title: [Nephrolithiasis--rational etiological assessment].
abstract: Although underlying metabolic abnormalities do not differ fundamentally in patients with either first or recurrent nephrolithiasis and 35% of patients with a first event may have to face a recurrence 5 years later, extended metabolic investigations in patients with a first renal calculus should be restricted to particular, exceptional cases. However, in patients with a first calculus basic investigations with respect to specific causes for a concrement such as primary hyperparathyroidism, incomplete renal-tubular acidosis, recurrent urinary tract infection and cystinuria are mandatory. This includes, in addition to a laboratory investigation of blood and urine after a 2-hour-fasting period, analysis of the stone and a urography. The extended metabolic investigation in patients with recurrences or a first occurrence in a patients with a risk constellation includes evaluation of the most important lithogenic (calcium, oxalate, phosphate, uric acid) and inhibiting components (citrate) in the 24-hour urine, in patients with cystine calculi quantitation of cystine. A metabolic investigation should never be undertaken in the hospital or under standardized diet, but always under accustomed, unrestricted nutrition. At least 2 urine samples should be investigated from each patient, preferably not prior to 3-4 months after the event when homeostasis of the patient is restored analogously to the onset of concrement development.
authors.affiliation: Urologisch-nephrologische Steinsprechstunde, Medizinische Universitätspoliklinik, Inselspital Bern.
authors.forename: B
authors.initials: B
authors.lastname: Hess
authors.forename: D
authors.initials: D
authors.lastname: Ackermann
mesh_terms: D000141:Acidosis, Renal Tubular / Q000150:complications / Q000175:diagnosis; D003555:Cystinuria / Q000150:complications / Q000175:diagnosis; D003937:Diagnosis, Differential; D006801:Humans; D006961:Hyperparathyroidism / Q000150:complications / Q000175:diagnosis; D007669:Kidney Calculi / Q000175:diagnosis / Q000209:etiology* / Q000378:metabolism; D012008:Recurrence; D014552:Urinary Tract Infections / Q000150:complications / Q000175:diagnosis; D014556:Urine / Q000737:chemistry
vernacular_title: Nephrolithiasis--Sinnvolle ätiologische Abklärungen.