Chapter 12: Hepatobiliary

INTRODUCTION

Abdominal pain is the most common chief complaint in patients presenting to the emergency department (ED), accounting for more than 12 million visits annually in the United States.¹ An estimated 15% of the U.S. population has gallstones with 1–4% becoming symptomatic per year, of whom 20% will develop acute cholecystitis.^2–4 This disease burden results in over 200,000 hospitalizations each year for acute cholecystitis.⁵ Point-of-care ultrasound (POCUS) has been used to both diagnose and exclude gallstone-related pathology with a high degree of confidence, resulting in improved clinical decision-making and ED throughput.^6–9 Emergency physicians who perform POCUS proficiently can impact the care of patients presenting with abdominal pain.

CLINICAL CONSIDERATIONS

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), endoscopic retrograde cholangiopancreatography (ERCP), magnetic resonance cholangiopancreatography (MRCP), and endoscopic ultrasound. Ultrasound has become the most commonly used initial diagnostic imaging modality in the workup of suspected acute hepatobiliary disease because it can be performed rapidly at the bedside and does not expose the patient to ionizing radiation.^10–12 Ultrasound has the highest sensitivity for detecting the presence of gallstones, while HIDA has a higher sensitivity for detecting the presence of acute cholecystitis.^13,14 Abdominal ultrasound alone has a very high negative predictive value (99%) for acute cholecystitis; thus, HIDA offers very limited additional utility to detect acute cholecystitis when the POCUS examination is normal.¹⁵ Of note, while HIDA offers a higher overall sensitivity and specificity for the diagnosis of acute cholecystitis, this modality is often more difficult to obtain and is not performed in a timely manner, leading to delayed time to surgery and longer lengths of stay.¹⁶ Delays in surgery for acute cholecystitis lead to more complications and undesirable outcomes.¹⁷ Although CT is limited by its inability to detect 25% of gallstones, CT may play a greater role when other causes of abdominal pain are being considered.^18,19 ERCP, MRCP, and endoscopic ultrasound are time consuming and resource heavy, limiting their overall clinical utility. ERCP may also have significant complications including pancreatitis, bleeding, cholangitis, perforation, and even death.²⁰

CLINICAL INDICATIONS

Indications for clinicians to perform point-of-care hepatobiliary ultrasound include the evaluation of the following:

• Biliary colic

• Acute cholecystitis

• Jaundice and biliary duct dilatation

• Sepsis

• Ascites

• Hepatic abnormalities

BILIARY COLIC

In the United States, more patients undergo cholecystectomies (both elective and emergent) than appendectomies. Emergency physicians expect to see biliary pathology in up to a third of all patients with abdominal pain, making the differentiation of acute and subacute pathology important.^21,22 The classic presentation of biliary colic portrays an obese woman of childbearing age with recurrent colicky pain in the right upper quadrant ...