What causes acalculous cholecystitis? The gallbladder in acalculous cholecystitis has stasis of bile within it and is also hypoperfused leading to inflammation (cholecystitis).  By definition it is cholecystitis that occurs without a gallstone being present in the gallbladder.  What are some risk factors for developing acalculous cholecystitis? Acalculous cholecystitis is typically seen in patients that are critically ill.  Risk factors include: immunosuppression recent surgery total parenteral nutrition (TPN) sepsis hypotension How is the diagnosis of acalculous cholecystitis made? The diagnosis is made based on findings in the history and physical exam along with laboratory tests and imaging.  Suspect acalculous cholecystitis in patients with risk factors (recent surgery, TPN, etc) who have…