Why may peritonitis lead to shock?

Peritonitis can lead to shock primarily because it creates a condition that causes fluid to shift from the bloodstream into the body's tissues. This phenomenon results from the inflammatory response triggered by the infection or irritation of the peritoneum. As inflammation occurs, the permeability of blood vessels increases, allowing fluids to leak out into the abdominal cavity and surrounding tissues.

When significant amounts of fluid leave the circulatory system, there is reduced blood volume within the vasculature. This decreased blood volume can cause a drop in blood pressure, ultimately leading to hypoperfusion of vital organs—one of the key factors contributing to shock. The cascade of events reflects the body's attempt to respond to the underlying infection or inflammation but also highlights the dangers of fluid loss and the importance of maintaining circulatory volume and pressure.

While other factors may be involved in peritonitis, such as potential hemorrhage, pain, or abdominal distension, the direct relationship to fluid shifts is what fundamentally underpins the development of shock in this context.