What is the Main Cause of Shock Liver?
The liver is the largest organ has a vital role in maintaining the physiological processes in the body. It is referred to as an important parenchymal organ with dual blood movement, from the portal vein and hepatic artery. It is the place of active metabolism, clearance of waste and significant blood volume reservoir. Any interrupt to the normal function of the liver can induce the deleterious effect in the human body.
What is the Main Cause of Shock Liver?
Shock liver also referred as “ischemic hepatitis,” occurs mainly because of reduction in systemic blood flow in the liver. This condition is called “hepatocytes hypo-perfusion” which causes liver injury. It is consequential from hemodynamic instability and inadequate blood flow due to reduced hepatic arterial flow and/or passive venous congestion. This is observed in most of the heart failure cases. Another factor inducing shock liver is “Hypoxic Hepatitis” that results from hypoxic insults such as respiratory failure and this condition is also termed “hypoxic hepatopathy”. Hypoxic hepatitis and ischemic hepatitis all refers the condition shock liver.
In shock liver, abnormal level of hepatic enzymes is observed. Aminotransferases and bilirubin levels are usually in mild elevated level and become high after hemodynamic shock. The abnormal elevation of liver enzymes and bilirubin can worsen the condition within few days if persistent hepatic microcirculatory failure is present.
In many cases, liver dysfunction occurs without any conspicuous symptoms in affected individuals. Several factors can induce this liver shock including hemorrhage, major surgery, respiratory failure, infection and persistent shock. Systemic failure of microcirculation, poor inflammatory response and adverse effects of treatment in patients in intensive care unit are some of the factors also causes liver shock.
There are multiple causes of low blood pressure, also called hypotension, which can lead to hepatic ischemia. The majority of the cases available in the scientific publication discuss the cardiac failure underlying hypoxic hepatitis, ranging from 39–70%. The conditions of cardiac failure resulting in a low output state, sepsis, and respiratory failure together account for >90% of cases. In the recent meta-analysis study, 78% of hypoxic hepatitis cases were found to be caused by an acute cardiac event. Patients are especially at risk when there is passive congestion of the liver related to right-sided heart failure.
Most prevalent among the other risk factors was the condition of septic shock. It is the result of an infection that causes drastic changes in the body. Some literature says that septic shock was identified in 32% of patients suffering from hypoxic hepatitis and was the leading cause of death. Other documented preconditions include hypovolemic shock, anemia, peritonitis, blackwater fever, extensive burns and sleep apnea. Certain drugs overdose can also induce ischemic hepatitis such as halothane anaesthetics, phenacetin, non-steroidal anti-inflammatory drugs and antimicrobial agents like sulpha drugs and chloramphenicol.
Multiple factors are responsible for the development of ischemic hepatitis. Development of jaundice in patients suffering from severe trauma or surgery is one of the serious factors. There may be increased bilirubin load following blood transfusion (especially stored blood), resorption of haematomas or extravasated blood in the tissues and sepsis. Impaired hepato-cellular function follows trauma, surgery, drugs, total parenteral nutrition and ischemia/hypoxia due to shock. Rarely cholestastic jaundice may develop. Clinical picture of ischemic hepatitis simulates that of acute viral hepatitis. There is marked elevation of AST, ALT, and LDH but bilirubin, alkaline phosphatase, gamma-glutamyl transferase and prothrombin time are slightly abnormal. The liver function returns to normal within 5–10 days with correction of the underlying cause.
Liver shock is also known as ischemic hepatitis, which is caused by insufficient blood flow and insufficient oxygen delivery to the liver. The decreased blood flow (perfusion) to the liver is usually due to shock or low blood pressure. Multiple factors are responsible for the development of ischemic hepatitis such as heart failure, respiratory failure, infection like viral hepatitis, blood clots after surgery, drugs, and toxin-mediated liver damage. It usually results as a consequence of a severe underlying illness state, such as cardiac, circulatory or respiratory failure, leading to a rate of in-hospital mortality of >50%.