Prospective validation of a current algorithm including bedside US performed by emergency physicians for patients with acute flank pain suspected for renal colic

Point-of-care ultrasound associated with shorter length of stay than computed tomography for renal colic

BACKGROUND

Despite similar diagnostic effectiveness for renal colic, computed tomography (CT) is more resource intensive than point-of-care ultrasound (PoCUS). We sought to compare Emergency Department (ED) length of stay (LOS) among patients with renal colic according to imaging modality utilized. We secondarily compared rates of infection, return ED visits, missed significant pathology, and urologic intervention.

METHODS

This was a 12-month (1/1/22-12/31/22) multi-site retrospective cohort study of all patients diagnosed with renal colic who presented to the ED on days when at least one patient had a billable renal PoCUS examination performed. Patients with a history of genitourinary malignancy, pregnancy, renal transplant, hemodialysis, single kidney, prior visit for renal colic in the previous 30 days, or an incomplete workup were excluded. Median ED LOS was compared using a Wilcoxon rank sum test, and the 95% confidence limits for the difference between medians was calculated. Secondary outcomes were compared using a Fisher's Exact test.

RESULTS

Of 415 patients screened, 325 were included for analysis: 150 had CT alone, 80 had PoCUS alone, 54 had PoCUS plus CT, and 41 had neither. Median LOS for PoCUS alone was 75.0 (95% CI 39.3-110.7) minutes shorter than CT alone (231.5 vs. 307.0 min, p < 0.0001). Similar rates of infection, return visits, and missed pathology occurred across all groups (p > 0.10). Urologic interventions were higher in the PoCUS plus CT (25.9%) group compared to CT alone (7.3%), PoCUS alone (2.5%), and neither (7.3%), p < 0.0001.

CONCLUSION

Among patients with renal colic, PoCUS was associated with shorter ED LOS compared to CT, without differences in infection rates, return visits, or missed pathology. Patients with PoCUS plus CT had a higher rate of urologic interventions, suggesting PoCUS may have a role in identifying patients who would most benefit from CT.

Elderly patients with non-specific complaints at the emergency department have a high risk for admission and 30-days mortality

BACKGROUND

Older adults have complex medical needs that causes increased use of resources at the emergency department (ED). The prevalence of non-specific complaint (NSC) as a chief-complaint in the ED is common among older adults and is not prioritized even though possibly having worse clinical outcome. The objective was to study hospital admission and mortality for older adults visiting the ED with NSC compared to specific complaints such as dyspnea, chest pain and abdominal pain.

METHODS

A retrospective observational study of older adults visiting the ED with NSC and specific complaints; dyspnea, chest pain and abdominal pain was performed. Chief-complaint were collected from electronic medical records. Fatigue, confusion, non-specific complaints, generalized weakness and risk of falling were defined as non-specific complaint (NSC) when registered as chief-complaint at the ED. Admission rate and 30-days mortality were the primary outcomes.

RESULTS

A total of 4927 patients were included in the study based on chief-complaint; patients with chest pain 1599 (32%), dyspnea 1343 (27%), abdominal pain 1460 (30%) and NSC 525 (11%). Patients with dyspnea and NSC had the highest hospital admission rate 79% vs 70% compared to patients with chest pain (63%) and abdominal pain (61%) (p =  < 0.001). Patients with NSC had a mean LOS 4.7 h at the ED which was significantly higher compared to chest pain, dyspnea and abdominal pain. Mean bed-days for the whole population was 4.2 days compared to patients with NSC who had a mean LOS of 5.6 days. NSC and dyspnea were both associated with the highest 30-day mortality.

CONCLUSION

Older patients who present with NSC at the ED are associated with a high risk for admission and 30-days mortality. In addition, patients with NSC have a longer LOS at the ED, a high admission rate and the highest number of bed-days once admitted. This study indicates that ED staff should be more vigilant when an elderly patient presents with NSC at the ED. Further studies and guidelines are needed to improve the management of these individuals.

The 2023 Core Content of advanced emergency medicine ultrasonography

In February 2023, the American Board of Emergency Medicine (ABEM) approved modifications to the Advanced Emergency Medicine Ultrasonography (AEMUS) Core Content, which defines the areas of knowledge considered essential for the practice of AEMUS. This manuscript serves as a revision of the AEMUS Core Content originally published in 2014. The revision of the Core Content for AEMUS training aims to establish standardized education and qualifications necessary for AEMUS fellowship program leadership, clinical application, administration, quality improvement, and research. The Core Content provides the organizational framework and serves as the basis for the development of content for the Focused Practice Examination (FPE) administered by ABEM. AEMUS fellowship directors may reference the Core Content when designing AEMUS fellowship curricula to help prepare graduates for the autonomous practice of AEMUS and the FPE. In this article, an updated revision of the previously published AEMUS Core Content is detailed, and the entire development of the Core Content is presented.

Evaluation of the usefulness of costovertebral angle tenderness in patients with suspected ureteral stone

Background

The usefulness of costovertebral angle (CVA) tenderness for the diagnosis of a suspected ureteral stone remains controversial.

Methods

This single-center, retrospective, observational study included patients aged 16-64 years with acute-onset unilateral lower back pain or abdominal pain. The diagnostic accuracy of CVA tenderness was investigated.

Results

In total, 132 patients met the criteria; 80 were diagnosed with ureteral stones. The sensitivity and specificity of CVA tenderness were 0.65 and 0.50, respectively; positive and negative likelihood ratios were 1.3 and 0.7, respectively.

Conclusions

CVA tenderness cannot be used as a single diagnostic indicator to confirm or exclude ureteral stone diagnosis.

Diagnostic Accuracy of Point-of-Care Ultrasound Integrated into Clinical Examination for Acute Diverticulitis: A Prospective Multicenter Study

PURPOSE

 Diverticulitis is a common cause of abdominal pain and CT scan is commonly used for its diagnosis in the emergency department (ED). The diagnostic performance of point-of-care ultrasound (POCUS) integrated into a clinical exam for diverticulitis is still not established. We evaluate the accuracy of clinical-sonographic assessment for the diagnosis of diverticulitis and whether POCUS could improve the selection of patients needing CT scan for complicated diverticulitis.

MATERIALS AND METHODS

 This is a multicentric observational study involving adult patients suspected of having diverticulitis presenting at 4 EDs. 21 sonographer physicians were asked to diagnose diverticulitis and complicated diverticulitis based on clinical-sonographic assessment. The final diagnosis was established by two reviewers, blinded to POCUS, based on data collected during the one-month follow-up comprehensive CT scan.

RESULTS

 Among 393 enrolled patients, 218 (55.5 %) were diagnosed with diverticulitis and 33 (8 %) had complicated diverticulitis. The time to diagnosis by the sonographer physicians was shorter compared to standard care (97 ± 102 vs. 330 ± 319 minutes, p < 0.001). Clinical-sonographic assessment showed optimal sensitivity (92.7 %) and specificity (90.9 %) for diverticulitis. However, the sensitivity (50 %) for complicated diverticulitis was low. The sonographer physician would have proceeded to CT scan in 194 (49.4 %) patients and the CT scan request compared to the final diagnosis of complicated diverticulitis demonstrated 94 % sensitivity.

CONCLUSION

 Clinical-sonographic assessment is rapid and accurate for the diagnosis of diverticulitis. Even if POCUS has low sensitivity for complicated diverticulitis, it can be used to safely select patients needing CT.

What are the clinical effects of the different emergency department imaging options for suspected renal colic? A scoping review

OBJECTIVES

Clinicians have minimal guidance regarding the clinical consequences of each radiologic imaging option for suspected renal colic in the emergency department (ED), particularly in relation to patient-centered outcomes. In this scoping review, we sought to identify studies addressing the impact of imaging options on patient-centered aspects of ED renal colic care to help clinicians engage in informed shared decision making. Specifically, we sought to answer questions regarding the effect of obtaining computed tomography (CT; compared with an ultrasound or delayed imaging) on safety outcomes, accuracy, prognosis, and cost (financial and length of stay [LOS]).

METHODS

We conducted a comprehensive search using Pubmed, EMBASE, Web of Science conference proceedings index, and Google Scholar, identifying studies pertaining to renal colic, urolithiasis, and ureterolithiasis. In a prior qualitative study, stakeholders identified 14 key questions regarding renal colic care in the domains of safety, accuracy, prognosis, and cost. We systematically screened studies and reviewed the full text of articles based on their ability to address the 14 key questions.

RESULTS

Our search yielded 2570 titles, and 68 met the inclusion criteria. Substantial evidence informed questions regarding test accuracy and radiation exposure, but less evidence was available regarding the effect of imaging modality on patient-oriented outcomes such as cost and prognosis (admissions, ED revisits, and procedures). Reviewed studies demonstrated that both standard renal protocol CT and low-dose CT are highly accurate, with ultrasound having lower accuracy. Several studies found that ureterolithiasis diagnosed by ultrasound was associated with overall reduced radiation exposure. Existing studies did not suggest choice of imaging influences prognosis. Several studies found no substantial differences in monetary cost, but LOS was found to be shorter if a diagnosis was made with point-of-care ultrasound.

CONCLUSION

There is a plethora of data related to imaging accuracy. However, there is minimal data regarding the effect of CT on many patient-centered outcomes. Further research could improve the patient-centeredness of ED care.

Prevalence of microhematuria in renal colic and urolithiasis: a systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis aims to investigate the prevalence of microhematuria in patients presenting with suspected acute renal colic and/or confirmed urolithiasis at the emergency department.

METHODS

A comprehensive literature search was conducted to find relevant data on prevalence of microhematuria in patients with suspected acute renal colic and/or confirmed urolithiasis. Data from each study regarding study design, patient characteristics and prevalence of microhematuria were retrieved. A random effect-model was used for the pooled analyses.

RESULTS

Forty-nine articles including 15'860 patients were selected through the literature search. The pooled microhematuria prevalence was 77% (95%CI: 73-80%) and 84% (95%CI: 80-87%) for suspected acute renal colic and confirmed urolithiasis, respectively. This proportion was much higher when the dipstick was used as diagnostic test (80 and 90% for acute renal colic and urolithiasis, respectively) compared to the microscopic urinalysis (74 and 78% for acute renal colic and urolithiasis, respectively).

CONCLUSIONS

This meta-analysis revealed a high prevalence of microhematuria in patients with acute renal colic (77%), including those with confirmed urolithiasis (84%). Intending this prevalence as sensitivity, we reached moderate values, which make microhematuria alone a poor diagnostic test for acute renal colic or urolithiasis. Microhematuria could possibly still important to assess the risk in patients with renal colic.

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.

External validation of the CHOKAI score for the prediction of ureteral stones: A multicenter prospective observational study

OBJECTIVE

The CHOKAI and STONE scores are clinical prediction rules to predict ureteral stones in patients presenting with renal colic. Both systems contribute to reducing diagnostic radiation exposure; however, few studies have compared the two scoring systems. Therefore, we aimed to compare these systems and assess their diagnostic accuracy for ureteral stones.

METHODS

This was a multicenter prospective observational study performed between 2017 and 2018, including patients aged >15 years with renal colic and suspected with ureteral stones. We calculated the CHOKAI and STONE scores of each patient based on their medical interviews and physical and laboratory findings. Primary outcome was differences in the area under the receiver operating characteristic curve in each model, and secondary outcome was diagnostic accuracy at the optimal cut-off point.

RESULTS

Of the 124 patients included, 84 were diagnosed with ureteral stones. The area under the curve of the CHOKAI score was 0.95, showing a sensitivity of 0.93, specificity of 0.90, positive likelihood ratio of 9.3, and negative likelihood ratio of 0.079, at an optimal cut-off point of 6. The area under the curve of the STONE score was 0.88, showing a sensitivity of 0.68, specificity of 0.90, positive likelihood ratio of 6.8, and negative likelihood ratio of 0.36, at an optimal cut-off point of 9. Thus, the area under the curve was significantly higher for the CHOKAI score than for the STONE score (p = 0.0028).

CONCLUSIONS

The CHOKAI score has a diagnostic performance superior to that of the STONE score in this population.

The Emergency Department Diagnosis and Management of Urinary Tract Infection

Urinary tract infection (UTI) is a common infection seen in the emergency department. The spectrum of UTI includes simple versus complicated infection and lower versus upper UTI. No one history or examination finding is definitive for diagnosis. Testing often includes urinalysis and/or urine dipstick, and several pitfalls may occur in interpretation. Urine cultures should be obtained in complicated or upper UTIs but not simple and lower tract UTIs, unless a patient is pregnant. Imaging often is not required. Most patients with simple cystitis and pyelonephritis are treated as outpatients. A variety of potentially dangerous conditions may mimic UTI and pyelonephritis.

Variability of renal colic management and outcomes in two Canadian cities

BACKGROUND

Some centres favour early intervention for ureteral colic while others prefer trial of spontaneous passage, and relative outcomes are poorly described. Calgary and Vancouver have similar populations and physician expertise, but differing approaches to ureteral colic. We studied 60-day hospitalization and intervention rates for patients having a first emergency department (ED) visit for ureteral colic in these diverse systems.

METHODS

We used administrative data and structured chart review to study all Vancouver and Calgary patients with an index visit for ureteral colic during 2014. Patient demographics, arrival characteristics and triage category were captured from ED information systems, while ED visits and admissions were captured from linked regional hospital databases. Laboratory results were obtained from electronic health records and stone characteristics were abstracted from diagnostic imaging reports. Our primary outcome was hospitalization or urological intervention from 0 to 60 days. Secondary outcomes included ED revisits, readmissions and rescue interventions. Time to event analysis was conducted and Cox Proportional Hazards modelling was performed to adjust for covariate imbalance.

RESULTS

We studied 3283 patients with CT-defined stones. Patient and stone characteristics were similar for the cities. Hospitalization or intervention occurred in 60.9% of Calgary patients and 31.3% of Vancouver patients (p<0.001). Calgary patients had higher index intervention rates (52.1% v. 7.5%), and experienced more ED revisits and hospital readmissions during follow-up. The data suggest that outcome events were associated with overtreatment of small stones in one city and undertreatment of large stones in the other.

CONCLUSIONS

An early interventional approach was associated with higher ED revisit, hospitalization and intervention rates. If these events are markers of patient disability, then a less interventional approach to small stones and earlier definitive management of large stones may reduce system utilization and improve outcomes for patients with acute ureteral colic.

Bilateral ureterolithiasis: A true positive and false negative PoCUS exam in a patient with renal colic

Acute flank pain from suspected urolithiasis is a common presenting complaint in the Emergency Department. Multiple computed tomography (CT) has traditionally been the standard imaging modality used to diagnose obstructive kidney stones, however point of care ultrasound (PoCUS) can play an important role in the diagnostic algorithm and risk stratification of acute flank pain. Here, we present the case of a 29-year-old female with suspected urolithiasis, who underwent PoCUS that revealed right-sided hydronephrosis and normal left kidney, bladder, and aorta. A subsequent KUB was negative. As the clinical course failed to improve with therapy, an abdominal and pelvic CT was ordered revealing a 5 mm distal obstructing ureteric calculus at the right vesico-ureteric junction and another 5 mm left mid ureteric calculus. To the best of our knowledge, this is the first case in which a patient presenting with acute right-sided flank pain demonstrated unilateral hydronephrosis on PoCUS, but had clinically significant bilateral ureteric stones on CT. Emergency physicians who employ PoCUS for evaluation of flank pain must be aware of its benefits and drawbacks and how they apply to each patient. As such, we have developed a script emergency physicians can use for shared decision-making with renal colic patients when deciding on the appropriate imaging modality.

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.

Hospital Medicine Point of Care Ultrasound Credentialing: An Example Protocol

Though the use of point-of-care ultrasound (POCUS) has increased over the last decade, formal hospital credentialing for POCUS may still be a challenge for hospitalists. This document details the Hospital Medicine Department Ultrasound Credentialing Policy from Regions Hospital, which is part of the HealthPartners organization in Saint Paul, Minnesota. National organizations from internal medicine and hospital medicine (HM) have not published recommended guidelines for POCUS credentialing. Revised guidelines for POCUS have been published by the American College of Emergency Physicians, though these are not likely intended to guide hospitalists when working with credentialing committees and medical boards. This document describes the scope of ultrasound in HM and our training, credentialing, and quality assurance program. This report is intended to be used as a guide for hospitalists as they work with their own credentialing committees and will require modification for each institution. However, the overall process described here should assist in the establishment of POCUS at various institutions.

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.

Internal validation of a scoring system to evaluate the probability of ureteral stones: The CHOKAI score

OBJECTIVE

The CHOKAI and STONE scores are prediction models for ureteral stones. The aims of the present study were to evaluate the diagnostic performance, to examine the optimal cut-off value, and to compare the diagnostic performance of each model.

METHODS

Patients who presented to our emergency department with renal colic were considered for this prospective study. We analyzed the predictive performance of both STONE and CHOKAI scores at their optimal cut-off values, using receiver operating characteristic (ROC) curve and area under the curve (AUC), as well as sensitivity, specificity, positive likelihood ratio (LR+), and negative likelihood ratio (LR-) at the optimal cut-off value.

RESULTS

Of the 96 patients who met the inclusion criteria, 79 were definitively diagnosed with ureteral stones. All patients were of Japanese descent. The AUC of the CHOKAI score was 0.971 at an optimal cut-off value of 6, showing a sensitivity of 0.911, specificity of 0.941, LR+ of 15.49, and LR- of 0.094. The AUC of the STONE score was 0.873 at an optimal cut-off value of 8, showing a sensitivity of 0.823, specificity of 0.824, LR+ of 4.662, and LR- of 0.215. The AUC of the CHOKAI score was significantly higher than that of the STONE score (p=0.010). Of the 73 patients with a CHOKAI score of ≥6, 98.6% had ureteral stones, and of the 68 patients with a STONE score of ≥8, 95.6% had ureteral stones.

CONCLUSIONS

The simplified CHOKAI score is a useful tool to screen for ureteral stones in patients with renal colic.

Ultrasound Use in Urinary Stones: Adapting Old Technology for a Modern-Day Disease

Ultrasound has become a mainstay tool in urologists' armamentarium for the diagnosis and management of nephrolithiasis. From starting as a rudimentary form of imaging, it has come to play a more prominent role over time, paralleling evolution in ultrasound technology. Throughout the medical community there is a growing emphasis on reducing the amount of ionizing radiation delivered to patients during routine imaging. As such there has been a resurgence of interest in ultrasound given its lack of associated radiation exposure and proven effectiveness as a diagnostic and therapeutic imaging modality. Herein, we provide a review of the history of ultrasound, how the use of ultrasound is expanding in both diagnosis and treatment of urinary stone disease, and finally how promising applications of ultrasound are shaping the future of kidney stone management.

STONE PLUS: Evaluation of Emergency Department Patients With Suspected Renal Colic, Using a Clinical Prediction Tool Combined With Point-of-Care Limited Ultrasonography

STUDY OBJECTIVE

We determine whether renal point-of-care limited ultrasonography (PLUS) used in conjunction with the Sex, Timing, Origin, Nausea, Erythrocytes (STONE) clinical prediction score can aid identification of emergency department (ED) patients with uncomplicated ureteral stone or need for urologic intervention.

METHODS

This was a prospective observational study of adult ED patients undergoing computed tomography (CT) scan for suspected ureteral stone. The previously validated STONE score classifies patients into risk categories of low (≈10%), moderate (≈50%), or high (≈90%) for symptomatic stone. Renal PLUS assessed for presence of hydronephrosis before CT scanning. The primary outcomes of symptomatic ureteral stone or acutely important alternative finding were abstracted from CT reports. The secondary outcome, urologic intervention, was assessed by 90-day follow-up interview and record review.

RESULTS

Of 835 enrolled patients, ureteral stone was identified in 53%, whereas 6.5% had an acutely important alternative finding on CT. Renal PLUS modestly increased sensitivity for symptomatic stone among low and moderate STONE score categories. Moderate or greater hydronephrosis improved specificity from 67% (62% to 72%) to 98% (93% to 99%) and 42% (37% to 47%) to 92% (86% to 95%) in low- and moderate-risk patients, with likelihood ratios of 22 (95% CI, 4.2-111) and 4.9 (95% CI, 2.9-8.3), respectively. Test characteristics among high-risk patients were unchanged by renal PLUS. For urologic intervention, any hydronephrosis was 66% sensitive (57% to 74%), whereas moderate or greater hydronephrosis was 86% specific overall (83% to 89%) and 81% (69% to 90%) sensitive and 79% 95% CI, (73-84) specific among patients with the highest likelihood of symptomatic stone.

CONCLUSION

Hydronephrosis on renal PLUS modestly improved risk stratification in low- and moderate-risk STONE score patients. The presence or absence of hydronephrosis among high-risk patients did not significantly alter likelihood of symptomatic stone but may aid in identifying patients more likely to require urologic intervention.

Can ureteral stones cause pain without causing hydronephrosis?

INTRODUCTION

While computerized tomography (CT) is the gold standard for diagnosis of ureterolithiasis, ultrasound is a less costly and radiation-free alternative which is commonly used to evaluate patients with ureteral colic. The purpose of this study was to evaluate the frequency with which patients with ureteral stones and renal colic demonstrate hydronephrosis in order to better understand the evaluation of these patients.

METHODS

Two hundred and forty-eight consecutive patients presenting with ureteral colic and diagnosed with a single unilateral ureteral stone on CT scan in an urban tertiary care emergency department were retrospectively reviewed. Radiology reports were reviewed for stone size, diagnosis, and degree of hydronephrosis.

RESULTS

Of the 248 patients evaluated for suspected ureteral stone, 221 (89.1 %) demonstrated any hydronephrosis, while 27 (10.9 %) did not. Hydronephrosis grade, available in 194 patients, was as follows: mild-70.6 %, moderate-27.8 %, and severe-1.5 %. Mean patient age was 47.0 years (SD 15.5), gender distribution was 35.9 % female and 64.1 % male, and mean stone axial diameter was 4.1 mm (SD 2.4). Stone location was as follows: ureteropelvic junction-4.1 %, proximal ureter-21 %, distal ureter-24.9 %, and ureterovesical junction-47.1 %. Axial stone diameter and coronal length (craniocaudal) were both significant predictors of degree of hydronephrosis (ANOVA, p < 0.001 for both). Age (ANOVA, p = NS), stone location (Chi square, p = NS), and gender (Chi square, p = NS) were not associated with degree of hydronephrosis.

CONCLUSIONS

In patients with ureteral stones and colic, nearly 11 % do not demonstrate any hydronephrosis and a majority (nearly 71 %) will demonstrate only mild hydronephrosis. Stone diameter appears to be related to degree of hydronephrosis, whereas age, gender, and stone location are not. The lower incidence of hydronephrosis for small stones causing renal colic may explain the lower diagnostic accuracy of ultrasound when compared to CT for detecting ureteral stones.

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

Introduction

Non-contrast computed tomography (CT) is widely regarded as the gold standard for diagnosis of urolithiasis in emergency department (ED) patients. However, it is costly, time-consuming and exposes patients to significant doses of ionizing radiation. Hydronephrosis on bedside ultrasound is a sign of a ureteral stone, and has a reported sensitivity of 72–83% for identification of unilateral hydronephrosis when compared to CT. The purpose of this study was to evaluate trends in sensitivity related to stone size and number.

Methods

This was a structured, explicit, retrospective chart review. Two blinded investigators used reviewed charts of all adult patients over a 6-month period with a final diagnosis of renal colic. Of these charts, those with CT evidence of renal calculus by attending radiologist read were examined for results of bedside ultrasound performed by an emergency physician. We included only those patient encounters with both CT-proven renal calculi and documented bedside ultrasound results.

Results

125 patients met inclusion criteria. The overall sensitivity of ultrasound for detection of hydronephrosis was 78.4% [95% confidence interval (CI)=70.2–85.3%]. The overall sensitivity of a positive ultrasound finding of either hydronephrosis or visualized stones was 82.4% [95%CI: 75.6%, 89.2%]. Based on a prior assumption that ultrasound would detect hydronephrosis more often in patients with larger stones, we found a statistically significant (p=0.016) difference in detecting hydronephrosis in patients with a stone ≥6 mm (sensitivity=90% [95% CI=82–98%]) compared to a stone <6 mm (sensitivity=75% [95% CI=65–86%]). For those with 3 or more stones, sensitivity was 100% [95% CI=63–100%]. There were no patients with stones ≥6 mm that had both a negative ultrasound and lack of hematuria.

Conclusion

In a population with CT-proven urolithiasis, ED bedside ultrasonography had similar overall sensitivity to previous reports but showed better sensitivity with increasing stone size and number. We identified 100% of patients with stones ≥6 mm that would benefit from medical expulsive therapy by either the presence of hematuria or abnormal ultrasound findings.

External Validation of the STONE Score, a Clinical Prediction Rule for Ureteral Stone: An Observational Multi-institutional Study

Study objective

The STONE score is a clinical decision rule that classifies patients with suspected nephrolithiasis into low-, moderate-, and high-score groups, with corresponding probabilities of ureteral stone. We evaluate the STONE score in a multi-institutional cohort compared with physician gestalt and hypothesize that it has a sufficiently high specificity to allow clinicians to defer computed tomography (CT) scan in patients with suspected nephrolithiasis.

Methods

We assessed the STONE score with data from a randomized trial for participants with suspected nephrolithiasis who enrolled at 9 emergency departments between October 2011 and February 2013. In accordance with STONE predictors, we categorized participants into low-, moderate-, or high-score groups. We determined the performance of the STONE score and physician gestalt for ureteral stone.

Results

Eight hundred forty-five participants were included for analysis; 331 (39%) had a ureteral stone. The global performance of the STONE score was superior to physician gestalt (area under the receiver operating characteristic curve=0.78 [95% confidence interval {CI} 0.74 to 0.81] versus 0.68 [95% CI 0.64 to 0.71]). The prevalence of ureteral stone on CT scan ranged from 14% (95% CI 9% to 19%) to 73% (95% CI 67% to 78%) in the low-, moderate-, and high-score groups. The sensitivity and specificity of a high score were 53% (95% CI 48% to 59%) and 87% (95% CI 84% to 90%), respectively.

Conclusion

The STONE score can successfully aggregate patients into low-, medium-, and high-risk groups and predicts ureteral stone with a higher specificity than physician gestalt. However, in its present form, the STONE score lacks sufficient accuracy to allow clinicians to defer CT scan for suspected ureteral stone.

My patient has abdominal and flank pain: Identifying renal causes

Acute flank and abdominal pain are common presenting complaints in the emergency department. With increasing access to point-of-care ultrasound (PoCUS), emergency physicians have an added tool to help identify renal problems as a cause of a patient's pain. PoCUS for hydronephrosis has a sensitivity of 72-83.3% and a varying specificity, similar to radiology-performed ultrasonography. In addition to assessment for hydronephrosis, PoCUS can help emergency physicians to exclude other serious causes of flank and abdominal pain such as the presence of an abdominal aortic aneurysm, or free fluid in the intraperitoneal space, which could represent hemorrhage. Use of PoCUS for the assessment of flank pain has resulted in more rapid diagnosis, decreased use of computed tomography, and shorter emergency department length of stay.

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.

Accuracy of bedside emergency physician performed ultrasound in diagnosing different causes of acute abdominal pain: a prospective study

OBJECTIVE

Abdominal pain is a common complaint in the emergency department and accurate diagnosis of its etiology may affect the patient's outcome.

METHOD

Patients with abdominal pain underwent ultrasound study first by trained emergency physicians and then by radiologists blinded to emergency physician's results.

RESULT

Emergency physician who performed bedside ultrasound had 78% diagnostic accuracy. Emergency physicians showed better results in diagnosing some entities (abdominal aortic aneurysm and renal stones) than the others (acute appendicitis, cholelithiasis, and cholecystitis).

CONCLUSION

Bedside ultrasound can accurately identify the etiology of acute nontraumatic abdominal pain in the hands of emergency physicians.

Proactive medicine: the "UCI 30," an ultrasound-based clinical initiative from the University of California, Irvine

This article discusses the benefits of integrating point-of-care diagnostic ultrasound into the four-year medical school curriculum. Handheld ultrasound devices have been used to teach medical students at the University of California (UC), Irvine, since August 2010, and the article explains how the use of this inexpensive, safe, and noninvasive tool enhances the ability of a physician conducting a standard physical exam to confirm suspected findings and uncover other suspected pathology at a reasonable cost. The authors describe the ultrasound curriculum at UC Irvine and the process of its implementation. In the appendix to the article, the authors describe the specific diagnostic benefits of using a handheld ultrasound device for each element of the Stanford 25 physical exam. Their ultrasound-enhanced approach to the physical exam is referred to as the "UCI 30." They make recommendations for how and when to integrate ultrasound into the physical exam. The article points out that early training of medical students in the use of ultrasound can avoid the diagnostic problems of ultrasound by maximizing students' comfort and ability to obtain accurate ultrasound images for diagnostic and procedural purposes.

Emergency point-of-care ultrasound diagnosis of hematocolpometra and imperforate hymen in the pediatric emergency department

A 12-year-old girl presented to the pediatric emergency department with a history of difficulty voiding and was found to have a firm, tender suprapubic mass on examination. Transabdominal emergency point-of-care ultrasound was used at the bedside to diagnose hematocolpometra due to an imperforate hymen. The diagnosis was confirmed by a comprehensive abdominal ultrasound and magnetic resonance imaging in the radiology suite. The patient was discharged on oral contraceptive medication and scheduled for an outpatient surgical hymenectomy following consultation with the gynecology service.

Correlation of volume, position of stone, and hydronephrosis with microhematuria in patients with solitary urolithiasis

Background

The aim of this study was to determine the relationship between hematuria and volume, position of stone, and hydronephrosis in patients with a solitary stone, using unenhanced multidetector computed tomography (MDCT).

Material/Methods

This retrospective study evaluated the clinical and radiological records of 83 patients undergoing MDCT for the evaluation of acute flank pain and suspected renal colic, who also underwent a microscopic urinalysis at the emergency department of our hospital during a 1-year period. Inclusion criteria of the MDCT study were solitary urolithiasis and cumulative stone diameter under 1 cm.

Results

A total of 83 patients were included in the study, with a mean age of 42.1±14.4 years; 48 (57.8%) were females and 35 (42.2%) were males. Detection of 5 or more red cells on urinalysis was regarded as microscopic hematuria, and was positive in 46 patients (55.4%). There was a positive correlation between the position of the stone (especially upper two-thirds ureteral stones) and microhematuria rate (r: 0.28, p=0.009). There was a statistically significant difference in presence of hydronephrosis between the microhematuria (36 patients, 78%) and non-microhematuria (12 patients, 32%) groups (p<0.001). The median stone volume between the microhematuria and non-microhematuria groups were not statistically different, 37.5 mm³ (range 5–425) and 28 mm³ (range 4–412), respectively (p=0.39).

Conclusions

Although stone volume is one of the best indicators of stone burden, it was not correlated with microhematuria. However, in patients with renal colic, microhematuria requires ultrasound examination whether hydronephrosis and ureteral stones are present or not. Further studies with larger sample sizes are warranted.

The renal resistive index as a predictor of acute hydronephrosis in patients with renal colic

INTRODUCTION

The objective of this study was to determine whether the renal resistive index (RI) can predict hydronephrosis in patients with renal colic (RC) and whether or not its performance is time-dependent.

MATERIALS AND METHODS

The study population was composed of 54 patients admitted for unilateral RC. At the time of the first observation (time point I, tpI), each patient underwent routine examinations, abdominal ultrasonography, and renal color Doppler ultrasound (CDUS) with measurement of the RI. The two imaging studies were repeated 6, 12, 18, 24, 36, and 48 h later (tpII, tpIII, tpIV, tpV, tpVI, tpVII). In addition, each patient underwent non-contrast urinary tract CT 48-60 h after admission. A mean renal RI of >0.70 (mRI+) for the symptomatic kidney was considered indicative of obstruction. Patients were retrospectively divided into two groups: those who developed dilatation (group A) and those who did not (group B).

RESULTS

A mRI+ on CDUS predicted the onset of hydronephrosis with 100% sensitivity, 84% specificity, 92.6% accuracy, PPV and NPV of 87.9% and 100%, and diagnostic efficiency of 84%. In group A, mRI+ were always observed before onset of hydronephrosis in a time-dependent manner. In group B, mRI+ were observed occasionally in 4/25 patients (16%) and all were recorded at tpII. In these cases, the RI had returned to normal by tpIII.

CONCLUSIONS

In our RC patients, renal RI obtained with CDUS predicted the onset of acute dilatation with higher sensitivity, specificity, accuracy, and diagnostic efficiency than ultrasonography, and it can be used routinely in the emergency department to supplement ultrasound findings.

Comparison of conventional radiography combined with ultrasonography versus nonenhanced helical computed tomography in evaluation of patients with renal colic

The aim of this study is to determine whether kidneys ureters bladder X-ray (KUB) film combined with ultrasound (US) can be effectively used in evaluation of renal colic and miss stones with clinically significant size identified on nonenhanced computed tomography (NECT) in patients with urolithiasis. This retrospective study evaluated the clinical and radiological records of 300 patients at our institution undergoing KUB and/or US and/or NECT for the evaluation of renal colic from June 2007 to December 2010. Of patients with negative findings on KUB and/or US, 22 had renal stones on NECT (mean size 4.4 mm, range 3-8), 3 had lower ureteral stone (mean size 3.3 mm, range 2-5). In patients with isolated suspicious renal ectasia without stone image, two had renal stone on NECT (mean size 4 mm, range 2-6), 5 had upper ureteral stone (mean size 4.4 mm, range 4-6), 7 had middle ureteral stone (mean size 3.7 mm, range 3-4) and 14 had lower ureteral stone (mean size 4 mm, range 2-6). The cost-effective and almost radiation-free combination of KUB and US should be preferred for diagnosis of urolithiasis, as it detects most of the ureteral and renal calculi which are clinically significant.

The learning curve of resident physicians using emergency ultrasonography for obstructive uropathy

BACKGROUND

Given the time, expense, and radiation exposure associated with computed tomography (CT), ultrasonography (US) is considered an alternative imaging study that could expedite patient care in patients with suspected obstructive uropathy. However, there is a paucity of literature regarding bedside US for obstructive uropathy in the emergency department (ED), and it is unknown how much experience is required for competency in such exams.

OBJECTIVES

The objective was to assess the learning curve for the detection of obstructive uropathy of resident physicians training in ED bedside US (EUS) during a dedicated EUS elective.

METHODS

This was a prospective cohort study of residents participating in an EUS elective. Patients presenting with acute abdominal or flank pain suggestive of an obstructive uropathy were enrolled and underwent EUS prior to noncontrast CT. Physicians who had previously performed at least 10 EUS exams for obstructive uropathy recorded results on a standardized data sheet, which was subsequently compared to the results of noncontrast CT read by board-certified radiologists blinded to the results of the EUS. In addition to an unadjusted chi-square test for trend, a multivariable logistic regression analysis, adjusting for stone size and operator, was performed. Finally, generalized estimating equations were used to describe test characteristics while accounting for potential clustering between exams by operator.

RESULTS

Twenty-three resident physicians participated and enrolled a convenience sample of 393 patients. A total of 157 patients (40%) were diagnosed with an obstructing ureterolith, and three (1%) were diagnosed with nonobstructing ureterolithiasis. An unadjusted chi-square test for trend demonstrated a statistically significant increase in both sensitivity (χ(2) = 11.4, p = 0.02) and specificity (χ(2) = 6.4, p = 0.04) for each level of increase in number of exams. On multivariable regression analysis, when adjusting for size of stone and operator, for every five additional exams after the first 10 EUS exams, the odds ratio for a true positive for obstruction increased by 1.7 (95% confidence interval [CI] = 1.2 to 2.5, p = 0.003). After accounting for clustering of exams by operator, overall EUS sensitivity and specificity for obstructive uropathy were 82% (95% CI = 77% to 87%) and 88% (95% CI = 85% to 92%). Stratifying by number of exams, the sensitivity was 72% (95% CI = 62% to 80%) for the 11th through 20th exams, 90% (95% CI = 83% to 96%) for the 21st through 30th exams, and 95% (95% CI = 91% to 99%) for the 31st through 43rd exams. Likewise, specificity was 82% (95% CI = 75% to 89%) for the 11th through 20th exams, 90% (95% CI = 85% to 95%) for the 21st through 30th exams, and 92% (95% CI = 86% to 98%) for the 31st through 50th exams.

CONCLUSIONS

Physicians training in EUS may be able to accurately assess for obstructive uropathy after 30 exams.

Patients presenting to the emergency department with non-specific complaints: the Basel Non-specific Complaints (BANC) study

OBJECTIVES

Patient management in emergency departments (EDs) is often based on management protocols developed for specific complaints like dyspnea, chest pain, or syncope. To the best of our knowledge, to date no protocols exist for patients with nonspecific complaints (NSCs) such as "weakness,""dizziness," or "feeling unwell." The objectives of this study were to provide a framework for research and a description of patients with NSCs presenting to EDs.

METHODS

Nonspecific complaints were defined as the entity of complaints not part of the set of specific complaints for which evidence-based management protocols for emergency physicians (EPs) exist. "Serious conditions" were defined as potentially life-threatening or those requiring early intervention to prevent health status deterioration. During a 6-month period, all adult nontrauma patients with an Emergency Severity Index (ESI) of 2 or 3 were prospectively enrolled, and serious conditions were identified within a 30-day period.

RESULTS

The authors screened 18,261 patients for inclusion. A total of 218 of 1,611 (13.5%) nontrauma ESI 2 and 3 patients presented with NSCs. Median age was 82 years (interquartile range [IQR]=72 to 87), and 24 of 218 (11%) were nursing home inhabitants. A median of 4 (IQR=3 to 5) comorbidities were recorded, most often chronic hypertension, coronary artery disease, and dementia. During the 30-day follow-up period a serious condition was diagnosed in 128 of 218 patients (59%). The 30-day mortality rate was 6%.

CONCLUSIONS

Patients with NSC presenting to the ED are at high risk of suffering from serious conditions. Sensitive risk stratification tools are needed to identify patients with potentially adverse health outcomes.

Can the degree of hydronephrosis on ultrasound predict kidney stone size?

OBJECTIVE

The aim of the study was to determine if the degree of hydronephrosis on focused emergency renal ultrasound correlates with kidney stone size on computed tomography.

METHODS

A retrospective study was performed on all adult patients in the emergency department who had a focused emergency renal ultrasound and ureterolithiasis on noncontrast computed tomography. Severity of hydronephrosis was determined by the performing physician. Ureteral stone size was grouped into 5 mm or less and larger than 5 mm based on likelihood of spontaneous passage.

RESULTS

One hundred seventy-seven ultrasound scans were performed on patients with ureteral calculi. When dichotomized using test characteristic analysis, patients with none or mild hydronephrosis (72.9%) were less likely to have ureteral calculi larger than 5 mm than those with moderate or severe hydronephrosis (12.4% vs 35.4%; P < .001) with a negative predictive value of 0.876 (95% confidence interval, 0.803-0.925).

CONCLUSION

Patients with less severe hydronephrosis were less likely to have larger ureteral calculi.

Portable ultrasound for remote environments, part II: current indications

BACKGROUND

With recent advances in ultrasound technology, it is now possible to deploy lightweight portable imaging devices in the field. Techniques and studies initially developed for hospital use have been extrapolated out of the hospital setting in a wide variety of environments in an effort to increase diagnostic accuracy in austere or prehospital environments.

OBJECTIVES

This review summarizes current ultrasound applications used in out-of-hospital arenas and highlights existing evidence for such use. The diversity of applications and environments is organized by indication to better inform equipment selection as well as future directions for research and development.

DISCUSSION

Trauma evaluation, casualty triage, and assessment for pneumothorax, acute mountain sickness, and other applications have been studied by field medical teams. A wide range of outcomes have been reported, from alterations in patient care to determinations of accuracy compared to clinical judgment or other diagnostic modalities.

CONCLUSIONS

The use of lightweight portable ultrasound shows great promise in augmenting clinical assessment for field medical operations. Although some studies of diagnostic accuracy exist in this setting, further research focused on clinically relevant outcomes data is needed.

Ultrasonography for ureteral stone detection in patients with or without caliceal dilatation

PURPOSE

To evaluate the relationship between the degree of hydronephrosis and the detection rates of ureteral stones with ultrasonography (US).

METHODS

Of 250 consecutive patients with suspected ureterolithiasis, 214 who were diagnosed with ureterolithiasis were enrolled in this study. First, both kidneys were observed by US to evaluate the intrarenal collecting systems. Thereafter, the possible course of the ureters and the bladder were searched to find any stones.

RESULTS

Stones were clearly observed in 80 (73%) of 109 patients with caliceal dilatation, whereas stones were clearly observed in 46 (44%) of 105 patients without dilatation (P < 0.05). Of the former 80 patients, 31 (39%) had stones in the ureterovesical junction (UVJ), whereas 51 (64%) had stones in the more proximal ureter. Of the latter 46 patients, 37 (80%) had stones in the UVJ or the bladder, whereas 9 (20%) had stones in the more proximal ureter.

CONCLUSION

The US detection rate of ureteral stones was high in patients with caliceal dilatation. The whole ureter should be scanned in patients with caliceal dilatation for detection of ureteral stones. Even when patients have no caliceal dilatation, it is still considered to be useful to scan the UVJ and the bladder.

Investigations for recognizing urinary stone

This study was done to identify the value of the commonly performed investigations available for identifying urinary stone disease, namely X-ray of the kidney, ureter and bladder (KUB) regions and ultrasound scan (USS) to recognize stones in patients suspected to have the disease. Two hundred patients who attended the stone clinic with symptoms suggestive of urinary stone disease and had either stone retrieved or have been followed up for minimum of 6 months were interviewed. The final opinion on stone disease was made after follow-up to assess the efficacy of the initial opinion based on the plain X-ray KUB or USS. The patients were classified as proved stone patients only after retrieval of stones. The efficacy of the initial screening investigation was assessed to calculate the specificity and sensitivity of the two modalities of investigation. Of the 200 patients studied, all had plain X-ray KUB. Only 166 patients had USS for recognizing stones in the urinary tract; 74 patients showed positive evidence of stones either by X-ray or USS. The findings of the two modalities of investigation are given below. Number of X-rays done, 200; number positive, 24; proved positive, 24 (stone retrieved); proved negative, 0; number negative, 176; proved positive, 32 (stone retrieved); proved negative, 144; number of USS done, 166; number positive, 120; proved positive, 50 (stone retrieved); proved negative, 70; number negative, 46; proved positive, 14 (stone retrieved); proved negative, 32. USS showed back presence effects in 62 patients. Of these, 12% showed stones in the ureter, whereas the rest did not show evidence of stones. Those selected as positive stones finally had either passed stones or had PCNL, URS, cystolithotripsy or open surgery or were put on high-dose chemotherapy. Forty-six patients who had no ROS in KUB and no stones in USS passed stones subsequently. It is concluded that the plain both X-ray KUB and USS should be performed in patients with suspected stone disease for identifying stone disease and also to exclude other pathology which may produce similar urinary symptoms.

Artificial neural network, genetic algorithm, and logistic regression applications for predicting renal colic in emergency settings

Background

Logistic regression is the most common statistical model for processing multivariate data in the medical literature. Artificial intelligence models like an artificial neural network (ANN) and genetic algorithm (GA) may also be useful to interpret medical data.

Aims

The purpose of this study was to perform artificial intelligence models on a medical data sheet and compare to logistic regression.

Methods

ANN, GA, and logistic regression analysis were carried out on a data sheet of a previously published article regarding patients presenting to an emergency department with flank pain suspicious for renal colic.

Results

The study population was composed of 227 patients: 176 patients had a diagnosis of urinary stone, while 51 ultimately had no calculus. The GA found two decision rules in predicting urinary stones. Rule 1 consisted of being male, pain not spreading to back, and no fever. In rule 2, pelvicaliceal dilatation on bedside ultrasonography replaced no fever. ANN, GA rule 1, GA rule 2, and logistic regression had a sensitivity of 94.9, 67.6, 56.8, and 95.5%, a specificity of 78.4, 76.47, 86.3, and 47.1%, a positive likelihood ratio of 4.4, 2.9, 4.1, and 1.8, and a negative likelihood ratio of 0.06, 0.42, 0.5, and 0.09, respectively. The area under the curve was found to be 0.867, 0.720, 0.715, and 0.713 for all applications, respectively.

Conclusion

Data mining techniques such as ANN and GA can be used for predicting renal colic in emergency settings and to constitute clinical decision rules. They may be an alternative to conventional multivariate analysis applications used in biostatistics.