A 23-year-old overweight Black woman with a history of hemolytic anemia presents to the emergency department with fever and right upper quadrant pain. A right upper quadrant ultrasound reveals gallstones, a thickened gallbladder wall, and pericholecystic fluid. Which patient characteristic puts her at the highest risk of developing acute cholecystitis? a. Female sex b. Young age c. Ethnicity d. Hemolytic anemia e. Obesity

d. Hemolytic anemia

The patient's history of hemolytic anemia puts her at the highest risk for developing acute cholecystitis in the context of the options provided. Hemolytic anemia can lead to increased bilirubin production, which in turn can lead to pigmented gallstone formation—a common cause of acute cholecystitis. Obesity is also a risk factor but is less specific than hemolytic anemia, which has a direct pathway to gallstone formation.

Extra: Acute cholecystitis is inflammation of the gallbladder that typically occurs due to blockage of the cystic duct, most commonly from gallstones. Other causes can include tumor, infection, or disorders that affect bile flow. Risk factors for gallstone formation and subsequent acute cholecystitis include the "Four Fs": Female, Fat, Forty, and Fertile, which describe the demographic most commonly affected.

Hemolytic anemia involves the premature destruction of red blood cells, which can lead to increased levels of bilirubin in the blood. Bilirubin is one of the substances that bile is made of, and if there is too much bilirubin, it can lead to the formation of bilirubin (pigmented) stones.

Obesity is another risk factor for gallstone formation because it is associated with increased cholesterol in bile, which can also lead to cholesterol stone formation. Age and ethnicity can also influence risk, but they are not as directly linked as the specific condition causing abnormal bilirubin metabolism, such as hemolytic anemia. Female sex is a general risk factor as women tend to have gallstones more often than men.