A 68-year-old man comes to the emergency department due to lower abdominal pain and nausea. His symptoms started the prior evening, when he began to feel abdominal fullness and discomfort. This progressed to pain over the lower abdomen and constant nausea without vomiting. The patient last urinated 24 hours ago. He has had difficulty initiating urination and a feeling of incomplete voiding for the last year but avoided seeing a physician. Temperature is 36.7 C (98 F), blood pressure is 150/90 mm Hg, and pulse is 95/min. Physical examination shows suprapubic tenderness and fullness without guarding or rebound. Rectal examination reveals an enlarged, smooth prostate. Serum creatinine is 2.6 mg/dL and blood urea nitrogen is 22 mg/dL. A urinary catheter is placed, with immediate collection of 800 mL of urine and relief of the patient's symptoms. The following day, serum creatinine is improved. This patient's condition is associated with increased risk for which of the following?

Question

A 68-year-old man comes to the emergency department due to lower abdominal pain and nausea.  His symptoms started the prior evening, when he began to feel abdominal fullness and discomfort.  This progressed to pain over the lower abdomen and constant nausea without vomiting.  The patient last urinated >24 hours ago.  He has had difficulty initiating urination and a feeling of incomplete voiding for the last year but avoided seeing a physician.  Temperature is 36.7 C (98 F), blood pressure is 150/90 mm Hg, and pulse is 95/min.  Physical examination shows suprapubic tenderness and fullness without guarding or rebound.  Rectal examination reveals an enlarged, smooth prostate.  Serum creatinine is 2.6 mg/dL and blood urea nitrogen is 22 mg/dL.  A urinary catheter is placed, with immediate collection of 800 mL of urine and relief of the patient's symptoms.  The following day, serum creatinine is improved.  This patient's condition is associated with increased risk for which of the following?

Quizplus · Accepted Answer

11ec160b_3a2c_d2e1_9249_a7cbe7b61e4f_MD0001_00 This patient with progressive lower urinary tract symptoms and an enlarged prostate has benign prostatic hyperplasia (BPH). Bladder-outlet obstruction with acute urinary retention is a common complication of BPH and can occur with progressive disease or be triggered by medications that decrease bladder contractility (eg, sympathomimetic or anticholinergic medications). Enlargement of the prostate (static obstruction) and contraction of prostatic smooth muscle (dynamic obstruction) compress the prostatic urethra, which increases the hydrostatic pressure required to overcome resistance to flow. As the bladder empties during micturition, urinary pressures diminish; if urinary pressure falls below the prostatic compressive pressure, urine flow stops, leaving a residual volume of urine in the bladder. Complete emptying of the bladder is a defense mechanism against urinary tract infection, but if the bladder does not empty completely, the residual urine can act as a growth medium for pathogenic bacteria. Other complications of BPH include bladder hypertrophy, hydroureter and hydronephrosis, and chronic kidney disease (obstructive uropathy). (Choice A) Major risk factors for bladder transitional cell carcinoma include smoking and occupational exposure to aromatic amine-containing dyes. The risk is not significantly increased in patients with BPH. (Choice B) Glomerulonephritis causes primary (intrarenal) azotemia and is not typically associated with BPH. Common causes of glomerulonephritis in adults include IgA nephropathy and membranoproliferative glomerulonephritis. (Choice C) Priapism is prolonged erection of the penis that is not due to ongoing sexual stimulation. It may occur secondary to conditions that impair venous outflow from the penis (eg, sickle cell) or due to use of certain medications (eg, phosphodiesterase-5 inhibitors, trazodone). BPH does not increase the risk for priapism. (Choice D) The risk for prostatic adenocarcinoma increases with age and is greatest in black patients and in individuals with a family history of prostate cancer. However, the risk is not appreciably increased in those with BPH or urinary obstruction. Educational objective: Benign prostatic hyperplasia can increase resistance to urine flow in the urethra and lead to incomplete bladder emptying during micturition. The residual urine can act as a growth medium for pathogenic bacteria and increase the risk for urinary tract infection. __________ References: Management of the complications of BPH/BOO (http://www.ncbi.nlm.nih.gov/pubmed/24744522)

A 68-Year-Old Man Comes to the Emergency Department Due to Lower