Hypoxic hepatitis related to profound anemia: how low can you go?

A Review: Haemonchus contortus Infection in Pasture-Based Sheep Production Systems, with a Focus on the Pathogenesis of Anaemia and Changes in Haematological Parameters

Simple Summary

Infection with Haemonchus contortus parasites (haemonchosis) is an important cause of anaemia in sheep. Haemonchosis is a global problem, although sheep that are kept in warm, high rainfall environments are at the greatest risk of infection due to the favourable conditions for H. contortus survival. Following ingestion, the parasites develop in the abomasum of sheep. Various factors such as age, breed, health, nutritional status, and larval challenge influence the severity of clinical disease. Hyperacute, acute, and chronic haemonchosis are reviewed, focusing on the pathophysiology of haemonchosis, associated clinical signs, and haematological and biochemical findings.

Abstract

Haemonchosis is an important cause of anaemia in sheep worldwide, particularly those that are kept in pasture-based systems in warm, high rainfall environments. Potential outcomes vary based on the severity of infection and the sheep’s immune response, however, in some sheep infection can lead to death. The consequences of Haemonchus contortus infection mean that it has been well-studied in a range of different farming systems. However, to our knowledge, there has not been a recent review focused on the pathophysiology of anaemia caused by haemonchosis. Thus, this review provides an in-depth discussion of the literature related to the pathophysiology of haemonchosis and associated clinical signs for hyperacute, acute, and chronic haemonchosis. Additionally, haematological and biochemical findings are presented, and various diagnostic methods are assessed.

Anemia-induced liver injury: A rare case revealing glucose-6-phosphate dehydrogenase deficiency

Hypoxic hepatitis may occur due to hemodynamic mechanisms of hypoxia secondary to anemia without any context of reduced blood flow, respiratory failure, or shock state. Etiology of anemia should be investigated in order to avoid recurrence.

Severe Pernicious Anemia Predisposing to Hypoxic Hepatitis

Hypoxic hepatitis or ischemic hepatitis is most commonly encountered in critical care patients, most of whom have shock states secondary to cardiac or respiratory failure. We report a case of severe pernicious anemia predisposing to hypoxic hepatitis that had a good prognosis with simple treatment. Care should be taken in management of severe anemia, interpretation of serum vitamin B12 levels after blood transfusion, and the use of intravenous fluids.

Acute Liver Impairment in a Young, Healthy Athlete: Hypoxic Hepatitis and Rhabdomyolysis following Heat Stroke

Any process that substantially diminishes arterial blood flow or arterial oxygen content to the liver can result in hypoxic (ischaemic) hepatitis. 90% of hypoxic hepatitis occurs in unstable patients in intensive care units with haemodynamic failure secondary to heart failure, respiratory failure and toxic shock. The rate of in-hospital mortality in hypoxic hepatitis is very high with studies recording mortalities of 61.5%. It tends to be very uncommon in healthy, young patients with no underlying medical problems. We report here the case of a young healthy athlete who developed heat stroke associated with rhabdomyolysis and hypoxic hepatitis while he was running the final stages of a marathon. The patient required intensive care admission and inotropic support for a few hours after he was admitted with heat stroke. He underwent a rapid recovery after he was resuscitated with fluids. N-acetyl cysteine was also given during the acute stage of the hepatitis. This case highlights an uncommon case of hypoxic hepatitis in a young, healthy patient secondary to hypotension and heat stroke. Inotropic support might have precipitated the hypoxic hepatitis in this young patient.

Hypoxic hepatitis

Hypoxic hepatitis (HH), an acute liver injury also known as 'ischaemic hepatitis' or 'shock liver', is frequently observed in intensive care units. HH is heralded by a massive but transient rise in serum aminotransferase activities caused by anoxic necrosis of centrilobular liver cells. Cardiac failure, respiratory failure and toxic-septic shock are the main underlying conditions accounting for more than 90% of cases, but HH may also occur in other circumstances. Until recently, liver ischaemia, i.e. a drop in hepatic blood flow, was considered the leading, and even the sole, hemodynamic mechanism responsible for HH, and it was generally held that a shock state was required. In reality, other hemodynamic mechanisms of hypoxia, such as passive congestion of the liver, arterial hypoxaemia and dysoxia, play an important role while a shock state is observed in only 50% of cases. Accordingly, 'ischaemic hepatitis' and 'shock liver' are misnomers. Therapy of HH depends primarily on the nature of the underlying condition. The prognosis is poor, with more than half of patients dying during the hospital stay.

Hepatic involvement in perinatal asphyxia

BACKGROUND

The pathogenetic mechanisms of hepatic injury in perinatal asphyxia (PNA) are similar to those in ischemic hepatitis, yet liver involvement is currently not considered a component of multi-organ failure in PNA.

METHODS

A retrospective study was done on 56 newborns with PNA. Hepatocyte injury was diagnosed based on elevated serum alanine transaminase level (>100 U/L, twice upper normal) with subsequent normalization.

RESULTS AND CONCLUSIONS

Twenty-two of the patients had hepatocyte injury. Fetal distress, thrombocytopenia, convulsions, pathologic findings on imaging of the central nervous system, and a high rate of intrauterine growth retardation were the factors significantly associated with hepatocyte injury. This damage was also associated with high mortality.

Hypoxic liver injury

Hypoxic liver injury is defined as a massive, but transient, increase in serum transaminase levels due to an imbalance between hepatic oxygen supply and demand in the absence of other acute causes of liver damage. It typically occurs in elderly individuals with right-sided congestive heart failure and low cardiac output. Precipitating factors include arrhythmias or pulmonary edema. Symptoms include weakness, shortness of breath, and right upper quadrant pain. Less commonly, hypoxic liver injury is seen in patients with severe hypoxemia or septic shock. Characteristically, the transaminase level is elevated 20-fold but normalizes rapidly over several days. Imaging studies reveal hypoechoic or hypodense lesions that resolve completely with reversal of the initiating event. Treatment and prognosis depend on the underlyIng disease.