Inflammation is a complex molecular and cellular event in response to various insults that results in cellular injury. It has three important components
- Humoral response – involving various inflammatory mediators
- Cellular response – with initial recruitment of leucocytes and later mononuclear cells
- Vascular response – resulting in vasodilatation and increased capillary permeability
The systemic inflammatory response can incur in response to major insults such as infection, major trauma, burns and pancreatitis. The degree of abnormality lies on a continuum.
This results in systemic vasodilation with loss of local auto-regulation (‘vasoplegia’) and organ dysfunction. When severe enough it can manifest as circulatory compromise (shock).
Organs can be variously affected such as:
- Lung – Acute lung Injury and Acute Respiratory Distress Syndrome
- Kidneys – Acute renal failure
- Myocardium – Myocardial depression
- GIT – Gut ischaemia
Diagnostic criteria have been developed to try to characterise this process
The limitations of current criteria has been the limited sensitivity and specificity