

The utility of renal ultrasonography in the diagnosis of renal colic in emergency department patients

Objective:

Computed tomography (CT) is an imaging modality used to detect renal stones. However, there is concern about the lifetime cumulative radiation exposure attributed to CT. Ultrasonography (US) has been used to diagnose urolithiasis, thereby avoiding radiation exposure. The objective of this study was to determine the ability of US to identify renal colic patients with a low risk of requiring urologic intervention within 90 days of their initial emergency department (ED) visit.

Methods:

We completed a retrospective medical record review for all adult patients who underwent ED-ordered renal US for suspected urolithiasis over a 1-year period. Independent, double data extraction was performed for all imaging reports and US results were categorized as “normal,” “suggestive of ureterolithiasis,” “ureteric stone seen” or “disease unrelated to urolithiasis.” Charts were reviewed to determine how many patients underwent subsequent CT and urologic intervention.

Results:

Of the 817 renal US procedures ordered for suspected urolithiasis during the study period, the results of 352 (43.2%) were classified as normal, and only 2 (0.6%) of these patients required urologic intervention. The results of 177 (21.7%) renal US procedures were suggestive of ureterolithiasis. Of these, 12 (6.8%) patients required urologic intervention. Of the 241 (29.5%) patients who had a ureteric stone seen on US, 15 (6.2%) required urologic intervention. The rate of urologic intervention was significantly lower in those with normal results on US (p &lt; 0.001) than in those with abnormal results on US.

Conclusion:

A normal result on renal US predicts a low likelihood for urologic intervention within 90 days for adult ED patients with suspected urolithiasis.

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.

Effect of provider experience on clinician-performed ultrasonography for hydronephrosis in patients with suspected renal colic

STUDY OBJECTIVE

Hydronephrosis is readily visible on ultrasonography and is a strong predictor of ureteral stones, but ultrasonography is a user-dependent technology and the test characteristics of clinician-performed ultrasonography for hydronephrosis are incompletely characterized, as is the effect of ultrasound fellowship training on predictive accuracy. We seek to determine the test characteristics of ultrasonography for detecting hydronephrosis when performed by clinicians with a wide range of experience under conditions of direct patient care.

METHODS

This was a prospective study of patients presenting to an academic medical center emergency department with suspected renal colic. Before computed tomography (CT) results, an emergency clinician performed bedside ultrasonography, recording the presence and degree of hydronephrosis. CT data were abstracted from the dictated radiology report by an investigator blinded to the bedside ultrasonographic results. Test characteristics of bedside ultrasonography for hydronephrosis were calculated with the CT scan as the reference standard, with test characteristics compared by clinician experience stratified into 4 levels: attending physicians with emergency ultrasound fellowship training, attending physicians without emergency ultrasound fellowship training, ultrasound experienced non-attending physician clinicians (at least 2 weeks of ultrasound training), and ultrasound inexperienced non-attending physician clinicians (physician assistants, nurse practitioners, off-service rotators, and first-year emergency medicine residents with fewer than 2 weeks of ultrasound training).

RESULTS

There were 670 interpretable bedside ultrasonographic tests performed by 144 unique clinicians, 80.9% of which were performed by clinicians directly involved in the care of the patient. On CT, 47.5% of all subjects had hydronephrosis and 47.0% had a ureteral stone. Among all clinicians, ultrasonography had a sensitivity of 72.6% (95% confidence interval [CI] 65.4% to 78.9%), specificity of 73.3% (95% CI 66.1% to 79.4%), positive likelihood ratio of 2.72 (95% CI 2.25 to 3.27), and negative likelihood ratio of 0.37 (95% CI 0.31 to 0.44) for hydronephrosis, using hydronephrosis on CT as the criterion standard. Among attending physicians with fellowship training, ultrasonography had sensitivity of 92.7% (95% CI 83.8% to 96.9%), positive likelihood ratio of 4.97 (95% CI 2.90 to 8.51), and negative likelihood ratio of 0.08 (95% CI 0.03 to 0.23).

CONCLUSION

Overall, ultrasonography performed by emergency clinicians was moderately sensitive and specific for detection of hydronephrosis as seen on CT in patients with suspected renal colic. However, presence or absence of hydronephrosis as determined by emergency physicians with fellowship training in ultrasonography yielded more definitive test results. For clinicians without fellowship training, there was no significant difference between groups in the predictive accuracy of the application according to experience level.

Does computed tomographic scan affect diagnosis and management of patients with suspected renal colic?

BACKGROUND

Patients with renal colic commonly present to the emergency department (ED) and are usually treated with analgesics, antiemetics and hydration. Computed tomographic (CT) scan is commonly utilized in evaluating patients with suspected renal colic.

OBJECTIVES

We compared diagnosis and treatment plans before and after CT in patients with suspected renal colic with the aim to evaluate how often changes in diagnosis, treatment and disposition are made.

METHODS

In this prospective observational study, we enrolled a convenience sample of clinically Stable ED patients older than 17 with suspected renal colic for whom CT was planned. Exclusion criteria were: chronic kidney disease, urinary tract infection, recent CT and history of previous kidney stone. Pre-CT and Post-CT surveys were completed by the treating provider.

RESULTS

The discharge diagnosis was renal colic in 62 of 93 enrolled patients (67%). Urinalysis showed blood in 52 of these patients (84%). CT confirmed obstructing kidney or bladder stone in 50 patients. There were five cases of alternative diagnoses noted on CT scan. After CT scan, 7 patients had changes in disposition. Sixteen providers felt that CT would not change management. In these cases, CT offered no alternative diagnosis and didn't change disposition.

CONCLUSION

CT scan didn't change management when providers did not expect it would. This indicates that providers who are confident with the diagnosis of renal colic should consider forgoing a CT scan. CT scan did occasionally find important alternative diagnoses and should be utilized when providers are considering other concerning pathology.

Accuracy of computed tomography of the kidneys, ureters and bladder interpretation by emergency physicians

OBJECTIVE

The study aims to determine the interpretation accuracy of computed tomography of the kidneys, ureters and bladder (CT-KUB) by emergency physicians (EPs) compared with the formal radiology report, as the reference standard, in patients with suspected acute urinary tract calculous disease.

METHODS

A sample of 20 consecutive CT-KUB scans for suspected acute calculous disease was compiled from the medical imaging department of an adult tertiary teaching hospital. Ten EPs with a minimum of 2 years' experience post-Fellowship interpreted each scan using a template form. The total sample of 200 reports by EPs was compared with the formal radiology report for agreement in detecting renal tract stones, signs of obstruction and other clinical findings. Interrater agreement and the kappa statistic were used for comparative data analysis.

RESULTS

There was a high level of agreement (%, kappa value) between EPs and radiologists for the detection of large (≥5 mm) calculi (94.5%, κ 0.89), signs of obstruction (93%, κ 0.86) and clinically significant findings (90%, κ 0.78). The level of agreement was low for the detection of small (<5 mm) calculi (79%, κ 0.48) and clinically non-significant findings (67.5%, κ 0.33).

CONCLUSION

EPs can accurately detect clinically significant acute calculous disease and signs of obstruction on CT-KUB, allowing for ongoing acute management and early disposition of the patient. However, their findings should be verified against the formal radiology report when available.

Ultrasound detection of obstructive pyelonephritis due to urolithiasis in the ED

Identifying acute pyelonephritis (APN) with early obstructive uropathy is clinically important in the emergency department (ED) because obstructive urolithiasis is an independent risk factor for inpatient death, prolonged hospitalization, and failure of outpatient APN therapy. Furthermore, diagnosis of an early obstructive uropathy can be difficult when based solely on clinical findings. Clinicians may assume the cause of the patient's symptoms to be APN alone, without considering the concurrent presence of an obstructing stone. A feasible screening test to detect early obstructive uropathy in cases of APN has not been previously identified. Plain film radiographs are insensitive in locating a suspected calcified stone. Computed tomography is readily available in most EDs and clearly defines urologic anatomy, but delivers unnecessary ionizing radiation, can prolong ED length of stay, and is not cost-effective as a screening test for all patients diagnosed with APN. We report a case in which a bedside ultrasound identifying hydronephrosis prompted confirmatory computed tomography imaging and emergency consultation of a patient with APN. In this case, hydronephrosis on bedside ultrasound examination was an indirect marker of a distal ureteral obstruction. By detecting the presence of hydronephrosis in patients with APN, emergency physicians may dramatically increase their ability to identify those patients that need further radiographic investigation and ultimately decrease the rate of outpatient treatment failure. Further surveillance data are needed to determine the statistical characteristics of this novel screening test and if routine renal evaluation of all patients with APN is warranted.

Nuclear imaging in the genitourinary tract: recent advances and future directions

For almost three decades, noninvasive radionuclide procedures for the evaluation of renal disease have been important components of nuclear medicine practice. With the introduction of new imaging agents and procedures, these techniques can provide valuable data on perfusion and function of individual kidneys. In general, these procedures are easy to perform and carry a low radiation burden and sedation is not required. Moreover, radionuclide imaging of the genitourinary tract has become an invaluable asset to clinicians in the evaluation of renal parenchyma and urologic abnormalities.