Critical Care Medicine-Gastrointestinal, Nutrition and Genitourinary Disorders>>>>>Liver
Question 2#

A patient presents with elevated aminotransferases approximately 15 times the upper limit of normal. Other laboratory values include:

• international normalized ratio of 1.9
• creatinine 0.9 mg/dL
• lactate of 1.9 mmol/L

The systemic arterial blood pressure is 90/50 mm Hg and the central venous pressure is 6 mm Hg. 

Which of the following is LEAST likely to be the etiology of the liver dysfunction?

A. Acute viral hepatitis
B. Ischemic hepatitis
C. Acetaminophen toxicity
D. Portal vein thrombosis
E. HELLP syndrome

Correct Answer is B

Comment:

Correct Answer: B

Although markedly elevated aminotransferases are often from ischemic or hypoxic hepatitis, other causes for marked elevations include acute viral hepatitis, hepatic toxins or drug reaction, autoimmune hepatitis, focal arterial or venous obstruction, or HELLP syndrome. Ischemic or hypoxic hepatitis is generally associated with global hypoperfusion or hypoxia. The normal creatinine and lactate in this case do not support global hypoperfusion or hypoxia. Hypotension from nonhepatic trauma (and hypovolemia) rarely causes ischemic hepatitis, but cardiogenic shock with elevated cardiac filling pressures (high CVP, leading to hepatic venous congestion) has been shown to promote development of ischemic hepatitis. Thus, despite the borderline low systemic blood pressure, normal central venous pressure makes ischemic hepatitis less likely. When ischemic hepatitis is suspected other etiologies should be investigated by testing for acetaminophen levels, acute viral hepatitis serologies, autoimmune markers, and right upper quadrant ultrasound with doppler. 

References:

1. Tapper EB, Sengupta N, Bonder A. The incidence and outcomes of ischemic hepatitis: a systemic review with meta-analysis. Am J Med. 2015;128(12):1314-1321.
2. Seeto RK, Fenn B, RockeyDC. Ischemic hepatitis: clinical presentation and pathogenesis. Am J Med. 2000;109(2):109.
3. Gitlin N, Serio KM. Ischemic hepatitis: widening horizons. Am J Gastroenterol. 1992;87(7):831.