BASIC PRESSURES OF VOIDING IN ADULT FEMALE

Basic extravesical and intravesical pressure changes involved in voiding were discriminated by simultaneously electronically recording intravesical, intraurethral, and intrarectal pressures in 65 adult females. Voiding was initiated by Valsalva stress in 39 per cent, by detrusor contraction in 33 per cent, and by mixed pressures in 28 per cent. Once voiding was established, the pressure of Valsalva stress frequently dropped out, leaving the evacuation phase of voiding to detrusor contraction. After-voiding contractions occurred as frequently from Valsalva stress as from detrusor contraction. Four patients with chronic partial urinary retention presented evidence which suggested that the etiology might have been due to intense psychic trauma incidental to vaginal plastic surgery. A precise mechanism of voiding for the adult female could not be established. Willful control over detrusor function was confirmed. © 1969.