The most appropriate management is percutaneous cholecystostomy. This ill patient presents with symptoms, signs, and imaging studies consistent with cholecystitis. Hospitalized patients can have acute cholecystitis without gallstones. This is known as acalculous cholecystitis and is thought to reflect either bacterial seeding of the gallbladder wall or gallbladder wall ischemia. Fever accompanying abdominal pain in a critically ill patient should prompt an assessment for cholecystitis. Diagnosis is usually made with ultrasound findings of acute cholecystitis or a radionuclide biliary scan that fails to visualize the gallbladder. Approximately 50% of these high-risk patients will develop cholangitis, empyema, gangrene, or gallbladder perforation during their hospitalization. Supportive treatment with intravenous antibiotic coverage of anaerobic and gram-negative bacteria is required. Definitive therapy with cholecystectomy is preferred but may be contraindicated in severely ill patients. Therapeutic decompression can be achieved with image-guided percutaneous cholecystostomy tube placement. The mortality rate for acute acalculous cholecystitis is between 10% and 50%.

An abdominal CT with contrast will add little useful information to this patient's clinical picture, and it might worsen his kidney disease.

Endoscopic retrograde cholangiopancreatography with sphincterotomy would be a consideration if this patient had gallbladder stones and/or a common bile duct stone. However, his normal liver chemistry studies and absence of biliary dilatation on ultrasound make a common bile duct stone unlikely.

Magnetic resonance cholangiopancreatography, similarly to CT, would not add important clinical information and would be difficult to perform in this ill, ventilated patient.