A 73-year-old woman with a long history of heavy smoking undergoes femoral aery-popliteal aery bypass for rest pain in her left leg. Because of serious underlying respiratory insufficiency, she continues to require ventilatory suppo for 4 days after her operation. As soon as her endotracheal tube is removed, she begins complaining of vague upper abdominal pain. She has daily fever spikes of 39degC (102.2degF) and a leukocyte count of 18,000/mL. An upper abdominal ultrasonogram reveals a dilated gallbladder, but no stones are seen. A presumptive diagnosis of acalculous cholecystitis is made. Which of the following is the next best step in her treatment?

The development of acute postoperative cholecystitis is an increasingly recognized complication of the severe illnesses that precipitate admissions to the ICU. The causes are obscure but probably lead to a common final pathway of gallbladder ischemia. The diagnosis is often extremely difficult because the signs and symptoms may be those of occult sepsis. Moreover, the patients are often intubated, sedated, or confused as a consequence of the other therapeutic or medical factors. Biochemical tests, though frequently revealing abnormal liver function, are nonspecific and nondiagnostic. Bedside ultrasonography is usually strongly suggestive of the diagnosis when a thickened gallbladder wall or pericholecystic fluid is present; nonvisualization of the gallbladder on a nuclear medicine (HIDA) scan can also be diagnostic. If diagnosis is delayed, moality and morbidity are very high. Percutaneous drainage of the gallbladder is usually curative of acalculous cholecystitis and affords stabilizing palliation if calculous cholecystitis is present. Antibiotics without drainage are too cautious a choice for a patient with a potentially fatal complication. Operative intervention is indicated only if less invasive methods of treatment (percutaneous cholecystostomy tube) have failed, and ERCP is not indicated in the absence of ductal obstruction.