Trends in imaging use during the emergency department evaluation of flank pain

The Incidence and Risk Factors for Emergency Department Imaging in Acute Renal Colic

Objective: To determine the incidence of and risk factors for imaging in patients presenting to the emergency department (ED) with renal colic. Subject/Patients and Methods: We conducted a population-based cohort study in the province of Ontario, utilizing linked administrative health data. Patients who presented to an ED with renal colic between April 1, 2010, and June 30, 2020, were included. The rate of initial imaging (CT scans and ultrasound [U/S]) and repeat imaging within 30 days was determined. Generalized linear models were utilized to evaluate patient and institutional-level characteristics associated with imaging, and specifically CT vs U/S. Results: There were 397,491 index renal colic events, of which 67% underwent imaging (CT 68%, U/S 27%, and CT+U/S same day 5%). Repeat imaging was performed in 21% of events (U/S in 12.5%, CT in 8.4%) at a median of 10 days. Of those with an initial U/S, 28% had repeat imaging compared with 18.5% for those with an initial CT. Undergoing an initial CT was associated with being male, urban residence, later year of cohort entry, history of diabetes mellitus and inflammatory bowel disease, and presentation to nonacademic hospitals of larger size, or with a higher volume of ED visits. Conclusion: Two-thirds of renal colic patients underwent imaging, and CT was the most utilized modality. Patients undergoing an initial CT had a lower likelihood of repeat imaging within 30 days. The utilization of CT increased over time and was more common in males and those presenting to nonacademic hospitals of larger size, or with higher ED volumes. Our study highlights the patient- and institution-level factors that need to be targeted with prevention strategies to reduce the utilization of CT scans, when possible, for cost reduction and to minimize patient exposure to ionizing radiation.

CT Use Reduction In Ostensive Ureteral Stone (CURIOUS)

INTRODUCTION

Computed tomography (CT) is performed in over 90% of patients diagnosed with ureteral stones, but only 10% of patients presenting to the emergency department (ED) with acute flank pain are hospitalized for a clinically important stone or non-stone diagnosis. Hydronephrosis can be accurately detected using point-of-care ultrasound and is a key predictor of ureteral stone and risk of subsequent complications. The absence of hydronephrosis is insufficient to exclude a stone. We created a sensitive clinical decision rule to predict clinically important ureteral stones. We hypothesized that this rule could identify patients at low risk for this outcome.

METHODS

We conducted a retrospective cohort study in a random sample of 4000 adults who presented to one of 21 Kaiser Permanente Northern California EDs and underwent a CT for suspected ureteral stone from 1/1/2016 to 12/31/2020. The primary outcome was clinically important stone, defined as stone resulting in hospitalization or urologic procedure within 60 days. We used recursive partition analysis to generate a clinical decision rule predicting the outcome. We estimated the C-statistic (area under the curve), plotted the receiver operating characteristic (ROC) curve for the model, and calculated sensitivity, specificity, and predictive values of the model based on a risk threshold of 2%.

RESULTS

Among 4000 patients, 354 (8.9%) had a clinically important stone. Our partition model resulted in four terminal nodes with risks ranging from 0.4% to 21.8%. The area under the ROC curve was 0.81 (95% CI 0.80, 0.83). Using a 2% risk cut point, a clinical decision tree including hydronephrosis, hematuria, and a history of prior stones predicted complicated stones with sensitivity 95.5% (95% CI 92.8%-97.4%), specificity 59.9% (95% CI 58.3%-61.5%), positive predictive value 18.8% (95% CI 18.1%-19.5%), and negative predictive value 99.3% (95% CI 98.8%-99.6%).

CONCLUSIONS

Application of this clinical decision rule to imaging decisions would have led to 63% fewer CT scans with a miss rate of 0.4%. A limitation was the application of our decision rule only to patients who underwent CT for suspected ureteral stone. Thus, this rule would not apply to patients who were thought to have ureteral colic but did not receive a CT because ultrasound or history were sufficient for diagnosis. These results could inform future prospective validation studies.

The role of serum and urinary markers in predicting obstructing ureteral stones and reducing unjustified non-contrast computerized tomographic scans in emergency departments

INTRODUCTION

The reported yield of non-contrast computed tomography (NCCT) in assessing flank pain and obstructive urolithiasis (OU) in emergency departments (EDs) is only ~ 50%. We investigated the potential capability of serum and urinary markers to predict OU and improve the yield of NCCT in EDs.

METHODS

All consecutive ED patients with acute flank pain suggestive of OU and assessed by NCCT between December 2019 and February 2020 were enrolled. Serum white blood cells (WBC), C-reactive protein (CRP) and creatinine (Cr) levels, and urine dipstick results were analyzed for association with OU, and unjustified NCCT scan rates were calculated.

RESULTS

NCCTs diagnosed OU in 108 of the 200 study patients (54%). The median WBC, CRP, and Cr values were 9,100/µL, 4.3 mg/L, and 1 mg/dL, respectively. Using ROC curves, WBC = 10,000/µL and Cr = 0.95 mg/dl were the most accurate thresholds to predict OU. Only WBC ≥ 10,000/µL (OR = 3.7, 95% CI 1.6-8.3, p = 0.002) and Cr ≥ 0.95 mg/dl (OR = 5, 95% CI 2.3-11, p < 0.001) were associated with OU. Positive predictive value and specificity for detecting OU among patients with combined WBC ≥ 10,000 and Cr ≥ 0.95 were 83% and 89%, respectively. Patients negative to the serum markers criteria underwent significantly more unjustified NCCTs (p = 0.03). The negative predictive value of the serum criteria for justified NCCT scanning was 81%.

CONCLUSIONS

WBC and Cr may be valuable serum markers in predicting OU among patients presenting to EDs with acute flank pain. They may potentially reduce the number of unjustified NCCT scans in the ED setting.

Potential Markers to Reduce Non-Contrast Computed Tomography Use for Symptomatic Patients with Suspected Ureterolithiasis

Most patients with ureterolithiasis are managed successfully with conservative treatment. In this context, delineation of clinical risk factors that identify patients with low risk for surgical intervention may reduce use of Non-Contrast Computed Tomography (NCCT). Here, emergency department patient files from a 14-month period were reviewed retrospectively, to identify patients who underwent NCCT and showed a ureteral stone. Demographic, clinical and laboratory information was collected. Patients were grouped to either requiring surgical intervention (Group 1) or having successful conservative management (Group 2). The cohort included 368 patients; 36.1% ultimately required surgical intervention (Group 1) and 63.9% were successfully treated conservatively (Group 2). On univariate analysis, patients who required surgical intervention were older, had longer duration of symptoms, had history of urolithiasis and surgical intervention for urolithiasis and had higher serum creatinine levels. Multivariate analysis identified the following risk factors associated with surgical intervention: creatinine >1.5 mg/dL, duration of symptoms ≥ 1.5 days and age > 45 years. Patients with 0, 1, 2 or 3 of the identified risk factors had 19%, 32%, 53% and 73% likelihood, respectively, of surgical intervention. Incorporating these data may reduce the use of NCCT scans in patients who are likely to pass a stone via conservative management.

Point‐of‐care renal ultrasound: Are longitudinal views of the kidney alone sufficient to rule out hydronephrosis?

Objective

Point‐of‐care ultrasound for the detection of hydronephrosis is frequently used by emergency physicians. The aim of this study was to assess the accuracy of longitudinal views of the kidney compared with a combination of longitudinal and transverse views of the kidney on emergency physician–performed renal point‐of‐care ultrasound to detect hydronephrosis.

Methods

This was a retrospective case‐control study of patients who received a renal point‐of‐care ultrasound examination performed and interpreted as hydronephrosis in the emergency department (ED). These were then matched with a cohort of kidneys from different patients without hydronephrosis. Longitudinal ultrasound views and transverse ultrasound views were reviewed for the presence of hydronephrosis by ultrasound‐trained emergency physicians. The gold standard of hydronephrosis was an overall interpretation based on the complete ultrasound examination consisting of both transverse and longitudinal views by ultrasound‐trained emergency physicians.

Results

Renal point‐of‐care ultrasound exams from 140 kidneys performed in the ED were enrolled in the study. The sensitivity and specificity of longitudinal ultrasound views compared with a combination of longitudinal and transverse ultrasound views of the kidney as a gold standard were 84.3% (95% confidence interval [CI], 77.2–89.9) and 92.9% (95% CI, 87.3–96.5), the positive predictive value was 92.2% (95% CI, 86.1–96.2), and the negative predictive value was 85.5% (95% CI, 78.9–90.7). The positive and negative likelihood ratios were 11.8 (95% CI, 6.5–21.5) and 0.2 (95% CI, 0.1–0.2), respectively.

Conclusions

Longitudinal views of the kidney on ultrasound showed good sensitivity and specificity to detect the presence of hydronephrosis compared with a combination of longitudinal and transverse ultrasound views of the kidney. However, a combination of longitudinal and transverse ultrasound views may still be warranted in high‐risk patients or in those with inadequate visualization of the upper pole of the kidney.

Ultra-low-dose CTKUB: the new standard of follow-up of ureteric calculi not visible on plain radiograph?

PURPOSE

With sensitivities over 95%, non-contrast computer tomography of kidney, ureter and bladder (CTKUB) is the investigation of choice in renal colic to diagnose or exclude ureteric calculi. CTKUB delivers an average effective radiation dose of 5.4 millisievert (mSv) and is used to follow-up calculi not visible on plain X-ray, whereas plain radiography has a radiation exposure of 0.7 mSv and is used to follow-up radio-opaque calculi. We assessed the effectiveness of using ultra-low-dose CTKUB (ULDCTKUB) for the follow-up of ureteric calculi not visible on plain radiograph of the kidneys, ureter and bladder (KUB), as an emerging option to reduce radiation exposure compared to standard dose CTKUB.

METHODS

Between 2013 and 2016 we retrospectively analysed 86 patients who underwent ULDCTKUB for CTKUB-confirmed ureteric calculi that were not visible on plain radiography. Patients were identified from our Radiology Management System with additional information from electronic patient records.

RESULTS

98% of ULDCTKUBs were of diagnostic quality; two patients required further cross-sectional imaging. 67% of patients had passed their calculi after the initial diagnostic CTKUB. In the remaining 33% who had persistent calculi on ULDCTKUB, 20% required surgical intervention and 13% required no intervention. The mean ULDCTKUB effective radiation dose was six times lower than conventional CTKUB (0.8 vs 5.4 mSv). 67% of patients had a radiation dose equivalent to X-ray KUB (< 1 mSv).

CONCLUSION

ULDCTKUB is a reliable and safe follow-up investigation of ureteric calculi and has absorbed radiation doses similar to plain radiography and lower than annual background radiation. We advocate ULDCTKUB as the primary imaging modality in the follow-up of ureteric calculi not visible on plain radiograph.

When should we give up on expectant management for patients with proximal ureteral stones?

Background:

Proximal ureteral stones (PUS) have relatively low rates of spontaneous expulsion. However, some patients do well on expectant management. Our aim was to compare risk factors for surgical intervention in patients with PUS who underwent primary intervention to those subjected to expectant management.

Materials and methods:

We retrospectively reviewed the medical charts of patients presented to the emergency room with symptoms of renal colic and underwent computerized tomography between August 2016 and August 2017. A total of 97 consecutive patients were identified with up to 10mm PUS. We collected patient demographics, clinical, and imaging data, and performed binary regression analysis for risk of intervention.

Results:

The average age was 49years (range 17-97) and average stone size was 7.1mm (range 3-10). Forty-one patients underwent immediate intervention while the remaining 56 patients were treated conservatively. Of the 56 patients treated conservatively, 26 underwent delayed intervention while 30 reported spontaneous stone expulsion. On univariate analysis of all 97 patients, statistically significant risk factors for intervention were found based on stone size, age, serum lymphocyte, platelet counts, and stone density. Of these risk factors, stone size ≥ 7mm (p = 0.012, odds ratio = 5.4) and platelet count ≤ 230K/μL (p = 0.027, odds ratio = 4.9) remained statistically significant on multivariate analysis.

Conclusion:

Stone size and platelet count were found to be risk factors for surgical intervention in patients with up to 10mm PUS. These findings may assist in identifying patients who are more suitable for conservative approach.

Predictors of renal infarction in patients presenting to the emergency department with flank pain: A retrospective observational study

Objectives

Flank pain is a common symptom in the emergency department and can be caused by a variety of diseases. Renal infarction (RI) is a very rare disease, and many RI patients complain of flank pain. However, there is no definitive predictor of RI when patients complain of flank pain. This study aimed to identify the clinical factors for predicting RI in patients with flank pain.

Methods

This retrospective single-center study was conducted on patients complaining of flank pain from January 2016 to March 2020 at a South Korean tertiary care hospital. Exclusion criteria included patients who did not undergo contrast-enhanced computed tomography, age < 18 years, and trauma. Demographic and laboratory data were obtained from medical records. Logistic regression analysis was conducted to identify predictors of RI occurrence.

Results

In all, 2,131 patients were enrolled, and 39 (1.8%) had RI. From a multivariable logistic regression analysis, an age ≥ 65 years (odds ratio [OR], 3.249; 95% confidence interval [CI], 1.366–7.725; p = 0.008), male sex (OR, 2.846; 95% CI, 1.190–6.808; p = 0.019), atrial fibrillation (OR, 10.386; 95% CI, 3.724–28.961; p < 0.001), current smoker (OR, 10.022; 95% CI, 4.565–22.001; p < 0.001), and no hematuria (OR, 0.267; 95% CI, 0.114–0.628; p = 0.002) were significantly associated with the occurrence of RI.

Conclusions

Five clinical factors, i.e., age ≥ 65 years, male sex, atrial fibrillation, current smoker, and no hematuria, were significantly associated with the occurrence of RI in patients with flank pain.

Can plain film radiography improve the emergency department detection of clinically important urinary stones?

OBJECTIVE

Physicians frequently use ultrasound to assess hydronephrosis in patients with suspected renal colic, but ultrasound has limited diagnostic sensitivity and rarely clarifies stone size or location. Consequently, up to 80% of emergency department (ED) renal colic patients undergo confirmatory CT imaging. Our goal was to estimate x-ray sensitivity for urinary stones and determine whether x-ray substantially improves stone detection (sensitivity) compared to hydronephrosis assessment alone.

METHODS

We reviewed imaging reports from all renal colic patients who underwent x-ray and CT at four EDs. For each patient, we documented stone size, location and hydronephrosis severity on CT and whether stones were identified on x-ray. We considered moderate and severe hydronephrosis (MS-Hydro) as significant positive findings, then calculated the sensitivity (detection rate) of MS-Hydro and x-ray for large stones ≥5 mm and for stones likely to require intervention (all ureteral stones >7 mm and proximal or middle stones >5 mm). We then tested a diagnostic algorithm adding x-ray to hydronephrosis assessment.

RESULTS

Among 1026 patients with 1527 stones, MS-Hydro sensitivity was 39% for large stones and 60% for interventional stones. X-ray sensitivity was 46% for large stones and 52% for interventional stones. Adding x-ray to hydronephrosis assessment increased sensitivity in all stone categories, specifically from 39% to 68% for large stones (gain = 29%; 95%CI, 23% to 35%) and from 60% to 82% for interventional stones (gain = 22%; 95%CI, 13% to 30%). Because CT and ultrasound show strong agreement for MS-Hydro identification, physicians who depend on ultrasound-based hydronephrosis assessment could achieve similar gains by adding x-ray.

CONCLUSIONS

Adding x-ray to hydronephrosis assessment substantially improves diagnostic sensitivity, enabling the detection of nearly 70% of large stones and over 80% of interventional stones. This level of sensitivity may be sufficient to reassure physicians about a renal colic diagnosis without CT imaging for many patients.

Radiation risk issues in recurrent imaging

Millions of patients benefit from medical imaging every single day. However, we have entered an unprecedented era in imaging practices wherein 1 out of 125 patients can be exposed to effective dose >50 mSv from a single CT exam and 3 out of 10,000 patients undergoing CT exams could potentially receive cumulative effective doses > 100 mSv in a single day. Recurrent imaging with CT, fluoroscopically guided interventions, and hybrid imaging modalities such as positron emission tomography/computed tomography (PET/CT) is more prevalent today than ever before. Presently, we do not know the cumulative doses that patients may be receiving across all imaging modalities combined. Furthermore, patients with diseases with longer life expectancies are being exposed to high doses of radiation enabling radiation effects to manifest over a longer time period. The emphasis in the past on improving justification of imaging and optimization of technique and practice has proved useful. While that must continue, the current situation requires imaging device manufacturers to urgently develop imaging technologies that are safer for patients as high doses have been observed in patients where imaging has been justified through clinical decision-support and optimized by keeping doses below the national benchmark doses. There is a need to have a critical look at the fundamental principles of radiation protection as cumulative doses are likely to increase in the coming years.

Deep learning model for automated kidney stone detection using coronal CT images

Kidney stones are a common complaint worldwide, causing many people to admit to emergency rooms with severe pain. Various imaging techniques are used for the diagnosis of kidney stone disease. Specialists are needed for the interpretation and full diagnosis of these images. Computer-aided diagnosis systems are the practical approaches that can be used as auxiliary tools to assist the clinicians in their diagnosis. In this study, an automated detection of kidney stone (having stone/not) using coronal computed tomography (CT) images is proposed with deep learning (DL) technique which has recently made significant progress in the field of artificial intelligence. A total of 1799 images were used by taking different cross-sectional CT images for each person. Our developed automated model showed an accuracy of 96.82% using CT images in detecting the kidney stones. We have observed that our model is able to detect accurately the kidney stones of even small size. Our developed DL model yielded superior results with a larger dataset of 433 subjects and is ready for clinical application. This study shows that recently popular DL methods can be employed to address other challenging problems in urology.

Evaluation of the patients with flank pain in the emergency department by modified STONE score

BACKGROUND/AIM

Computed tomography (CT) is generally used for ureteral stone diagnosis. Unnecessary imaging use should be reduced to prevent increased radiation exposure and lower costs. For this reason, scoring systems that evaluate the risk of ureteral stones have been developed. In this study, we aimed to investigate the diagnostic accuracy of the modified STONE score (MSS) and its ability to predict ureteral stones.

MATERIALS AND METHODS

The research was conducted as a multi-center, prospective and observational study. Patients aged 18 and over who presented to EDs with complaints of flank pain and who received a CT were included. Patients were divided into two groups based on the presence or absence of stones, and the categories of the MSS were determined. The ability of the MSS to predict the ureteral stone and its diagnostic accuracy were calculated.

RESULTS

The median age (min/max) of the 367 study patients was 37 (18/91), and 244 (66.5%) were male. A ureteral stone was present in 228 (73.0%) patients. Male gender, previous stone history, duration of pain less than 6 h, presence of hematuria, and CRP value below 0.5 mg/dL were significantly more common in the group with stones. The prevalence of ureter stones in the MSS high-risk group was 96.0%. The area under the receiver operating characteristic curve and sensitivity of the MSS was 0.903 and 0.81, respectively.

CONCLUSION

The modified STONE score has high diagnostic performance in suspected urinary stone cases. This scoring system can assist clinicians with radiation reducing decision-making.

Can obstructive urolithiasis be safely excluded on contrast CT? A retrospective analysis of contrast-enhanced and noncontrast CT

PURPOSE

The aim of this study was to determine if contrast-enhanced CT can safely exclude obstructive urolithiasis in patients with flank plain. We performed a retrospective cohort analysis to compare the negative predictive values of contrast-enhanced and non-contrast CTs for the detection of obstructing urolithiasis.

METHODS

Through report analysis, we identified all non-contrast and contrast-enhanced CT examinations of the abdomen and pelvis performed on adult patients in the emergency department at a single, multi-site academic medical institution in 2017 with an indication of flank pain. The prevalence of obstructive urolithiasis in each group was calculated. We subsequently analyzed 200 consecutive studies from each of these groups (reported negative for obstructive urolithiasis) for negative predictive value calculation. Follow up abdominal imaging within 7 days from original presentation was used as a reference standard for analysis.

RESULTS

In the noncontrast group, 1 study out of 200 was false negative (negative predictive value = 99.5%). In the contrast-enhanced group, there were no false negatives (negative predictive value = 100%). The prevalence of obstructive urolithiasis was 44.0% (351/797) in the noncontrast group and 18.7% (86/459) in the contrast-enhanced group.

CONCLUSION

Our results suggest that contrast-enhanced CT can safely exclude obstructing ureteral calculi in the setting of acute flank pain. This finding is of clinical relevance given the inherent benefit of IV contrast in diagnosing abdominopelvic pathology.

Development and validation of a score for emergency intervention in patients with acute renal colic secondary to ureteric stones

Objectives: To develop and validate a scoring system to assess the need for emergency intervention (EI) in patients with uncomplicated acute renal colic (ARC) due to ureteric stones. Patients and methods: From May 2017 to April 2019, 382 adult patients presented to emergency department with ARC due to ureteral stones diagnosed by non-contrast computed tomography. Patients with solitary kidney, complications secondary to obstruction (intractable vomiting, fever or sepsis), bilateral ureteric stones, Stage ≥3 chronic kidney disease or those who underwent treatment of urolithiasis within the past 6 months were excluded. EI was performed in cases with persistent or recurrent pain despite analgesics. Multivariate analysis was performed for the first 200 patients to detect risk factors for EI. The score was developed from significant factors. Sensitivity and specificity of the ARC score were calculated using receiver operator characteristic (ROC) curve analysis. The data of last 182 patients were used for validation of the score. Results: In the first 200 patients, EI was needed in 119 patients (59.5%) and included ureteric stents in 92, ureteroscopy in 25 and percutaneous nephrostomy in two. Significant factors for EI were stone location (relative risk [RR] 3.34, P = 0.026), creatinine level (RR 1.04, P < 0.001), leucocyte count (RR 1.69, P < 0.001), and stone length (RR 1.85, P < 0.001). A score using these four variables was developed. The ARC score sensitivity was 86%, specificity was 80% and the area under the ROC curve was 0.902. Validation of the score showed strong correlation between ARC score and need for EI (r = 0.788, P < 0.001). Conclusions: The ARC score is a validated, highly sensitive and specific novel score to determine the need for EI in patients with uncomplicated ARC secondary to ureteric stones. Abbreviations: ARC: acute renal colic; AUC: area under the ROC curve; CDR: clinical decision rules; CKD: chronic kidney disease; ED: emergency department; EI: emergency intervention; MET: medical expulsive therapy; NCCT: non-contrast CT; PCNL, percutaneous nephrolithotomy; ROC: receiver operator characteristic; S.T.O.N.E.: stone size (S), tract length (T), obstruction (O), number of involved calyces (N), and essence or stone density (E); SWL: extracorporeal shockwave lithotripsy; URS: ureteroscopy; WBC: white blood cell.

The Introduction and Development of the H-index for Imaging Utilizers: A Novel Metric for Quantifying Utilization of Emergency Department Imaging

OBJECTIVE

The objective was to develop a novel metric for quantifying patient-level utilization of emergency department (ED) imaging.

METHODS

Using 2009 to 2015 Truven Health MarketScan commercial claims and encounters database, all ED visits and associated imaging services were identified. To measure imaging resource intensity, total imaging relative value units (RVUs) were calculated for each patient per ED visit. An individual's annual imaging h-index is defined as the largest number, h, such that h ED visits by that individual in a given year is associated with total medical imaging RVUs of a value of at least h.

RESULTS

Over 7 years, in a sample of 86,506,362 privately insured individuals (232,919,808 person-years) in all 50 states and the District of Columbia, 38,973,716 ED visits were identified. A total of 9.5% of person-years had one ED visit and 2.7% had two or more (the remainder had none). From 2009 to 2015, the percentage of ED patients undergoing imaging increased from 25.1% to 34.6%. Individuals with two or more ED visits each associated with two or more imaging RVUs (ED imaging h-index ≥ 2) comprised 0.2% of the sample and 1.4% of ED visitors; however, they accounted for 4.0% of ED visits and the use of 18.6% of imaging resources. From 2009 to 2015, imaging resource allocation for such patients increased from 16.5% to 21.0%.

CONCLUSIONS

The ED imaging h-index allows identification of patients who undergo significant ED imaging, based on a single-digit patient-specific metric that incorporates both annual ED visit number and medical imaging resource intensity per visit. While ED patients with an ED imaging h-index ≥ 2 represented a minuscule fraction of privately insured individuals, they were associated with one-fifth of all ED imaging resources.

Renal Colic Imaging: Myths, Recent Trends, and Controversies

There has been a substantial increase in the utilization of imaging, particularly of multi-detector computed tomography (MDCT), for the evaluation of patients with suspected urolithiasis over the past 2 decades. While the diagnostic accuracy of computed tomography (CT) for urolithiasis is excellent, it has also resulted in substantial medical expenditures and increased ionizing radiation exposure. This is especially concerning in patients with known nephrolithiasis and in younger patients. This pictorial review will focus on recent trends and controversies in imaging of patients with suspected urolithiasis, including the current roles of ultrasound (US), MDCT, and magnetic resonance imaging, the estimated radiation dose from MDCT and dose reduction strategies, as well as imaging of suspected renal colic in pregnant patients. The current epidemiological, clinical, and practice management literature will be appraised.

A clinical prediction rule for uncomplicated ureteral stone: The STONE score; a prospective observational validation cohort study

Introduction

Renal colic is one of the most common complaints in patients admitted to Emergency Department (ED). Computed Tomography (CT) is the reference standard for the diagnosis of any stones in the kidneys or ureters. However, CT has classical disadvantages, such as radiation exposure, cost and availability. Recently, STONE clinical prediction criteria were suggested to identify uncomplicated ureteral stone cases among patiens admitted to the ED with abdominal pain. Primary objective of this study was the external validation of the STONE criteria.

Methods

This was a diagnostic accuracy study conducted on a prospective, observational cohort. All consecutive patients who underwent a non-enhanced abdominopelvic CT scan in the ED with an initial diagnosis of ureteral stone disease were enrolled. Using a pre-prepared checklist, all data and the final diagnosis according to the CT scan were recorded. STONE score was calculated for all patients. The area under the curve (AUC) of the STONE Score and the CT, the reference standard, were compared using the ROC curve analysis.

Results

Totally, 237 patients (59.9% male) with an average age of 41.54 years (SD: 13.37) were evaluated, and 156 cases (65.8%) were proved to have renal stone. The mean (SD) STONE scores in the groups of patients with renal stone and in the group of patients without renal stone group were 9.1 (2.6) and 6.0 ( 2.8), respectively (p < 0.001). The area under the curve (AUC) for the STONE score was 0.789 (95% confidence interval (CI) 0.725 to 0.852). The optimum threshold value of the STONE score for the diagnosis of a renal stone was 8 or more, which had a sensitivity of 75.0% and a specificity of 70.4%.

Conclusion

Despite the acceptable diagnostic accuracy, further modifications and enhancements of the STONE score are needed to differentiate patients with low risk prior to imaging.

Pediatric Urinary Stone Disease in the United States: The Urologic Diseases in America Project

OBJECTIVE

To examine the recent epidemiology of pediatric urinary stone disease (USD) in the United States.

METHODS

We utilized the 2004-2016 Optum^© Clinformatics® Data Mart database, a de-identified adjudicated administrative health claims database that includes 15-18 million individuals covered annually by commercial insurance in all 50 US states. The analysis included 12,739,125 children aged 0-18 years. We calculated annual rates of USD, ambulatory visits, and procedures, and the prevalence of prescription fills.

RESULTS

The 2005-2016 USD rate was 59.5 cases per 100,000 person-years. The annual rate rose gradually from 2005 to a peak of 65.2 cases per 100,000 person-years in 2011. The USD rate increased with increasing age, and was highest among females compared to males, non-Hispanic Whites compared to other race/ethnic groups, and those residing in the South compared to other geographic regions. The overall 2005-2016 rate in the 120 days following a USD episode was 1.9 for ambulatory visits, 0.24 for surgical procedures, and 1.1 for imaging procedures. Ureteroscopy was the most common surgical procedure and CT scan was the most common imaging procedures, although ultrasound utilization increased over time. Medications were filled in 46.9% of cases, and use was lowest among males (43.1%), Asians (34.8%), and in the Northeast (34.3%). Opiate agonists were the most prevalent prescription (39.9%).

CONCLUSION

Our study provides one of the most comprehensive examinations of pediatric USD to date, demonstrating shifting rates and treatment patterns over time, as well as differences by age, gender, race/ethnicity, and geographic region.

Contemporary Analysis of Calculous Nephrectomy Utilization and Outcomes in the United States

Introduction: Calculous nephrectomy was a mainstay of treatment of complex upper tract stone disease up until the 1970s, but data on its contemporary utilization in the current era of rising rates of stone disease are lacking. We characterized the nationwide utilization and outcomes for calculous nephrectomy in the United States. Patients and Methods: The National/Nationwide Inpatient Sample databases for 2001 to 2014 were queried for adults with a principal diagnosis of upper urinary tract calculi (UUTCs), who underwent nephrectomy as well as other inpatient surgeries for UUTCs. Per-population trend in utilization of calculous nephrectomy was analyzed using negative binomial regression. The proportion of calculous nephrectomy as a fraction of all inpatient surgical procedures for UUTCs was analyzed using the Cochran-Armitage test. Patient demographics, hospital characteristics, perioperative outcomes, and complications were analyzed using appropriate statistical tests. Results: Of almost 1.42 million inpatient UUTC procedures performed over the study period, 9232 (0.65%) were calculous nephrectomies. Per-population utilization rate for calculous nephrectomy decreased significantly over time (incidence rate ratio = 0.82; 95% confidence interval = 0.73-0.91, p < 0.001). The proportion of calculous nephrectomy as a fraction of all inpatient surgical procedures for UUTC also decreased significantly over time (p < 0.0001). Majority of the procedures were performed in females, in urban teaching hospitals, and in the Southern United States. The overall complication rate was 38.3%, most commonly hemorrhage requiring transfusion (15.6%). Older age, female gender, and nonprivate insurance or lack of insurance were significant predictors of increased risk of complications, whereas hospitalization in urban hospitals was a predictor of lower risk. Conclusions: Despite increasing prevalence of stone disease in the United States in the contemporary era, utilization of calculous nephrectomy is low and is declining. Inpatient complication rates are moderately high and influenced by patient sociodemographic and hospital characteristics.

CT imaging history for patients presenting to the ED with renal colic--evidence from a multi-hospital database

Background

Patients with renal colic have a 7% chance of annual recurrence. Previous studies evaluating cumulative Abbreviations: computed tomography (CT) exposure for renal colic patients were typically from single centers.

Methods

This was an observational cohort study. Inner-city ED patients with a final diagnosis of renal colic were prospectively identified (1/10/16–10/16/16). Authors conducted structured electronic record reviews from a 6-hospital system encompassing over 192,000 annual ED visits. Categorical data analyzed by chi-square; continuous data by t-tests. Primary outcome measure was the proportion of study group patients with prior history CT abdomen/pelvis CT.

Results

Two hundred thirteen patients in the study group; 59% male, age 38+/− 10 years, 67% Hispanic, 62% prior stone history, flank pain (78%), dysuria (22%), UA (+) blood (75%). 60% (95% CI = 53–66%) of patients received an EDCV CT; hydronephrosis seen in 55% (95% CI = 46–63%), stone in 90%(95% CI = 83–94%). No significant differences observed in the proportion of EDCV patients who received CT with respect to: female vs. male (62% vs. 56%; p = 0.4), mean age (37+/− 9 years vs. 39+/− 11 years; p = 0.2), and Hispanic vs. non-Hispanic white (63% vs.63%; p = 0.96). Patients with a prior stone history were more likely than those with no history to receive an EDCV CT (88% vs. 16%; p < 0.001). 118 (55%; 95% CI = 49–62%) of patients had at least one prior CT, 46 (22%; 95% CI = 16–28%) had ≥3 prior CTs; 29 (14%; 95% CI = 10–19%), ≥ 10 prior CTs. Patients who did not receive an EDCV CT had a significantly higher mean prior number of CTs than those who had EDCV CT (5.1+/− 7.7 vs 2.2+/− 4.9; p < 0.001). Patients with prior stone were more likely to receive only U/S during EDCV (33% vs. 15%; p = 0.003).

Conclusions

Within our EDCV cohort of renal colic patients, 55% had at least one prior CT. The mean number of prior CTs was lower for patients receiving CT on EDCV, and Ultrasound (US) alone was used more often in patients with prior stone history vs. those with no prior history.

Name That Nephrogram: Asymmetric Renal Enhancement in the Acute Care Setting

Disorders of the kidney and urinary collecting system are common encountered in the acute care setting. Computed tomography has progressively replaced intravenous pyelography for the evaluation of most urinary tract pathology including acute flank pain, suspected malignancy, congenital abnormalities, anatomical variants, and inflammatory/vascular conditions through evaluation of the "nephrogram" produced by intravenous contrast material filtering through the kidneys. In this review, we describe the most common types of abnormal nephrograms seen on renal computed tomography, and highlight the salient features and conditions associated with them, in addition to a pictorial review with specific and interesting related cases. The types of abnormal nephrograms reviewed are absent, unilateral delayed, striated, spotted, and persistent.

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.

Osmangazi University score to reduce ionizing radiation in renal colic patients in emergency department

Objective:

Computerized tomography remains the gold standard imaging in renal colic patients. In this study, we develop a scoring system to select patients in emergency department for unnecessary computerized tomography imaging in order to decrease radiation exposure.

Methods:

Computerized tomography imaging of patients with renal colic in emergency department were retrospectively reviewed. Symptoms, laboratory results were recorded. Significant parameters were determined by univariate and multivariate analysis. Coefficients were found to obtain score points and receiver operating curve was used to find a cut-off value.

Results:

A total of 123 patients with a mean age of 42 years (18–75 years) were enrolled in the study. About, 20.3% of patients were stone-free in computerized tomography. Mean stone size was 6.1 ± 1.89 mm. According to analysis, four parameters were significant; nausea, stone history, creatinine, and hematuria with a total score 9 called as Osmangazi University STONE score. Cut-off value was found as >3, which computerized tomography imaging is recommended.

Conclusion:

Osmangazi University STONE score is useful and simple tool in emergency department to reduce unnecessary computerized tomography imaging in renal colic patients and also lowers cost and ionizing radiation exposure.

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.

Keeping an Open Mind about Acute Flank Pain in Emergency Department: Acute Kidney Infarction

Differential diagnosis of the acute flank pain in a patient without nephrolithiasis is challenging in emergency department. Renal infarction should be suspected if accompanying cardiac arrhythmia, heart failure or valvular disease is present. Activated protein C resistance is the most common thrombophilia that triggers venous-obstructive conditions and rarely arterial thromboembolism. We described a young male with a history of non-ischemic dilated cardiomyopathy and coexisting activated protein C resistance presented with new onset acute flank pain due to acute renal infarction.

Evaluation of Kidney Stones with Reduced-Radiation Dose CT: Progress from 2011-2012 to 2015-2016-Not There Yet

Purpose To determine if the use of reduced-dose computed tomography (CT) for evaluation of kidney stones increased in 2015-2016 compared with that in 2011-2012, to determine variability in radiation exposure according to facility for this indication, and to establish a current average radiation dose for CT evaluation for kidney stones by querying a national dose registry. Materials and Methods This cross-sectional study was exempt from institutional review board approval. Data were obtained from the American College of Radiology dose registry for CT examinations submitted from July 2015 to June 2016. Study descriptors consistent with single-phase unenhanced CT for evaluation of kidney stones and associated RadLex® Playbook identifiers (RPIDs) were retrospectively identified. Facilities actively submitting data on kidney stone-specific CT examinations were included. Dose metrics including volumetric CT dose index, dose-length product, and size-specific dose estimate, when available, were reported, and a random effects model was run to account for clustering of CT examinations at facilities. A z-ratio was calculated to test for a significant difference between the proportion of reduced-radiation dose CT examinations (defined as those with a dose-length product of 200 mGy · cm or less) performed in 2015-2016 and the proportion performed in 2011-2012. Results Three hundred four study descriptors for kidney stone CT corresponding to data from 328 facilities that submitted 105 334 kidney stone CT examinations were identified. Reduced-dose CT examinations accounted for 8040 of 105 334 (7.6%) CT examinations, a 5.6% increase from the 1010 of 49 903 (2%) examinations in 2011-2012 (P < .001). Mean overall dose-length product was 689 mGy · cm (95% confidence interval: 667, 712), decreased from the mean of 746 mGy · cm observed in 2011-2012. Median facility dose-length product varied up to sevenfold, from less than 200 mGy · cm to greater than 1600 mGy · cm. Conclusion Use of reduced-radiation dose CT for evaluation of kidney stones has increased since 2011-2012, but remains low; variability of radiation dose according to facility continues to be wide. National mean CT radiation exposure for evaluation of renal colic during 2015-2016 decreased relative to 2011-2012 values, but remained well above what is reasonably achievable. ^© RSNA, 2017.

Derivation of decision rules to predict clinically important outcomes in acute flank pain patients

OBJECTIVE

Routine CT for patients with acute flank pain has not been shown to improve patient outcomes, and it may unnecessarily expose patients to radiation and increased costs. As preliminary steps toward the development of a guideline for selective CT, we sought to determine the prevalence of clinically important outcomes in patients with acute flank pain and derive preliminary decision rules.

METHODS

We analyzed data from a randomized trial of CT vs. ultrasonography for patients with acute flank pain from 15 EDs between October 2011 and February 2013. Clinically important outcomes were defined as inpatient admission for ureteral stones and alternative diagnoses. Clinically important stones were defined as stones requiring urologic intervention. We sought to derive highly sensitive decision rules for both outcomes.

RESULTS

Of 2759 participants, 236 (8.6%) had a clinically important outcome and 143 (5.2%) had a clinically important stone. A CDR including anemia (hemoglobin <13.2g/dl), WBC count >11000/μl, age>42years, and the absence of CVAT had a sensitivity of 97.9% (95% CI 94.8-99.2%) and specificity of 18.7% (95% 17.2-20.2%) for clinically important outcome. A CDR including hydronephrosis, prior history of stone, and WBC count <8300/μl had a sensitivity of 98.6% (95% CI 94.5-99.7%) and specificity of 26.0% (95% 24.2-27.7%) for clinically important stone.

CONCLUSIONS

We determined the prevalence of clinically important outcomes in patients with acute flank pain, and derived preliminary high sensitivity CDRs that predict them. Validation of CDRs with similar test characteristics would require prospective enrollment of 2100 patients.

A 10-Year Retrospective Review of Nephrolithiasis in the Navy and Navy Pilots

PURPOSE

Little is known about the incidence of nephrolithiasis in the United States Navy. Navy pilots must be kidney stone-free and are often referred for treatment of small asymptomatic stones. The primary objectives of this study were to determine the incidence of nephrolithiasis and computerized tomography, proportion undergoing treatment and incidence of stone related mishaps in Navy pilots compared with other Navy personnel.

MATERIALS AND METHODS

We retrospectively studied the records of all Navy service members from 2002 to 2011 for nephrolithiasis based on ICD-9 stone codes to determine the mentioned rates. We also reviewed NSC (Naval Safety Center) data for a history of accidents associated with nephrolithiasis. Rates of disease were calculated using person-years of followup and inferential statistics were done using univariable and multivariable analyses.

RESULTS

We evaluated 667,840 Navy personnel with a total of 3,238,331 person-years of followup. The annual incidence of nephrolithiasis was 240/100,000 person-years with a 5-year recurrence rate of 35.3%. On multivariable analysis pilots had nephrolithiasis incidence and treatment rates similar to those of the overall Navy population. Women had a higher incidence of nephrolithiasis compared with men (OR 1.17, p <0.0001). The rate of computerized tomography was lower in pilots than in the rest of the Navy (39 vs 66/10,000 person-years, p <0.0001). No recorded accidents were associated with kidney stones.

CONCLUSIONS

Navy pilots had a similar incidence of nephrolithiasis and were no more likely to undergo a surgical procedure. Given that no accidents were associated with nephrolithiasis, this study suggests reconsidering current military policies necessitating pilots to be completely stone-free.

Trends in Imaging Use for the Evaluation and Followup of Kidney Stone Disease: A Single Center Experience

PURPOSE

Recent reports support renal ultrasound as the initial imaging study to evaluate patients with suspected renal colic. However, urologists often advocate for computerized tomography to better define stone size and location, especially before proceeding with endourological intervention. One concern with using ultrasound as initial imaging is that computerized tomography may be required later, obviating the reduction in costs and radiation gained by using ultrasound.

MATERIALS AND METHODS

We retrospectively reviewed the electronic health records of 10,680 episodes of stone disease in a total of 7,659 patients who presented to the emergency department or walk-in clinic with a chief complaint or visit diagnosis of urolithiasis from 2009 to 2015 at a single institution. Images obtained during the index encounter and in the following 90 days were recorded.

RESULTS

The index encounter included computerized tomography in 47% of episodes, ultrasound in 20%, plain x-ray of the kidneys, ureters and bladder in 12% and no imaging in 29%. Of the index visits 49% included multiple testing. If no computerized tomography was obtained during the index visit, 10% of patients underwent computerized tomography later in the episode. Total imaging costs and radiation exposure during 90 days were significantly higher when computerized tomography was done at the index visit. If the initial image obtained during an episode was ultrasound, computerized tomography was performed in 20% of cases within 90 days.

CONCLUSIONS

Of patients who underwent an initial ultrasound 80% avoided computerized tomography imaging. Avoiding computerized tomography at the index visit was associated with substantial reductions in radiation exposure and imaging costs.

The Diagnosis and Management of Patients with Renal Colic across a Sample of US Hospitals: High CT Utilization Despite Low Rates of Admission and Inpatient Urologic Intervention

Objectives

Symptomatic ureterolithiasis (renal colic) is a common Emergency Department (ED) complaint. Variation in practice surrounding the diagnosis and management of suspected renal colic could have substantial implications for both quality and cost of care as well as patient radiation burden. Previous literature has suggested that CT scanning has increased with no improvements in outcome, owing at least partially to the spontaneous passage of kidney stones in the majority of patients. Concerns about the rising medical radiation burden in the US necessitate scrutiny of current practices and viable alternatives. Our objective was to use data from a diverse sample of US EDs to examine rates of and variation in the use of CT scanning, admission, and inpatient procedures for patients with renal colic and analyze the influence of patient and hospital factors on the diagnostic testing and treatment patterns for patients with suspected renal colic.

Methods

We conducted a retrospective cohort study of adult patients who received a diagnosis of renal colic via a visit to an ED at 444 US hospitals participating in the Premier Healthcare Alliance database from 2009–2011. We modeled use of CT, admission, and inpatient urologic intervention as functions of both patient characteristics and hospital characteristics.

Results

Over the 2-year period, 307,612 patient visits met inclusion criteria. Among these patients, 254,211 (82.6%) had an abdominal CT scan, with 91.5% being non-contrast (“renal protocol”) CT scans. Nineteen percent of visits (58,266) resulted in admission or transfer, and 9.8% of visits (30,239) resulted in a urologic procedure as part of the index visit. On multivariable analysis male patients, Hispanic patients, uninsured patients, and privately insured patients were more likely to have a CT scan performed. Older patients and those covered by Medicare were more likely to be admitted, and once admitted, white patients and privately insured patients were more likely to have a urologic intervention. Only hospital region was associated with variation in CT rates, and this variation was minimal. Region and size of the hospital were associated with admission rates, and hospitals with more practicing urologists had higher intervention rates.

Conclusions

In this dataset, the majority of patients did not require admission or immediate intervention. Despite this, the large majority received CT scans, in a cohort representing 15–20% of all US ED visits. The CT rate was minimally variable at the hospital level, but the admission rates varied 2-fold, suggesting that hospital-level factors affect patient management. The high rate of CT usage coupled with the low rate of immediate intervention suggests that further research is warranted to identify patients who are at low risk for an immediate intervention, and could potentially be managed with ultrasound alone, expectant management, or delayed CT.

Does the use of bedside ultrasonography reduce emergency department length of stay for patients with renal colic?: a pilot study

Objective

The aim of this study was to evaluate the effect of adding bedside ultrasonography to the diagnostic algorithm for nephrolithiasis on emergency department (ED) length of stay.

Methods

A prospective, randomized, controlled pilot study was conducted from October 2014 to December 2014 with patients with acute flank pain. In the non-ultrasonography group (NUSG), non-contrast computed tomography was selected based on clinical features and hematuria in the urinalysis. In the ultrasonography group (USG), non-contrast computed tomography was selected based on clinical features and hydronephrosis on bedside ultrasonography. The primary outcome was ED length of stay. The secondary outcomes were radiation exposure, amount of analgesics, proportion of patients with diseases other than ureteral calculus, and proportion of patients with unexpected ED revisits within 7 days from the index visit.

Results

A total of 103 patients were enrolled (NUSG, 51; USG, 52). The ED length of stay for the USG (89.0 minutes) was significantly shorter than that for the NUSG (163.0 minutes, P<0.001). There were no significant differences between the two groups in the radiation exposure dose (5.29 and 5.08 mSv, respectively; P=0.392), amount of analgesics (P=0.341), proportion of patients with diseases other than ureteral calculus (13.0% and 6.8%, respectively; P=0.486), and proportion of patients with unexpected ED revisits within 7 days from the index visit (7.8% and 9.6%, respectively; P=1.000).

Conclusion

The use of early bedside ultrasonography for patients with acute flank pain could reduce the ED length of stay without increasing unexpected ED revisits.

Sex-related Differences in Emergency Department Renal Colic Management: Females Have Fewer Computed Tomography Scans but Similar Outcomes

BACKGROUND

Sex-related differences occur in many areas of medicine. Emergency department (ED) studies have suggested differences in access to care, diagnostic imaging use, pain management, and intervention. We investigated sex-based differences in the care and outcomes for ED patients with acute renal colic.

METHODS

This was a multicenter population-based retrospective observational cohort study using administrative data and supplemented by structured chart review. All patients seen in Calgary Health Region EDs between January 1 and December 31, 2014, with an ED diagnosis of renal colic based on the following ICD-10 codes were eligible for inclusion: calculus of kidney (N200), calculus of ureter (N201), calculus of kidney with calculus of ureter (N202), hydronephrosis with renal and ureteral calculous obstruction (N132), unspecified renal colic (N23), and unspecified urinary calculus (N209). ED visit data and test results were accessed in the regional ED clinical database. Stone characteristics were captured from diagnostic imaging reports. Regional hospital databases were used to identify subsequent ED encounters, hospital admissions, and surgical procedures within 60 days. Outcomes were stratified by sex. The primary outcome, intended as a marker of overall effectiveness of ED care, was the unscheduled 7-day ED revisit rate among patients who were discharged home after their index ED visit. Secondary outcomes included ED pain management as reflected by administration of narcotics or intravenous nonsteroidals, the performance of advanced imaging-either ultrasound (US) or computed tomography (CT), and the proportion of patients who required hospitalization or surgical intervention within 60 days.

RESULTS

From January 1 to December 31, 2014, a total of 3,104 eligible patients were studied: 1,111 women (35.8%) and 1,993 men (64.2%). Baseline characteristics, access times, analgesic use, and admission rates were similar in both groups. Men were more likely to have CT (68.9% vs. 58.5%, difference = 10.4%, 95% confidence interval [CI] = 6.8 to 14.0) while women were more likely to have US (20.8% vs. 9.6%, difference = 11.2%, 95% CI = 8.4 to 13.9). At 7 days, 17.9% of women and 19.0% of men who were discharged after their index ED visit required an ED revisit (difference = 1.1%, 95% CI = -2.8 to 4.9). Men were more likely to be hospitalized at 7 days (9.8% vs. 6.5%, difference = 3.3%, 95% CI = 0.6 to 6.0).

CONCLUSION

This study shows greater reliance on US in females but no other sex-specific differences in the management of ED patients with acute renal colic. Higher CT use in men was not associated with improved outcomes, and we found no important differences in access to care, diagnostic or treatment intensity, or revisit rates as a marker of care effectiveness.

Do C-reactive protein level, white blood cell count, and pain location guide the selection of patients for computed tomography imaging in non-traumatic acute abdomen?

The value of abdominal computed tomography in non-traumatic abdominal pain has been well established. On the other hand, to manage computed tomography, appropriateness has become more of an issue as a result of the concomitant increase in patient radiation exposure with increased computed tomography use. The purpose of this study was to investigate whether C-reactive protein, white blood cell count, and pain location may guide the selection of patients for computed tomography in non-traumatic acute abdomen. Patients presenting with acute abdomen to the emergency department over a 12-month period and who subsequently underwent computed tomography were retrospectively reviewed. Those with serum C-reactive protein and white blood cell count measured on admission or within 24 h of the computed tomography were selected. Computed tomography examinations were retrospectively reviewed, and final diagnoses were designated either positive or negative for pathology relating to presentation with acute abdomen. White blood cell counts, C-reactive protein levels, and pain locations were analyzed to determine whether they increased or decreased the likelihood of producing a diagnostic computed tomography. The likelihood ratio for computed tomography positivity with a C-reactive protein level above 5 mg/L was 1.71, while this increased to 7.71 in patients with combined elevated C-reactive protein level and white blood cell count and right lower quadrant pain. Combined elevated C-reactive protein level and white blood cell count in patients with right lower quadrant pain may represent a potential factor that could guide the decision to perform computed tomography in non-traumatic acute abdomen.

Accuracy of ultrasonography for renal stone detection and size determination: is it good enough for management decisions?

OBJECTIVES

To determine the sensitivity and specificity of ultrasonography (US) for detecting renal calculi and to assess the accuracy of US for determining the size of calculi and how this can affect counselling decisions.

MATERIALS AND METHODS

We retrospectively identified all patients at our institution with a diagnosis of nephrolithiasis who underwent US followed by non-contrast computed tomography (CT) within 60 days. Data on patient characteristics, stone size (maximum axial diameter) and stone location were collected. The sensitivity, specificity and size accuracy of US was determined using CT as the standard.

RESULTS

A total of 552 US and CT examinations met the inclusion criteria. Overall, the sensitivity and specificity of US was 54 and 91%, respectively. There was a significant association between sensitivity of US and stone size (P < 0.001), but not with stone location (P = 0.58). US significantly overestimated the size of stones in the 0-10 mm range (P < 0.001). Assuming patients with stones 0-4 mm in size will be selected for observation and those with stones ≥5 mm could be counselled on the alternative of intervention, we found that in 14% (54/384) of cases where CT would suggest observation, US would lead to a recommendation for intervention. By contrast, when CT results would suggest intervention as management, US would suggest observation in 39% (65/168) of cases. An average of 22% (119/552) of patients could be inappropriately counselled. Stones classified as 5-10 mm according to US had the highest probability (43% [41/96]) of having their management recommendation changed when CT was performed. The use of plain abdominal film of kidney, ureter and bladder and US increases sensitivity (78%), but 37% (13/35) of patients may still be counselled inappropriately to undergo observation.

CONCLUSIONS

Using US to guide clinical decision-making for residual or asymptomatic calculi is limited by low sensitivity and inability to size the stone accurately. As a result, one in five patients may be inappropriately counselled when using US alone.

Urinary Stone Disease: Advancing Knowledge, Patient Care, and Population Health

Expanding epidemiologic and physiologic data suggest that urinary stone disease is best conceptualized as a chronic metabolic condition punctuated by symptomatic, preventable stone events. These acute events herald substantial future chronic morbidity, including decreased bone mineral density, cardiovascular disease, and CKD. Urinary stone disease imposes a large and growing public health burden. In the United States, 1 in 11 individuals will experience a urinary stone in their lifetime. Given this high incidence and prevalence, urinary stone disease is one of the most expensive urologic conditions, with health care charges exceeding $10 billion annually. Patient care focuses on management of symptomatic stones rather than prevention; after three decades of innovation, procedural interventions are almost exclusively minimally invasive or noninvasive, and mortality is rare. Despite these advances, the prevalence of stone disease has nearly doubled over the past 15 years, likely secondary to dietary and health trends. The NIDDK recently convened a symposium to assess knowledge and treatment gaps to inform future urinary stone disease research. Reducing the public health burden of urinary stone disease will require key advances in understanding environmental, genetic, and other individual disease determinants; improving secondary prevention; and optimal population health strategies in an increasingly cost-conscious care environment.

External validation of the STONE score and derivation of the modified STONE score

OBJECTIVE

The STONE score is a clinical prediction rule for the presence of uncomplicated ureter stones with a low probability of acutely important alternative findings. This study performed an external validation of the STONE score, focusing on the Korean population, and a derivation of the modified STONE score for better specificity and sensitivity.

METHODS

We retrospectively reviewed medical records of patients complaining of flank pain at a single emergency department from January 2013 to December 2014. Patients were categorized into 3 groups according to their STONE score. The prevalence of ureter stones and other alternative findings were calculated in each group. We derived a modified STONE score based on a multivariable analysis and performed an interval validation.

RESULTS

From the 700 patients included in the analysis, 555 patients (79%) had a ureter stone. The area under the receiver operating characteristic curve of the STONE score was 0.92. The sensitivity of the high stone score was 0.56. In the modified STONE score, nausea, vomiting, and racial predictors were substituted by C-reactive protein and previous stone history. The area under the receiver operating characteristic curve and sensitivity of the modified STONE score in the internal validation group significantly increased to 0.94 and 0.80, respectively.

CONCLUSION

The STONE score can be used to predict a ureter stone with a low probability of other alternative findings. The modified STONE score might increase the diagnostic performance in suspicious urinary stone cases.

KEY POINTS

We performed external validation of the STONE score and derivation of the modified STONE score. This scoring system could help the clinicians with radiation reducing decision making.

Ureteral Stones: Implementation of a Reduced-Dose CT Protocol in Patients in the Emergency Department with Moderate to High Likelihood of Calculi on the Basis of STONE Score

Purpose To determine if a reduced-dose computed tomography (CT) protocol could effectively help to identify patients in the emergency department (ED) with moderate to high likelihood of calculi who would require urologic intervention within 90 days. Materials and Methods The study was approved by the institutional review board and written informed consent with HIPAA authorization was obtained. This was a prospective, single-center study of patients in the ED with moderate to high likelihood of ureteral stone undergoing CT imaging. Objective likelihood of ureteral stone was determined by using the previously derived and validated STONE clinical prediction rule, which includes five elements: sex, timing, origin, nausea, and erythrocytes. All patients with high STONE score (STONE score, 10-13) underwent reduced-dose CT, while those with moderate likelihood of ureteral stone (moderate STONE score, 6-9) underwent reduced-dose CT or standard CT based on clinician discretion. Patients were followed to 90 days after initial imaging for clinical course and for the primary outcome of any intervention. Statistics are primarily descriptive and are reported as percentages, sensitivities, and specificities with 95% confidence intervals. Results There were 264 participants enrolled and 165 reduced-dose CTs performed; of these participants, 108 underwent reduced-dose CT alone with complete follow-up. Overall, 46 of 264 (17.4%) of patients underwent urologic intervention, and 25 of 108 (23.1%) patients who underwent reduced-dose CT underwent a urologic intervention; all were correctly diagnosed on the clinical report of the reduced-dose CT (sensitivity, 100%; 95% confidence interval: 86.7%, 100%). The average dose-length product for all standard-dose CTs was 857 mGy · cm ± 395 compared with 101 mGy · cm ± 39 for all reduced-dose CTs (average dose reduction, 88.2%). There were five interventions for nonurologic causes, three of which were urgent and none of which were missed when reduced-dose CT was performed. Conclusion A CT protocol with over 85% dose reduction can be used in patients with moderate to high likelihood of ureteral stone to safely and effectively identify patients in the ED who will require urologic intervention. (©) RSNA, 2016 Online supplemental material is available for this article.

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.

Quality of Acute Care for Patients With Urinary Stones in the United States

OBJECTIVE

To describe guideline adherence for patients with suspected upper tract stones.

PATIENTS AND METHODS

We performed a cross-sectional analysis of visits recorded by the National Hospital Ambulatory Medical Care Survey (emergency department [ED] component) in 2007-2010 (most recent data). We assessed adherence to clinical guidelines for diagnostic laboratory testing, imaging, and pharmacologic therapy. Multivariable regression models controlled for important covariates.

RESULTS

An estimated 4,956,444 ED visits for patients with suspected kidney stones occurred during the study period. Guideline adherence was highest for diagnostic imaging, with 3,122,229 (63%) visits providing optimal imaging. Complete guideline-based laboratory testing occurred in only 2 of every 5 visits. Pharmacologic therapy to facilitate stone passage was prescribed during only 17% of eligible visits. In multivariable analysis of guideline adherence, we found little variation by patient, provider, or facility characteristics.

CONCLUSION

Guideline-recommended care was absent from a substantial proportion of acute care visits for patients with suspected kidney stones. These failures of care delivery likely increase costs and temporary disability. Targeted interventions to improve guideline adherence should be designed and evaluated to improve care for patients with symptomatic kidney stones.

Usefulness of Nonenhanced Computed Tomography for Diagnosing Urolithiasis without Pyuria in the Emergency Department

We compared the clinical utility of nonenhanced computed tomography (NECT) and intravenous urography (IVU) in patients with classic symptoms of renal colic without evidence of a urine infection. This was a retrospective analysis of IVU and NECT performed in adult patients with suspected renal colic at an emergency department between January 2005 and December 2013. The records of all patients in NECT and IVU groups were reviewed, and the patients were categorized according to the cause of their symptoms. A total of 2218 patients were enrolled. Of these patients, 1525 (68.8%) underwent IVU and 693 (31.2%) underwent NECT. The patients in NECT group were older (45.48 ± 14.96 versus 42.37 ± 13.68 years, p < 0.001), had less gross hematuria (7.6 versus 2.9%, p < 0.001), and were admitted more often (18.6 versus 12.0%, p < 0.001) than the patients in IVU group. Urinary stones were detected in 1413 (63.7%) patients. NECT had a higher detection rate of urolithiasis than IVP (74.0 versus 59.0%, p < 0.001). No significant difference was observed in the incidence of urinary stones greater than 4mm between groups from the radiologic findings (p = 0.79) or the full medical record review (p = 0.87).

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

CONTEXT

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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