emDocs Cases - November 19, 2018 - Authors: Schmitz G and Hockstein M
Edited by: Koyfman A and Long B
Key Points:
- The combination of an obstructed stone with a UTI is a urologic emergency. About 8% of patients presenting with acute nephrolithiasis will also have a UTI.
- Patients with decreased renal function, previous urologic interventions, and symptoms of infection are historical features for poor outcome in patients with stones.
- The presence of pyuria has only moderate sensitivity in patients with positive urine cultures.
- Fever was absent in 50% of patients with stone and confirmed UTI.
- Hydronephrosis and hydroureter may be secondary signs of ureteral obstruction. However, this finding is not specific and can be caused by other things including rapid administration of IV fluids.
- In a subset of low risk patients, renal ultrasound may be an alternative to CT imaging without exposing patients to ionizing radiation. The absence of hydronephrosis in these patients may predict the spontaneous passage of stone without urologic intervention.
- Antibiotic penetration in staghorn calculi is poor, the potential for urosepsis is increased until the stone is removed. Surgical treatment is generally required for staghorn calculi.
- Patients with acute flank pain have many etiologies, including cardiovascular and pulmonary catastrophes. Isolated kidney stones should not cause shock.