Kidney Stone Protocols to Reduce Emergency Department Overcrowding

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Shital Shah Dino P Rumoro Mollie Pillman Samuel Hohmann


Background: As emergency department (ED) overcrowding affects timely patient care, strategies such as standardize protocols are required.

Objective: The purpose of this study was to 1) investigate impact of utilizing various Computed Tomography (CT) scans modalities namely CT without contrast (WO), with contrast (W), and with and without contrast (WWO) in diagnosing kidney stones on ED operational metrics (i.e., CT order to report time, room to discharge, and ED length of stay), and 2) develop, implement, and test kidney stone protocols.

Methods: The study included both retrospective, cross-sectional and pre/post analyses of patients presenting to the ED of a large, academic medical center with suspicion of kidney stone who received CT scans from December 2010 to December 2011. ANOVA, t-test, Chi-Square test, and linear regression were used for statistical analyses.

Results: During pre implementation, statistically significant difference of at least  41.7 minutes were observed between  CT WO and CT WWO for all operational metrics   After implementation of the kidney stone protocol (i.e., switching to CT WO contrast) the order compliance rate improved from 35.9% to 72.8%, with similar savings for CT order to report times.

Conclusions: With 37% additional patients evaluated using CT WO and ¾ to 1 hour savings in CT order to report time, the estimated net capacity gain is 32 to 43 routine ED patients for a 50,000 volume ED. Thus, standardization of protocol using the developed framework for other common diseases (e.g., abdominal pain) may add ED capacity and revenue while reducing ED overcrowding issues.

Article Details

How to Cite
SHAH, Shital et al. Kidney Stone Protocols to Reduce Emergency Department Overcrowding. Medical Research Archives, [S.l.], v. 2, n. 2, sep. 2015. ISSN 2375-1924. Available at: <>. Date accessed: 16 june 2024.
Overcrowding, Kidney Stone; Protocols; CT Scans; Emergency Department
Research Articles


Agency for Healthcare Research and Quality. (1995 (revised 2011)). ACR appropriateness criteria® acute onset flank pain — suspicion of stone disease.

Burt, C. W., & McCaig, L. F. (2006). Staffing, capacity, and ambulance diversion in emergency departments: United states, 2003-04. Advance Data, (376)(376), 1-23.

Foster, G., Stocks, C. & Borofsky, M. (2012). Emergency department visits and hospital admissions for kidney stone disease, 2009. HCUP statistical brief #139. july 2012. agency for healthcare research and quality, rockville, MD.

Graham, A., Luber, S., & Wolfson, A. B. (2011). Urolithiasis in the emergency department. Emergency Medicine Clinics of North America, 29(3), 519-538. doi:10.1016/j.emc.2011.04.007

King, D. L., Ben-Tovim, D. I., & Bassham, J. (2006). Redesigning emergency department patient flows: Application of lean thinking to health care. Emergency Medicine Australasia, 18(4), 391-397.

Kinsman, L., Champion, R., Lee, G., Martin, M., Masman, K., May, E., . . . Zalstein, S. (2008). Assessing the impact of streaming in a regional emergency department. Emergency Medicine Australasia : EMA, 20(3), 221-227. doi:10.1111/j.1742-6723.2008.01077.x

Lotan, Y. (2009). Economics and cost of care of stone disease. Advances in Chronic Kidney Disease, 16(1), 5-10. doi:10.1053/j.ackd.2008.10.002

Marsh, A., Anderson, W., Bastani, A., & Bastani, A. (2004/10). Decreasing emergency department wait times for available inpatient beds by removing artificial variation. Annals of Emergency Medicine, 44(Supplement 1), S28-S29.

MedlinePlus.Kidney stones.

Nash, K., Zachariah, B., Nitschmann, J., & Psencik, B. (2007). Evaluation of the fast track unit of a university emergency department. Journal of Emergency Nursing, 33(1), 14-20.

Oakley, E., & Braitberg, G. (2005). Processes and impediments in moving patients from the emergency department: Pilot study. Emergency Medicine Australasia, 17(3), 266-273.

Pines, J. M. (2009). Trends in the rates of radiography use and important diagnoses in emergency department patients with abdominal pain. Medical Care, 47(7), 782-786. doi:10.1097/MLR.0b013e31819748e9

Terris, J., Leman, P., O'Connor, N., & Wood, R. (2004). Making an IMPACT on emergency department flow: Improving patient processing assisted by consultant at triage. Emergency Medicine Journal, 21(5), 537-541.

Westphalen, A. C., Hsia, R. Y., Maselli, J. H., Wang, R., & Gonzales, R. (2011). Radiological imaging of patients with suspected urinary tract stones: National trends, diagnoses, and predictors. Academic Emergency Medicine : Official Journal of the Society for Academic Emergency Medicine, 18(7), 699-707. doi:10.1111/j.1553-2712.2011.01103.x; 10.1111/j.1553-2712.2011.01103.x

Wilson, M. J., & Nguyen, K. (2004). Bursting at the seams: Improving patient flow to help America’s emergency departments. Retrieved from