What are the findings on abdominal ultrasound in a patient with vomiting?

From the Guidelines

In a patient presenting with vomiting, an abdominal ultrasound should be performed to identify potential structural abnormalities and conditions that could explain the symptoms, with a focus on the gastrointestinal tract, gallbladder, pancreas, liver, appendix, and kidneys, as recommended by the most recent guidelines 1. When evaluating a patient with vomiting, it is essential to consider the potential causes, including gastrointestinal tract obstructions, such as pyloric stenosis or small bowel obstruction, as well as other conditions like cholecystitis, pancreatitis, or appendicitis.

• The ultrasound examination should include an assessment of the gallbladder for signs of cholecystitis, stones, or sludge that could trigger vomiting.
• The pancreas should be evaluated for inflammation or masses, and the liver should be checked for hepatitis, masses, or abscesses.
• The appendix should be assessed for appendicitis, particularly if the patient presents with right-sided pain.
• The kidneys should be examined for hydronephrosis or stones that might cause referred symptoms.
• Additionally, the ultrasound should look for free fluid in the abdomen, suggesting ascites or peritonitis, and assess for any masses or enlarged lymph nodes that could indicate malignancy. The use of ultrasound in this context is supported by recent studies, which highlight its value in quickly and non-invasively evaluating abdominal organs, even in unstable patients 1.
• Ultrasound is particularly useful in emergency settings, where it can provide real-time imaging and help determine the cause of vomiting.
• While other imaging modalities, such as CT, may be used in certain cases, ultrasound remains a valuable first-line tool for evaluating patients with vomiting, due to its non-invasive nature and lack of radiation exposure.

From the Research

Abdominal Ultrasound Findings in Patients with Vomiting

• The use of abdominal ultrasound in patients with vomiting can aid in the diagnosis of various gastrointestinal disorders 2, 3, 4, 5, 6.
• A study published in the Ultrasound quarterly journal found that abdominal ultrasound can demonstrate a dilated aperistaltic distal esophagus in patients with chronic abdominal pain and vomiting, which can be indicative of achalasia 3.
• In neonates, ultrasound plays a central role in the diagnostic imaging workup for infantile vomiting, and can help identify causes such as bilious vomiting, nonbilious vomiting, and projectile vomiting 4.
• Gastrointestinal ultrasound (GIUS) can also be used to diagnose intestinal emergencies such as bowel obstruction, gastrointestinal perforation, and acute ischemic bowel disease, with a sensitivity and specificity comparable to computed tomography (CT) in some cases 5.
• In children, abdominal ultrasound is often the first investigation in cases of moderate to severe abdominal pain with localizing findings, and can help identify surgical causes such as malrotation, intussusception, and acute appendicitis 6.

Diagnostic Accuracy and Pitfalls

• The diagnostic accuracy of abdominal ultrasound in patients with vomiting can vary depending on the specific condition being diagnosed and the experience of the operator 2, 5.
• Common pitfalls in the use of abdominal ultrasound in patients with vomiting include the potential for false negatives or false positives, and the need for careful interpretation of ultrasound findings in the context of clinical presentation and other diagnostic tests 2, 5.

Clinical Applications

• Abdominal ultrasound can be used as a point-of-care ultrasound tool to aid in the diagnosis and management of patients with vomiting in various clinical settings, including emergency departments and outpatient clinics 2, 6.
• The use of abdominal ultrasound in patients with vomiting can help reduce the need for more invasive diagnostic tests, such as endoscopy or surgery, and can provide a rapid and non-invasive means of assessing gastrointestinal function 3, 5.