Retention refers to that condition where the urine has been accumulating in the bladder for a considerable time over twelve hours and cannot be passed. It may follow an obstruction from disease, to which is added temporary swelling and nervous contraction of some part of the urinary passage; or it may be due to spasm and closure of the outlet from nervous irritation, as in the cases of injuries and surgical operations in the vicinity of the sexual organs, the rectum, or in other parts of the body. Overdistention of the bladder from failure to pass water for a long time may lead to a condition where urination becomes an impossibility. Various general diseases, as severe fevers, and conditions of unconsciousness, and other disorders of the nervous system, are frequently accompanied by retention of urine. In retention of urine there is often an escape of a little urine from time to time, and not necessarily entire absence of outflow.
Treatment. Retention of urine is a serious condition. If not relieved, it may end in death from toxæmia, caused by back pressure on the kidneys, or from rupture of the bladder. Therefore surgical assistance is demanded as soon as it can be obtained. Failing this, begin with the simpler methods. A hot sitz bath, or, if the patient cannot move, hot applications, as a hot poultice or hot cloths applied over the lower part of the belly, may afford relief. Injections of hot water into the bowel are often more efficient still. A single full dose of opium in some form, as fifteen drops of laudanum or two teaspoonfuls of paregoric or one quarter grain of morphine, will frequently allow of a free passage of urine. The introduction of a suppository into the bowel, containing one quarter grain each of morphine sulphate, and belladonna extract, is often preferable to giving the drug by the mouth. These measures proving of no avail, the next endeavor should be to pass a catheter. If a soft rubber or elastic catheter is used with reasonable care, little damage can be done, even by a novice. The catheter should be boiled in water for ten minutes, and after washing his hands thoroughly the attendant should anoint the catheter with sweet oil (which has been boiled) or clean vaseline and proceed to introduce the catheter slowly into the urinary passage until the urine begins to flow out through the instrument.
A medium sized catheter is most generally suitable, as a No. 16 of the French scale, or a No. 8 1/2 of the English scale.