Imaging patients with renal colic-consider ultrasound first

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.

A Multicentric Audit to Reevaluate the Guidelines Adherence in Computed Tomography of Kidneys, Ureters, and Bladder (CT-KUB) X-ray Imaging in Jordan

Background With the increasing use of imaging techniques involving ionizing radiation, the area of the body scanned should be restricted to what is required to answer the clinical question. Therefore, this is a retrospective audit that intends to evaluate the presence of overscanning in renal computed tomography (CT) scan images during the process of evaluation for urinary symptoms. Objective This study aims to reduce the unnecessary scan length and exposure to radiation in patients who undergo CT scans for urinary symptoms. Materials and Methods In two months duration, patients from different clinics underwent CT imaging, and the resulting radiographic images were collected and analyzed. Overscanning was defined to be more than 10% of the total scan. Subsequently, the total length of the CT scan was measured which is used to measure the unnecessary overscan above the highest kidney margin as a percentage of the total length. Results Out of the 88 patients who were evaluated, 100% did not meet the guidelines for renal CT imaging and were exposed to a high radiation dose. However, the minimum percentage of overscanned patients was 20-40%. Conclusion A significant number of scans demonstrated surplus overscanning above the highest kidney. Therefore, recognizing the suitable anatomical landmarks for scanning and establishing a follow-up audit are suggested measures to minimize the noxious effects of radiation exposure.

Acute Pelvic Pain: Role of Imaging in the Diagnosis and Management

Acute pelvic pain is defined as a new symptom that has been present for less than 3 months. It is a common symptom seen in 15%-24% of women and is the indication for 20% of laparoscopies and 2%-10% of outpatient gynecologic visits. The pregnancy status and correlation of the physical symptoms with clinical findings are important. Ultrasound is the imaging modality of choice, not only to diagnose gynecological causes, but also bowel or urinary tract related causes of pelvic pain. When an ultrasound scan is inconclusive, a computed tomography scan is the preferred means of additional imaging and is particularly useful in gastrointestinal and urogenital causes of pelvic pain. Gynecological causes of acute pelvic pain include uterine, tubal, or ovarian pathology; non-gynecological causes include bowel diseases, such as appendicitis and diverticulitis; urogenital causes such as ureteral, bladder stones, and urinary tract infection as well as vascular causes. Ultrasound imaging alone may provide a definitive diagnosis in underlying conditions that require prompt medical or surgical intervention in gynecological conditions, such as ovarian torsion, ectopic pregnancy, and non-gynecological condition, such as in acute appendicitis.

Progression of asymptomatic nephrolithiasis in children: How often should patients receive follow-up ultrasound imaging?

INTRODUCTION

The natural history of asymptomatic nephrolithiasis (AN) in children is not well defined. Furthermore, there is no guidance on the utility of repeated renal ultrasound evaluations in this same population. Follow-up ultrasound studies are often obtained as frequently as every 6 months. The goal of this study is to assess the follow-up ultrasound interval in the management of these patients.

METHODS

A retrospective IRB approved chart review was performed for patients seen for non-cysteine AN between 2012 and 2019. AN was defined as patients without obstructive uropathy abdominal, flank pain and/or gross hematuria. Asymptomatic stones were discovered incidentally or after an acute stone event. Patients with pre-existing renal anomalies and the timepoints with stone passage or stone procedure were excluded. Descriptive statistics were used for demographic information. Multiple linear regression was used to analyze risk factors. Statistical significance was set to p < 0.05.

RESULTS

Twenty-nine patients had 90 ultrasounds. The average age at diagnosis was 10.8 ± 6.2 years. The average number of ultrasound studies per patient was 3.2 ± 1.7. The median time between follow-up ultrasounds was 5.2 months [IQR 2.8-10.0]. Median follow-up of patients was 10.6 months [IQR 4.9-21.9]. The change in total stone burden occurred at a rate of 0.11 mm/month (CI [-0.06-0.28], p = 0.20, r² = 0.42) or 0.66 mm/6 months. Patients with more renal stones had almost a threefold increase in stone burden compared to patients with fewer renal stones (2.98 [CI 1.34-4.62], p=0.001, r²=0.33). Patients with a family history of stones had a twofold increase in the size of their largest stone when compared to patients without a family history (1.97 [CI 0.26-3.68], p=0.02, r²=0.60.

CONCLUSION

A complex interplay of multiple factors influence the progression of AN in children. Children with a greater number of stones have a higher increase in total stone burden and children with a family history of stones have a faster increase in largest stone size. These patients may require more frequent imaging studies. The small change in stone size over time favors a longer than 6-month interval for many children.

A Preliminary Investigation on the “Swinging Kidney”: A Sonographic Sign Useful for Diagnosing Renal Colic

Objective:

During acute renal colic due to nephrolithiasis, a new sonographic diagnostic sign was noted, called “a swinging kidney.” This term was given due to a characteristic anteroposterior “rolling” movement of the kidney. A preliminary investigation was conducted to evaluate the correlation between this new diagnostic sign and nephrolithiasis.

Materials and Methods:

An exploratory observational investigation was conducted on adult patients who accessed an emergency medicine department, with acute renal colic, between June 1, 2019, and October 31, 2019.

Results:

Thirty-seven patients were enrolled. The “swinging kidney” was present in 26 cases (70%). This sign was correlated with a stone’s diameter of less than 10 mm (χ2: 4.68; P = .031), and with a stone localization in the juxtavesical ureter tract site (χ2: 10.83; P = .029). Spontaneously stone expulsion was correlated with the presence of the “swinging kidney” (χ2: 4.66; P = .031); with the minor degree of hydronephrosis (χ2: 16.82; P = .0008), and with a distal localization of the stone (χ2: 25.11; P = 1:47 × 10−5).

Conclusion:

The “swinging kidney” may be a promising diagnostic sign that could be useful in diagnosing nephrolithiasis besides the other indirect sonographic signs. This new diagnostic sign could have a prognostic role.

Resolution of Hydronephrosis and Pain to Predict Stone Passage for Patients With Acute Renal Colic

OBJECTIVE

To study patients who presented to the Emergency Department with acute renal colic to determine if resolution of hydronephrosis and pain accurately predicts stone passage on follow-up CT.

MATERIALS AND METHODS

This is a secondary analysis of a multicenter prospective randomized clinical trial of patients diagnosed by computed tomography (CT) scan with a symptomatic ureteral stone < 9 mm in diameter. Participants were followed after randomization to evaluate for analgesic use and to assess stone passage and hydronephrosis on a repeat CT scan obtained at 29-36 days.

RESULTS

Four-hundred-three patients were randomized in the original study and patients were included in this analysis if they did not have surgery for stone removal and had a CT scan and information on pain medication at follow-up (N = 220). Hydronephrosis was detected in 181 (82%) on initial CT. At follow-up CT, 43 (20%) participants had a persistent ureteral stone. Of these patients, 36 (84%) had no pain, 26 (60%) did not have hydronephrosis, and 23 (53%) had neither pain nor hydronephrosis. Resolution of hydronephrosis was associated with stone passage (RR 4.6, 95% CI 1.9, 11.0), while resolution of pain was not (RR 1.1, 95% CI 0.9, 1.4).

CONCLUSION

In patients with urinary stone disease, stone passage is associated with resolution of hydronephrosis but not resolution of pain. In patients with persistent ureteral stones, neither pain nor hydronephrosis are consistently present. These findings have important implications on follow-up imaging of patients with urinary stone disease.

Comparison of nonenhanced computed tomography and ultrasonography for detection of ureteral calculi in cats: A prospective study

BACKGROUND

Radiographs and ultrasound (US) are the primary imaging modalities used to assess ureteral calculi in cats. Reports describing the use of nonenhanced computed tomography (CT) are scarce.

HYPOTHESIS/OBJECTIVES

To compare US and nonenhanced CT for detection, number and localization of ureteral calculi in cats.

ANIMALS

Fifty-one cats with at least 1 ureteral calculus, and 101 ureters.

METHODS

Prospective case series. All cats underwent an US followed by a nonenhanced CT. Cats were included in the study if at least 1 ureteral calculus was diagnosed on either modality. Number of calculi and their localization (proximal, middle, and distal) were recorded on both modalities. Pelvic dilatation and maximal ureteral diameter were recorded with US.

RESULTS

More calculi were detected by nonenhanced CT (126) compared to US (90), regardless of localization (P < .001). More ureters were affected on nonenhanced CT (70) compared to US (57; P < .001). The number of calculi detected was significantly different between US and nonenhanced CT in the proximal (P = .02) and distal ureteral region (P < .001). Bilateral calculi were more frequent with nonenhanced CT (19 cats) compared to US (9 cats; P < .001). A pelvic size superior to 5 mm and a maximal ureteral diameter value superior to 3 mm were always associated with ureteral calculi.

CONCLUSIONS AND CLINICAL IMPORTANCE

Computed tomography is an emerging imaging modality in cats with a suspected ureteral obstruction. Combination of CT and US can be beneficial for case management.

Implementation of a Ureteric Colic Telemedicine Service: A Mixed Methods Quality Improvement Study

OBJECTIVE

To assess the effectiveness of a telemedicine service for ureteric colic patients in reducing the number of unnecessary face-to-face consultations and shortening waiting time for appointments.

METHODS

A telemedicine workflow was implemented as a quality improvement study using the Plan-Do-Study-Act method. All patients presenting with ureteric colic without high-risk features of fever, severe pain, and hydronephrosis, were recruited, and face-to-face appointments to review scan results were replaced with phone consultations. Data were prospectively collected over 3 years (January 2017 to December 2019). Patient outcomes including the reduction in face-to-face review visits, time to review, reattendance and intervention rates, were tracked in an interrupted time-series analysis, and qualitative feedback was obtained from patients and clinicians.

RESULTS

Around 53.2% of patients presenting with ureteric colic were recruited into the telemedicine workflow. A total of 465 patients (46.2%) had normal scan results and 250 patients (24.9%) did not attend their scan appointments, hence reducing the number of face-to-face consultations by 71.1%. A total of 230 patients (22.9%) required subsequent follow-up with urology, while 61 patients (6.1%) were referred to other specialties. Mean (SD) time to review was 30.0 (6.2) days, 6-month intervention rate was 3.4% (n = 34) and unplanned reattendance rate was 3.2% (n = 32). Around 93.1% of patients reported satisfaction with the service.

CONCLUSION

The ureteric colic telemedicine service successfully and sustainably reduced the number of face-to-face consultations and time to review without compromising on patient safety. The availability of this telemedicine service has become even more important in helping us provide care to patients with ureteric colic in the current COVID-19 pandemic.

The gap between ultrasonography and computed tomography in measuring the size of urinary calculi

Objective

Due to a lack of studies regarding the need for computed tomography (CT) in measuring the size of each urinary calculus before surgery, this study was conducted to elucidate the difference between ultrasonography (US) and CT in measuring the size of urinary stones.

Methods

A retrospective review of 100 stones from 83 patients. Each urinary stone was measured using both US and CT; both measurements were then compared.

Results

Of 83 patients, the mean age was 39.29 ± 23.76 years; 47 (56.62%) were male and 36 (43.37%) were female. Most of the urinary stones were <10 mm (50.0%) followed by 11-20 mm (42.0%), (P < 0.001). A cross-tabulation test revealed strong compatibility between US and CT in measuring the size of urinary stones (73.7% in stones <10 mm, 66.7% in stones 11-20 mm and 50% in stones >21 mm), (P < 0.001). Spearman's rho correlation test revealed strong compatibility between stone diameters measured by US and CT (r = 0.755), (P = 0 < 0.001). T-test for equality of means revealed no significant difference in the measured size using US and CT (mean = 11.80 ± 5.83 vs. 11.65 ± 6.59, respectively), mean difference = 0.15, and P = 0.865, 95% confidence interval: -1.584-1.884.

Conclusion

No significant difference in measuring the size of urinary stones using US and CT. However, US may slightly overestimate small stones in some cases.

Risk Factors Predicting the Necessity of Renal Ultrasound in the Emergency Department

Objectives:

Renal ultrasound (US) is widely used for diagnosing renal pathologies, though few of them, such as obstructive uropathy, require emergent urological intervention. During on-call hours, when medical staff is limited, it is important to prioritize which renal US examinations will be done. The aim of this study was to evaluate patient risk factors to predict the necessity of emergent renal US in the emergency department (ED).

Material and Methods:

All adult patients referred for renal US from the ED, during on-call hours from May 2015 to April 2017, were retrospectively included. The mean age was 64 years (18–98). Data were collected from the patients’ medical records. Urological intervention performed within the first 24 h following the US examination was recorded. Multivariate analysis was performed.

Results:

About 66% of the patients did not have a permanent urethral catheter, history of renal stones, or known abdominal or pelvic mass. None of these patients required an urgent urological intervention. The receiver operating characteristic curve was calculated at 0.883, 95% CI (0.84–0.92).

Conclusion:

Using only three variables, we can greatly reduce the number of renal US examinations done at on-call hours allowing for prioritization of only the necessary examinations.

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

Context

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

Aims

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

Settings and Design

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

Materials and Methods

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

Statistical Analysis Used

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

Results

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

Conclusions

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

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.

Epidemiological and imaging features that can affect the detection of ureterolithiasis on ultrasound

Objective

To identify, in patients with clinical suspicion of ureterolithiasis, epidemiological and imaging features that affect calculus detection on ultrasound, as well as to compare ultrasound with multidetector computed tomography (MDCT).

Materials and Methods

We searched our database for patients who underwent ultrasound, followed by MDCT (if the ultrasound was negative), for suspected ureterolithiasis in an emergency setting. Patients were divided into three groups: positive ultrasound (US+); negative ultrasound/positive MDCT (US−/MDCT+); and negative ultrasound/negative MDCT (US−/MDCT−). We evaluated age, gender, ureterolithiasis laterality, location of the calculus within the ureter, body mass index, calculus diameter, and calculus attenuation on MDCT.

Results

Of a total of 292 cases of suspected ureterolithiasis, 155 (53.1%) were in the US+ group, 46 (15.7%) were in the US−/MDCT+ group, and 91 (31.2%) were in the US−/MDCT− group. There were no significant differences among the groups in terms of age, gender, ureterolithiasis laterality, and mean MDCT attenuation values. Distal ureterolithiasis was most common in the US+ group, and calculi at other ureteral locations were more common in the US−/MDCT+ group. The mean body mass index was significantly higher in the US−/MDCT+ group than in the US+ group, and the mean calculus diameter was significantly greater in the US+ group than in the US−/MDCT+ group.

Conclusion

A high body mass index, large calculus diameter, and calculus location in the distal third of the ureter are the major factors favoring ureterolithiasis detection on ultrasound.

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

Objective:

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

Methods:

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

Results:

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

Conclusion:

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

Feasibility of non-linear beamforming ultrasound methods to characterize and size kidney stones

Purpose

Ultrasound methods for kidney stone imaging suffer from poor sensitivity and size overestimation. The study objective was to demonstrate feasibility of non-linear ultrasound beamforming methods for stone imaging, including plane wave synthetic focusing (PWSF), short-lag spatial coherence (SLSC) imaging, mid-lag spatial coherence (MLSC) imaging with incoherent compounding, and aperture domain model image reconstruction (ADMIRE).

Materials and methods

The ultrasound techniques were evaluated in an in vitro kidney stone model and in a pilot study of 5 human stone formers (n = 6 stones). Stone contrast, contrast-to-noise ratio (CNR), sizing, posterior shadow contrast, and shadow width sizing were compared among the different techniques and to B-mode. CT imaging within 60 days was considered the gold standard stone size. Paired t-tests using Bonferroni correction were performed to evaluate comparing each technique with B-mode.

Results

Mean CT measured stone size was 6.0mm (range 2.9–12.2mm) with mean skin-to-stone distance 10.2cm (range 5.4–16.3cm). Compared to B-mode, stone contrast was best with ADMIRE (mean +12.2dB), while SLSC and MLSC showed statistically improved CNR. Sizing was best with ADMIRE (mean +1.3mm error), however this was not significantly improved over B-mode (+2.4mm). PWSF performed similarly to B-mode for stone contrast, CNR, SNR, and stone sizing. In the in vitro model, the shadow contrast was highest with ADMIRE (mean 10.5 dB vs 3.1 dB with B-mode). Shadow sizing was best with SLSC (mean error +0.9mm ± 2.9), however the difference compared to B-mode was not significant.

Conclusions

The detection and sizing of stones are feasible with advanced beamforming methods with ultrasound. ADMIRE, SLSC, and MLSC hold promise for improving stone detection, shadow contrast, and sizing.

A role of the endothelial nitric oxide system in acute renal colic caused by ureteral stone

BACKGROUND AND AIMS

Endothelial nitric oxide synthase gene polymorphisms play a role in some pathophysiological processes. In this study, the possible effects of endothelial nitric oxide synthase gene polymorphisms on ureteral stone disease in patients who were admitted to the emergency department with severe pain due to renal colic are examined.

MATERIALS AND METHODS

The study groups were designed as controls and patients. The control group was formed from the healthy volunteers who applied to the blood center next to the emergency service. The patient group comprised patients who were diagnosed with ureteral stone disease with severe pain. All of the genetic studies were based on extracted peripheral blood samples using the necessary procedures from the Genome and Stem Cell Center at Erciyes University (GENKOK). The data were analyzed with SPSS (IBM, ver 20, United Sate).

RESULTS

The study group comprised 62 females and 138 males, and the control group comprised 64 females and 136 males. All of the stones that caused renal colic were found to be localized in the ureters and the ureterovesical junction. The genotypes of the intron 4 polymorphism were found to be as follows: 4a/4a in 10 people, 4b/4a in 115, and 4b/4b in 275 people. The GG genotype of the eNOS-G894T polymorphism was found in 108 patients in the study group and in117 of the healthy individuals. There was no statistically significant difference between the two groups regarding these data.

CONCLUSION

Although this study is the first in the literature to examine the relationship between renal colic and endothelial nitric oxide synthase gene polymorphisms, our study demonstrated that no relation was found.

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.

Evolving Guidance on Ureteric Calculi Management in the Acute Setting

Ureteric colic is a common presentation to acute emergency services. The gold standard test for the diagnosis of acute ureteric colic is a non-contrast computer tomography of the kidneys ureters and bladder (CT KUB). Non-steroidal anti-inflammatory drugs (NSAIDs) should be used as first-line analgesia, with studies showing that there is no role for steroid or phosphodiesterase-5 inhibitors. There is emerging evidence that a high body mass index (BMI) is a risk factor. The drugs used to facilitate stone passage are known as medical expulsive therapy (MET). The most evaluated being alpha-blockers. The Spontaneous Urinary Stone Passage Enabled by Drugs (SUSPEND) trial was designed to evaluate the use of MET (tamsulosin and nifedipine). This trial showed that there was no difference with MET and placebo for the spontaneous passage of ureteric stones. There is an emerging role for the use of primary ureteroscopy in the management of non-infective ureteric stones.

Ultrasonography of the Kidney: A Pictorial Review

Ultrasonography of the kidneys is essential in the diagnosis and management of kidney-related diseases. The kidneys are easily examined, and most pathological changes in the kidneys are distinguishable with ultrasound. In this pictorial review, the most common findings in renal ultrasound are highlighted.