Urologic manifestations of nonurologic disease urolithiasis

Acute renal failure after ingestion of guaifenesin and dextromethorphan

BACKGROUND

Guaifenesin is a common nonprescription medication that has been implicated in drug-induced nephrolithiasis. Dextromethorphan, a nonprescription antitussive found in some guaifenesin-containing preparations, is increasingly recognized as a substance of abuse by many youth and young adults. Renally excreted medications known to have poor solubility in urine have the potential to precipitate when ingested in large quantity, leading to acute obstruction of the ureters and renal failure.

OBJECTIVE

We describe the case of a 22-year-old male who developed severe bilateral flank pain, hematuria, and oliguria after an isolated recreational ingestion of guaifenesin and dextromethorphan.

CASE REPORT

The patient was found to have bilateral ureteral obstruction and acute renal failure, suspected to be secondary to precipitation of medication metabolites in the urine.

CONCLUSIONS

This case highlights the potential for acute renal failure secondary to guaifenesin and dextromethorphan abuse.

Testicular Sarcoidosis: Sonographic Findings

Testicular sarcoidosis is a rare but benign entity. It is often mistaken for testicular neoplasm, leading to orchiectomy. It is, therefore, extremely important to identify and correctly diagnose testicular sarcoidosis on sonography to avoid unnecessary orchiectomy. This case study reports a young patient who had a prior history of unilateral orchiectomy for cryporchidism and presented with testicular lesions on the contralateral testis. He was later found to have skin lesions and chest symptoms that led to a diagnosis of sarcoidosis.

Gas-containing renal stones

Emphysematous pyelonephritis is a rare, but potentially lethal, possible sequela of nephrolithiasis, occurring most commonly in diabetic patients. The diagnosis of emphysematous pyelonephritis relies on the radiologic finding of gas in the renal parenchyma. We present the case of a patient with sarcoidosis, diabetes, and obstructing, gas-containing ureteral stones. Gas-containing renal stones are exceedingly rare, but have been linked to serious renal infections. The case management and a brief review of the published reports follow. We propose that gas-containing stones be considered evidence of emphysematous pyelonephritis in certain clinical settings.

Can ureteral stent encrustation analysis predict urinary stone composition?

OBJECTIVES

To determine the value of mid-infrared spectroscopy (MIRS) of ureteral stent encrustations in predicting urinary stone composition.

METHODS

A retrospective study analyzed the composition of stent encrustations and urinary stones by MIRS in patients who had had a stent for ureteral obstruction between 2001 and 2003. The overall correlation was evaluated. The correlation coefficient kappa for agreement between the proportions of each component was calculated.

RESULTS

A total of 72 stents and 72 stones from 72 patients were analyzed. The mean stent indwelling time was 55.5 days (range 14 to 102). The stents had been placed for fever (52 cases, 72%), pain refractory to analgesics (15 cases, 21%), and impairment of kidney function (5 cases, 7%). The overall correlation between stone composition and stent encrustation was 71.4%, excluding biofilm analysis. The kappa value was 0.78 for the main component (n = 72; P < 0.0005), 0.61 for the secondary component (n = 72; P < 0.0005), and 0.91 for the agreement between the composition of encrustations at each end of a stent (n = 30; P < 0.0005).

CONCLUSIONS

MIRS analysis of stent encrustations is a reliable method of predicting stone composition when the stone cannot be retrieved. Systematic MIRS analysis of stent encrustations is not recommended but can be very useful in clinical situations in which no stone is available.