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A30) Abdominal pain and distension
Review the Learning Outcomes, Hx, PE and Labs, and begin the module with your Provisional Diagnosis. Keep hitting "Next" to move through the module.
Learning Outcomes
- Identify the role of consulting diagnostic radiologists in evaluating a patient with abdominal pain.
- Generate a list of possible diagnoses for a patient with lower abdominal pain based on their symptoms and medical history.
- Analyze the appropriate imaging modalities and spectrum of imaging findings for evaluating a patient with abdominal pain.
History
A 75-year-old female with a history of cholelithiasis presents to the emergency department with two days of severe, crampy, sharp lower abdominal pain. She also reports nausea, vomiting, constipation, and abdominal distension. She is unable to pass flatus. Additionally, she mentions experiencing 3-4 months of postprandial, crampy, right upper quadrant abdominal pain that worsens after consuming fatty foods.
Physical Exam
BP: 125/80, HR 110, RR 16, Temp 100.8 F, O2 saturation 100%. BMI: 32 kg/m2
Abdominal: Moderate diffuse tenderness, distended, tympanic to percussion, and audible high-pitched bowel sounds. There is no hepatosplenomegaly.
Labs
WBC: 14.0 x 109/L (Reference: 4.0 - 11.0 x 109/L);
BUN: 32 mg/dL (Reference: 7 - 30 mg/dL);
Creatinine: 1.34 mg/dL (Reference: 0.7 - 1.2 mg/dL);
BUN/Creatinine ratio: 23.88 (Reference: >20);
LFTs: Within normal limits;
Lipase: Within normal limits.
Provisional Diagnosis
Select the Dx you believe is most appropriate
Given the patient's history of nausea, vomiting, constipation, and abdominal distention, small bowel obstruction is the most appropriate provisional diagnosis. The elevated creatinine and BUN/creatinine ratio suggests hypovolemia from dehydration.
Well done. You were correct
Potential Acuity
What is your assessment of the likely acuity for this patient?
Well done. You were correct
The patient requires urgent workup and management.
First Imaging Study
What is the first imaging study you will order?
A CT of the abdomen and pelvis is a fast and non-invasive imaging technique that can efficiently assess the presence of a small bowel obstruction, its etiology, and any accompanying complications.
Well done. You were correct
Pertinent Imaging Observations
Click on the links below to view images from the study, and assess these key findings as best you can.
CT abdomen and pelvis with IV contrast
There is an obstructing lesion.
There is a mixed-density, circular, calcified structure within the small bowel in the left hemiabdomen which is consistent with an obstructing gallstone.
What best describes the findings in the biliary tree?
There is gas present in the biliary tree. In gallstone ileus, a gallstone enters the small intestine by creating a fistula between the gallbladder and the small bowel. This connection allows gas from the bowel to enter the biliary tree and cause pneumobilia.
The patient has:
The patient has dextroscoliosis, as the spine curves toward the patient’s right side.
View the full study if you'd like to take a look yourself.
Second Imaging Study
What is the next imaging study you will order?
None, the diagnosis of small bowel obstruction secondary to an obstructing gallstone has been confirmed by CT.
Well done. You were correct
What is your Diagnosis now that you have seen the imaging results?
The imaging findings are consistent with all the above diagnoses.
Current Acuity
Initially, you selected and we suggested acuity.
Has your concern for this patient changed?
The patient requires urgent workup and management.
Assessment and Plan
Please provide your assessment and plan for this patient
The patient, a 75-year-old female with a history of cholelithiasis, presents with symptoms consistent with gallstone ileus. CT imaging confirms a small bowel obstruction caused by a gallstone in the small bowel with pneumobilia secondary to a cholecystoduodenal fistula. General surgery should be consulted for evaluation and management. Treatment options include surgical enterolithotomy and possible cholecystectomy with biliary-enteric fistula closure. In the interim, the patient should be made NPO, started on IV fluids, and undergo nasogastric decompression.
Lessons Learned:
- Gallstone ileus is a rare but serious condition that can cause mechanical bowel obstruction.
- Symptoms of small bowel obstruction include nausea, vomiting, abdominal pain, abdominal distension, and obstipation. These symptoms can be vague and nonspecific, so a high degree of clinical suspicion is necessary to make the diagnosis.
- CT imaging is an important diagnostic tool for gallstone ileus, and can reveal the presence of a gallstone in the small bowel, pneumobilia, a small bowel obstruction (Rigler’s triad), and a cholecystoduodenal fistula.
- Similarly, if an X-ray was obtained, it can reveal a gallstone, pneumobilia, and small bowel obstruction.
- Risk factors for gallstone ileus include elderly age, chronic cholecystitis, and a history of gallstones larger than 2cm.
- Surgical enterolithotomy is the first-line treatment for gallstone ileus, and generally involves the removal of the obstructing gallstone through an enterotomy, cholecystectomy, and closure of the biliary-enteric fistula.
Socioeconomic Factors: Careful post-operative follow-up is important for all patients undergoing surgery for small bowel obstruction, but it is especially important for Medicare and Medicaid patients who may have higher readmission rates.
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