A 73-year-old man with dementia is brought to the emergency department by nursing home staff because he has been moaning continuously and gripping his lower abdomen for the past 36 hours. The patient is unable to give any history, but staff members say that he refused oral intake the previous day. He has had no vomiting or diarrhea. His last bowel movement was 2 days ago. The patient uses adult diapers, which were last changed 2 days ago. He has a history of benign prostatic hyperplasia, external hemorrhoids, hypertension, and hyperlipidemia. One year ago, he was hospitalized for diverticular bleeding that resolved spontaneously. His medications review shows that his primary care physician started amitriptyline 8 days ago for chronic neck pain. On physical examination, the patient is afebrile. His blood pressure is 160/70 mm Hg and his pulse is 100/min. The mucous membranes are moist. His lung fields are clear to auscultation. Palpation of the abdomen shows fullness and tenderness along the midline below the umbilicus without guarding or rigidity. Bowel sounds are heard in all 4 quadrants. Which of the following is the best initial management for this patient?

Question

A 73-year-old man with dementia is brought to the emergency department by nursing home staff because he has been moaning continuously and gripping his lower abdomen for the past 36 hours.  The patient is unable to give any history, but staff members say that he refused oral intake the previous day.  He has had no vomiting or diarrhea.  His last bowel movement was 2 days ago.  The patient uses adult diapers, which were last changed 2 days ago.  He has a history of benign prostatic hyperplasia, external hemorrhoids, hypertension, and hyperlipidemia.  One year ago, he was hospitalized for diverticular bleeding that resolved spontaneously.  His medications review shows that his primary care physician started amitriptyline 8 days ago for chronic neck pain.  On physical examination, the patient is afebrile.  His blood pressure is 160/70 mm Hg and his pulse is 100/min.  The mucous membranes are moist.  His lung fields are clear to auscultation.  Palpation of the abdomen shows fullness and tenderness along the midline below the umbilicus without guarding or rigidity.  Bowel sounds are heard in all 4 quadrants.  Which of the following is the best initial management for this patient?

Quizplus · Accepted Answer

This patient's abdominal pain and suprapubic fullness are consistent with amitriptyline-induced urinary retention. Amitriptyline is a tricyclic antidepressant with anticholinergic properties. The bladder empties under muscarinic control with both detrusor muscle contraction and internal urethral sphincter relaxation. Anticholinergic agents can cause urinary retention by reducing detrusor contraction and preventing urethral sphincter relaxation. In addition, elderly male patients often have some degree of underlying benign prostatic hyperplasia and are at risk for urinary retention. Both the anticholinergic properties of amitriptyline and pressure from urinary retention could have caused this patient's constipation as well. This patient's clinical presentation is sufficient to initiate prompt urinary catheterization for suspected urinary retention. Bedside ultrasound or bladder scan (if available) can also help in diagnosis but should not delay urinary catheterization. Urinary catheterization can document a postvoid residual bladder volume (>50 mL is considered diagnostic for urinary retention) and provides symptomatic relief by draining urine from the distended bladder. This patient should also discontinue amitriptyline therapy. (Choice A) An abdominal CT scan would reveal a distended bladder in this patient and may also show hydronephrosis and hydroureter. However, CT scans are more expensive and time-consuming than urinary catheterization and will not provide symptomatic relief. (Choice B) Barium enemas are used to diagnose luminal abnormalities of the colon, such as colon cancer or diverticulosis. (Choice C) Intravenous fluids, analgesics, and observation are the treatment for nephrolithiasis (kidney stones). Patients with kidney stones typically present with intense flank pain and hematuria instead of suprapubic fullness. Intravenous fluids could potentially worsen this patient's obstructive urinary symptoms. (Choice D) Upright abdominal x-ray is not as reliable for evaluating urinary retention as it may not show a distended bladder (unless obstructed by a bladder stone). Abdominal x-rays are more useful for diagnosing ileus or small-bowel obstruction. Amitriptyline may cause ileus, but these patients typically develop nausea, vomiting, hypoactive bowel sounds, distended abdomen, diffuse mild abdominal pain, and abdominal imaging showing dilated bowel loops without air/fluid levels. This patient's normal bowel sounds, infraumbilical fullness, and lack of wet diapers for 2 days make urinary retention more likely than ileus. (Choice E) Surgical consultation is indicated for suspected acute abdomen (eg, bowel perforation, mechanical obstruction). Obstruction typically presents with vomiting, moderate-to-severe abdominal pain, hyperactive bowel sounds, possible peritoneal signs (eg, guarding), and dilated bowel loops with air fluid levels on imaging. Perforation usually has absent bowel sounds. This patient's absence of guarding/rigidity or gastrointestinal symptoms (eg, vomiting) makes these less likely. Educational objective: Drugs with anticholinergic properties can cause acute urinary retention by preventing detrusor muscle contraction and urinary sphincter relaxation. The treatment involves urinary catheterization and discontinuing the medication. References: Management of acute urinary retention. (http://www.ncbi.nlm.nih.gov/pubmed/16507048)

A 73-Year-Old Man with Dementia Is Brought to the Emergency