Teaching Case

A 51-year-old male presented to the emergency department with a one-day history of right upper quadrant abdominal pain, vomiting and diarrhoea. He had no known chronic diseases. He recovered from uncomplicated Covid-19 two weeks prior to the admission. He was alert and afebrile (36.0°C) but restless, tachypnoeic (30 respirations/min) and hypertensive (155/100 mmHg).

Abdominal ultrasound showed normal gallbladder but revealed multiple gaseous echogenic foci in the liver (Figures 1a, b). Immediate contrast-enhanced abdominal CT showed two extensive areas of emphysematous parenchyma in the VI and VII liver segments, measuring up to 9 cm and 5 cm respectively (Figure 2). Portal vein pneumatosis was also detected (Figures 3a, b, c, d, e). CT also demonstrated initial signs of shock, such as decreased enhancement of the renal parenchyma (Figures 4a, b) and bilateral adrenal gland hyperenhancement on the venous phase images (Figure 5). In addition, a thin layer of gas was seen under the front wall of the right heart ventricle (Figures 6a, b, c).

After intubation and CBCT-guided percutaneous catheter drainage of liver collections, a supine AP chest X-ray was performed in the ICU, which shows two drainage catheters under the right diaphragm as well as hepatic emphysema (Figure 7).

Background

Emphysematous hepatitis (EH) is a very rare, but severe liver infection with a fulminant course and usually fatal outcome. It is a necrotizing, gas-forming infection of the hepatic parenchyma caused by Escherichia coli, Enterococcus faecium, Klebsiella, Enterobacter, Pseudomonas, and so on [1, 2, 3].

Not many patients were reported since the first case in 2001 and only four of them survived [2, 4]. Most patients died within three days of admission because of sepsis and multiorgan failure [2, 3].

The risk factors for EH include diabetes mellitus, cancer, other immunosuppressive conditions, and recent abdominal surgery [1, 2, 3]. The presented case raised the suspicion of a potential association between emphysematous hepatitis and Covid-19 infection. In theory, Covid-19 patients could be more susceptible to secondary bacterial infections of the liver due to weakened immune response and SARS-CoV-2-induced liver injury [5]. However, additional research is needed to establish a link between Covid-19 and EH.

Clinical Perspective

Clinical manifestations of EH are nonspecific: epigastric tenderness or right upper quadrant abdominal pain, nausea, vomiting, occasional fever, hepatomegaly, icterus or altered mental status. Contrast-enhanced abdominal CT is crucial for diagnosis [1, 2, 3, 4]. Laboratory findings include leucocytosis, raised inflammatory markers, and elevated liver enzymes.

Imaging Perspective

Contrast-enhanced abdominal CT plays a key role in the diagnosis of EH as the diagnosis relies on the typical finding of hepatic necrosis, predominantly filled with gas and, in contrast to a hepatic abscess, almost no fluid [1, 2]. In patients whose disease has already progressed to septic shock, CT imaging can also demonstrate signs of shock [6, 7], as in our case.

Outcome

Although there is still discussion regarding the appropriate management of the disease, EH requires prompt and aggressive treatment including intravenous fluid replacement, broad-spectrum antibiotics, hemodynamic support, percutaneous drainage, or urgent laparotomy with surgical debridement [3].

We presented a case of EH in a 51-year-old man without known risk factors, who recovered from an uncomplicated Covid-19 infection two weeks prior to presenting to the emergency room. Soon after admission, the patient’s cardiopulmonary state deteriorated, and he was transferred to the intensive care unit for the treatment of septic shock. Despite intubation, intensive intravenous fluid resuscitation, rapidly commenced empirical broad-spectrum antimicrobial therapy, aggressive supportive treatment and percutaneous drainage, the patient's condition rapidly deteriorated. He died due to a multiple organ failure on the second day of hospitalisation. Escherichia coli and Clostridium perfringens were found in the liver punctate sample and blood culture.

Take-home messages

• Emphysematous hepatitis is a very rare, fulminant, usually fatal liver infection, often associated with diabetes mellitus or other immunosuppressive conditions. It is a necrotizing, gas-forming infection of the hepatic parenchyma.
• Contrast-enhanced CT imaging facilitates fast and accurate diagnosis of EH. Early diagnosis plays a vital role in the management of patients with EH as prompt and aggressive management may improve patient outcome.

All patient data have been completely anonymised throughout the entire manuscript and related files.