Multi-organ dysfunction syndrome

Multi-organ dysfunction refers to progressive organ dysfunction whereby homeostasis cannot be maintained without intervention.

Multiple organ dysfunction syndrome (MODS), also known as multi-organ failure (MOF), is a severe clinical syndrome that is seen in critically ill patients. It is characterised by progressive organ dysfunction with a failure to maintain homeostasis without intervention.

MODS is commonplace in the intensive treatment unit (ITU) setting and usually present at the time of ITU admission and/or at the time of death. MODS is broadly defined as primary or secondary:

• Primary: direct, identifiable injury (e.g. liver failure due to a hepatotoxic agent)
• Secondary: no direct attributable cause. Due to host response to an injury (e.g. severe bacterial sepsis)

Multi-organ dysfunction syndrome is commonly the result of sepsis.

Multi-organ dysfunction syndrome represents the end stage of a severe illness, which may be infectious or non-infectious:

• Infectious (e.g. bacterial sepsis, severe COVID-19)
• Non-infectious (e.g. necrotising pancreatitis, thyroid storm)

MODS is a complex process and the exact underlying mechanisms remain unknown. However, it is suggested that MODS is the result of a proinflammatory response with the release of many immunological mediators (e.g. tumor necrosis factor-α and interleukin (IL)-1β) that promote inflammation and leads to organ dysfunction. This overwhelming immune response causes free radicals to be generated that can damage tissue, as well as promoting hypoperfusion and hypoxia that further cause cellular damage.

Scoring systems are used to help define organ dysfunction in the setting of MODS.

There is no universal definition for individual organ dysfunction in MODS, which is broadly defined as the dysfunction of ≥2 organs that occurs simultaneously. Consequently, scoring systems have been derived in an attempt to categorise and diagnose the organ dysfunction in MODS. One of the most well recognised is the Sequential Organ Failure Assessment (SOFA) score.

These scores look at different parameters to determine the presence, and severity, of organ dysfunction.

• Respiratory dysfunction: Pa0₂, Fi0₂, need for ventilation
• Cardiovascular dysfunction: Blood pressure, need for inotropes
• Renal dysfunction: Acute kidney injury
• Haematological dysfunction: Platelet count, coagulation
• Liver dysfunction: Bilirubin
• Neurological dysfunction: Glasgow coma score

There are no specific treatments that are available for the treatment of MODS.

Management of MODS largely comprises organ support in an ITU setting with the treatment of the underlying disease process and any secondary complications (e.g. secondary infection). Scoring systems used to help define organ dysfunction may also be used to help predict mortality and can be sequentially monitored to provide prognostic information.

Last updated: July 2022