Strategies to Optimize Nephrolithiasis Emergency Care (STONE): Prospective Evaluation of an Emergency Department Clinical Pathway

OBJECTIVE

To convene a multi-disciplinary panel to develop a pathway for Emergency Department (ED) patients with suspected nephrolithiasis and then prospectively evaluate its effect on patient care.

MATERIALS AND METHODS

The STONE Pathway was developed and linked to order sets within our Electronic Health Record in April 2019. Records were prospectively reviewed for ED patients who underwent ultrasound or Computerized Tomography (CT) to evaluate suspected nephrolithiasis between January 2019 and August 2019 within our institution. The primary outcome measure was the proportion of patients whose ED CT was low dose (<4 mSv). Secondary outcome measures included receipt of pathway-concordant pain medications and urine strainers. Order set utilization was evaluated as a process measure. Balance measures assessed included repeat ED visits, imaging, hospitalizations, and a urologic clinic visit or surgery within 30 days of discharge.

RESULTS

441 patients underwent ED imaging, of whom 261 (59%) were evaluated for suspected nephrolithiasis. The STONE Pathway was used in 50 (30%) eligible patients. Patients treated with the Pathway were more likely to undergo low-dose CTs (49% vs. 23%, p<0.001), and receive guideline-concordant pain medications such as NSAIDs (90% vs. 62%, p<0.001), and were less likely to return to the ED within 30 days (13% vs. 2%, p=0.01). These measures demonstrated special cause variation following Pathway release.

CONCLUSIONS

Clinical pathways increase compliance with evidence-based practices for pain control and imaging in nephrolithiasis emergency care and may improve the delivery of value-based care.

CT KUB scans for renal colic: Optimisation of scan range to reduce patient radiation burden

INTRODUCTION

Non-contrast CT KUB scans performed to assess renal colic should be limited to scanning between the upper pole of the highest kidney and the pubic symphysis to minimise unnecessary irradiation. This audit aimed to assess the amount of overscanning in CT KUBs outside this range.

METHODS

CT KUB scans taken over a 10-day period were assessed. Unnecessary overscan above the highest kidney was measured as a percentage of the total scan range. A target of less than 10% overscanning was set. The vertebral position of the upper pole of the highest kidney was also measured and compared to the actual level of the scan.

RESULTS

88 patients were assessed. 89.8% (79/88) of scans didn't meet the target of less than 10% overscanning above the highest kidney, and were associated with a higher radiation dose to the patient. The average overscanning above the highest pole of the kidney was 16.4% of the whole scan. The average overscan below the pubic symphysis was 1.54%. We also found that 100% of scanned kidneys lied below the upper border of the T11 vertebra, in spite of scans starting as high as T7.

CONCLUSION

A large proportion of scans included unnecessary overscanning above the highest kidney. We have identified the upper border of the T11 vertebral body as a potential location from which to begin the upper margin of a CT KUB scan.

IMPLICATIONS FOR PRACTICE

By starting CT KUB scans at the upper border of the T11 vertebral body, we can allow the whole kidney to be imaged while minimising unnecessary overscanning above the kidney, thus lowering excess patient irradiation while still producing high quality scans.

Management of alternative pathology detected using CT KUB in suspected ureteric colic

Acute flank pain is a common presentation to the emergency department (ED), and imaging studies play an important role in establishing an accurate diagnosis. Computed Tomography of Kidneys, Ureters, Bladder (CT KUB) has surpassed all other imaging modalities to become the gold standard in detection of ureteric calculi. The purpose of this study is to identify the range and management of alternative diagnoses established by CT KUB in patients with suspected ureteric colic. Two hundred and fifteen consecutive CT KUB examinations ordered in the ED of a tertiary-care centre for suspected ureteric colic were retrospectively reviewed. This comprised of 134 male (62.3%) and 81 female (37.7%) patients with a mean age of 53 years old. The positive detection rate for ureteric calculi in males was 43.3% compared to a lower rate for females of 29.6% (p < 0.05). Almost two-thirds of patients were discharged following CT KUB imaging, and admission rates were significantly higher in those with alternative radiological findings (p < 0.04) Alternative radiological findings occurred in 72 patients (33.5%), including 15 patients (7.0%) who had clinically important alternative pathology. The rate of clinically important alternative findings was significantly higher in males than females, 9.7% versus 2.5% respectively (p = 0.04). Surgical intervention was more common in patients with alternative radiological findings classified as gastrointestinal (18.2%) compared to non-gastrointestinal (3.6%), however this did not reach statistical significance (p = 0.07). In conclusion, significant alternative pathology was identified using CT KUB in 7% of patients with suspected ureteric colic. The low rates of detection of ureteric calculi and significant alternative pathology in female patients suggests a more thorough clinical assessment is warranted to improve their management, prior to ordering investigations with exposure to radiation.