Inflammatory Outcomes
Resolution is a possible outcome at this stage on condition that less
than a critical number of cells have been destroyed. For more patients that
come to our attention, this is an unlikely scenario.
Suppuration,
in the presence of infective microorganisms will result in pus formation. Pus
consists of dead cell debris, living, dead and dying polymorphs suspended in
the inflammatory exudate. Clearly the presence of an infection will delay the
healing of a wound.
Chronic
inflammation does not necessarily imply inflammation of long duration, and may
follow a transient or prolonged acute inflammatory stage. Essentially there are
two forms of chronic inflammation: either the chronic reaction supervenes on
the acute reaction or may in fact develop slowly with no initial acute phase.
Chronic supervening on acute almost always involves some suppuration while
chronic ab initio can have many causes including local irritants, poor
circulation, some micro-organisms or immune disturbances. Chronic inflammation
is usually more productive than exudative – it produces more fibrous material
than inflammatory exudate. Frequently there is some tissue destruction,
inflammation and attempted healing occurring simultaneously.
Healing
by fibrosis will most likely be taking place in the tissue repair scenario
considered here. The fibrin deposits from the inflammatory stage will be partly
removed by the fibrinolytic enzymes and will be gradually replaced by
granulation tissue which becomes organized to form the scar tissue. Macrophages
are largely responsible for the removal of the fibrin, allowing capillary
budding and fibroblastic activity to proceed (proliferation). The greater the
volume of damaged tissue, the greater the extent of, and the greater the
density of, the resulting scar tissue. Chronic inflammation is usually
accompanied by some fibrosis even in the absence of significant tissue
destruction. The effects of acute inflammation are largely beneficial. The
fluid exudate dilutes the toxins and escaped blood products include antibodies
(and systemic drugs). The fibrinogen forms fibrin clots providing a mechanical
barrier to the spread of micro-organisms (if present) and additionally assist
phagocytosis. The gel-like consistency of the inflammatory exudate also makes a
positive contribution by preventing the spread of the inflammatory mediators to
surrounding, intact tissues.
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