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March 2008
By Phillips Perera, MD, RMDS, and Diku Mandavia, MD, FACEP, FRCPC
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Presentation:
A 46-year-old woman presents to your emergency department complaining of severe abdominal pain for the last few hours after eating a burrito. She describes the pain as being in the right upper quadrant and epigastric areas of her abdomen, intense at times, radiating to her back, and associated with nausea and vomiting. She has had similar episodes with minor discomfort in the past but did not seek medical attention.
Her vital signs are: heart rate, 90; blood pressure, 140/70; temperature, 98ºF; respirations, 12. She has tenderness in her right upper quadrant during palpation. You order an intravenous line, lab work, and analgesia. The ultrasound machine is brought to the bedside, and you perform a focused examination of the patient’s right upper quadrant. You obtain the image of the gallbladder shown here.
Click for diagnosis and discussion |
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Diagnosis and discussion:
The image shown on the previous page demonstrates a large gallstone impacted at the neck of the gallbladder, while a normal gallbladder is shown here for comparison.
Because the majority of biliary-related causes of pain are associated with gallstones, a focused ultrasound examination of the right upper quadrant is essentially a search for cholelithiasis. Acalculous cholecystitis is rare in a patient presenting to the emergency department. It is more commonly seen in sick, hospitalized patients or in those with compromised immune systems.
The first step in an ultrasound examination of the right upper quadrant is to accurately locate the gallbladder; this can be challenging in many patients. Start by placing the probe in either a high lateral position or in a subcostal orientation. Rolling the patient into the left lateral decubitus position will bring the gallbladder closer to the subcostal probe position and allow for better evaluation of the sonographic Murphy’s sign. Most larger gallstones appear on ultrasound as bright or hyperechoic areas lying within the gallbladder with posterior acoustic shadowing. These shadows occur because the hard mineral deposits of the stone are not penetrated by ultrasound waves.
Once a gallstone has been found, the examiner should check for the sonographic Murphy’s sign by pushing the probe gently toward the gallbladder and checking for tenderness. The examiner can also look for secondary signs of cholecystitis such as thickening or edema of the gallbladder wall and pericholecystic fluid. In this case, the patient was found to have a single gallstone without other signs of acute cholecystitis. Her lab assessment was normal, her pain was reduced dramatically with analgesia, and after observation she was referred for outpatient follow-up with a surgeon. |
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Dr. Perera is an assistant clinical professor of emergency medicine at Columbia University College of Physicians and Surgeons and Weill Cornell Medical College and director of emergency ultrasound at New York Presbyterian Hospital in New York City. Dr. Mandavia is a clinical associate professor of emergency medicine and director of emergency ultrasound at Los Angeles County-USC Medical Center and an attending staff physician at Cedars-Sinai Medical Center in Los Angeles.
Emerg Med 40(3):11-2, 2008
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