Introduction: Radical cystectomy is an intervention with an important morbidity. Urinary diversion is a possible cause of metabolic complications like hyperammonaemic encephalopathy.
Case report: We present the case of a patient treated with a radical cystectomy and modified ureterosigmoidostomy after diagnosis of bladder cancer. After surgery the patient presented in 4 ocasions recurrent episodic confusion. Laboratory and image tests were normal. Levels of seric ammonium was increased. After supportive treatment and hemodyalisis symptoms disappeared. Later patient was reoperated and a reconstruction to ileal conduit was made.
Discussion: Continent urinary diversions are advised due to important negative impact on quality of life produced by ileal conduit. However these diversions have several complications, like encephalopathy secondary to non-hepatic hyperammonaemia. Increased absortion of ammonium by intestinal tissue of the new-ladder induces encephalopathy. Early diagnosis of this complication is essencial in order to administer an effective treatment.