The measurement of residual urine in the evaluation of incontinent nursing home residents.

Seventy-six nursing home residents with urinary incontinence (59 females, 17 males, Mean age = 84 years) underwent an evaluation which included the measurement of residual urine and cystometric studies. Upon catheterization 18 subjects were found to have urine volumes greater than 100 ml. Only two subjects had urine volumes greater than 250 ml. Cystometry revealed detrusor instability in the majority (83%) of the 76 subjects. Although the measurement of the post-voiding residual urine is a simple method to assess for ineffective bladder emptying, at volumes less than 250 ml, it is not always possible to predict the type of bladder dysfunction without additional studies. There can be problems in obtaining an accurate measurement of the post-voiding residual urine in elderly institutionalized patients. Many of our subjects (36 subjects) experienced difficulty urinating prior to catheterization. The residual urine measurement should not be solely relied upon in the prediction of bladder dysfunction in the elderly. This measurement should be combined with other data to effectively investigate the etiology of urinary incontinence.