Review Question - QID 107149

This patient most likely has acute kidney injury (AKI) and a renal stone secondary to tumor lysis syndrome (TLS). The chief TLS prevention is hydration and diuresis to increase urine flow rate.

TLS is a condition following chemotherapy treatment which causes tumor cells to lyse and release uric acid, a metabolite of tumor nucleic acid. Importantly, the best management of TLS is prevention, as opposed to treating once symptoms begin. Note that uric acid stones require an acidic environment to precipitate, while magnesium ammonium phosphate (struvite) stones require an alkaline environment to precipitate.

Frassetto et al. review risk factors and prevention of kidney stones, which are increasingly prevalent among women and the elderly. Obesity, medications such as protease inhibitors and diuretics, high-animal protein diets, and dehydration all promote stone formation. The authors advocate vegetable-rich diets and supplemental citrate to prevent uric acid, calcium oxalate, and cystine stones.

Coiffier et al. propose new guidelines in the prevention and management of patients at risk of developing TLS. Prevention strategies include hydration, prophylactic rasburicase, and allopurinol. The aggressiveness of treatment depends on the individual patient's degree of TLS risk. Of note, they do not recommend urine alkalinization as a preventative measure.

Incorrect Answers:
Answer 2: Urine alkalinization, not acidification, has been proposed as a preventative measure for TLS but does not have a large body of supporting evidence.
Answer 3: Allopurinol, not colchicine, has been used in the prevention of TLS.
Answer 4: Steroids do not have a role in the prevention of TLS.
Answer 5: While dialysis may be used in extreme cases of AKI secondary to TLS, it is not the preferred preventative therapy.