What are the risk factors for acalculous cholecystitis?
1. critical illness (e.g. major surgery, burns, sepsis, or trauma) 2. prolonged fasting or TPN (both predispose to bile stasis) 3. shock 4. immunodeficiency 5. vasculitis (e.g. SLE, polyarteritis nodosa)
Hepatobiliary ultrasound demonstrates marked thickening of the gallbladder wall (0.9 cm), no gallstones were demonstrated. The CBD was not dilated. Pancreas and liver were unremarkable (not shown). Positive Murphy sign during the examination.