Bilateral obstruction higher up the ureters may be due to extensive lymph node metastases to the pelvic and para-aortic nodes from distant malignancy, retroperitoneal fibrosis, and rarely bilateral ureteric stones. Evidence of a malignancy elsewhere may be found on clinical examination. The diagnosis is usually made on the basis of excluding obstruction at the outlet of the bladder and in the lower ureters and by radiographic imaging (ultrasound and abdominal CT).
Oliguria is scanty urine production, and more precisely is defined as urine production of less than 400 mL/day in adults and less than 1 mL/kg of bodyweight per hour in children. The causes are prerenal (e.g., hypovolaemia, hypotension), renal (e.g., acute vasculitis, acute glomerular lesions, acute interstitial nephritis, and acute tubular necrosis from nephrotoxic drugs, toxins, or
1. PRESENTING SYMPTOMS OF UROLOGICAL EMERGENCIES 5
sepsis), and postrenal causes (as for anuria, but where the degree of obstruction has not yet reached a level critical enough to stop urine production completely).
Suprapubic pain can be caused by overdistention of the bladder, and inflammatory, infective, and neoplastic conditions of the bladder. All such conditions may present as an emergency. Bladder overdistention may result from bladder outflow obstruction, e.g., by enlarged prostate, urethral stricture, etc. Painful inability to empty the bladder is defined as urinary retention.
Urinary tract infection is usually associated with urethral burning or scalding on voiding; frequent, low-volume voiding; and a feeling of incomplete bladder emptying with an immediate desire to void again. The urine may be offensive to smell.
Inflammatory conditions of the bladder such as interstitial cystitis can also cause suprapubic pain as can carcinoma in situ. Gynaecological causes of suprapubic pain include endometriosis, fibroids, and ovarian pathology. Gastrointestinal causes of suprapubic pain include inflammatory and neoplastic bowel disease and irritable bowel syndrome.