A 68-year-old man is brought to the hospital due to acute fever, malaise, lower abdominal discomfort, and right flank pain. Six months ago, he was hospitalized for similar symptoms and was diagnosed with a urinary tract infection; at that time, his urine culture grew Escherichia coli, and his symptoms completely resolved with antibiotic therapy. Over the past year, the patient has experienced frequent nighttime urination and dribbling but no gross hematuria. Medical history is significant for major depressive disorder and mild idiopathic pulmonary fibrosis. Temperature is 38.7 C (101.7 F), blood pressure is 130/80 mm Hg, and pulse is 98/min. The patient appears acutely ill. Bilateral basal crackles are present. There is right costovertebral angle tenderness. Laboratory results are as follows: Which of the following is the most likely underlying cause of the patient's current condition?

Question

A 68-year-old man is brought to the hospital due to acute fever, malaise, lower abdominal discomfort, and right flank pain.  Six months ago, he was hospitalized for similar symptoms and was diagnosed with a urinary tract infection; at that time, his urine culture grew Escherichia coli, and his symptoms completely resolved with antibiotic therapy.  Over the past year, the patient has experienced frequent nighttime urination and dribbling but no gross hematuria.  Medical history is significant for major depressive disorder and mild idiopathic pulmonary fibrosis.  Temperature is 38.7 C (101.7 F), blood pressure is 130/80 mm Hg, and pulse is 98/min.  The patient appears acutely ill.  Bilateral basal crackles are present.  There is right costovertebral angle tenderness.  Laboratory results are as follows:  Which of the following is the most likely underlying cause of the patient's current condition?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d927_bdea_bc81_4d852b2c2ff4_MD0003_00 This patient's fever, costovertebral angle tenderness, leukocytosis, and urinalysis findings of bacteriuria, pyuria, and hematuria (due to urinary tract inflammation) are consistent with acute pyelonephritis. Urinary tract infections (eg, pyelonephritis) are uncommon in men due to the distance between the anus and urethral opening, the length of the male urethra, and the antibacterial substances in prostatic fluid. However, risk is elevated with benign prostatic hyperplasia (BPH) because periurethral prostatic enlargement impinges the urethra and prevents complete evacuation of the bladder; this allows fecal flora that have contaminated the urinary tract to proliferate rather than be evacuated with urination. Bacterial ascent to the kidneys can lead to unilateral (or less commonly bilateral) pyelonephritis. As seen in this patient, BPH usually presents with manifestations of gradual urethral impingement, including: Voiding symptoms (slow stream, split stream, hesitancy, straining) Incomplete bladder emptying (eg, elevated postvoid residual volumes) with bladder storage symptoms (eg, frequency, nocturia, urgency). This patient's pulmonary crackles on examination are likely due to pulmonary fibrosis rather than prostatic or infectious issues. (Choice A) Detrusor overactivity can cause urinary frequency, urgency, nocturia, and incontinence. However, voiding symptoms (eg, decreased force of stream, dribbling) and recurrent urinary tract infections are atypical because outlet obstruction does not occur. (Choice C) Urethritis is most commonly caused by Chlamydia trachomatis and Neisseria gonorrhoeae. Symptoms generally include dysuria and urethral discharge; flank pain and costovertebral tenderness would not be seen. (Choice D) Selective IgA deficiency can be associated with respiratory tract (eg, sinusitis, pneumonia) and gastrointestinal (eg, giardiasis) infections but the risk of urinary tract infection is not generally increased. This patient's lung crackles are consistent with pulmonary fibrosis and do not indicate a respiratory infection. (Choice E) Staghorn calculi are caused by urease-producing organisms (eg, Proteus, Klebsiella) and are usually present with flank pain and hematuria. Escherichia coli is not a urease-producing organism. Furthermore, the presence of voiding symptoms makes underlying BPH with elevated post-void residuals the most likely inciting factor. Educational objective: Benign prostatic hyperplasia can gradually compress the prostatic urethra, leading to incomplete bladder emptying and an increased risk for recurrent urinary tract infections.

A 68-Year-Old Man Is Brought to the Hospital Due to Acute