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Flashcards in Urology - Urological emergencies Deck (29)
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What patients are more at risk of urinary retention?

Urinary retention is one of the most common urological emergencies and occurs most commonly in elderly men. It is defined as the inability to urinate and therefore empty the bladder.

Urinary retention can either be acute or chronic and either spontaneous or precipitated by another condition - e.g. UTI


What are the causes of urinary retention?

The exact cause of retention is unknown, but several different conditions can contribute towards it and are classified into 4 different groups. These are:
1) Obstruction - either mechanical or dynamic (i.e. increase in smooth muscle tone)
2) Inflammatory - UTI, prostatitis
3) Neurological
4) Over distension - post anaesthesia, high alcohol intake, drugs (e.g. ephedrine, antidepressants)


How is acute urinary retention managed?

The first line treatment of retention is catheterisation. This should relieve the patients discomfort straight away. It is important to monitor the amount of urine passed in the first 10-15 minutes which should be <1L.

Fluid management is important following relief of retention as patients undergo a diuresis.


When are patients offered a TWOC?

Patients presenting with retention can be offered a trial without catheter (TWOC) after 2-3 days of alpha blocker therapy (e.g. tamsulosin). If a TWOC fails then patients can be managed on a long term catheter or offered prostatic surgery.


What does a volume of greater than 1L suggest?

If the volume drained is greater than 1L it suggests chronic retention. Chronic urinary retention is associated with less pain and patients often have fewer urinary symptoms. Classically, patients describe nocturnal eneuresis (bed wetting), which is felt to be overflow incontinence due to loss of voluntary sphincter tone during sleep.


What can be associated with chronic urinary retention?

Chronic retention may be associated with altered renal function and upper tract dilation. In these cases, immediate catheterisation is necessary to decompress the upper tract and allow renal function to recover. A period of diuresis may follow requiring close monitoring of electrolytes, blood pressure and weight. A TWOC is not appropriate in these cases and patients (if fit enough) should undergo prostatic surgery or be managed with a long term catheter.


How does renal colic present?

Colic presents as a severe, sudden onset pain which the patient often states as "the worst pain ever". Clinically, the pain starts in the flank and radiates around the front of the abdomen to the groin (loin to groin). Sometimes to the scrotum in men or the labia in women.

Pain in renal colic is caused by dilatation, stretching and spasm caused by acute ureteral obstruction. Nausea and vomiting often occurs and patients may have haematuria.


What are the examination findings of renal colic?

Examination of the abdomen is often unremarkable with only a few patients showing loin or groin tenderness. Commonly though, patients are unable to sit still and are restless due to the pain. This is in contrast to a peritonitic abdomen, where patients lay still.


What investigations are important in a presentation of renal colic?

Urinalysis is key. Over 85% of patients will have microscopic haematuria on urine dipstick. If no blood is demonstrated then other diagnoses such as appendicities, salpingitis, diverticulitis, and ruptured AAA should be considered.

Bloods to include renal function and bHCG in women of child bearing age.


What imaging is used in renal colic?

Imaging has moved away from plain film x ray and IVU. Non contrast CT scans of the abdomen and pelvis are now first line.


How are patients with renal colic managed?

Initial management of patients with renal colic is resuscitation with crystalloids, anti-emetics and analgesia. NSAIDs such as diclofenac (provided no significant cardiac risk) should be used before opiate based analgesia as they provide more effective pain relief with fewer side effects.


How is the likelihood of spontaneous stone passage related to stone size?

A stone of <4mm is almost 90% likely to pass on its own. This decreases to 50% in stones of between 4-6mm and 20% for stones >6mm.


How should patients with an infected stone be managed?

Stones increase the risk of infection. An infected and obstructed kidney is a urological emergency. Typically patients are systemically unwell with a history of fever and rigors. Once diagnosed they need an urgent percutaneous decompression with nephrostomy, IV antibiotics, and fluids.


What is testicular torsion?

Testicular torsion occurs due to twisting of the testes on the spermatic cord which impedes blood flow and venous drainage resulting in oedema, ischaemia and necrosis.


What age group does testicular torsion most affect?

There is a bimodal distribution of incidence of torsion with the first peak age at 1-2 years and the second peak in older teenage years. Torsion is relatively uncommon in males over 40.


What is the most common cause of torsion?

The most common reason for torsion is a malformed tunica vaginalis, which normally attaches the upper pole of the testes to the posterior scrotum, fixing it in place. When the tunica vaginalis extends over the whole testes fixing it in a horizontal position, this is called "bell clapper" deformity and prediposes it to torsion.


What is the most common presentation of torsion?

Torsion commonly presents with testicular pain and swelling. The history is important in distinguishing torsion from other causes of acute painful testes such as epididymitis. Torsion typically has a quicker onset of pain, and patients may have had previous episodes of pain indicating intermittent torsion.


What investigations are important in torsion?

Urinalysis may be normal in torsion. Colour flow doppler ultrasound may be used to demonstrate absent or poor blood flow to the testes but should not delay surgical exploration. There is not one test that is diagnostic or torsion, so if it is clinically suspected then immediate surgical exploration is required.


How does the timing of surgical exploration in suspected torsion relate to torsion salvage rates?

Salvage rates decrease with time. At 6 hours rates are about 80%, whereas at 8 hours this decreases to around 60%. At 12 hours post onset of pain the salvage rate decreases dramatically to about 10%.


What is the surgical treatment for torsion?

Surgery consists of detorting the affected testes and fixing the testes to the scrotal wall using non absorbable sutures or by placement within the dartos pouch. If the testes is not salvageable then an orchidectomy is performed. The unaffected testes is explored, because tunical malformations contributing to testicular torsion are often bilateral. The unaffected testes should also be fixed to the scrotal wall.


What is a paraphimosis?

Paraphimosis is a common condition that occurs in uncircumcised men. It occurs when the foreskin becomes fixed in the retracted position and cannot be reduced. It therefore constricts venous return from the glans penis causing swelling of the glans.


What causes paraphimosis?

Paraphimosis is often related to a prior phimosis, with a constriction band on the prepuce acting as a torniquet, preventing retraction as well as venous and lymphatic drainage. The most common cause however it iatrogenic, with medical staff failing to retract the foreskin during catheterisation.


How is a paraphimosis managed?

The initial step is adequate analgesia, which may involve a penile nerve block. Manual decompression is the next step and involves compressing the glans to reduce the oedema and then attempting to replace the foreskin over the glans. Surgery can be performed in cases where conservative management fails. This involves a dorsal slit on the penis which divides the constriction band and allows reduction of the foreskin. Circumcision is the definitive treatment and prevents future episodes.


What is priapism? What are the different types?

Priapism is male erection that persists beyond or is unrelated to sexual stimulation. There are 2 types of priapism:

(i) low flow or ischaemic priapism results from decreased venous and lymphatic drainage of the corpus cavernosa
(ii) high flow or non ischaemic priapism results from unregulated arterial blood flow often related to trauma.

The main complication of priapism is erectile dysfunction and the aim of treatment is to prevent this.


What are the features and causes of low flow priapism?

Low flow priapism is painful, more common, and most cases are caused by medication or drug use. The incidence is much greater in men with sickle cell disease and blood dyscrasias. The decreased venous return and lymphatic drainage can cause thrombosis and further ischaemia, resulting in fibrosis of the corpus cavernosae and erectile dysfunction.

Causes include:
- Haematological: sickle cell, leukaemia, thrombophilia
- Medications for erectile dysfunction: intracavernosal papaverine, intracavernosal PGE E2, intracavernosal alprostadil
- Drugs: antihypertensives, antipsychotics, alcohol


What are the features of high flow pripaism?

High flow priapism is much less common and often less painful. It often follows perianal and penile trauma (commonly straddle type injuries) producing a cavernosal artery laceration, subsequent arteriovenous fistula and this unregulated arterial flow within the corpora cavernosae.


How is priapism managed?

This depends on whether there is low flow or high flow priapism. The definitive diagnosis can be made with penile blood gas analysis aspirated from the corpus cavernosum.

Primary treatment for low flow priapism involves aspiration and irrigation of the corpora and possibly intracavernosal injection of phenylephrine (requires cardiac monitoring). If this is unsuccessful then a surgical shunt between the corpora cavernosa and spongiosa is required and potentially penile prosthesis insertion.

Treatment for high flow priapism is less urgent and cases can be observed prior to arteriography and selective embolisation.


Pelvic fracture + lower abdominal peritonism

This should raise the suspicion of bladder rupture (especially if the patient cannot pass urine)

Investigate - IVU or cystogram


Pelvic fracture + highly displaced prostate

Think membranous urethral rupture
Mainly males
Blood at the meatus
Manage with a suprapubic catheter