Physiological insult/injury: pathophysiology and consequences

This article provides a review of the pathophysiological responses of the body to an insult. Once the initial insult has occurred, common pathways are identifiable: the inflammatory immune response (IIR), the neuroendocrine system is stimulated, and endothelial damage initiates the clotting cascade, all of which play an important role in maintaining haemodynamic normality and promote healing. However, after an injury/insult patients are exposed to treatments, invasive procedures and may develop complications which can stimulate further these physiological processes. This can lead to alterations in oxygen supply and demand, metabolism and to the distribution of circulating volume. In some situations this can lead to overstimulation of the processes which, instead of promoting healing, cause damage. Why this downward progression and overstimulation occurs in some patients, despite optimum efforts at treatment, are not fully understood, but can lead to serious organ damage and even death days or weeks after the insult.