At your urgent care the NP is treating 46-year-old female. She reports severe abdominal pain, nausea, and vomiting starting approximately six hours ago. The symptoms have steadily worsened. The pain is severe, sharp, and centered in the right upper quadrant, radiating to her back and right shoulder.
On exam, the patient is diaphoretic and appears quite ill. Vital signs show blood pressure of 135/75, pulse 95, temperature 100.9, respiratory rate 25, and oxygen saturation of 99% on room air. There is tenderness to palpation in the right upper quadrant with rebound, guarding, and a positive Murphy sign.
Laboratory findings are significant for elevated CRP and WBC count of 11,000/mm3.
A right upper quadrant ultrasound shows mild gallbladder wall thickening, but inconclusive evidence of stones or pericholecystic fluid.
What is the next best diagnostic step?
Explanation
Answer: C - In this patient with risk factors for biliary colic and gallstones (female, 40’s, obese), her symptoms of fever, RUQ pain radiating to the back, and nausea are strongly suggestive of acute cholecystitis, as well as her elevated CRP and elevated WBC count. However, her RUQ ultrasound results are not consistent with her clinical symptoms. In a patient presenting with clinical symptoms suggestive of acute cholecystitis who have inconclusive findings on ultrasound, abdominal CT is recommended to more accurately assess wall thickening, gallbladder enlargement, and the presence of stones.
An MRI of the abdomen and HIDA are useful if both ultrasound and CT findings are equivocal. Exploratory laparotomy is the least favorable diagnostic option. A serum lipase level would be useful if there was a suspicion of acute gallstone pancreatitis.
