PAEA Surgery End Of Rotation (EOR) Practice Exam

In the case of nephrolithiasis, an alkaline urine pH indicates the presence of which type of salts?

1. Struvite salts

2. Calcium salts

3. Uric acid salts

4. Creatinine salts

The correct answer is: Calcium salts

In the context of nephrolithiasis, an alkaline urine pH is primarily associated with the presence of struvite salts, which are magnesium ammonium phosphate salts. These salts form in urine that has a higher pH, usually as a result of infection with urease-producing bacteria. Conversely, calcium salts, which include calcium oxalate and calcium phosphate stones, can form in either alkaline or acidic urine. However, their formation is not specifically indicated by an alkaline urine pH. Uric acid stones are typically associated with acidic urine rather than alkaline, as uric acid solubility decreases in low pH environments. Therefore, alkaline urine would not suggest the presence of uric acid stones. Creatinine salts do not typically form stones and are more of a waste product rather than a contributor to nephrolithiasis. Understanding these relationships between urine pH and the type of urinary crystals or stones can help in diagnosing and managing nephrolithiasis effectively.