Acute Urinary Retention Case File

Acute Urinary Retention Case File

Eugene C. Toy, MD, Barry C. Simon, MD, Terrence H. Liu, MD, MHP, Katrin Y. Takenaka, MD, Adam J. Rosh, MD, MS

Case 23

A 64-year-old man presents to the emergency department (ED) because of an inability to urinate for the past 24 hours. In addition, he complains of an unintentional weight loss of 20 lb over the past 6 months, night sweats, and generalized fatigue. On examination, he is thin and in moderate distress. His blood pressure is 168/92 mm Hg, heart rate is 102 beats per minute, temperature is 37.7°C (98.8°F), and respiratory rate is 22 breaths per minute. The abdominal examination reveals a tender mass in the suprapubic area. On rectal examination, the prostate is firm, nontender, and somewhat irregular.

⯈ What is the most likely diagnosis?

⯈ How would you confirm the diagnosis?

⯈ What is the next step in treatment?

ANSWER TO CASE 23:

Acute Urinary Retention

Summary: A 64-year-old man presents with an inability to void for the past 24 hours and a tender mass in the lower abdomen. The patient has signs and symptoms suggestive of prostate cancer, including unintentional weight loss, night sweats, a decrease in energy, and an enlarged irregular firm prostate gland.

• Most likely diagnosis: Acute urinary retention likely due to prostate cancer.
• Confirming the diagnosis: Thorough history and physical examination including a rectal examination, urinalysis, electrolytes and renal function tests, along with bedside ultrasound, if available. Prostate-specific antigen may help in the diagnosis of neoplastic disease if results will be available in the ED.
• Next steps in treatment: Draining the bladder by inserting a urethral catheter should relieve the patient’s pain; if not, a suprapubic catheter can be placed. Treatment of the underlying disease process is also necessary.

ANALYSIS

Objectives

1. Recogniz e the typical signs and symptoms of acute urinary retention.
2. Know how to treat and manage acute urinary retention in the emergency department.
3. Identify when patients with acute urinary retention require hospitalization.

Considerations

Many disease processes, trauma, and medications can result in acute urinary retention (Table 23–1). In elderly men, the most common cause is prostatic hypertrophy. As with this patient, a thorough history and physical examination can help elucidate the etiology of the urinary retention. Passage of a urethral catheter to alleviate the obstruction will bring about significant pain relief. Assessment of renal function is important, as is obtaining a urinalysis to rule out concomitant urinary tract infection. Imaging studies in the ED are rarely necessary for these patients, although bedside ultrasound may help identify bladder distention or a clot in the bladder. Depending on this patient’s renal function and physical status after drainage of his bladder, he may require admission.

Approach To:

Acute Urinary Retention

DEFINITIONS

ACUTE URINARY RETENTI ON: Sudden, complete inability to void accompanied by abdominal discomfort, with a palpable or percussible distended bladder containing greater than 150 mL of urine.

AZOTEMIA: Presence of nitrogenous bodies, especially urea, in the blood that develops in urinary tract obstruction when overall excretion function is impaired.

BENIGN PROSTATIC HYPERPLASIA: Overgrowth and proliferation of the epithelium and fibromuscular tissue of the prostate.

HYDRONEPHROSIS: Dilation of the renal pyelocalyceal system because of obstruction of the urinary tract system.

CLINICAL APPROACH

Because un treated urinary obstruction may lead to chronic renal failure, relieving the blockage is critical. Loss of urinary concentrating ability, azotemia, renal 

^αType III RTA is often not considered a distinct clinical entity. Thus many texts only describe Types I, II, and IV RTAs.

tubular acidosis (Table 23–2), hyperkalemia, and renal salt wasting may occur. Hypertension is common in acute urinary retention because of the increased release of renin by the involved kidneys. The most common presenting symptoms are urinary hesitancy, decreased force, terminal dribbling, nocturia, and typically overflow incontinence. Other symptoms include urinary urgency, hesitancy, and frequency, straining to void, and a sensation of incomplete bladder emptying. Pain due to bladder distention is the symptom that usually provokes the need for ED evaluation. A detailed history and physical examination will often help to identify the cause of the obstruction. History of previous instrumentation of the urinary tract, trauma, neurologic disease, prostatectomy, urologic malignancy, or chronic systemic illness may aid in the proper diagnosis and treatment. Evaluation of medications taken may help in identifying pharmacologic agents that may contribute to urinary retention (Table 23–3).

On physical examination, a palpable mass above the symphysis pubis that disappears after insertion of a urethral catheter is highly suggestive of a distended bladder (acute urinary retention). The meatus should be inspected for evidence of stenosis

and the penis palpated for fistulae or masses. Digital rectal examination may reveal prostatic nodules, asymmetry, tenderness, bogginess, or the typical stony hard enlargement of prostate cancer. A benign prostate on examination does not eliminate it as a cause of obstruction. Testing rectal sphincter tone, perianal sensation, and the bulbocavernosus reflex can be important in cases of suspected neurogenic bladder. In females, a pelvic examination should be performed to rule out inflammation, lesions, or an adenexal mass. Patient may also present febrile, tachypneic, or hypotensive suggesting an infection or sepsis.

Electrolytes and blood urea nitrogen (BUN)/creatinine levels should be obtained to assess renal function. The BUN may be elevated due to significant resorption secondary to the obstruction. A urinalysis is helpful to rule out concomitant infection, which would require antibiotics. Nephrolithiasis, neoplasm, or infection may cause hematuria. Imaging studies are rarely necessary in the ED, although a bedside ultrasound may help identify bladder distention or a clot in the bladder.

Management

Any patient with acute urinary retention requires relief of the obstruction as soon as possible in order to prevent progressive renal dysfunction. Initial efforts should be attempted with a standard urethral catheter. Lidocaine gel should be inserted into the urethra to anesthetize and lubricate the urethra before inserting a 16- or 18-F Foley catheter. If the ED physician is unable to pass the catheter because of an enlarged prostate, a 14- or 18-F coudé catheter may help. Occasionally a catheter may not pass secondary to urethral strictures. A urethral catheter should never be forced because urethral trauma and false passages may be created. In these situations, a urologist should be consulted. If consultation is not available, a suprapubic catheter may be placed or percutaneous bladder aspiration can be performed. These procedures may be performed with bedside ultrasound guidance.

After successful bladder drainage, complications may occur, including transient hematuria, hypotension, and postobstructive diuresis. Postobstructive diuresis can cause electrolyte abnormalities, profound fluid loss, and hypotension. Patients with this condition require monitoring of their urine output and fluid replacement. Risk factors for postobstructive diuresis include chronic bladder obstruction, fluid overload, and chronic renal disease. 

Many patients with acute urinary retention can be discharged home with an indwelling urethral catheter and outpatient urologic follow-up. Admission should be considered for patients with renal dysfunction, a serious infection, or volume overload and for those who are unable to care for themselves.

COMPREHENSION QUESTIONS

23.1 An 88-year-old woman is seen in the ED complaining of significant lower abdominal pain and inability to void. She is noted to have a very full bladder. After a urethral catheter is placed, 1400 mL of urine is drained. She is afebrile with a blood pressure of 130/64 mm Hg, pulse of 74 beats per minute, and respiratory rate of 20 breaths per minute. Her laboratory results are remarkable for a BUN of 65 mg/dL and a urinalysis with moderate leukocyte esterase and many bacteria. Which of the following is the most appropriate management for this patient?

A. Discharge home with oral hydration and recheck the BUN in 48 hours.

B. Discharge home with home health nurse visits.

C. Place the patient on oral antibiotic therapy and arrange follow-up in

1 week.

D. Admit to the hospital for further therapy.

23.2 A 65-year-old man presents to the ED with progressive inability to void, suprapubic pain, and a lower abdominal mass. He has never experienced this type of pain before and is in moderate discomfort. Which of the following is your next step in management?

A. Rectal examination

B. Decompression of bladder with a urethral catheter

C. Computed tomography of the abdomen

D. Percutaneous bladder aspiration

23.3 A 35-year-old woman without any previous medical problems presents with acute urinary retention. She reports a history of increased fatigue with exertion and intermittent paresthesias but denies any history of diabetes, hypertension, or recurrent urinary infections. One year ago, she had some difficulty with double vision that had resolved spontaneously. Which of the following is the most likely diagnosis?

A. Drug abuse

B. Multiple sclerosis

C. Ovarian cancer

D. Spastic bladder

23.4 A 22-year-old woman complains of acute urinary retention, associated with vulvar burning and tingling. A urethral catheter is placed and the bladder decompressed. Which of the following is the best therapy for this patient?

A. Acyclovir

B. Azithromycin

C. Ceftriaxone

D. Doxycycline

ANSWERS

23.1 D. This patient needs to be hospitalized because of a concomitant urinary tract infection and renal dysfunction. At 88 years of age, she may also have difficulty caring for herself.

23.2 B. Decompression of the bladder with a urethral catheter should be performed before examination of the prostate. Percutaneous bladder aspiration is not indicated unless other attempts to decompress the bladder have failed.

23.3 B. Acute urinary retention may be the presenting symptom of multiple sclerosis (MS) in a young healthy female with no previous medical problems. MS is characterized by chronic waxing and waning of neurologic symptoms.

23.4 A. This is likely caused by herpes simplex virus with associated urethral irritation and urinary retention. The best treatment is acyclovir.

CLINICAL PEARLS

⯈ A thorough history and physical examination will often help to identify the cause of acute urinary retention.

⯈ Bladder decompression should be performed as quickly as possible to prevent further damage to the urinary system.

⯈ Consultation with a urologist may be necessary if urethral catheterization cannot be accomplished with a Foley or coudé catheter.

⯈ Admission should be considered for patients with renal dysfunction, a serious infection, or volume overload and for those who are unable to care for themselves.

References

Ferri FF. Ferri’s Clinical Ad visor. Philadelphia, PA: Mosby Elsevier; 2011. 

Kahler J, Harwood-Nuss AL. Selected urologic problems. In: Marx JA, Hockberger RS, Walls RM, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 6th ed. Philadelphia, PA: Mosby Elsevier; 2010. 

Karafin L, Schwartz GR. Renal calculi (kidney stones) In: Principles and Practice of Emergency Medicine. 4th ed. Williams; & Wilkins; 2001:762-763. 

McCuskey CF. Chapter 37. Genitourinary emergencies. In: Stone CK, Humphries RL, eds. Current Diagnosis & Treatment: Emergency Medicine. 6th ed. Available at: http://www.accessmedicine.com/content. aspx?aID=3109311. Accessed March 31, 2012. 

Nicks BA, Manthey DE. Male genital problems. In: Tintinalli JE, Kelen GD, Stapczynski JS, eds. Emergency Medicine: A Comprehensive Study Guide. 6th ed. New York, NY: McGraw-Hill; 2011: Chapter 96. 

Severyn FA. Urinary-related Complaints. In: Mahadevan SV, Garmel GM, eds. An Introduction to Clinical Emergency Medicine. New York, NY: Cambridge University Press; 2005:543-554. 

Yen DH, Lee C. Acute urinary retention. In: Tintinalli JE, Kelen GD, Stapczynski JS, eds. Emergency Medicine: A Comprehensive Study Guide. 6th ed. New York, NY: McGraw-Hill; 2011: Chapter 95.

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