Adam Jones, Kevin Turner, and Ashok Handa discuss the most common conditions

Most urological complaints are not emergencies. There may well be serious underlying pathology such as bladder, prostate, or renal cancer, but rapid action is rarely required. However, although most hospitals now have a specialised urological department, it is not uncommon for general surgical house officers to cover urology patients or admissions. Similarly, urological complaints comprise a large part of general practice workload.

Acute retention of urine

• The most common urological emergency is acute retention of urine. This is managed by insertion of a urethral or suprapubic catheter. Insertion of catheters is a skill best learnt by bedside teaching, and we will not discuss technique here. Certain points about catheterisation do deserve highlighting, however.
• If a urethral catheter will not pass easily, then do not persist but ask for advice. Difficult catheterizations should be done by those with more experience.
• Always record the amount of urine drained on initial passage of the catheter (residual urine). This gives a guide to the type of retention (acute or chronic) and may influence further management and prediction of outcome.
• In the trauma patient in acute retention, remember ruptured urethra (see below).
• If you suspect that your patient may have a urinary tract infection, then remember that catheterisation can precipitate sepsis (usually Gram negative).
• In patients with chronic retention, beware post-catheterisation diuresis. If significant diuresis occurs (>400ml/hr) then replace with intravenous normal saline. A rough guide is to give 90% of the previous hour's urine output. Ask for advice early though, as the management of fluid balance in these patients can be tricky.

In the remainder of this article we cover four urological emergencies that you might come across where emergency management decisions do make a difference.

Torsion of the testicle

The diagnosis of testicular torsion should be considered in any man presenting with testicular pain. The patient's age will give you some guide to the likely cause: torsion usually occurs in adolescents and is rare in men over 20; in older men the cause is more likely to be epididymoorchitis. Don't forget that children localise pain poorly; the testicles must always be examined in any child presenting with abdominal pain. It is often difficult to exclude torsion confidently, and most urologists will have a low threshold for performing a scrotal exploration. Remember too that 10% of testicular tumours can present with acute testicular pain.

The typical symptoms of torsion are sudden onset severe testicular pain +/- lower abdominal pain +/- vomiting. It is not uncommon for young boys to be woken suddenly at night with this pain. There may be a history of similar milder episodes due to intermittent twisting and untwisting of the testicle. On examination the testis may lie higher in the scrotum (twisting of the cord essentially shortens it and therefore elevates the testicle); the testicle may also lie horizontally. The testicle is usually swollen and exquisitely tender. Epididymitis rather than torsion is suggested if the pain is relieved by elevation of the affected testicle (a positive Prehn's sign), but this test is of dubious reliability. The presence of dysuria and blood/protein in the urine points more towards a diagnosis of infection. Doppler ultrasound may assist in the diagnosis, but if there is still sufficient clinical doubt then discretion is the better part of valour and the patient will need exploring. If there is any doubt about the diagnosis (and there usually is) keep the patient "nil by mouth" and get a senior urological or surgical opinion urgently. Remember that torsion of the testis cuts off the blood supply to the testis and therefore every minute of delay will increase the ischaemic damage that may render the testis non-viable. Tissue necrosis occurs after 6-8 hours.

Spinal cord compression

One of the commonest causes of cord compression is metastatic prostate cancer. Missing the diagnosis of cord compression can be a disaster. Symptoms are often rapidly progressive and are rarely reversible. Prompt diagnosis and decompression by surgery or radiotherapy is the only way to minimise subsequent disability. The diagnosis of prostate cancer or another malignancy with a tendency to boney metastases may have been made already. (Though it sounds crazy, if you remember these as the 5 B's of bostate, breast, byroid, bidney and bronchus you will never forget them.) When cord compression occurs as a primary presentation the diagnosis can be very difficult.

The typical patient is an old man with prostate cancer "off his legs." It is easy to assume that this is just due to general decline, but, though this may be true, the diagnosis of cord compression must always be considered. Specific symptoms to ask for are:

• altered sensation or paraesthesia in the legs
• leg weakness or difficulty walking
• any new urinary incontinence or retention
• faecal incontinence.

Carry out a neurological examination and look specifically for:

• decreased muscle tone of lower limbs
• decreased power
• abnormal sensation
• the presence of a "sensory level."
  To demonstrate this, slowly "wiggle" your finger down the patient's chest and abdomen in the midline starting from the jugular notch, asking them if the sensation changes. The dermatome that any sensory level corresponds to is approximately indicative of the level of compression. Pay particular attention to perianal sensation (S3-S5 nerve roots) as these nerve routes are the ones that are generally lost first. The bulbocavernosus reflex is contraction of the anus seen visually on either squeezing the glans penis or stroking the perianal skin. Loss of this reflex and inability of the patient to "squeeze" a finger inserted anally are important signs suggesting cord compression.

If you think there is any suggestion of cord compression get a senior opinion urgently and request a CT or MRI scan. Corticosteroids may reduce oedema of the cord. In metastatic prostate cancer some kind of androgen deprivation, if not commenced already, will also be necessary.

Renal colic - special cases

As a surgical or urological house officer you will probably admit one patient with renal colic almost every time you are on call. With the registrar in theatre or clinic, it may be some time before anyone else sees them. Most of these patients just need analgesia initially and can be treated expectantly, but a few special cases exist.

• Remember that "classic left sided renal colic" in an elderly patient may in fact be a ruptured abdominal aortic aneurysm - always feel for a pulsatile mass and arrange an ultrasound if in doubt. Never accept the diagnosis of renal colic in an elderly patient until an aneurysm has been excluded.
• Patients with solitary kidneys are obviously at risk of rapid renal failure if their only kidney is obstructed by a calculus.
• Patients with complete obstruction and infection (pyrexia, rigors, raised white cell count) are at risk of renal damage if the obstruction is not relieved promptly. For this reason, imaging (usually an intravenous urogram - IVU) in patients with the symptoms and signs of both urinary calculi and infection should not be delayed. In this situation, obstruction is normally relieved by insertion of a percutaneous nephrostomy tube.

Ruptured urethra

In a major trauma case where the more senior people do the "glamorous" stuff at the top end like central lines and chest drains, the house officer will probably be asked to put in the catheter. Remember, however, that fractured pelvis is a common occurrence in major trauma and that around 10% of patients with a fractured pelvis will have an associated urethral injury, usually in the membranous urethra. Catheterising a patient with a urethral injury may convert a partial rupture into a complete one and should therefore only be done, if at all, by an experienced person. The features to look out for are:

• desire but inability to pass urine. If voiding has occurred then extravasated urine may be evident in the scrotum and anterior abdominal wall.
• a perineal haematoma. Classically this is described as a butterfly distribution. In the trauma situation, any bruising behind the scrotum is worrying
• blood at the urethral meatus
• a "high riding" prostate. This will be a prostate that is hard to feel or one that you can only feel the base of. If any of these features exist then be very suspicious of a urethral injury and get senior help.

Kevin Turner research fellow in urology
Molecular Oncology Group, Institute of Molecular Medicine, John Radcliffe Hospital, Oxford Ashok Handa clinical lecturer, Nuffield Department of Surgery, John Radcliffe Hospital, Oxford

Further reading

1. Gomella LG (ed) The 5-minute urology consult. Philadelphia: Lippincott Williams and Wilkins, 2000.
2. Kuban DA, el-Mahidi AM, Sigred SV, Schellhammer PF, Babb TJ. Characteristics of spinal cord compression in adenocarcinoma of the prostate. Urology 1986;28(5):364-9.