An 80-year-old woman is brought to the hospital with progressively increasing abdominal pain, nausea, vomiting, and an inability to keep food down since yesterday. Her only medical condition is chronic paroxysmal atrial fibrillation, for which she takes metoprolol and apixaban, and she has never had any surgeries. The patient does not use tobacco or alcohol. Temperature is 37.1 C (98.8 F), blood pressure is 150/80 mm Hg, pulse is 96/min and regular, and respirations are 16/min. Oral examination shows dry mucous membranes. Cardiopulmonary examination reveals no abnormalities. The abdomen is distended and tympanic, but there is no tenderness, rebound, or rigidity. Bowel sounds are increased and high-pitched. Rectal examination shows no stool in the rectal vault and no masses. Fullness and tenderness are noted in the right groin area. The extremities are without cyanosis, clubbing, or edema. Laboratory testing yields a hemoglobin level of 13.2 g/dL, blood urea nitrogen of 38 mg/dL, and creatinine of 1.6 mg/dL. Abdominal x-ray reveals distended bowel loops with air-fluid levels. Which of the following most likely predisposed this patient to her current condition?
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This elderly woman has progressive abdominal pain, nausea/vomiting (leading to dehydration with dry mucous membranes and elevated creatinine), abdominal distension, and high-pitched bowel sounds on examination. In association with the abdominal x-rays demonstrating distended loops of bowel with air-fluid levels, this presentation suggests a small bowel obstruction (SBO). The presence of fullness and tenderness within the right groin suggest the SBO is due to an incarcerated hernia of the groin.
Groin hernias (ie, inguinal, femoral) result from protrusion of intraabdominal (eg, small bowel) or pelvic contents through the abdominal wall. Uncomplicated hernias typically present as a groin bulge that becomes more prominent with increased intraabdominal pressure (eg, cough, Valsalva). Although inguinal hernias are much more common, femoral hernias occur more frequently in elderly women and are much more likely to lead to complications. Incarceration occurs when hernia contents become trapped within the hernia sac, which can result in SBO; reduced venous outflow eventually leads to ischemia and necrosis (strangulation).
(Choice A) Groin hematomas can cause extrinsic compression resulting in an SBO, and are more common in anticoagulated patients. However, patients typically have a history of trauma, and anemia and ecchymosis would be expected.
(Choices B and E) Small bowel adhesions and strictures typically occur as a complication of Crohn disease or intraabdominal surgery. These can cause SBO but are unlikely in this patient without a history of surgery or inflammatory bowel disease. In addition, these disorders are not associated with groin findings.
(Choice D) Small bowel intussusception can cause SBO but usually occurs in children and is very rare in adults. Hematochezia is common, and patients typically have a history of intermittent abdominal pain (due to recurrent telescoping of the bowel). Groin findings are unexpected.
(Choice F) Superior mesenteric artery occlusion can occur in the setting of atrial fibrillation due to embolization of a cardiac thrombus. However, patients typically experience acute-onset, severe periumbilical pain with nausea and vomiting; slowly progressive groin pain and high-pitched bowel sounds are unlikely. In addition, this patient is anticoagulated on apixaban and is unlikely to develop thromboembolic disease.
(Choice G) Watershed bowel hypoperfusion typically occurs with chronic mesenteric ischemia and affects the splenic flexure and rectosigmoid junction of the colon. It usually occurs in patients with hypotension and/or significant atherosclerotic disease. Patients classically have abdominal pain out of proportion to examination findings, and occult blood may be present in the stool. Groin findings are unexpected.
Educational objective:
Femoral hernias are more common in elderly women and are more likely than inguinal hernias to develop complications (eg, incarceration, strangulation). Small bowel obstruction can occur and typically presents with progressive abdominal pain, nausea/vomiting, high-pitched bowel sounds on examination, and distended loops of bowel with air-fluid levels on x-ray.