The prevalence of hepatobiliary disease in the emergency and acute care settings is high. Ultrasound allows for accurate diagnosis in a large number of these cases. Emergency physicians who can effectively perform ultrasound benefit enormously from the ability to make rapid bedside diagnoses, especially in undifferentiated cases of vague abdominal pain.
The primary tools in the evaluation of acute hepatobiliary disease are ultrasound, hepatobiliary iminodiacetic acid scintigraphy (commonly referred to as HIDA scan or cholescintigraphy), computed tomography (CT), and endoscopic retrograde cholangiopancreatography (ERCP). Prior to the late 1980s and early 1990s, several imaging modalities were in use to diagnose hepatobiliary disease, such as oral and intravenous cholangiography. These methods took an extraordinary amount of time, required consumption or injection of potentially harmful contrast agents, and exposed the patient to radiation.1 Ultrasound largely replaced these imaging modalities in the 1980s. Ultrasound has the highest sensitivity for detecting the presence of gallstones while HIDA has a reported higher sensitivity for detecting the presence of acute cholecystitis.2 Data derived solely from a set of emergency department patients, however, suggest that emergency ultrasound of the gallbladder may prove as useful for the detection of acute cholecystitis as HIDA.3, 4 Although CT also has a role in the evaluation of patients with suspected hepatobiliary disease, its application is limited by its inability to detect 25% of gallstones. CT may play a greater role when other causes of abdominal pain are also being considered in the work-up of abdominal pain.5, 6 Ultrasound also has the added advantage of not exposing the patient to ionizing radiation. ERCP has its own unique risks, including pancreatitis and even death, and the test consumes a great deal of time and resources.
The clinical indications for performing emergency bedside hepatobiliary ultrasound by clinicians include
- gallstones and biliary colic,
- acute cholecystitis,
- jaundice and biliary duct dilatation,
- abdominal sepsis,
- ascites, and
- hepatic abnormalities.
Emergency physicians expect to see biliary pathology in up to a third of all abdominal pain cases they encounter.7 The classic presentation of biliary colic portrays an obese woman of child-bearing age with recurrent colicky pain in the right upper quadrant shortly after the consumption of a fatty meal. While gallstones are more prevalent in young, multiparous women than in young men, the ratio balances out with advancing age.8 In older patients, the pain does not wax and wane after meals but is constant and occurs mostly at night at predictable hours, lasting for an average of 1–5 hours.9 Physiologic studies conducted on patients while they were undergoing cholecystectomy concluded that a majority of patients with cholelithiasis will experience epigastric discomfort or dyspepsia with mechanical stimulation of the gallbladder. In fact, some feel that symptoms tend not to migrate to the right upper quadrant until the inflamed gallbladder irritates the peritoneum.10–12 Patients who experience right-sided pain may present complaining of right flank pain, shoulder pain, ...