ACP InternistMKSAP Quiz: 4-hour History of Left Flank Pain

Options for treatment include intravenous 0.9% saline, lithotripsy, tamsulosin, or observation.

A 38-year-old woman presents to the emergency department with a 4-hour history of left flank pain radiating to the groin. She has no other medical issues and is not on any medications. A noncontrast helical CT scan reveals an 11-mm stone in the proximal ureter, accompanied by dilation of the renal calyces. Analgesics have been initiated for pain management.

Kidney stones larger than 10 mm are extremely unlikely to pass spontaneously. In fact, only 50% of stones larger than 6 mm will pass, generally within a two-week period. Urologic intervention becomes necessary for larger stones, especially when there are signs of ureteral obstruction, which can lead to kidney damage.

Question

Which of the following is the most appropriate additional treatment for this patient?

• Intravenous 0.9% Saline: Administering intravenous 0.9% saline aims to increase urinary flow. However, there is no evidence to suggest that this approach facilitates more rapid transit of kidney stones or decreases the use of pain medication.
• Lithotripsy: Lithotripsy involves breaking up the kidney stone using either shock waves or laser technology. Both methods have similar rates of stone clearance, although laser lithotripsy is more expensive and requires anesthesia.
• Tamsulosin: Tamsulosin has been used to facilitate stone passage, but its efficacy is a subject of ongoing debate. Trials may last up to 4 weeks, and the risk associated with its use is minimal.
• Observation: Observation is an option for patients with small stones, mild pain, no evidence of infection, and no signs of impending kidney damage. Frequent reevaluation is required.

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