Smiths General Urology, Seventeenth Edition (LANGE Clinical Medicine)

Authors: Macfarlane, Michael T.

Title: Urology, 4th Edition

Copyright 2006 Lippincott Williams & Wilkins

> Table of Contents > Part One - Chief Presentations > Chapter 14 - Urologic Emergencies

Chapter 14

Urologic Emergencies

Neonatal/Pediatric

Abdominal Masses

More than 50% of neonatal abdominal masses arise from the kidney. Hydronephrosis and multicystic kidney are the most common etiologies, followed by polycystic kidney, renal vein thrombosis, and solid tumors. Workup should include careful physical examination and abdominal palpation, ultrasound, plain film, and intravenous (IV) urography. Note the immature neonatal kidney requires high doses of contrast, up to 4 mL/kg, because of its poor concentrating ability (see Chapter 15).

Hematuria

Hematuria in the neonate, particularly gross hematuria, is an emergency. Consider renal vein or artery thrombosis, renal cortical necrosis, obstructive uropathy, cystic renal disease, and tumors.

Hypertension

The kidney is the second most common cause of systemic hypertension in the neonate. Renal artery thrombosis is the most important etiology to rule out but also consider hydronephrosis secondary to obstruction or reflux, adrenogenital syndrome, and, rarely, pheochromocytoma, Cushing's disease, and hyperaldosteronism.

Delayed Micturition

Delay of micturition for more than 24 hours after birth, especially if associated with a distended palpable bladder, is cause for immediate concern. Ninety percent of newborns will have urinated about 10 mL within the first 24 hours of life. Consider lower

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urinary tract obstruction such as posterior urethral valves. Note that magnesium sulfate given to the mother for toxemia during delivery can cause transient neonatal urinary retention.

Scrotal Mass

A scrotal mass is rare in the neonate but must be given immediate attention. Consider torsion, epididymitis, incarcerated inguinal hernia, torsion of the appendix testis or epididymis, and testicular tumor. Management is generally surgical exploration (see Chapter 10).

Ambiguous Genitalia

Ambiguous genitalia are medical and social emergencies and require immediate evaluation (see Chapter 16).

Ascites

Urine is the most common reason for ascites in the neonate, and obstructive uropathy is the most common underlying cause. Posterior urethral valves and ureteropelvic junction obstruction are the most frequent etiologies, followed by urethral stricture or atresia, ectopic ureterocele, and neurogenic bladder. Voiding cystourethrography (VCUG) and IV urography are essential to diagnosis.

Renal Vein Thrombosis

Renal vein thrombosis can occur at any age but is most common in the neonatal period. Early diagnosis is dependent on having a high index of suspicion. Renal vein thrombosis in infancy equally affects males and females and left and right kidneys. More than half of the cases present within the first 2 weeks of life, most often in neonates with diarrhea and severe dehydration or in infants with diabetic mothers. Less commonly associated conditions include sepsis, traumatic deliveries, congenital heart disease, and maternal ingestion of thiazides or cytomegalovirus infection. Infants present with a flank mass, hematuria, thrombocytopenia, and nonvisualization of the involved kidney on IV urography.

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Although once considered only for surgical therapy, unilateral renal vein thrombosis is now treated medically with correction of underlying disorders such as dehydration or sepsis.

Exstrophy

Cloacal exstrophy with its extensive array of problems will require immediate attention. Classic exstrophy should be considered for prompt surgical intervention within the first 24 to 48 hours in those patients who are suitable for reconstruction (see Chapter 34).

Absence of Abdominal Wall Musculature

Defective abdominal wall musculature should alert one to typical prune belly uropathy and may occasionally need prompt intervention (see Chapter 34).

Imperforate Anus

Imperforate anus, particularly with supralevator lesions, is associated with other urologic abnormalities in up to 50% of patients (see Chapter 34).

Adult

Acute Urinary Retention

Acute urinary retention must be dealt with urgently to alleviate acute pain (see Chapter 1).

Testicular Torsion

Testicular torsion is less common in adults than in children. However, it must always head any list of differential diagnoses for an acute, painful testicular mass (see Chapter 10).

Priapism

The difficulty in treating and the complications arising from priapism increase significantly the longer the condition is allowed to exist. Early reversal is recommended (see Chapter 9).

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Fournier's Gangrene

Fournier's gangrene is a rapidly fulminating, gangrenous infection of the genitalia. It begins as an extension of an infection from urinary, perianal, abdominal, or retroperitoneal sites or secondary to local trauma. A wide range of both aerobic and anaerobic organisms is encountered. It can present in any age group, but most occur after age 50. Most patients will have some underlying systemic disease, in particular diabetes. It often presents abruptly with severe pain of the penis, scrotum, or perineum, with rapid progression from erythema to necrosis, sometimes within hours. Other cases will have a more insidious onset with generalized symptoms of malaise, fever, chills or sweats, and genital discomfort. A mortality rate of up to 50% has been reported.

Diagnosis

A careful history should be taken with special attention to possible underlying disorders such as diabetes mellitus, immunosuppression, steroid medications, alcohol abuse, or other infections. The physical diagnosis is not difficult. Areas of erythema, induration, skin necrosis, and crepitus are usual, and the overwhelming fetid odor is unmistakable. It is important to determine the full extent of the process and to search for the source, particularly in the anorectal and urogenital areas. The infection not uncommonly extends all the way up the abdominal wall. Proctoscopy and a retrograde urethrogram may be helpful.

Management

The mainstay of treatment is aggressive surgical debridement and triple drug antibiotic therapy. Blood, urine, and wound cultures should be taken before starting antibiotic therapy. Metronidazole (Flagyl), ampicillin, and gentamicin are reasonable choices for initial therapy. Immediate surgical debridement under anesthesia must follow. An exploratory laparotomy or diverting colostomy is occasionally necessary. After debridement, the wounds are left open and packed with fine-mesh gauze soaked in Dakin's solution (hypochlorite Clorox). Dressings should be changed two to three times a day. Antibiotics should be continued until there is no evidence of active infection and the wound is clean with a base of granulation tissue.

Autonomic Dysreflexia

Autonomic dysreflexia is a syndrome characterized by a major sympathetic nervous response to afferent visceral stimulation in

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the patient with spinal cord injury. Clinical manifestations include dangerous systolic hypertension, sweating, a pounding headache, paradoxical bradycardia, a widened pulse pressure, and a subjective sense of impending doom on the part of the patient. This can occur in response to stimulation of the bladder, urethra, or rectum in patients with cord lesions above T6, usually in the cervical region, and most frequently during the 3 to 8 months after injury. Acute bladder filling as occurs during cystoscopy or urodynamic testing can trigger an episode. Catheter drainage of the bladder can be used to minimize chronic autonomic dysreflexia.

Treatment

In a hypertensive crisis, sodium nitroprusside (50 mg in 250 mL of D5W) can be titrated IV to bring pressure down within 5 minutes (1 3 g/kg per minute). An -blocker such as phentolamine (Regitine) 5 mg IV bolus can also be used to treat an acute episode along with removal of the afferent stimulus (i.e., drain the bladder). Chlorpromazine (Thorazine), 25 mg intramuscular (IM) every 6 hours (q6h), and oral -blockers can be used prophylactically in patients with the potential for such a response during cystoscopy. Spinal anesthesia will block dysreflexia during surgery better than a general anesthetic.

Lower Extremity Weakness in Advanced Prostate Cancer

Occasionally, patients present with untreated metastatic prostate cancer and signs of incipient spinal cord compression (e.g., lower extremity weakness and lax anal sphincter tone). These patients need emergency treatment to decrease tumor mass and relieve the cord compression. Motor function is lost first with spinal cord compression, and pinprick sensation is the last to go. Patients who have retained pinprick sensation may safely be given a trial of other forms of treatment before resorting to a decompression laminectomy. Neurologic consultation should be obtained. Options for treatment are as follows:

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