Urinary Concentrating Ability and Growth Failure in Urinary Tract Disorders

Results of a pitressin concentration test are described in 50 control patients and 63 patients with urinary tract infection and/or hydronephrosis. In affected cases the test was unable to predict either the presence of significant radiological abnormalities or likely recurrence of infection and is not thought to be a reliable discriminator between renal and lower urinary tract infection. In 37 cases maximal urinary concentration correlated with endogenous creatinine clearance. It is proposed that artificially-fed infants with urinary tract infection and hydronephrosis may have a concentration defect of such severity as to preclude a normal caloric intake.