Ultrasound is not a useful screening tool for acute acalculous cholecystitis in critically ill trauma patients

Acute acalculous cholecystitis remains a diagnostic challenge in critically ill trauma patients. Laboratory studies are nonspecific and associated injuries or mental status changes may mask clinical signs and symptoms. We conducted a retrospective study to assess the utility of ultrasound in the diagnosis of acute acalculous cholecystitis. We hypothesized that ultrasound is inadequate as a screening tool for acute acalculous cholecystitis. The abdominal ultrasounds of all patients undergoing evaluation for acute acalculous cholecystitis in a 40-month period at our Level I trauma center were reviewed. Thickened gallbladder wall, pericholecystic fluid and emphysematous gallbladder were considered positive sonographic criteria. Sludge, cholelithiasis, and hydrops were considered suggestive. Patients who did not undergo cholecystectomy had their gallbladders evaluated either during subsequent laparotomy or at autopsy or they were discharged from the hospital without need for intervention. Sixty-two patients were included. Twenty-one patients underwent cholecystectomy for presumed acute acalculous cholecystitis. The data revealed a sensitivity of 30 per cent (6/20) and a specificity of 93 per cent (39/42) for ultrasound evaluation. Twenty patients had subsequent hepatobiliary scans [hepato-iminodiacetic acid (HIDA)] with a sensitivity of 100 per cent (12/12) and specificity of 88 per cent (7/8). Our data do not support ultrasound as a reliable routine screening tool for acute acalculous cholecystitis. Despite its convenience as a bedside procedure ultrasound has insufficient sensitivity to justify its use and a more sensitive diagnostic tool should be used.