The necessity of central imaging in patients diagnosed with hepatic encephalopathy in the emergency department

Introduction The term hepatic encephalopathy (HES) describes the spectrum of transient and potentially reversible neuropsychiatric abnormalities that occur in 50-70% of patients with chronic liver dysfunction. Patients present with a variety of symptoms. The most common are confusion or changes in mental status. Many patients with liver disease and altered mental status have a CT scan or diffusion-weighted MR of the head during admission of emergency unit. This is often done even if there are no obvious signs of neurological problems. Currently, there are no universally accepted protocols for deciding whether patients with suspected HES in emergency medicine should receive a central imaging. The aim of this study is to evaluate the central imaging results of patients diagnosed with HES who have applied to the emergency department with cirrhosis and to assess the demographic, clinical and laboratory data associated with pathologies observed in central imaging. Material and methods The study involved 216 patients who were diagnosed with HES in the emergency department and also had a head CT and diffusion-weighted MR scan between April 2018 and June 2022. Patients without central imaging were not included in this retrospective study. Among the descriptive characteristics, age and gender were evaluated. The symptoms, findings and vital signs at the time of emergency department admission were included in the analyses. Cirrhosis etiologies were evaluated by patient files. Laboratory tests requested from the patients for diagnosis and differential diagnosis were included in our study. These laboratory tests included glucose, urea, creatinine, sodium, potassium, C-reactive protein, ammonia, white blood cell count, haemoglobin, platelet, INR, pH and lactate level. Results The mean age of the patients was 63.9 ± 11.1 years (23-90 years). 50.9% of the patients were female and 49.1% were male. The female/male ratio was 1.03/1. The most common symptoms were impaired consciousness (97.2%), abnormal speech (34.7%), somnolence (27.8%) and fatigue (12.0%) The most common findings on physical examination were disorientation and co-operation (83.3%), confusion (51.4%), lethargy (29.6%), slowing in motor functions (17.1%) and flapping tremor (11.6%). The frequent causes of cirrhosis were cryptogenic (36.6%), HBV (21.3%), malignancy (9.7%), HCV (7.4%), alcoholic (7.4%) and autoimmune (7.4%) cirrhosis and NASH (6.9%), respectively. In patients who undergo brain imaging for newly developing central pathology or event, pathology was detected in diffusion MRI in 6% of cases and in cranial CT in 3.7%. When both imaging methods were evaluated together, central pathology was observed in only 7.4% of cases. Demographic and clinical characteristics and laboratory results of patients with and without central pathology were compared. However, no variable associated with the presence of central pathology was found. Conclusion Pathology is rarely observed on central imaging in HES patients admitted to emergency unit. Demographic and clinical features alone may not be guiding in the planning of cranial imaging. In order to prevent unnecessary imaging and reduce health costs associated with imaging, physicians' awareness of HES should be increased and imaging planning algorithms can be established. Key words: Hepatic encephalopathy, Cranial imaging, Head CT, Diffusion-weighted MR, Emergency department