E1808. Diagnostic Yield Of Hepatic Ultrasound in COVID-19 Patients Prompted by Abnormal Liver Function Tests
Texas A&M University
An outbreak of SARS-CoV-2 (namely COVID-19) infection is ongoing worldwide with rapidly increasing number of cases. Abnormal liver function tests (LFT’s) are frequently present in these patients, prompting abdominal ultrasound (US) studies primarily to evaluate for etiologies such as biliary obstruction and acalculous cholecystitis, which might require surgical or image guided intervention. Proposed mechanisms of hepatic damage include direct virus-induced effects, immune-induced damage due to excessive inflammatory responses, and drug-induced injury. However, there is little literature on the incidence of these processes in COVID-19 patients. Hence, we wanted to estimate the diagnostic yield of hepatic US in COVID-19 patients prompted by abnormal LFT’s.
Materials and Methods:
A hospital-wide PACS database of COVID-19 RT-PCR positive patients was used to identify patients who had imaging performed between March and April 2020. Cases were then filtered for hepatic US prompted by abnormal LFT’s. Demographic and laboratory data were collected. Imaging reports and charts were reviewed for imaging findings and whether patients required surgical or image-guided hepatobiliary intervention.
Results: Among 234 COVID-19 cases in PACS, n=30 (12.8%) had hepatic US for elevated LFT’s. Mean age was 58.4 +/- 16.1 (18 male, 12 female). 26/30 (86.7%) cases were negative for biliary obstruction or acalculous cholecystitis. 3/30 (10%) cases had equivocal findings of gallbladder wall thickening, edema and/or pericholecystic fluid, which were attributed to global volume overload or acute hepatitis. One (3.3%) case was suspicious for acalculous cholecystitis, and HIDA scan was recommended but not performed. This patient improved with conservative management. Those with equivocal or positive findings (n=4) were more likely to have elevated total (Tbili) and direct (Dbili) bilirubin than negative cases (n=26) (Tbili = 8.7 +/- 6.2 mg/dl vs. 1.8 +/- 2.5 mg/dl; p=0.007 and Dbili = 4.2 +/- 3.7 vs. 1.4 +/- 2.5 mg/dl; p=0.02). AST, ALT, Alk Phos and WBC were not significantly different among groups.
Conclusion: Our limited data suggest that while LFT abnormalities are frequently seen in COVID-19, they are rarely due to biliary etiology or require biliary intervention. Our data support a limited role for use of abdominal sonography in work up of LFT abnormalities in COVID-19, focusing on those with elevated bilirubin, although our sample size was small. Abnormalities such as gallbladder wall thickening or edema and pericholecystic fluid can occasionally be seen in COVID-19 patients, and should be interpreted with caution.
We demonstrate limited diagnostic yield of hepatic US for workup of elevated LFT’s in COVID-19 patients. LFT abnormalities are common in COVID-19 patients and rarely due to biliary pathology. Limiting US evaluation to those patients with elevated serum bilirubin may be a more efficient use of healthcare resources during this challenging pandemic.