What is acalculous cholecystitis?

DEFINITION Acute cholecystitis without evidence of gallstones; thought to be due to biliary stasis. INCIDENCE Ten percent of cases of acute cholecystitis. RISK FACTORS Most often seen in intensive care unit (ICU) patients with multiorgan system failure, trauma (especially after major surgery), burns, sepsis, and TPN. DIAGNOSIS Labs: Leukocytosis, with or without increased ALP, LFTs, amylase, and total bilirubin. Ultrasound: Biliary sludge and inflammation wall (> 4 mm); can also detect complications (e.g., gangrene, empyema, or perforation of the gallbladder). HIDA scan: To confirm diagnosis TREATMENT Urgent cholecystectomy; Percutaneous cholecystostomy in patients with high surgical risk