Hepatobiliary disease is a common problem in patients presenting to emergency departments or primary care settings. Unfortunately, clinical examinations and laboratory evaluations lack the necessary sensitivity and specificity to accurately diagnose many of these entities without further testing. Focused bedside ultrasonography (BUS) is an increasingly available and helpful diagnostic tool that can further evaluate patients with suspected biliary disease.
In one study, test characteristics of emergency physician bedside ultrasonography were similar to that of radiology-performed ultrasonography for detection of cholecystitis.
Bedside ultrasonography for gallbladder disease is also a skill that can be learned by physicians at all levels of training.
The benefits of focused bedside biliary sonography include the following:
Helps accurately diagnose biliary pathology
. Sensitivity of 90-96%, Specificty of 88-96%, positive predictive value 88-99%, and a negative predictive value of 73-96%.
Helps assess the degree of obstruction in choledocholithiasis
Can help diagnose gallstones definitively, which makes alternative diagnoses less likely
Can be performed rapidly at the bedside
Can provide bedside radiographic corroboration of physical examination findings for the treating physician
Does not involve ionizing radiation and, as such, is safe in pregnant patients and children
Necessary equipment includes the following:
Ultrasound machine with color flow Doppler
Low frequency (2-5 MHz) curvilinear or phased array transducer
Acoustic coupling gel
Appropriate materials to drape the patient
Patients should be evaluated in the supine position but can be positioned in the upright, standing, or left lateral decubitus positions for improved visualization. Male patients should have their entire right hemithorax exposed for the examination. Take care with female patients to drape appropriately and to minimize exposure of sensitive areas.
Contrast-enhanced ultrasound is a minimally invasive diagnostic technique that is useful in visualizing not only the shape of cancer lesions and some areas of direct invasion to the liver, but also metastasis.
Anesthesia is generally not necessary for abdominal sonography; however, pain management should not be delayed and patients may experience some discomfort due to probe pressure. For improved patient comfort, consider using warmed ultrasound conducting gel, if available.
When emergent treatments such as intravenous fluids, antibiotics, or pressors are indicated, performance of abdominal sonography should not delay the initiation of these treatments. Ongoing resuscitation and extremis, however, are not contraindications. While challenging to perform in such situations, bedside biliary sonography can be easily incorporated into the flow of patient care.
For more information, see the Medscape Gallbladder and Biliary Disease Resource Center.