Current Trends in Metabolic Evaluation of Patients with Urinary Tract Lithiasis

Abstract

Abstract Urolithiasis is one of the most frequent disorders of the urinary tract with a high prevalence among the general population. The etiology is multifactorial and is related primarily with, race, age, gender, occupation, hygienic-dietetic issues, lifestyle factors, geographic and climatic aspects, hereditariness, and metabolic changes. Therefore, for prevention of the disease, the metabolic causes responsible for stone formation should be addressed before and particularly after treatment. Key point for the metabolic evaluation is to perform stone analysis and to classify patients into low- and high-risk group. In low-risk patients, basic metabolic evaluation is proposed comprising basic urine and blood tests. Spot urinalysis should include red cells, white blood cells, nitrite, urine pH, urine microscopy, and culture if indicated. Basic blood testing includes blood cell count, creatinine, uric acid, ionized calcium, sodium, potassium, and C-reactive protein if indicated. In high-risk stone formers, apart from the basic workup, analysis of two 24-h urine samples should be examined for evaluation of the total urine volume as well as the concentration of creatinine, calcium, phosphate, oxalate, urea nitrogen, uric acid, citrate, magnesium, sodium, and if indicated of cystine. Further examination should be based on the composition of stone. The follow-up of stone formers is still matter of debate, but most experts agree that the follow-up should be individualized according to stones composition, the underlying metabolic cause, and the treatment that has been offered.