Mr Jones is a 75-year-old gentleman admitted with a history of fever, cough, and shortness of breath. He was diagnosed with community-acquired pneumonia and started on levofloxacin. On admission his vitals were stable. The on-call intern gets a call at 2 AM by the nurse, stating Mr Jones has been complaining of excruciating constant abdominal pain (epigastric and periumbilical pain) radiating to the flank for the past 15 to 20 minutes. His pain is associated with nausea and vomiting but no fever or chills, hematuria, dysuria, or chest pain. He had a normal bowel movement today. Past medical history includes HTN, type 2 DM, and CAD; no h/o renal or gallstones. Social history is significant for smoking, and the patient reports no alcohol use. Medications include levofloxacin, hydrochlorothiazide, aspirin, metoprolol, and lovastatin; no NSAID use is noted. On physical examination, he looks to be in moderate distress.
Blood pressure lying down is 120/60, heart rate is 100, and the patient is afebrile. Heart and lung examinations are unremarkable. Abdominal examination reveals obese abdomen with moderate, diffuse tenderness without guarding or rigidity; bowel sounds are present but hypoactive. Pulses are diminished in the lower extremities. Rectal examination reveals Hemoccult-negative stool.
1. What should be included in your differential diagnosis (DDX)?
- Diverticular rupture (although pain would be expected more in the left lower quadrant [LLQ])
- Peptic ulcer disease unless associated with perforation with signs of peritonitis (rebound tenderness and rigidity)
- Ruptured abdominal aortic aneurysm (AAA)
Abdominal Aortic Aneurysm
The classic presentation of an AAA is a man with a history of HTN who has the triad of severe abdominal pain, a pulsatile abdominal mass, and hypotension. Physical examination is not sufficiently sensitive to rule out AAA. Although atherosclerosis is the most common cause for an AAA, there are a number of nonatherosclerotic causes, which include cystic medial necrosis, and infections such as syphilis and those caused by Salmonella. Aneurysms also occur with diseases such as Marfan syndrome or Ehlers-Danlos syndrome. Risk factors include smoking, male gender, family history, advanced age, and uncontrolled hypertension. Complications include aortic aneurysm rupture. Rates of rupture rise as the aneurysm increases in diameter size. Mortality with rupture is 70% to 90%. Bedside emergent ultrasound has been demonstrated to be highly accurate with a sensitivity of 96% to 100% and a specificity of 98% to 100%. For screening, ultrasound is preferred. Treatment may be surgical or medical. Urgent surgical management is used when the AAA has ruptured. For an asymptomatic AAA, repair is recommended when an aneurysm is greater than or equal to 5.5 cm, is tender, or has increased in size by more than 1 cm in 1 year. For smaller aneurysms that have not ruptured, medical management with smoking cessation, statin therapy, and blood pressure control is initiated.
Alternative diagnoses to ...