Prevention of infection of urinary tract in presence of indwelling catheters; description of electromechanical valve to provide intermittent drainage of the bladder.

Catheters kept in the urinary bladder as long as four days provoke bacteriuria in almost every case. The technique here described prevents this complication by continuous irrigation with 0.25% acetic acid through a catheter with three lumens. One passage permits distention of the retaining balloon; the other two passages are for inflow and outflow. The method was successful in more than 100 patients. The rate of inflow of the acetic acid solution was roughly equal to that of urine production, but it was adjusted so that the effluent was kept at pH 5.0 or less and the bacterial count at less than 1 million per milliliter. Outflow was interrupted periodically by use of an electromechanical valve to permit filling of the bladder and avoid prolonged contraction. In some patients it was possible to leave the catheter in situ as long as 60 days without inducing bacteriuria.