Question 2 of 14

A 48-year-old man complains of colicky, severe, “10/10” right flank pain that extends around his abdomen and radiates into the right groin. Although the pain waxes/wanes, it does not resolve totally between episodes. There have been no previous similar episodes. On examination, the patient is writhing in pain on the stretcher and seems unable to find a comfortable position. The patient has severe right CVA tenderness but a benign abdomen. You suspect renal calculi. A basic metabolic panel is still pending. Which of the following additional features is an indication to undergo a more extensive metabolic evaluation?

Persistent nausea and vomiting despite medication.

An ultrasound shows right-sided hydronephrosis.

A CT scan shows multiple small bilateral calculi.

Finding a stone lodged in the calyx of the right kidney.

The patient is 48 years of age.

Renal stones may affect up to 7% of the US population and patients with renal colic are commonly seen in the emergency department. For a patient with the initial diagnosis of an isolated renal stone, many sources advise the routine evaluation of serum electrolytes, creatinine, calcium, uric acid, and phosphorus. Indications for additional metabolic evaluation include residual calculi after lithotripsy or surgical treatment, an initial presentation with multiple calculi, significant family history, or more than a single stone in the past year. In these cases, evaluation is aimed at diagnosing less common conditions associated with renal stones including Crohn's disease, milk-alkali syndrome, hypernitraturia, hyperuricosuria, sarcoidosis, gout, renal tubular acidosis (type I), and chronic laxative abuse. Additionally, it is advisable to aggressively evaluate, diagnose, and treat patients who initially develop stones in their teens or twenties because this group is more likely to experience recurrent stone formation.