A 60-year-old woman is recovering from a major pelvic cancer operation and develops severe abdominal pain and sepsis. Following a positive HIDA scan, laparotomy is performed. The gallbladder is severely inflamed and removed. There is no evidence of gallbladder stones (acalculous cholecystitis). Cholecystectomy is performed. Which is true of acalculous cholecystitis?

Acute acalculous cholecystitis is most commonly encountered in critically ill patients after trauma, other unrelated surgical operations, burns, sepsis, and multiorgan failure. The HIDA scan fails to visualize the gallbladder, and a sonogram may show a distended gallbladder with wall thickening and pericholecystic fluid. Acalculous cholecystitis carries a mortality rate of 10-30%. Delay in diagnosis and hence treatment is accompanied by severe complications, such as gangrene and perforation of the gallbladder in a patient who usually has other debilitating illnesses.