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A15. Evaluation and management of urological emergencies: Renal colic, suprapubic pain, acute scrotum, gross haematuria, anuria, and urinary retention

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Renal colic

Clinical features

Kidney stones may be asymptomatic, especially if they are in the renal pelvis. Kidney stones may also cause haematuria. Concurrent fever with renal colic is a sign of infection together with urinary obstruction, which may be severe.

Renal colic

When a kidney stone passes from the renal pelvis into the ureter, it may get stuck. This causes episodes of severe flank pain. This pain is typically colicky, meaning that it starts and stops abruptly. There may be visible haematuria. The pain may radiate to the ipsilateral testicle or labium. The patient usually has a severe urge to move.

Acute scrotum

Acute scrotum refers to acute pain in the scrotum that develops over the course of minutes or a few days. Causes range from urological emergencies which are life-threatening to harmless.

Causes

Testicular torsion

Testicular torsion refers to sudden twisting of spermatic cord, usually internal rotation. 1/3 of cases are due to external rotation. It's most frequent in childhood and adolescents. It's mostly idiopathic, but in some cases it may be related to bell-clapper deformity. It causes abrupt onset testicular pain and a swollen testicle and is therefore one cause of acute scrotum. The testicle lies transversally in the scrotum rather than longitudinally as usual.

It results in irreversible necrosis within hours. The Sertoli cells die before the Leydig cells.

Diagnosis and evaluation

  • Mainly clinical, after differentiated from acute epididymitis
    • Negative Prehn sign (i.e., no relief of pain from lifting the affected testicle.
    • Absent cremaster reflex
  • Duplex ultrasound can help in the diagnosis
    • Decreased blood flow in case of torsion

Management

  • Should be within 6 hours
  • Manual detorquation (manual untwisting, also called detorsion)
    • Externally rotate the testes one or two full 360 degree turns
      • Clockwise for right testicle
      • Counter-clockwise for left testicle
    • Can be tried, but should not delay surgery
    • If there is pain relief, the testis lies lower in the scrotum, and Doppler shows blood flow, it was a success
      • If not, detorqutation in the opposite direction may be tried
  • Surgery
    • In all cases!
      • Surgery should be performed even if manual untwisting was performed, to prevent recurrence and to make sure the untwisting is complete
    • Surgical detorqutation
    • Orchidopexy of both testicles = fixation the testis to the scrotum, to prevent recurrence
    • Orchidectomy if necrotic testis

Fournier gangrene

Perineal necrotising soft tissue infection, commonly called Fournier gangrene, is a necrotising soft tissue infection occuring in the perineum, scrotum, and penis. It's a polymicrobial infection with bacteria entering the region through abscess, fissure, fistula, colon perforation, etc. It's more common in immunocompromised people. It's a rare cause of acute scrotum.

Fournier gangrene is a urological emergency as it has a high (20%) mortality and requires urgent treatment to improve prognosis.

Clinical features

  • Pain
  • Foul smell
  • Skin necrosis
  • Fever
  • Sepsis

Management

  • Wide spectrum antibiotic therapy
    • Against both aerobes and anaerobes
  • Suprapubic catheter (to relieve the infected area)
  • Surgical excision and debridement
  • Hyperbaric oxygen therapy

Acute epididymitis

Acute epididymitis is the acute inflammation of the epididymis. It's one of the most common cause of acute scrotum. Symptoms include unilateral scrotal pain and swelling, usually of gradual onset.

50% of acute epididymis cases also include inflammation of the testicles, called epididymo-orchitis.

Etiology

Acute epididymitis is most commonly due to a sexually transmitted infection like Neisseria gonorrhoeae and Chlamydia trachomatis. It may also be secondary to a lower urinary tract infection.

Diagnosis and evaluation

The diagnosis is clinical, when other causes of acute scrotum (like torsion and Fournier gangrene) are ruled out. The Prehn sign is positive, meaning that the pain is reduced when the scrotum is elevated. There may be concurrent symptoms of UTI or STI. The cremaster reflex is intact (as opposed to testicular torsion). Inflammatory markers may be elevated.

Urine dipstick test may show evidence of UTI, and PCR may be positive for STI pathogens.

Management

The choice of empiric antibiotics depends on whether the epididymitis is presumed to be secondary to UTI or STI. If presumed due to UTI, sulfamethoxazole and trimethoprim can be a first choice, and if presumed due to STI, doxycycline can be a first choice.

Elevation of the painful testicle and analgesics are indicated for supportive therapy.

Haematuria

Haematuria refers to the presence of blood in the urine. We distinguish between microscopic haematuria, when the concentration of blood is too low to be macroscopically visible, and macroscopic haematuria (also called gross haematuria), where the concentration is so high that the urine is visible coloured red. Haematuria is defined as the presence of > 3 RBCs per field of view at 400x when examining a urine sample under the microscope, or by it's detection by laboratory methods.

Haematuria may be a sign of kidney or urinary tract pathology, including glomerulonephritis, urinary tract infection, and bladder cancer. In many, however, haematuria is transient or no underlying pathology can be found.

Severe gross haematuria, especially when there is concurrent urinary retention or voiding of blood clots, is a urological emergency as it may cause bladder tamponade.

Etiology

Gross haematuria:

Management

In most cases haematuria doesn't directly require management, as it's more a sign of disease than a problematic thing in itself. The exception is severe gross haematuria, which can cause bladder tamponade. Severe gross haematuria must be managed with bladder catheterisation with a large lumen 3-way catheter to provide continous irrigation of the bladder with saline. The bladder can also be manually irrigated with a syringe. Cystoscopy may be necessary for clot evacuation and for stopping the bleeding source with cautery or ablation.

For cases which are uncontrolled despite cystoscopy, embolisation of the bleeding artery is an option, as is intravesical tranexamic acid. The last resort is cystectomy.

Acute urinary retention

Acute urinary retention refers to when there is an acute inability to pass urine. It's a urological emergency which can cause permanent injury to the bladder and kidneys, severe suprapubic pain, and bladder rupture in severe cases. Initial management involves bladder catheterisation to drain the bladder.

Urinary retention is more common in males, mostly because of benign prostatic hyperplasia.

Urinary retention can also be chronic, which is a painless condition characterised by increased residual urine volume.

Bladder tamponade is a special and severe form of acute urinary retention where blood and blood clots fill the entire bladder.

Etiology

Most common causes according to age:

Bladder tamponade typically occurs following urological surgery or bleeding from urinary tract malignancy.

Clinical features

Acute onset suprapubic or lower abdominal pain, an urge to urinate, as well as not passing urine, are the typical symptoms. For elderly, urinary retention may present with only delirium. Patients are often restless and appear in distress.

The bladder is usually tender on palpation and felt to be distended.

Complications

If treated early, complications rarely occur. Otherwise, acute urinary retention can have severe complications. Pressure may spread upward in the urinary tract, causing hydronephrosis and acute kidney injury.

Large urine volumes in the bladder causes overdistension of the bladder. The stretching of the bladder detrusor muscle fibres injure them and makes the bladder atonic, possibly permanently. Injury is more severe the higher the volume and the longer time the retention has lasted. Bladder volume of more than 2000 mL is associated with permanent atonic bladder. Volume < 1000 mL usually has very good detrusor recovery.

In the most severe cases, the bladder can rupture, causing urinary extravasation into the pelvic cavity.

Diagnosis

The diagnosis is confirmed if bladder ultrasound shows a bladder volume of > 300 mL, or if after bladder catheterisation > 200 mL of urine is drained. To measure the bladder volume on ultrasound we measure the width, depth, and height of the bladder and multiply by 0.7 (to account for the bladder not being cube-shaped). The ultrasound should be performed post-void, i.e., after the patient has (tried to) pass urine.

After the bladder has been drained, the underlying cause should be sought, and the patient should be evaluated for complications. Urinary dipstick analysis can show signs of haematuria in case of stone disease or signs of infection. Kidney ultrasound may show hydronephrosis. Kidney function tests can show acute kidney injury. CT can show stone.

Management

If the clinical suspicion is high enough and ultrasound cannot be performed, or if the ultrasound showed signs of retention, urgent bladder catheterisation is indicated to decompress the bladder. Previously, it was recommended to drain the bladder intermittently, 750 mL at a time to reduce complications, but nowadays we know that this is not necessary.

Bladder catheterisation is usually performed transurethrally, however this is contraindicated in case of recent urethral or bladder surgery, or acute prostatitis. In these cases, suprapubic catheterisation should be performed instead.

Following catheterisation, one must decide whether to leave the catheter in place (permanently or temporarily) or to remove it after full bladder drainage. This decision depends on the amount of urine drained and if any complications have occured, and whether the presumed cause is reversible. If urinary retention has caused complications, or if the drained volume is > 400 mL the catheter should be left in place. In other cases, it may be safe to remove it.

Voiding trial

A voiding trial refers to removal of a bladder catheter, followed by the patient trying to pass urine normally (after giving it some time for urine to be produced), followed by a bladder ultrasound to determine whether a lot of urine remains in the bladder, which indicates whether the patient can pass the normal amount of urine. A post-voiding residual (PVR) volume of < 100 mL is physiological, but even volumes < 200 mL is considered a success for voiding trial purposes.

The optimal time to wait until attempting a voiding trial has not been determined by studies and mostly varies accoring to local practices and experience. Generally, if the retention is determined to be due to a reversible cause it's appropriate to attempt a voiding trial after the cause is reversed. For irreversible causes, it may be appropriate to attempt a voiding trial after 7-10 days if the maximum bladder volume was < 800 mL. In other cases, the voiding trial should wait until 2-3 weeks.

If the patient can empty their bladder satisfactorily, the catheter does not need to be re-inserted. If not, the patient must either receive a new indwelling bladder catheter and attempt a new voiding trial a few weeks later, or the patient must be taught clean intermittent catheterisation, where they catheterise themselves multiple times a day. If the patient is unable to self-catheterise, or if the second voiding trial fails, the patient should use an indwelling catheter permanently.