[Urine stream pressure and urethral energy loss].

In the present paper is reported on the estimation of several physical parameters of the urinary stream leaving the urethra in boys. Normal values which we determined in 33 boys could be compared with the measuring values in patients with subvesical disturbances of the passage. Proximal stenoses are characterized by a low residual energy of the urinary stream. In distal stenoses it is normal to increased. The clinical importance may result from the possibility of the diagnosis of disturbances in which quickly is to be reckoned with the development of secondary changes of the upper urinary tract with the help of a non-invasive method. The calculation of the urethral loss of energy allows further informations. It demands a suprapubic puncture of the urinary bladder for measuring the pressure.