Retention of Urine

The Causes of retention of urine are classified as follows:-

A. Mechanical:

a) Urinary Bladder - stone, tumor, blood clot and contracture of the bladder neck.

b) Prostate - Prostatic abscess, benign and malignant enlargements

c) Urethra - Urethral stricture, rupture, congenital valves, foreign body, acute urethritis, stone , growth, pin-hole meatus, meatal ulcer

d) Prepuce - Phimosis

From Outside-

Pregnancy (retroverted gravid uterus), fibroid, ovarian cyst, carcinoma of the cervix uteri and rectum and any pelvic growth and paraphimosis

B. Neurogenic:

a) Spinal cord diseases eg. disseminated sclerosis, tabes dorsalis, transverse myelitis etc.

b) Injuries and diseases of the spine eg. fracture-dislocation, Pott's disease etc

c) Miscellaneous eg. postopertive retention, hysteria, tetanus, drugs such as anticholinergics, smooth muscle relaxants, tranqillizers etc.

Retention of urine means accumulation of urine in the urinary bladder. Patient is unable to pass urine or passes small quantity of urine. It must be remembered that kidneys excrete urine normally. In anuria also patient does not not pass urine but in this condition the kidneys fail to excrete urine and there is no urine in the bladder, hence collapsed. There are two forms of retention of urine - acute retention and chronic retention.

Acute retention is sudden inability to pass urine and it is a painful condition. Chronic retention is grdual accumulation of urine in the bladder due to inability of the patient to empty the bladder completely. The result is an enlarged painless bladder. If infection supervenes on chronic retention it becomes painful and it is often described as acute-on-chronic retention. It may be called 'infection-on-chronic retention'.

Acute Retention - It must be remembered that acute retention in a normal bladder is extremely rare and occurs only after anaesthesia, an injury to the urethra or after surgical operation. In majority of cases there has been a chronic retention before the acute attack. These cases may be called acute-on-chronic retention. The patient is likely to have some symptoms related to chronic retention previous to the acute episode. Sudden inability to pass urine with severe pain and with an exaggerated desire to micturate is the main presenting feature of this condition.

On examination, the urinary bladder is sufficiently enlarged to become palpable, tense and dull arising out of pelvis. Pressure on this swelling increases the patient's desire to micturate.

Rectal examination will reveal that the prostate or uterus is pushed backwards and downwards by the bladder which can be easily felt as a cystic mass. It must be remembered that one cannot assess the size of the prostate gland when the bladder is full. One must try to feel the other organs of the pelvis as well. Sensory, motor and reflex functions of the nerves of the perineum and lower limbs should be assessed carefully.

Chronic retention - Elderly individuals are mainly affected by this disease. Chronic retention is a painless condition and the patient is often unaware of his/her distended bladder. The symptomps may be in the form of increased frequency of micturition, difficulty of micturition or even overflow incontinence.

On examination the foreskin and urethral meatus should be examined for phimosis or meatal stenosis. The length of the urethra as far as the bulb should be palpated for a sticture, periurethral abscess or presence of a stone or a foreign body.